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Importance: In the ICU, opioids treat pain and improve ventilator tolerance as part of an analgosedation approach. Identifying predictors of opioid consumption during the ICU course might highlight actionable items to reduce opioid consumption., Objectives: To identify risk factors for opioid use during a postoperative ICU course., Design, Setting, and Participants: Patients enrolled in the Michigan Genomics Initiative single-center prospective observational cohort study completed baseline preoperative sociodemographic and mental/physical health questionnaires and provided blood samples for genetic analysis. Included patients were 18 years old and older, admitted to ICU postoperatively, and received opioids postoperatively., Main Outcomes and Measures: The primary outcome was ICU mean daily oral morphine equivalent (OME) use. The association between OME and phenotypic risk factors and genetic variants previously associated with pain were analyzed through univariable and multivariable linear regression models., Results: The cohort consisted of 1865 mixed-surgical patients with mean age of 56 years (sd, 15 yr). Preoperative opioid users were more likely to continue to receive opioids throughout their ICU stay than opioid-naive patients. OME (log10 scale) was most strongly associated with ICU mechanical ventilation (β = 0.27; 95% CI, 0.15-0.38; p < 0.0001; effect size 1.85 for receiving > 24 hours of mechanical ventilation), preoperative opioid use (β = 0.22; 95% CI, 0.16-0.29; p < 0.0001; effect size 1.67 for receiving preoperative opioids), major surgery (β = 0.21; 95% CI, 0.12-0.30; p < 0.0001; effect size 1.62 compared with minor surgery), and current/former illicit drug use (β = 0.12; 95% CI, 0.01-0.23; p = 0.04; effect size 1.30 for drug use). Younger age, centralized pain, and longer anesthetic duration were also significantly associated with OME but with smaller effect sizes. Selected genetic variants (FKBP5, COMT, and OPRM1) were not associated with OME use., Conclusions and Relevance: Mechanical ventilation and preoperative opioids were the strongest risk factors for postoperative ICU opioid consumption, whereas psychologic factors and genetic variants were not associated., Competing Interests: Dr. Brummett is a consultant for Vertex Pharmaceuticals and Merck Pharmaceuticals; he provides expert medical testimony; and he previously served as a consultant for Heron Therapeutics. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Background: The accurate diagnosis of heart failure (HF) before major noncardiac surgery is frequently challenging. The impact of diagnostic accuracy for HF on intraoperative practice patterns and clinical outcomes remains unknown., Methods: We performed an observational study of adult patients undergoing major noncardiac surgery at an academic hospital from 2015 to 2019. A preoperative clinical diagnosis of HF was defined by keywords in the preoperative assessment or a diagnosis code. Medical records of patients with and without HF clinical diagnoses were reviewed by a multispecialty panel of physician experts to develop an adjudicated HF reference standard. The exposure of interest was an adjudicated diagnosis of heart failure. The primary outcome was volume of intraoperative fluid administered. The secondary outcome was postoperative acute kidney injury (AKI)., Results: From 40 659 surgeries, a stratified subsample of 1018 patients were reviewed by a physician panel. Among patients with adjudicated diagnoses of HF, those without a clinical diagnosis (false negatives) more commonly had preserved left ventricular ejection fractions and fewer comorbidities. Compared with false negatives, an accurate diagnosis of HF (true positives) was associated with 470 ml (95% confidence interval: 120-830; P=0.009) lower intraoperative fluid administration and lower risk of AKI (adjusted odds ratio:0.39, 95% confidence interval 0.18-0.89). For patients without adjudicated diagnoses of HF, non-HF was not associated with differences in either fluids administered or AKI., Conclusions: An accurate preoperative diagnosis of heart failure before noncardiac surgery is associated with reduced intraoperative fluid administration and less acute kidney injury. Targeted efforts to improve preoperative diagnostic accuracy for heart failure may improve perioperative outcomes., (Published by Elsevier Ltd.)

Background: Postoperative nausea and vomiting (PONV) is a key driver of unplanned admission and patient satisfaction following surgery. Because traditional risk factors do not completely explain variability in risk, we hypothesize that genetics may contribute to the overall risk for this complication. The objective of this research is to perform a genome-wide association study of PONV, derive a polygenic risk score for PONV, assess associations between the risk score and PONV in a validation cohort, and compare any genetic contributions to known clinical risks for PONV., Methods: Surgeries with integrated genetic and perioperative data performed under general anesthesia at Michigan Medicine and Vanderbilt University Medical Center were studied. PONV was defined as nausea or emesis occurring and documented in the PACU. In the Discovery Phase, genome-wide association studies were performed on each genetic cohort and the results were meta-analyzed. Next, in the Polygenic Phase, we assessed whether a polygenic score, derived from genome-wide association study in a derivation cohort from Vanderbilt University Medical Center, improved prediction within a validation cohort from Michigan Medicine, as quantified by discrimination (C-statistic) and net reclassification index., Results: Of 64,523 total patients, 5,703 developed PONV (8.8%). We identified 46 genetic variants exceeding P<1x10-5 threshold, occurring with minor allele frequency > 1%, and demonstrating concordant effects in both cohorts. Standardized polygenic score was associated with PONV in a basic model, controlling for age and sex, (aOR 1.027 per standard deviation increase in overall genetic risk, 95% CI 1.001-1.053, P=0.044), a model based on known clinical risks (aOR 1.029, 95% CI 1.003-1.055, P=0.030), and a full clinical regression, controlling for 21 demographic, surgical, and anesthetic factors, (aOR 1.029, 95% CI 1.002-1.056, P=0.033). The addition of polygenic score improved overall discrimination in models based on known clinical risk factors (c-statistic: 0.616 compared to 0.613, P=0.028) and improved net reclassification of 4.6% of cases., Conclusion: Standardized polygenic risk was associated with PONV in all three of our models, but the genetic influence was smaller than exerted by clinical risk factors. Specifically, a patient with a polygenic risk score > 1 standard deviation above the mean, has 2-3% greater odds of developing PONV when compared to the baseline population, which is at least an order of magnitude smaller than the increase associated with having prior PONV/motion sickness (55%), having a history of migraines (17%), or being female (83%), and is not clinically significant. Furthermore, the use of a polygenic risk score does not meaningfully improve discrimination compared to clinical risk factors and is not clinically useful., Competing Interests: Declarations of Interest: CD is a consultant to Exact Sciences and founder of Belay Diagnostics is compensated with income and equity. Exact Sciences is a molecular diagnostics company specializing in the detection of early-stage cancers. Belay Diagnostic is a platform for the detection of brain and spinal cord cancers using cerebrospinal fluid. The companies named above as well as other companies have licensed previously described technologies. Licenses to these technologies are or will be associated with equity or royalty payments to the inventors as well as Johns Hopkins University. The terms of all of these arrangements are being managed by Johns Hopkins in accordance with its conflict-of-interest policies. CD’s involvement with both companies is unrelated to the scope of the research presented in this manuscript. CJW is currently employed by Regeneron Pharmaceuticals Inc and holds stock and options. KHW is currently employed by Regeneron Pharmaceutical Inc. MM received funding paid to the University of Michigan from Chiesi USA for work unrelated to the scope of the research presented in this manuscript., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Anesthesiologists.)

Objectives: To determine if angiotensin II is associated with improved outcomes as measured by 30- and 90-day mortality as well as other secondary outcomes such as organ dysfunction and adverse events., Design: Retrospective, matched analysis of patients receiving angiotensin II compared with both historical and concurrent controls receiving equivalent doses of nonangiotensin II vasopressors., Setting: Multiple ICUs in a large, university-based hospital., Patients: Eight hundred thirteen adult patients with shock admitted to an ICU and requiring vasopressor support., Interventions: None., Measurements and Main Results: Angiotensin II use had no association with the primary outcome of 30-day mortality (60% vs 56%; p = 0.292). The secondary outcome of 90-day mortality was also similar (65% vs 63%; p = 0.440) as were changes in Sequential Organ Failure Assessment scores over a 5-day monitoring period after enrollment. Angiotensin II was not associated with increased rates of kidney replacement therapy (odds ratio [OR], 1.39; 95% CI, 0.88-2.19; p = 0.158) or receipt of mechanical ventilation (OR, 1.50; 95% CI, 0.41-5.51; p = 0.539) after enrollment, and the rate of thrombotic events was similar between angiotensin II and control patients (OR, 1.02; 95% CI, 0.71-1.48; p = 0.912)., Conclusions: In patients with severe shock, angiotensin II was not associated with improved mortality or organ dysfunction and was not associated with an increased rate of adverse events., Competing Interests: The authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Study Objective: To quantify preoperative heart failure (HF) diagnostic agreement and identify characteristics of patients in whom physicians agreed versus disagreed about the diagnosis., Design: Observational cohort study., Setting: Patients undergoing major non-cardiac surgery at an academic center between 2015 and 2019., Patients: 40,659 patients undergoing major non-cardiac surgery, among which a stratified subsample of 1018 patients with and without documented HF was reviewed., Interventions: Via a panel of physicians frequently managing patients with HF (cardiologists, cardiac anesthesiologists, intensivists), detailed chart reviews were performed (two per patient; median review time 32 min per reviewer per patient) to render adjudicated HF diagnoses., Measurements: Adjudicated diagnostic agreement measures (percent agreement, Krippendorf's alpha) and univariate comparisons (standardized differences) between patients in whom physicians agreed versus disagreed about the preoperative HF diagnosis., Main Results: Among patients with documented HF, physicians agreed about the diagnosis in 80.0% of cases (consensus positive), disagreed in 13.8% (disagreement), and refuted the diagnosis in 6.3% (consensus negative). Conversely, among patients without documented HF, physicians agreed about the diagnosis in 88.0% (consensus negative), disagreed in 8.4% (disagreement), and refuted the diagnosis in 3.6% (consensus positive). The estimated agreement for the 40,659 cases was 91.1% (95% CI 88.3%-93.9%); Krippendorff's alpha was 0.77 (0.75-0.80). Compared to patients in whom physicians agreed about a HF diagnosis, patients in whom physicians disagreed exhibited fewer guideline-defined HF diagnostic criteria., Conclusions: Physicians usually agree about HF diagnoses adjudicated via chart review, although disagreement is not uncommon and may be partly explained by heterogeneous clinical presentations. Our findings inform preoperative screening processes by identifying patients whose characteristics contribute to physician disagreement via chart review. Clinical Trial Number / Registry URL: Not applicable., Competing Interests: Declaration of Competing Interest The authors declare: Dr. Mathis receives funding from the US National Institutes of Health (R01DK133226) unrelated to the present work. Dr. Golbus receives funding from the US National Institutes of Health (L30HL143700, 1K23HL168220–01) and National Science Foundation (Grant No. 2014003) and receives salary support by an American Heart Association grant (grant number 20SFRN35370008). Dr. Engoren serves on a data safety monitoring board for use of extracorporeal membrane oxygenation in patients with out-of-hospital cardiac arrest and for use of varying oxygenation strategies for patients with respiratory failure, unrelated to this work. Dr. Sjoding receives funding from the US National Institutes of Health (R01HL158626 and R01LM013325) unrelated to the present work. No other relationships or activities existed that could appear to have influenced the submitted work., (Copyright © 2023. Published by Elsevier Inc.)

Background: Conflicting evidence exists regarding the risks and benefits of inotropic therapies during cardiac surgery, and the extent of variation in clinical practice remains understudied. Therefore, the authors sought to quantify patient-, anesthesiologist-, and hospital-related contributions to variation in inotrope use., Methods: In this observational study, nonemergent adult cardiac surgeries using cardiopulmonary bypass were reviewed across a multicenter cohort of academic and community hospitals from 2014 to 2019. Patients who were moribund, receiving mechanical circulatory support, or receiving preoperative or home inotropes were excluded. The primary outcome was an inotrope infusion (epinephrine, dobutamine, milrinone, dopamine) administered for greater than 60 consecutive min intraoperatively or ongoing upon transport from the operating room. Institution-, clinician-, and patient-level variance components were studied., Results: Among 51,085 cases across 611 attending anesthesiologists and 29 hospitals, 27,033 (52.9%) cases received at least one intraoperative inotrope, including 21,796 (42.7%) epinephrine, 6,360 (12.4%) milrinone, 2,000 (3.9%) dobutamine, and 602 (1.2%) dopamine (non-mutually exclusive). Variation in inotrope use was 22.6% attributable to the institution, 6.8% attributable to the primary attending anesthesiologist, and 70.6% attributable to the patient. The adjusted median odds ratio for the same patient receiving inotropes was 1.73 between 2 randomly selected clinicians and 3.55 between 2 randomly selected institutions. Factors most strongly associated with increased likelihood of inotrope use were institutional medical school affiliation (adjusted odds ratio, 6.2; 95% CI, 1.39 to 27.8), heart failure (adjusted odds ratio, 2.60; 95% CI, 2.46 to 2.76), pulmonary circulation disorder (adjusted odds ratio, 1.72; 95% CI, 1.58 to 1.87), loop diuretic home medication (adjusted odds ratio, 1.55; 95% CI, 1.42 to 1.69), Black race (adjusted odds ratio, 1.49; 95% CI, 1.32 to 1.68), and digoxin home medication (adjusted odds ratio, 1.48; 95% CI, 1.18 to 1.86)., Conclusions: Variation in inotrope use during cardiac surgery is attributable to the institution and to the clinician, in addition to the patient. Variation across institutions and clinicians suggests a need for future quantitative and qualitative research to understand variation in inotrope use affecting outcomes and develop evidence-based, patient-centered inotrope therapies., (Copyright © 2023 American Society of Anesthesiologists. All Rights Reserved.)

Background: Reliable diagnosis of heart failure during preoperative evaluation is important for perioperative management and long-term care. We aimed to quantify preoperative heart failure diagnostic accuracy and explore characteristics of patients with heart failure misdiagnoses., Methods: We performed an observational cohort study of adults undergoing major noncardiac surgery at an academic hospital between 2015 and 2019. A preoperative clinical diagnosis of heart failure was defined using keywords from the history and clinical examination or administrative documentation. Across stratified subsamples of cases with and without clinically diagnosed heart failure, health records were intensively reviewed by an expert panel to develop an adjudicated heart failure reference standard using diagnostic criteria congruent with consensus guidelines. We calculated agreement among experts, and analysed performance of clinically diagnosed heart failure compared with the adjudicated reference standard., Results: Across 40 555 major noncardiac procedures, a stratified subsample of 511 patients was reviewed by the expert panel. The prevalence of heart failure was 9.1% based on clinically diagnosed compared with 13.3% (95% confidence interval [CI], 10.3-16.2%) estimated by the expert panel. Overall agreement and inter-rater reliability (kappa) among heart failure experts were 95% and 0.79, respectively. Based upon expert adjudication, heart failure was clinically diagnosed with an accuracy of 92.8% (90.6-95.1%), sensitivity 57.4% (53.1-61.7%), specificity 98.3% (97.1-99.4%), positive predictive value 83.5% (80.3-86.8%), and negative predictive value 93.8% (91.7-95.9%)., Conclusions: Limitations exist to the preoperative clinical diagnosis of heart failure, with nearly half of cases undiagnosed preoperatively. Considering the risks of undiagnosed heart failure, efforts to improve preoperative heart failure diagnoses are warranted.

Background: Postoperative hemodynamic deterioration among cardiac surgical patients can indicate or lead to adverse outcomes. Whereas prediction models for such events using electronic health records or physiologic waveform data are previously described, their combined value remains incompletely defined. The authors hypothesized that models incorporating electronic health record and processed waveform signal data (electrocardiogram lead II, pulse plethysmography, arterial catheter tracing) would yield improved performance versus either modality alone., Methods: Intensive care unit data were reviewed after elective adult cardiac surgical procedures at an academic center between 2013 and 2020. Model features included electronic health record features and physiologic waveforms. Tensor decomposition was used for waveform feature reduction. Machine learning-based prediction models included a 2013 to 2017 training set and a 2017 to 2020 temporal holdout test set. The primary outcome was a postoperative deterioration event, defined as a composite of low cardiac index of less than 2.0 ml min-1 m-2, mean arterial pressure of less than 55 mmHg sustained for 120 min or longer, new or escalated inotrope/vasopressor infusion, epinephrine bolus of 1 mg or more, or intensive care unit mortality. Prediction models analyzed data 8 h before events., Results: Among 1,555 cases, 185 (12%) experienced 276 deterioration events, most commonly including low cardiac index (7.0% of patients), new inotrope (1.9%), and sustained hypotension (1.4%). The best performing model on the 2013 to 2017 training set yielded a C-statistic of 0.803 (95% CI, 0.799 to 0.807), although performance was substantially lower in the 2017 to 2020 test set (0.709, 0.705 to 0.712). Test set performance of the combined model was greater than corresponding models limited to solely electronic health record features (0.641; 95% CI, 0.637 to 0.646) or waveform features (0.697; 95% CI, 0.693 to 0.701)., Conclusions: Clinical deterioration prediction models combining electronic health record data and waveform data were superior to either modality alone, and performance of combined models was primarily driven by waveform data. Decreased performance of prediction models during temporal validation may be explained by data set shift, a core challenge of healthcare prediction modeling., (Copyright © 2022, the American Society of Anesthesiologists. All Rights Reserved.)

Background: There are few data to guide the intraoperative management of patients with reduced left ventricular ejection fraction (LVEF). This study aimed to describe how patients with reduced LVEF are managed differently and to identify and treatments had a different risk profile in this population., Methods: We performed a retrospective cohort study of adult patients who underwent general anesthesia for non-cardiac surgery. The effect of anesthesia medications and fluid balance was compared between those with and without a reduced preoperative LVEF. The primary outcome was a composite of acute kidney injury, myocardial injury, pulmonary complications, and 30-day mortality. Multivariable logistic regression was used to adjust for confounders. Treatments that affected patients with reduced LVEF differently were defined as those associated with the primary outcome that also had a significant interaction with LVEF., Results: A total of 9420 patients were included. Patients with reduced LVEF tended to have a less positive fluid balance. Etomidate, calcium, and phenylephrine were use more frequently, while propofol and remifentanil were used less frequently. Remifentanil affected patients with reduced LVEF differently than those without (interaction term OR 2.71, 95% CI 1.30-5.68, p = 0.008). While the use of remifentanil was associated with fewer complications in patients with normal systolic function (OR 0.54, 95% CI 0.42-0.68, p < 0.001), it was associated with an increase in complications in patients with reduced LVEF (OR = 3.13, 95% CI 3.06-5.98, p = 0.026)., Conclusions: Patients with a reduced preoperative LVEF are treated differently than those with a normal LVEF when undergoing non-cardiac surgery. An association was found between the use of remifentanil and an increase in postoperative adverse events that was unique to this population. Future research is needed to determine if this relationship is secondary to the medication itself or reflects a difference in how remifentanil is used in patients with reduced LVEF., (© 2022. The Author(s).)

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination., (© 2022 The Authors. Liver Transplantation published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.)

Purpose: Patients receiving veno-arterial Extracorporeal Membrane Oxygenation (V-A ECMO) may require transfusion due to bleeding risk and desire to optimize oxygen delivery. The purposes of this study were to determine the transfusion requirements in patients receiving V-A ECMO and to determine if transfusion was associated with hospital mortality or complications., Material and Methods: Retrospective chart review of adult patients at University of Michigan between 1/1/2000-6/1/2017. Survivors and decedents were compared. Logistic regression was used to determine factors independently associated with mortality, hemorrhage, and ischemic events., Results: One hundred eighty-seven patients received V-A ECMO. Median number of red cells transfused was 9 units (interquartile range 3.5-20), platelets 4 (1-11) packs, plasma 2 (0-6) units, cryoprecipitate 0 (0,0) units. Only 69 (37%) patients survived to hospital discharge. Hemorrhage occurred in 108 (58%) patients and 27 (14%) suffered ischemic complications. Renal replacement therapy (OR 2.94, 95% confidence interval: 1.51-5.68, p < 0.001) and ECMO duration (OR 1.01, 95% confidence interval: 1.00-1.01, p = 0.005) but not transfusion, were associated with increased odds of death., Conclusion: Most patients receiving V-A ECMO are transfused multiple units of blood products. Receipt of transfusion or having a bleeding or ischemic complication was not associated with increased mortality., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Weaning parameters are well studied in patients undergoing first time extubation. Fewer data exists to guide re-extubation of patients who failed their first extubation attempt. It is reasonable to postulate that improved weaning parameters between the first and second extubation attempt would lead to improved rates of re-extubation success. To investigate, we studied a cohort of patients who failed their first extubation attempt and underwent a second attempt at extubation. We hypothesized that improvement in weaning parameters between the first and the second extubation attempt is associated with successful reextubation., Interventions: Rapid shallow breathing index (RSBI), maximum inspiratory pressure (MIP), vital capacity (VC), and the blood partial pressure of CO2 (PaCO2) were measured and recorded in the medical record prior to extubation along with demographic information. We examined the relationship between the change in extubation and re-extubation weaning parameters and re-extubation success., Measurements and Main Results: A total of 1283 adult patients were included. All weaning parameters obtained prior to re-extubation differed between those who were successful and those who required a second reintubation. Those with reextubation success had slightly lower PaCO2 values (39.5 ± 7.4 mmHg vs. 41.6 ± 9.1 mmHg, p = 0.0045) and about 13% higher vital capacity volumes (1021 ± 410 mL vs. 907 ± 396 mL, p = 0.0093). Lower values for RSBI (53 ± 32 breaths/min/L vs. 69 ± 42 breaths/min/L, p < 0.001) and MIP (-41 ± 12 cmH2O vs. -38 ± 13 cm H2O), p = 0.0225) were seen in those with re-extubation success. Multivariable logistical regression demonstrates lack of independent associated between the change in parameters between the 2 attempts and re-extubation success., Conclusions: The relationship between the changes in extubation parameters through successive attempts is driven primarily by the value obtained immediately prior to re-extubation. These findings do not support waiting for an improvement in extubation parameters to extubate patients who failed a first attempt at extubation if extubation parameters are compatible with success.

Variability persists in intraoperative red blood cell (RBC) transfusion rates, despite evidence supporting associated adverse sequelae. We evaluated whether beliefs concerning transfusion risk and safety are independently associated with the inclination to transfuse. We surveyed intraoperative transfusion decision-makers from 33 cardiac surgery programs in Michigan. The primary outcome was a provider's reported inclination to transfuse (via a six-point Likert Scale) averaged across 10 clinical vignettes based on Class IIA or IIB blood management guideline recommendations. Survey questions assessed hematocrit threshold for transfusion ("hematocrit trigger"), demographic and practice characteristics, years and case-volume of practice, knowledge of transfusion guidelines, and provider attitude regarding perceived risk and safety of blood transfusions. Linear regression models were used to estimate the effect of these variables on transfusion inclination. Mixed effect models were used to quantify the variation attributed to provider specialties and hematocrit triggers. The mean inclination to transfuse was 3.2 (might NOT transfuse) on the survey Likert scale (SD: .86) across vignettes among 202/413 (48.9%) returned surveys. Hematocrit triggers ranged from 15% to 30% (average: 20.4%; SE: .18%). The inclination to transfuse in situations with weak-to-moderate evidence for supporting transfusion was associated with a provider's hematocrit trigger ( p < .01) and specialty. Providers believing in the safety of transfusions were significantly more likely to transfuse. Provider specialty and belief in transfusion safety were significantly associated with a provider's hematocrit trigger and likelihood for transfusion. Our findings suggest that blood management interventions should target these previously unaccounted for blood transfusion determinants., (© Copyright 2021 AMSECT.)

Background: Severe hypocalcaemia is associated with increased transfusion in the trauma population. Furthermore, trauma patients developing severe hypocalcaemia have higher mortality and coagulopathy. Electrolyte abnormalities associated with massive transfusion have been less studied in the surgical population. Here, we tested the primary hypothesis that volume of packed red blood cells and fresh frozen plasma transfused intraoperatively is associated with lower nadir ionised calcium in the surgical population receiving massive resuscitation., Methods: We performed a retrospective observational study at an academic quaternary care centre to characterise hypocalcaemia following large volume (4 or more units packed red blood cells) intraoperative transfusion. We used multivariable linear regression to assess if volume of transfusion with packed red blood cells and fresh frozen plasma were independently associated with a lower ionised calcium. We then used multivariable logistic regressions to assess the association between ionised calcium and transfusion with: (i) mortality, (ii) acute kidney injury, and (iii) postoperative coagulopathy., Results: Hypocalcaemia following large volume resuscitation in the operating room is a very frequent occurrence (70% of cases). After controlling for demographic variables and intraoperative variables, the volume transfused intraoperative was independently associated with hypocalcaemia on multivariable linear regression. Hypocalcaemia, intraoperative transfusion of packed red blood cells, and intraoperative transfusion of fresh frozen plasma were not shown to be associated with clinical outcomes., Conclusions: Hypocalcaemia was associated with increased transfusion volume in this single-centre study. Unlike the trauma population, hypocalcaemia was not associated with increased mortality during surgical care. Our findings suggest that despite improved practice patterns of calcium supplementation, intraoperative hypocalcaemia occurs with relatively high frequency following large volume intraoperative transfusion., (© 2021 British Blood Transfusion Society.)

Objective: Despite advances in echocardiography and hemodynamic monitoring, limited progress has been made to effectively quantify left ventricular function during cardiac surgery. Traditional measures, including left ventricular ejection fraction (LVEF) and cardiac index, remain dependent on loading conditions; more complex measures remain impractical in a dynamic surgical setting. However, the Smith-Madigan Inotropy Index (SMII) and potential-to-kinetic energy ratio (PKR) offer promise as measures calculable during cardiac surgery and potentially predictive of outcomes. Using echocardiographic and hemodynamic monitoring data, the authors aimed to calculate SMII and PKR values after cardiopulmonary bypass and understand associations with postoperative outcomes, adjusting for previously identified risk factors., Design: Observational cohort study., Setting: Tertiary care academic hospital., Patients: The study comprised 189 elective adult cardiac surgical procedures from 2015-2016., Intervention: None., Measurements and Main Results: The primary outcome was postoperative mortality or organ system complication (stroke, prolonged ventilation, reintubation, cardiac arrest, acute kidney injury, new-onset atrial fibrillation). After adjustment, SMII <0.83 W/m 2 independently predicted the primary outcome (adjusted odds ratio 2.19, 95% confidence interval 1.08-4.42); whereas PKR, LVEF, and cardiac index demonstrated no associations. When SMII and PKR were incorporated into a EuroSCORE II risk model, predictive performance improved (net reclassification index improvement 0.457; p = 0.001); whereas a model incorporating LVEF and cardiac index demonstrated no improvement (0.130; p = 0.318)., Conclusion: The present study demonstrated that SMII, but not PKR, as a measure of cardiac function was associated with major complications. The study's data may guide investigations of more suitable perioperative goal-directed therapies to reduce complications after cardiac surgery., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: While reduced left ventricular ejection fraction (LVEF) is a known risk factor for complications after coronary artery bypass grafting (CABG), the relevance of higher LVEF values has not been established. Currently, most risk stratification tools consider LVEF values above a certain point as normal. However, since this does not account for insufficient ventricular filling or increased adrenergic tone, higher values may have clinical significance. To improve our understanding of this situation, we investigated the relationship of preoperative LVEF values with short- and long-term outcomes after CABG using a strategy that allowed for the identification of nonlinear relationships. We hypothesised that both higher and lower values are independently associated with increased postoperative complications and death in this population., Methods: We performed a single-centre retrospective cohort study of patients undergoing isolated CABG surgery. All patients had a preoperative measurement of their LVEF. Surgery involving mitral valve repair was excluded in order to eliminate the impact of mitral regurgitation. The primary outcome was long-term mortality; secondary outcomes included atrial fibrillation, operative mortality, and a composite outcome including any postoperative adverse event. Fractional polynomial equations were used to model the relationship between LVEF and outcomes so we could account for nonlinear relationships if present. Adjustments for confounders were made using multivariable logistic regression and Cox models., Results: A total of 7,932 subjects were included in the study. After adjusting for patient and surgical characteristics, LVEF remained associated with the primary outcome as well as the composite outcome of any postoperative adverse event. Both these relationships were best described by a J-shaped curve given that higher LVEF values were associated with increased risk, albeit not as high has lower values. Regarding long-term mortality, individuals with a preoperative LVEF of 60% demonstrated the longest survival. A statistically significant relationship was not found between LVEF and operative mortality or atrial fibrillation after adjustment for confounders., Conclusions: Higher preoperative LVEF values may be associated with increased risk for patients undergoing CABG surgery. Future studies are needed to better characterise this phenotype., (Copyright © 2020 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Background: While flexible epidural catheters reduce the risk of paresthesia and intravascular cannulation, they may be more challenging to advance beyond the tip of a Tuohy needle. This may increase placement time, number of attempts, and possibly complications when establishing labor analgesia. This study investigated the ability to advance flexible epidural catheters through different epidural needles from 2 commonly used, commercially available, epidural kits., Methods: We hypothesized that the multiorifice wire-reinforced polyamide nylon blend epidural catheters will have a higher rate of successful first attempt insertion than the single-end hole wire-reinforced polyurethane catheters for the establishment of labor analgesia. The primary outcome was a difference in proportions of failure to advance the epidural catheter between the 2 epidural kits and was tested by a χ2 test. Two-hundred forty epidural kits were collected (n = 120/group) for 240 laboring patients requesting epidural analgesia in this open-label clinical trial from November 2018 to September 2019. Two-week time intervals were randomized for the exclusive use of 1 of the 2 kits in this study, where all patients received labor analgesia through either the flexible epidural catheter "A" or the flexible epidural catheter "B." Engineering properties of the equipment used were then determined., Results: Flexible epidural catheter "A," the single-end hole wire-reinforced polyurethane catheter, did not advance at the first attempt in 15% (n = 18 of 120) of the parturients compared to 0.8% (n = 1 of 120) of the catheter "B," the multiorifice wire-reinforced polyamide nylon blend epidural catheter (P < .0001). Twenty-five additional epidural needle manipulations were recorded in the laboring patients who received catheter "A," while 1 epidural needle manipulation was recorded in the parturients who received catheter "B" (P < .0001). Bending stiffness of the epidural catheters used from kit "B" was twice the bending stiffness of the catheters used from kit "A" (bending stiffness catheters "A" 0.64 ± 0.04 N·mm2 versus bending stiffness catheters "B" 1.28 ± 0.20 N·mm2, P = .0038), and the angle formed by the needle and the epidural catheter from kit "A" was less acute than the angle formed from kit "B" (kit "A" 14.17 ± 1.72° versus kit "B" 21.83 ± 1.33°, P = .0036), with a mean difference of 7.66° between the 2 kits' angles., Conclusions: The incidence of an inability to advance single-end hole wire-reinforced polyurethane catheter was higher compared to the use of multiorifice wire-reinforced polyamide nylon blend epidural catheter. Variation of morphological features of epidural needles and catheters may play a critical role in determining the successful establishment of labor epidural analgesia., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 International Anesthesia Research Society.)

Background: Bleeding and venous thromboembolic disease are considered important sources of postoperative morbidity and mortality. Clinically, treatment of these 2 disorders is often competing. We sought to better understand the relative contributions of bleeding and venous thromboembolic disease to postoperative attributable mortality in a national cohort., Methods: A retrospective analysis of the 2006-2017 American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database was performed to assess the adjusted odds ratio and attributable mortality for postoperative bleeding and venous thromboembolism, adjusted by year., Results: After adjustment for confounding variables, bleeding exhibited a high postoperative attributable mortality in every year studied. Venous thromboembolism appeared to contribute minimal attributable mortality., Conclusions: Bleeding complications are a consistent source of attributable mortality in surgical patients, while the contribution of venous thromboembolic disease appears to be minimal in this analysis. Further studies are warranted to better understand the etiology of this disparity.

Purpose: To determine if baseline lipid levels contribute to the relationship between lipid levels during sepsis and outcomes., Materials and Methods: We conducted a retrospective cohort study at a tertiary-care academic medical center. Multivariable logistic regression models were used to adjust for confounders. Both Systemic Inflammatory Response Syndrome (SIRS) and Sequential Organ Failure Assessment (SOFA) score-based definitions of sepsis were analyzed., Measurements and Main Results: After adjusting for patient characteristics and severity of illness, baseline values for both low density lipoprotein (LDL) cholesterol and triglycerides were associated with mortality (LDL cholesterol odds ratio [OR] 0.44, 95% confidence interval [CI] 0.23-0.84, p = .013; triglyceride OR 0.54, 95% CI 0.37-0.78, p = .001) using a SIRS based definition of sepsis. An interaction existed between these two variables, which resulted in increased mortality with higher baseline low density lipoprotein (LDL) cholesterol values for individuals with triglycerides below 208 mg/dL and the opposite direction of association above this level (interaction OR 1.48, 95% CI 1.02-2.16, p = .039). When using a SOFA score-based definition, only triglycerides remained associated with the mortality (OR 0.55, 95% CI 0.35-0.86, p = .008)., Conclusions: Baseline lipid values, particularly triglyceride concentrations, are associated with hospital mortality in septic patients., Competing Interests: Declaration of Competing Interest There are no conflicts of interest or financial relationships to report., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Heart failure with reduced ejection fraction (HFrEF) is a condition imposing significant health care burden. Given its syndromic nature and often insidious onset, the diagnosis may not be made until clinical manifestations prompt further evaluation. Detecting HFrEF in precursor stages could allow for early initiation of treatments to modify disease progression. Granular data collected during the perioperative period may represent an underutilized method for improving the diagnosis of HFrEF. We hypothesized that patients ultimately diagnosed with HFrEF following surgery can be identified via machine-learning approaches using pre- and intraoperative data., Methods: Perioperative data were reviewed from adult patients undergoing general anesthesia for major surgical procedures at an academic quaternary care center between 2010 and 2016. Patients with known HFrEF, heart failure with preserved ejection fraction, preoperative critical illness, or undergoing cardiac, cardiology, or electrophysiologic procedures were excluded. Patients were classified as healthy controls or undiagnosed HFrEF. Undiagnosed HFrEF was defined as lacking a HFrEF diagnosis preoperatively but establishing a diagnosis within 730 days postoperatively. Undiagnosed HFrEF patients were adjudicated by expert clinician review, excluding cases for which HFrEF was secondary to a perioperative triggering event, or any event not associated with HFrEF natural disease progression. Machine-learning models, including L1 regularized logistic regression, random forest, and extreme gradient boosting were developed to detect undiagnosed HFrEF, using perioperative data including 628 preoperative and 1195 intraoperative features. Training/validation and test datasets were used with parameter tuning. Test set model performance was evaluated using area under the receiver operating characteristic curve (AUROC), positive predictive value, and other standard metrics., Results: Among 67,697 cases analyzed, 279 (0.41%) patients had undiagnosed HFrEF. The AUROC for the logistic regression model was 0.869 (95% confidence interval, 0.829-0.911), 0.872 (0.836-0.909) for the random forest model, and 0.873 (0.833-0.913) for the extreme gradient boosting model. The corresponding positive predictive values were 1.69% (1.06%-2.32%), 1.42% (0.85%-1.98%), and 1.78% (1.15%-2.40%), respectively., Conclusions: Machine-learning models leveraging perioperative data can detect undiagnosed HFrEF with good performance. However, the low prevalence of the disease results in a low positive predictive value, and for clinically meaningful sensitivity thresholds to be actionable, confirmatory testing with high specificity (eg, echocardiography or cardiac biomarkers) would be required following model detection. Future studies are necessary to externally validate algorithm performance at additional centers and explore the feasibility of embedding algorithms into the perioperative electronic health record for clinician use in real time.

Background: Despite the significant healthcare impact of acute kidney injury, little is known regarding prevention. Single-center data have implicated hypotension in developing postoperative acute kidney injury. The generalizability of this finding and the interaction between hypotension and baseline patient disease burden remain unknown. The authors sought to determine whether the association between intraoperative hypotension and acute kidney injury varies by preoperative risk., Methods: Major noncardiac surgical procedures performed on adult patients across eight hospitals between 2008 and 2015 were reviewed. Derivation and validation cohorts were used, and cases were stratified into preoperative risk quartiles based upon comorbidities and surgical procedure. After preoperative risk stratification, associations between intraoperative hypotension and acute kidney injury were analyzed. Hypotension was defined as the lowest mean arterial pressure range achieved for more than 10 min; ranges were defined as absolute (mmHg) or relative (percentage of decrease from baseline)., Results: Among 138,021 cases reviewed, 12,431 (9.0%) developed postoperative acute kidney injury. Major risk factors included anemia, estimated glomerular filtration rate, surgery type, American Society of Anesthesiologists Physical Status, and expected anesthesia duration. Using such factors and others for risk stratification, patients with low baseline risk demonstrated no associations between intraoperative hypotension and acute kidney injury. Patients with medium risk demonstrated associations between severe-range intraoperative hypotension (mean arterial pressure less than 50 mmHg) and acute kidney injury (adjusted odds ratio, 2.62; 95% CI, 1.65 to 4.16 in validation cohort). In patients with the highest risk, mild hypotension ranges (mean arterial pressure 55 to 59 mmHg) were associated with acute kidney injury (adjusted odds ratio, 1.34; 95% CI, 1.16 to 1.56). Compared with absolute hypotension, relative hypotension demonstrated weak associations with acute kidney injury not replicable in the validation cohort., Conclusions: Adult patients undergoing noncardiac surgery demonstrate varying associations with distinct levels of hypotension when stratified by preoperative risk factors. Specific levels of absolute hypotension, but not relative hypotension, are an important independent risk factor for acute kidney injury.

Background: "Lung-protective ventilation" describes a ventilation strategy involving low tidal volumes (VTs) and/or low driving pressure/plateau pressure and has been associated with improved outcomes after mechanical ventilation. We evaluated the association between intraoperative ventilation parameters (including positive end-expiratory pressure [PEEP], driving pressure, and VT) and 3 postoperative outcomes: (1) PaO2/fractional inspired oxygen tension (FIO2), (2) postoperative pulmonary complications, and (3) 30-day mortality., Methods: We retrospectively analyzed adult patients who underwent major noncardiac surgery and remained intubated postoperatively from 2006 to 2015 at a single US center. Using multivariable regressions, we studied associations between intraoperative ventilator settings and lowest postoperative PaO2/FIO2 while intubated, pulmonary complications identified from discharge diagnoses, and in-hospital 30-day mortality., Results: Among a cohort of 2096 cases, the median PEEP was 5 cm H2O (interquartile range = 4-6), median delivered VT was 520 mL (interquartile range = 460-580), and median driving pressure was 15 cm H2O (13-19). After multivariable adjustment, intraoperative median PEEP (linear regression estimate [B] = -6.04; 95% CI, -8.22 to -3.87; P < .001), median FIO2 (B = -0.30; 95% CI, -0.50 to -0.10; P = .003), and hours with driving pressure >16 cm H2O (B = -5.40; 95% CI, -7.2 to -4.2; P < .001) were associated with decreased postoperative PaO2/FIO2. Higher postoperative PaO2/FIO2 ratios were associated with a decreased risk of pulmonary complications (adjusted odds ratio for each 100 mm Hg = 0.495; 95% CI, 0.331-0.740; P = .001, model C-statistic of 0.852) and mortality (adjusted odds ratio = 0.495; 95% CI, 0.366-0.606; P < .001, model C-statistic of 0.820). Intraoperative time with VT >500 mL was also associated with an increased likelihood of developing a postoperative pulmonary complication (adjusted odds ratio = 1.06/hour; 95% CI, 1.00-1.20; P = .042)., Conclusions: In patients requiring postoperative intubation after noncardiac surgery, increased median FIO2, increased median PEEP, and increased time duration with elevated driving pressure predict lower postoperative PaO2/FIO2. Intraoperative duration of VT >500 mL was independently associated with increased postoperative pulmonary complications. Lower postoperative PaO2/FIO2 ratios were independently associated with pulmonary complications and mortality. Our findings suggest that postoperative PaO2/FIO2 may be a potential target for future prospective trials investigating the impact of specific ventilation strategies for reducing ventilator-induced pulmonary injury.

Objectives: Multi-arterial bypass grafting with bilateral internal thoracic (BITA-MABG) or radial (RA-MABG) arteries improves long-term survival, but its increased complexity raises perioperative safety concerns. We compared perioperative outcomes of RA-MABG and BITA-MABG using the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS-ACSD)., Methods: We analysed the 2004-2015 BITA-MABG and RA-MABG experience in STS-ACSD. Primary end points were operative mortality (OM) and deep sternal wound infections (DSWI). Risk-adjusted odds ratios [AOR (95% confidence interval)] were derived via multivariable logistic regression. Sensitivity analyses were done in patient sub-cohorts and based on institutional BITA-utilization rates (<5%, 5-10%, 10-20%, 20-40% and >40%)., Results: Eighty-five thousand nine hundred five RA-MABG (82.5% men; 61 years) and 61 336 BITA-MABG (85.1% men; 59 years) patients were analysed; 41.6% of BITA-MABG and 27.3% of RA-MABG cases came from institutions with low MABG utilization rates (<10%). Unadjusted OM was equivalent for both techniques (BITA-MABG versus RA-MABG: 1.3% vs 1.2%, P = 0.79), while DSWI was lower for RA-MABG (1.0% vs 0.6%, P < 0.001). RA-MABG was associated with lower adjusted OM [AOR = 0.80 (0.69-0.96)] and DSWI [AOR = 0.39 (0.32-0.46)]. Sensitivity analyses confirmed robustness of these findings. Equivalent outcomes were observed at high BITA-use institutions where BITA cases comprised >20% of all cases for OM and ≥40% for DSWI., Conclusions: This analysis of the STS-ACSD showed that RA-MABG is a generally safer form of multi-arterial coronary artery bypass grafting surgery. However, this advantage is mitigated at institutions with substantial BITA experience., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: Compared with historic ventilation strategies, modern lung-protective ventilation includes lower tidal volumes (VT), lower driving pressures, and application of positive end-expiratory pressure (PEEP). The contributions of each component to an overall intraoperative protective ventilation strategy aimed at reducing postoperative pulmonary complications have neither been adequately resolved, nor comprehensively evaluated within an adult cardiac surgical population. The authors hypothesized that a bundled intraoperative protective ventilation strategy was independently associated with decreased odds of pulmonary complications after cardiac surgery., Methods: In this observational cohort study, the authors reviewed nonemergent cardiac surgical procedures using cardiopulmonary bypass at a tertiary care academic medical center from 2006 to 2017. The authors tested associations between bundled or component intraoperative protective ventilation strategies (VT below 8 ml/kg ideal body weight, modified driving pressure [peak inspiratory pressure - PEEP] below 16 cm H2O, and PEEP greater than or equal to 5 cm H2O) and postoperative outcomes, adjusting for previously identified risk factors. The primary outcome was a composite pulmonary complication; secondary outcomes included individual pulmonary complications, postoperative mortality, as well as durations of mechanical ventilation, intensive care unit stay, and hospital stay., Results: Among 4,694 cases reviewed, 513 (10.9%) experienced pulmonary complications. After adjustment, an intraoperative lung-protective ventilation bundle was associated with decreased pulmonary complications (adjusted odds ratio, 0.56; 95% CI, 0.42-0.75). Via a sensitivity analysis, modified driving pressure below 16 cm H2O was independently associated with decreased pulmonary complications (adjusted odds ratio, 0.51; 95% CI, 0.39-0.66), but VT below 8 ml/kg and PEEP greater than or equal to 5 cm H2O were not., Conclusions: The authors identified an intraoperative lung-protective ventilation bundle as independently associated with pulmonary complications after cardiac surgery. The findings offer insight into components of protective ventilation associated with adverse outcomes and may serve as targets for future prospective interventional studies investigating the impact of specific protective ventilation strategies on postoperative outcomes after cardiac surgery.

Objectives: We evaluated the presence of an 'obesity paradox' in coronary artery bypass grafting (CABG) patients, determined its time course and ascertained whether it is associated with improved cardiovascular (CV) survival versus non-CV survival., Methods: A retrospective analysis of 3 prospectively collected databases was conducted. A fifteen-year Kaplan-Meier analysis in 7091 CABG patients was performed and repeated in 5 body mass index [BMI (kg/m2)] cohorts [Normal (18.5-24.99 kg/m2), Overweight (25-29.99 kg/m2), Obese I (30-34.99 kg/m2), Obese II (35-39.99 kg/m2) and Obese III (≥40 kg/m2)]. Mortality hazard ratios {HR [95% confidence interval (CI)]} were derived using comprehensive multivariable competing risk Cox regression, accounting for BMI categories for overall (0-15), Early (0-1), Intermediate (1-8) and Late (8-15) postoperative years, to relax the proportional hazards assumption. The regression was repeated using BMI as a continuous variable. Mortality was classified into any, CV and non-CV., Results: Obese patients were younger with more comorbidities. Fifteen-year survival was improved in the Overweight and Obese I groups (P < 0.001). Adjusted 15-year mortality was reduced in the Overweight [HR (95% CI) = 0.88 (0.79-0.98)] and Obese I [HR = 0.88 (0.78-0.99)] groups driven by improved CV and non-CV survival. This trend was noted in the early (Overweight) and intermediate postoperative periods (Overweight and Obese I) with no significance in the late period. Higher mortality in the Obese III [HR = 1.28 (1.06-1.55)] group was driven by a decreased CV survival. Using BMI as a continuous variable, a BMI of 29 kg/m2 was associated with optimal survival., Conclusions: We identified a protective partial obesity paradox in the early and intermediate postoperative periods among Overweight and mildly obese (Obese I) patients with improved CV and non-CV survival. The morbidly obese (the Obese III group) had higher early and late CV mortality.

Introduction: Incomplete coronary revascularization is associated with suboptimal outcomes. We investigated the long-term effects of Incomplete, Complete, and Supra-complete revascularization and whether these effects differed in the setting of single-arterial and multi-arterial coronary artery bypass graft (CABG)., Methods: We analyzed 15-year mortality in 7157 CABG patients (64.1 ± 10.5 years; 30% women). All patients received a left internal thoracic artery to left anterior descending coronary artery graft with additional venous grafts only (single-arterial) or with at least one additional arterial graft (multi-arterial) and were grouped based on a completeness of revascularization index (CRI = number of grafts minus the number of diseased principal coronary arteries): Incomplete (CRI ≤ -1 [N = 320;4.5%]); Complete (CRI = 0 [N = 2882;40.3%]; reference group); and two Supra-complete categories (CRI = +1[N = 3050; 42.6%]; CRI ≥ + 2 [N = 905; 12.6%]). Risk-adjusted mortality hazard ratios (AHR) were calculated using comprehensive propensity score adjustment by Cox regression., Results: Incomplete revascularization was rare (4.5%) but associated with increased mortality in all patients (AHR [95% confidence interval] = 1.53 [1.29-1.80]), those undergoing single-arterial CABG (AHR = 1.27 [1.04-1.54]) and multi-arterial CABG (AHR = 2.18 [1.60-2.99]), as well as in patients with 3-Vessel (AHR = 1.37 [1.16-1.62]) and, to a lesser degree, with 2-Vessel (AHR = 1.67 [0.53-5.23]) coronary disease. Supra-complete revascularization was generally associated with incrementally decreased mortality in all patients (AHR [CRI = +1] = 0.94 [0.87-1.03]); AHR [CRI ≥ +2] = 0.74 [0.64-0.85]), and was driven by a significantly decreased mortality risk in single-arterial CABG (AHR [CRI = +1] = 0.90 [0.81-0.99]; AHR [CRI ≥ +2] = 0.64 [0.53-0.78]); and 3-Vessel disease patients (AHR [CRI = +1] = 0.94 [0.86-1.04]; and AHR [CRI ≥ +2] = 0.75 [0.63-0.88]) with no impact in multi-arterial CABG (AHR [CRI = +1] = 1.07 [0.91-1.26]; AHR [CRI ≥ +2] = 0.93 [0.73-1.17])., Conclusions: Incomplete revascularization is associated with decreased late survival, irrespective of grafting strategy. Alternatively, supra-complete revascularization is associated with improved survival in patients with 3-Vessel CAD, and in single-arterial but not multi-arterial CABG., (© 2018 Wiley Periodicals, Inc.)

Objectives: Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting. Although transient, POAF is linked to increased late mortality. We hypothesized that POAF increases late cerebrovascular (CeV) and composite cerebrovascular/cardiovascular/vascular (CV* = CeV + CV + Other-V) but not non-cardiovascular (Non-CV) mortality., Methods: We analysed 8807 non-salvage coronary artery bypass grafting patients (1994-2011). Fifteen-year and time-segmented (early, 0-1 year; intermediate, 1-6 years and late, 6-15 years) all-cause and cause-specific mortality were compared for POAF versus No-POAF patients. Corresponding POAF versus No-POAF adjusted hazard ratios [AHRs (95% confidence interval, CI)] were derived using the competing risk Cox regression., Results: POAF occurred in 1992 (23%) patients. Complications other than POAF occurred in 1875 (21%) patients but were more frequent among POAF patients (31% vs 18%; P < 0.001). Overall mean follow-up was 9 ± 4 years. POAF patients had a higher 15-year unadjusted mortality (53% vs 39%; P < 0.001) and were consequently associated with higher adjusted all-cause [AHR (95% CI) = 1.23 (1.14-1.33)] and composite cardiovascular [CV*: AHR (95% CI) = 1.15 (1.02-1.30)] mortality. The trends towards a higher 15-year CeV [AHR (95% CI) = 1.34 (0.94-1.91)] and Non-CV [AHR (95% CI) = 1.12 (0.99-1.26)] mortality were not significant. Time-segmented analyses showed that (i) POAF increased all-cause mortality early, and this persisted in the intermediate and late periods and (ii) CeV [AHR (95% CI) = 2.14 (1.14-4.04)] and CV* [AHR (95% CI) = 1.31 (1.06-1.62)] mortality rates were increased in the intermediate but not in the early or late periods. Non-CV mortality was similar in POAF and No-POAF for all time intervals. These findings were corroborated in propensity-matched sub-cohorts and in sensitivity analyses in patients free of any other complication., Conclusions: POAF is associated with worse long-term survival principally driven by increased intermediate-term cerebrovascular and cardiovascular mortality, while Non-CV mortality was similar.

Background: The multiarterial grafting survival advantage noted in the overall population undergoing coronary artery bypass grafting is not well defined in the obese. We investigated the early to late survival effects of the radial artery in left internal thoracic artery-based multiarterial bypass grafting (radial artery-multiarterial bypass grafting) versus single arterial bypass grafting (left internal thoracic artery-single arterial bypass grafting) in obese patients., Methods: We analyzed 15-year Kaplan-Meier survival in 6102 patients receiving primary, left internal thoracic artery-based coronary artery bypass grafting with 2 or more grafts divided into body mass index groups: nonobese (<30 kg/m 2 ) and all-obese, comprised of mildly obese (30-35 kg/m 2 ) and morbidly obese (>35 kg/m 2 ). Risk-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of radial artery-multiarterial bypass grafting versus left internal thoracic artery-single arterial bypass grafting were derived via Cox regression and applied separately for early (<0.5 years), intermediate (0.5-5 years), and late (5-15 years) follow-up in each body mass index cohort. Propensity score matching between radial artery-multiarterial bypass grafting and left internal thoracic artery-single arterial bypass grafting cohorts within the body mass index groups was performed as a corroborating analysis., Results: Radial artery-multiarterial bypass grafting was more frequently used in obese patients who were younger (62 ± 10 years; mild/morbid: 45.4%/54.4% radial artery-multiarterial bypass grafting) compared with nonobese patients (66 ± 10 years; 37.4% radial artery-multiarterial bypass grafting). Unadjusted 15-year survival was significantly better for radial artery-multiarterial bypass grafting in all body mass index groups. Multivariate analysis showed a survival benefit of radial artery-multiarterial bypass grafting over the entire 0- to 15-year study period in the all-obese cohort (HR, 0.85; 95% CI, 0.74-0.98) and was more pronounced in the mildly obese (HR, 0.79; 95% CI, 0.66-0.96) versus morbidly obese (HR, 0.88; 95% CI, 0.69-1.13). The radial artery-multiarterial bypass grafting survival benefit was realized between 0.5 and 5 years postoperatively and was comparable for all-obese (HR, 0.69; 95% CI, 0.51-0.94) and nonobese (HR, 0.68; 95% CI, 0.52-0.88) groups. Propensity score matching was confirmatory., Conclusions: Radial artery-multiarterial bypass grafting confers a long-term survival advantage in both obese and nonobese patients., (Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: It is unknown if the plasma lipidome is a useful tool for improving our understanding of the acute respiratory distress syndrome (ARDS). Therefore, we measured the plasma lipidome of individuals with ARDS at two time-points to determine if changes in the plasma lipidome distinguished survivors from non-survivors. We hypothesized that both the absolute concentration and change in concentration over time of plasma lipids are associated with 28-day mortality in this population., Methods: Samples for this longitudinal observational cohort study were collected at multiple tertiary-care academic medical centers as part of a previous multicenter clinical trial. A mass spectrometry shot-gun lipidomic assay was used to quantify the lipidome in plasma samples from 30 individuals. Samples from two different days were analyzed for each subject. After removing lipids with a coefficient of variation > 30%, differences between cohorts were identified using repeated measures analysis of variance. The false discovery rate was used to adjust for multiple comparisons. Relationships between significant compounds were explored using hierarchical clustering of the Pearson correlation coefficients and the magnitude of these relationships was described using receiver operating characteristic curves., Results: The mass spectrometry assay reliably measured 359 lipids. After adjusting for multiple comparisons, 90 compounds differed between survivors and non-survivors. Survivors had higher levels for each of these lipids except for five membrane lipids. Glycerolipids, particularly those containing polyunsaturated fatty acid side-chains, represented many of the lipids with higher concentrations in survivors. The change in lipid concentration over time did not differ between survivors and non-survivors., Conclusions: The concentration of multiple plasma lipids is associated with mortality in this group of critically ill patients with ARDS. Absolute lipid levels provided more information than the change in concentration over time. These findings support future research aimed at integrating lipidomics into critical care medicine.

Background: More than 90% of coronary artery bypass grafting (CABG) is performed with a single-arterial bypass graft (SABG), based on the left internal thoracic artery (ITA) with supplemental vein grafts. This practice, often justified by safety concerns with multiple-arterial grafting (MABG), defies evidence of improved late survival achieved with bilateral ITA (BITA-MABG) or left ITA plus radial artery (RA-MABG). We hypothesized that MABG and SABG are equally safe., Methods: We analyzed The Society of Thoracic Surgeons National Database (2004 to 2015) to assess the operative safety of BITA-MABG (n = 73,054) and RA-MABG (n = 97,623) vs SABG (n = 1,334,511). Primary end points were operative (30-day or same hospitalization) mortality (OM) and deep sternal wound infections (DSWI). Risk-adjusted odds ratios (AOR) and 95% confidence intervals (CIs) were derived from by logistic regression with sensitivity analyses in multiple subcohorts including MABG use rate., Results: SABG (73.8% men; median age, 66 years), BITA-MABG (85.1% men; median age, 59 years), and RA-MABG (82.5% men; median age, 61 years) showed distinctly different patient characteristics. Compared with SABG (1.91% OM; 0.73% DSWI), observed OM was lower for BITA-MABG (1.19%, p < 0.001) and RA-MABG (1.19%, p < 0.001). DSWI was higher among BITA-MABG (1.08%, p < 0.001) and similar for RA-MABG (0.71%, p = 0.55). BITA-MABG showed marginally increased, likely not clinically significant, OM (AOR, 1.14; 95% CI, 1.00 to 1.30; p = 0.05) and doubled DSWI (AOR, 2.09; 95% CI, 1.80 to 2.43; p < 0.001). RA-MABG had similar OM (AOR, 1.01; 95% CI, 0.89 to 1.15; p = 0.85) and DSWI (AOR, 0.97; 95% CI, 0.83 to 1.13; p = 0.70). Results were consistent across multiple subcohorts. A U-shaped OM vs BITA use relation was documented, with worse OM at hospitals with low (<5%: AOR, 1.38; 95% CI, 1.18 to 1.61; p < 0.001) and high (≥40%: AOR, 1.31; 95% CI, 1.00 to 1.70; p = 0.049) BITA use., Conclusions: MABG in the United States is associated with OM comparable to SABG and increased DSWI risk with BITA-MABG. Our findings highlight the importance of surgeon and institutional experience and careful patient selection for BITA-MABG. Our short-term results should not in any way dissuade the use of MABG, given its well-established long-term survival advantage., (Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: Limited data exists on potential genetic contributors to acute kidney injury. This review examines current knowledge of AKI genomics., Materials and Methods: 32 studies were selected from PubMed and GWAS Catalog queries for original data studies of human AKI genetics. Hand search of references identified 3 additional manuscripts., Results: 33 of 35 studies were hypothesis-driven investigations of candidate polymorphisms that either did not consistently replicate statistically significant findings, or obtained significant results only in few small-scale studies. Vote-counting meta-analysis of 9 variants examined in >1 candidate gene study showed ≥50% non-significant studies, with larger studies generally finding non-significant results. The remaining 2 studies were large-scale unbiased investigations: One examining 2,100 genes linked with cardiovascular, metabolic, and inflammatory syndromes identified BCL2, SERPINA4, and SIK3 variants, while a genome-wide association study (GWAS) identified variants in BBS9 and the GRM7|LMCD1-AS1 intergenic region. All studies had relatively small sample sizes (<2300 subjects). Study heterogeneity precluded candidate gene and GWA meta-analysis., Conclusions: Most studies of AKI genetics involve hypothesis-driven (rather than hypothesis-generating) candidate gene investigations that have failed to identify contributory variants consistently. A limited number of unbiased, larger-scale studies have been carried out, but there remains a pressing need for additional GWA studies., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Recent evidence shows that multi-arterial coronary artery bypass grafting (MABG) based on bilateral internal thoracic (BITA) or left internal thoracic (LITA) and radial artery (RA) improves long-term outcomes compared with single arterial coronary artery bypass grafting (SABG) (LITA + saphenous vein graft). How this evidence affected the worldwide use of MABG, if at all, is not well defined. Accordingly, we report 10-year temporal trends of MABG utilization from 2 continents. A study population of 1,683,434 non-emergent, primary, isolated LITA-based coronary artery bypass grafting (CABG) (≥2 grafts) patients was derived from the Society of Thoracic Surgeons (STS) (1,307,528 (79.5%) of 1,644,388 isolated CABG; total 1179 centers) and the Australia New Zealand Cardiothoracic (ANZ) Databases (34,213 (87%) of 39,046 isolated CABG; 24 centers) between 2004 and 2014. Patients were excluded based on the following: (1) no LITA, (2) if arterial grafts were other than RA or ITA, or (3) if grafting data were missing. The 3 MABG groups were LITA + RA, BITA, and BITA + RA, each with or without supplemental vein grafts. Grafting trends and their associated patient demographics were analyzed. SABG (89.3% STS, 51.4% ANZ) was the most common grafting strategy. MABG was most frequently accomplished by LITA + RA: (STS: 6.1%; ANZ: 42.6%), followed by BITA: (STS: 4.1%; ANZ: 4.3%), while ≥3 (BITA + RA) was rare in the STS (0.5%), but more common in ANZ (5.9%). In the STS, between 2004 and 2014, SABG rates systematically increased from 85.2% to 91.7%, BITA grafting was essentially unchanged from 3.6% to 4.3%, while RA use decreased systematically from 10.5% to 3.7%. In the ANZ, SABG rates increased from 17.3% to 51.4%, BITA grafting decreased from 6.3% to 3.6%, while RA grafting decreased from 65.8% to 39.0%. Compared with SABG patients, BITA patients were younger (STS: median age 59 vs 66, P < 0.001; ANZ: mean age 62 vs 68, P < 0.001), predominately male (STS: 84% vs 73%, P < 0.001; ANZ: 86% vs 79%, P < 0.001), less obese (body mass index >30 kg/m 2 ) in STS (37% vs 42%, P < 0.001), more obese in ANZ (33% vs 32%, P = 0.001), and less diabetic (STS: 26% vs 43%, P < 0.001; ANZ: 25% vs 37%, P < 0.001), whereas RA patients were intermediate in age (STS: 61; ANZ: 65), in male sex (STS: 82%; ANZ: 81%), in the prevalence of diabetes (STS: 40%; ANZ: 34%), and were most obese (STS: 47%; ANZ: 34%). A decade-long analysis of STS data reveals a counterintuitive decline in the use (driven by decreasing RA use) of MABG: a potentially superior grafting strategy compared with SABG. In contra distinction, the smaller but growing ANZ data document a distinctly different CABG practice pattern, with a higher MABG utilization rate, but a similarly declining RA use. The reasons for these practice patterns and declining MABG are likely diverse and require further assessment., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Patients with left ventricular assist devices presenting for noncardiac surgery are increasingly commonplace; however, little is known about their outcomes. Accordingly, the authors sought to determine the frequency of complications, risk factors, and staffing patterns., Methods: The authors performed a retrospective study at their academic tertiary care center, investigating all adult left ventricular assist device patients undergoing noncardiac surgery from 2006 to 2015. The authors described perioperative profiles of noncardiac surgery cases, including patient, left ventricular assist device, surgical case, and anesthetic characteristics, as well as staffing by cardiac/noncardiac anesthesiologists. Through univariate and multivariable analyses, the authors studied acute kidney injury as a primary outcome; secondary outcomes included elevated serum lactate dehydrogenase suggestive of left ventricular assist device thrombosis, intraoperative bleeding complication, and intraoperative hypotension. The authors additionally studied major perioperative complications and mortality., Results: Two hundred and forty-six patients underwent 702 procedures. Of 607 index cases, 110 (18%) experienced postoperative acute kidney injury, and 16 (2.6%) had elevated lactate dehydrogenase. Of cases with complete blood pressure data, 176 (27%) experienced intraoperative hypotension. Bleeding complications occurred in 45 cases (6.4%). Thirteen (5.3%) patients died within 30 days of surgery. Independent risk factors associated with acute kidney injury included major surgical procedures (adjusted odds ratio, 4.4; 95% CI, 1.1 to 17.3; P = 0.03) and cases prompting invasive arterial line monitoring (adjusted odds ratio, 3.6; 95% CI, 1.3 to 10.3; P = 0.02) or preoperative fresh frozen plasma transfusion (adjusted odds ratio, 1.7; 95% CI, 1.1 to 2.8; P = 0.02)., Conclusions: Intraoperative hypotension and acute kidney injury were the most common complications in left ventricular assist device patients presenting for noncardiac surgery; perioperative management remains a challenge.

Objective: We sought to determine if decreased left ventricular systolic function was associated with an increased risk of postoperative infectious, respiratory, or renal complications in patients undergoing noncardiac surgery., Design: Retrospective cohort study., Setting: Single tertiary-care, university-based medical center., Patients: We studied individuals who participated in the American College of Surgeons National Quality Improvement Program and had a preoperative echocardiogram conducted at our institution., Interventions: None., Measurements: The incidences of postoperative respiratory (need for postoperative mechanical ventilation or unplanned intubation), renal (acute renal failure or renal insufficiency), and infectious (pneumonia, urinary tract infection, sepsis, or wound infection) complications were analyzed., Main Results: Postoperative infections (n=175, 10%) represented the most common postoperative complication seen in the study population of 1692 individuals. Respiratory complications occurred in 77 (5%) and renal complications occurred in 29 (2%) participants. The time between the echocardiogram and surgery ranged from 7 months (interquartile range [IQR] 1.8-15.7) for those with severely reduced left ventricular ejection fraction (LVEF) to 24 months (IQR 2.5-38.6) for those with a normal LVEF (P=.038). Univariate analysis demonstrated a relationship between decreased preoperative LVEF and infectious and renal complications, but not respiratory complications. After adjusting for preoperative characteristics, decreased preoperative LVEF was associated with infectious (odds ratio, 1.33; 95% confidence interval, 1.03-1.68; P=.0265) and renal (odds ratio, 1.69; 95% confidence interval, 1.12-2.48; P=.0142) complications., Conclusions: Decreased preoperative LVEF is associated with postoperative infections and renal complications., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Assessment of need for intravascular volume resuscitation remains challenging for anesthesiologists. Dynamic waveform indices, including systolic and pulse pressure variation, are demonstrated as reliable measures of fluid responsiveness for mechanically ventilated patients. Despite widespread use, real-world reference distributions for systolic and pulse pressure variation values have not been established for euvolemic intraoperative patients. The authors sought to establish systolic and pulse pressure variation reference distributions and assess the impact of modifying factors., Methods: The authors evaluated adult patients undergoing general anesthetics for elective noncardiac surgery. Median systolic and pulse pressure variations during a 50-min postinduction period were noted for each case. Modifying factors including body mass index, age, ventilator settings, positioning, and hemodynamic management were studied via univariate and multivariable analyses. For systolic pressure variation values, effects of data entry method (manually entered vs. automated recorded) were similarly studied., Results: Among 1,791 cases, per-case median systolic and pulse pressure variation values formed nonparametric distributions. For each distribution, median values, interquartile ranges, and reference intervals (2.5th to 97.5th percentile) were, respectively, noted: these included manually entered systolic pressure variation (6.0, 5.0 to 7.0, and 3.0 to 11.0 mmHg), automated systolic pressure variation (4.7, 3.9 to 6.0, and 2.2 to 10.4 mmHg), and automated pulse pressure variation (7.0, 5.0 to 9.0, and 2.0 to 16.0%). Nonsupine positioning and preoperative β blocker were independently associated with altered systolic and pulse pressure variations, whereas ventilator tidal volume more than 8 ml/kg ideal body weight and peak inspiratory pressure more than 16 cm H2O demonstrated independent associations for systolic pressure variation only., Conclusions: This study establishes real-world systolic and pulse pressure variation reference distributions absent in the current literature. Through a consideration of reference distributions and modifying factors, the authors' study provides further evidence for assessing intraoperative volume status and fluid management therapies., Competing Interests: : None

Study Objective: To facilitate the identification of drugs and patient factors associated with hemodynamically significant anaphylaxis., Design: Using an existing database containing complete perioperative records, instances of hemodynamically significant anaphylaxis were identified using a physiologic and treatment-based screening algorithm. All cases were manually reviewed by 2 clinicians, with a third adjudicating disagreements, and confirmed cases were matched 3:1 with control cases. Intraoperative medications given in instances of hemodynamically significant anaphylaxis and patient risk factors were compared with control cases., Setting: University of Michigan Hospital, a large, tertiary care hospital., Patients: All adult patients undergoing surgery between January 1, 2004, and January 5, 2015., Interventions: None., Measurements: Incidence of hemodynamically significant anaphylaxis during anesthesia. Patient risk factors and intraoperative medications associated with hemodynamically significant anaphylaxis., Main Results: Hemodynamically significant anaphylaxis occurred in 55 of 461 986 cases (1 in 8400). Hemodynamically significant anaphylaxis occurred in 52 patients, with 1 patient experiencing 3 instances and another patient 2 instances. Only 1 drug was associated with an increased risk of hemodynamically significant anaphylaxis: protamine (odds ratio, 11.78; 95% confidence interval, 1.40-99.26; P=.0233). No category of drugs was associated with increased risk. Of patient risk factors, only personal history of anaphylaxis was associated with an increased risk (odds ratio, 77.1; 95% confidence interval, 10.46-567.69; P=<.0001). Postoperative follow-up and evaluation of patients were low at our institution. A serum tryptase level was sent in only 49% of cases, and 41% of levels were positive, an overall positive rate of 20% of cases. Following instances of hemodynamically significant anaphylaxis, only 29% of patients were seen and evaluated by an allergist at our institution., Conclusions: Hemodynamically significant anaphylaxis is a rare complication of anesthesia, with an incidence consistent with the existing literature. Contrary to most existing literature, only protamine was associated with increased risk. A personal history of anaphylaxis appears to best predict risk of hemodynamically significant anaphylaxis., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Red blood cell transfusion after coronary artery bypass graft surgery has been associated with increased late all-cause death. Yet, whether this association is, first, independent of the packed red blood cells and perioperative morbidity association, and second, of a cardiac versus noncardiac etiology remains unknown., Methods: We analyzed patients undergoing coronary artery bypass graft surgery at two Ohio hospitals (n = 6,947) from 1994 to 2007. Salvage operations and patients with preoperative renal failure were excluded. Long-term outcomes and leading cause of death (cardiac, noncardiac, all cause) were derived from the US Social Security Death Index and later from Ohio Department of Health Death Index. Fifteen-year mortality cumulative incidence functions were compared for transfusion groups (yes, n = 2,540; no, n = 4,806) overall, and then stratified based on perioperative complications status (yes, n = 2,638; no, n = 4,708). Comprehensive, 32 covariates, risk-adjusted transfusion effects were estimated by competing risk regression. Results were confirmed by propensity score adjusted analysis., Results: Perioperative transfusions and complications occurred in 33.9% and 35.2% of patients, respectively. In all, 3,108 deaths (48.1%) have been documented (median time to death, 7.43 years). Both transfusion rates (25.6% versus 49.1%, p < 0.001) and deaths (58.2% versus 38.5%, p < 0.001) were more frequent among complications patients. Red blood cells transfusion increased intermediate to late mortality risk overall (15-year adjusted hazard ratio [AHR] 1.21, 95% confidence interval [CI]: 1.11 to 1.31), and for complications (AHR 1.24, 95% CI: 1.11 to 1.39) and no complications (AHR 1.16, 95% CI: 1.03 to 1.31). The increased mortality was true for cardiac and noncardiac etiologies (AHR 1.19, 95% CI: 1.03 to 1.36, and AHR 1.14, 95% CI: 1.01 to 1.29, respectively). Red blood cell transfusion increased mostly cardiac deaths (AHR 1.38, 95% CI: 1.14 to 1.66) among the complications group, and noncardiac mortality (AHR 1.24, 95% CI: 1.05 to 1.47) for the no complications group. A parallel propensity matched sensitivity analysis confirmed these findings., Conclusions: Perioperative red blood cells transfusion is associated with significant adverse late death effects among both complicated patients and noncomplicated patients, principally seen between 0 and 5 years postoperatively, and is driven by both increased cardiovascular and noncardiovascular mortality. Further studies are needed to elucidate the mechanisms behind these findings, including their potential dose dependence., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Even small elevations in preoperative troponin levels have been shown to be associated with adverse outcomes. However, there are currently limited data on the relationship between troponin increase and timing of surgery., Methods: We performed a single-institution, retrospective cohort study of 6030 individuals with a troponin measurement made during the 30 days preceding a noncardiac surgical procedure. Subjects with detectable troponin levels were separated into terciles based on both the magnitude of the value and the time elapsed between this value and the surgery. For those undergoing nonemergent procedures, these 9 cohorts were compared with the group of individuals with undetectable preoperative troponin levels using bivariable and multivariable logistic regression., Results: Thirty-day mortality was 4.7% in the group with undetectable troponin levels and increased with higher concentrations, with rates of 8.9%, 12.7%, and 12.7% in the low, medium, and high tercile groups, respectively. Unadjusted risk of 30-day mortality was highest in those with the highest troponin levels and shortest duration between the measurement and surgery (odds ratio, 4.497; 95% confidence interval, 2.058-9.825). After adjusting for subject characteristics, troponin remained associated with 30-day mortality in several groups, including individuals with troponin levels in the normal range., Conclusions: Higher levels of preoperative cardiac troponin I were associated with higher postoperative mortality, and longer time to surgery appeared to reduce this risk for individuals with mild preoperative troponin elevations. Prospective studies are needed to determine whether delaying surgery in patients with elevated preoperative troponin levels improves postoperative outcomes.

Blood pressure exhibits substantial short- and long-term variability (BPV). We assessed the hypothesis that the complexity of beat-to-beat BPV will be differentially altered in salt-sensitive hypertensive Dahl rats (SS) versus rats protected from salt-induced hypertension (SSBN13) maintained on high-salt versus low-salt diet. Beat-to-beat systolic and diastolic BP series from nine SS and six SSBN13 rats (http://www.physionet.org) were analyzed following 9 weeks on low salt and repeated after 2 weeks on high salt. BP complexity was quantified by detrended fluctuation analysis (DFA), short- and long-range scaling exponents (αS and αL), sample entropy (SampEn), and traditional standard deviation (SD) and coefficient of variation (CV(%)). Mean systolic and diastolic BP increased on high-salt diet (P < 0.01) particularly for SS rats. SD and CV(%) were similar across groups irrespective of diet. Salt-sensitive and -protected rats exhibited similar complexity indices on low-salt diet. On high salt, (1) SS rats showed increased scaling exponents or smoother, systolic (P = 0.007 [αL]) and diastolic (P = 0.008 [αL]) BP series; (2) salt-protected rats showed lower SampEn (less complex) systolic and diastolic BP (P = 0.046); and (3) compared to protected SSBN13 rats, SS showed higher αL for systolic (P = 0.01) and diastolic (P = 0.005) BP Hypertensive SS rats are more susceptible to high salt with a greater rise in mean BP and reduced complexity. Comparable mean pressures in sensitive and protective rats when on low-salt diet coupled with similar BPV dynamics suggest a protective role of low-salt intake in hypertensive rats. This effect likely reflects better coupling of biologic oscillators., (© 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.)

Background: Intraoperative electrocardiographic monitoring is considered a standard of care. However, there are no evidence-based algorithms for using intraoperative ST segment data to identify patients at high risk for adverse perioperative cardiac events. Therefore, we performed an exploratory study of statistical measures summarizing intraoperative ST segment values determine whether the variability of these measurements was associated with adverse postoperative events. We hypothesized that elevation, depression, and variability of ST segments captured in an anesthesia information management system are associated with postoperative serum troponin elevation., Methods: We conducted a single-institution, retrospective study of intraoperative automated ST segment measurements from leads I, II, and III, which were recorded in the electronic anesthesia record of adult patients undergoing noncardiac surgery. The maximum, minimum, mean, and SD of ST segment values were entered into logistic regression models to find independent associations with myocardial injury, defined as an elevated serum troponin concentration during the 7 days after surgery. Performance of these models was assessed by measuring the area under the receiver operator characteristic curve. The net reclassification improvement was calculated to quantify the amount of information that the ST segment values analysis added regarding the ability to predict postoperative troponin elevation., Results: Of 81,011 subjects, 4504 (5.6%) had postoperative myocardial injury. After adjusting for patient characteristics, the ST segment maximal depression (e.g., lead I: odds ratio [OR], 1.66; 95% confidence interval [CI], 1.26-2.19; P = 0.0004), maximal elevation (e.g., lead I: OR, 1.70; 95% CI, 1.34-2.17; P < 0.0001), and SD (e.g., lead I: OR, 0.16; 95% CI, 0.06-0.42; P = 0.0002) were found to have statistically significant associations with myocardial injury. Increased SD was associated with decreased risk when accounting for the maximal amount of ST segment depression and elevation and for patient characteristics. The ST segment summary statistics model had fair discrimination, with an area under the receiver operator characteristic curve of 0.71 (95% CI, 0.68-0.73). Addition of ST segment data produced a net reclassification improvement of 0.0345 (95% CI, 0.00016-0.0591; P = 0.0474)., Conclusions: Analysis of automated ST segment values obtained during anesthesia may be useful for improving the prediction of postoperative troponin elevation.

Background: Postoperative deep vein thrombosis (DVT) is associated with significant morbidity. Even with maximal thromboprophylaxis, postoperative DVT is present in 10% of cardiac surgery patients, and is linked to receiving transfusion. We hypothesized that the incidence of DVT varies with the transfused blood product type, and increases with transfusion dose., Study Design and Methods: 139/1070 cardiac surgery patients have DVT despite maximal chemo and mechanical prophylaxis. DVTs were detected via serial perioperative duplex venous scans (DVS). Red blood cells (RBC), platelets (PLT), plasma (FFP) and cryoprecipitate transfusion data were collected., Results: Transfusion was used in 506(47%) patients: RBC [468(44%); 4.0 ± 4.2u]; FFP [155(14.5%); 3.5 ± 2.3 u]; PLT [185(17.3%); 2.2 ± 1.3 u] and Cryoprecipitate [51(4.8%); 1.3 ± 0.6 u]. Isolated RBC transfusion accounted for 92.6% patients receiving one product, and their DVT rate was increased considerably compared to no transfusion (16.7% versus 7.3%; P<0.001). Incidence of DVT increased substantially for multiple product transfusions; particularly when both RBC and FFP are used (25%-40%). Relative to no RBC (n=602), multivariate logistic regression analysis identified a significant RBC-DVT dose dependent relation (P<0.001) with: 1-3 RBC units [n=285, AOR=1.95(1.23-3.07), adjusted odds ratio (95% confidence interval)]; 4-6 units [n=117; AOR=1.65(0.86-3.20)]; and ≥ 7 RBC units [n=66; 3.19(1.52-6.70)]. This relation also increased according to an RBC∗FFP interaction term [AOR=1.87(1.11-3.22); P=0.022]., Conclusion: RBC transfusion is associated with increased risk of DVT after cardiac surgery in a dose-dependent fashion that is exacerbated when accompanied with FFP. Postoperative screening diagnostic DVS are warranted in this transfused, high risk for DVT population to facilitate timely therapeutic intervention., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Left internal thoracic artery (LITA) and radial artery (RA) multi-arterial CABG (MABG) is generally associated with improved long-term survival compared with traditional LITA and saphenous vein single arterial CABG (SABG). We examined the hypothesis that this multi-arterial survival advantage persists irrespective of left ventricular ejection fraction (LVEF)., Methods: We retrospectively analyzed the primary, non-salvage multi-graft CABG experience (n = 11,261; 64.4 ± 10.4 years, 70.4% men) from 2 institutions (1995 to 2011). Risk-adjusted 15-year survival was pairwise compared for the MABG versus SABG grafting approaches within 3 LVEF subcohorts (>0.50, n = 4,833 [44% MABG]; 0.36 to 0.50, n = 4,465 [39% MABG]; and ≤ 0.35, n = 1,963 [35% MABG]) using propensity-matched and covariate adjusted Cox regression (all patients) comparisons., Results: Propensity matching yielded 1,317 (LVEF > 0.50), 1,179 (LVEF, 0.36 to 0.50), and 470 (LVEF ≤ 0.35) well-matched grafting method pairs. Acute perioperative mortality was equivalent between MABG and SABG within each LVEF group, but increased with decreasing LVEF. MABG was uniformly associated with better 15-year survival compared with SABG for all LVEF categories. The associated matched-adjusted hazard ratios (95% confidence intervals) were consistent across EF groups at 0.79 (0.68 to 0.93), 0.80 (0.69 to 0.93), and 0.82 (0.66 to 1.0), respectively. Covariate adjusted HR in all patients concurred with matched results., Conclusions: MABG results in significantly enhanced long-term survival compared with LITA/SVG SABG regardless of the degree of LV dysfunction. These results favor MABG as the therapy of choice in patients with LV dysfunction., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: Recent studies have indicated that coronary artery bypass grafting (CABG) outcomes in patients with prior stents are suboptimal. We aimed to study the impact of prior percutaneous coronary intervention (PCI) with stenting (PCI-S) on late CABG mortality in diabetic patients with triple-vessel disease., Methods: We reviewed the primary nonemergency CABG experience from a single U.S. institution (n = 7005; 1996-2007, Toledo, Ohio). Diabetics with triple-vessel disease (n = 1583) were identified and divided into 2 groups: (1) prior PCI-S (n = 202); and (2) no prior PCI (No-PCI [n = 1381]). Hierarchic Cox proportional hazards models were used to assess the effect of prior PCI-S on 5-year mortality after CABG. A propensity score for PCI-S and No-PCI patients was derived using a nonparsimonious logistic regression and used to generate a 1:1 (PCI-S to No-PCI) matched cohort., Results: In model 1, after adjusting for preoperative clinical characteristics, medications, off-pump surgery, and isolated CABG surgery status, prior PCI-S was associated with a 39% increased risk of mortality (hazard ratio [HR] = 1.39, with 95% confidence interval [CI; 1.02, 1.90]; P = .04). Further adjustment for date of surgery (model 2) (HR = 1.39, with 95% CI [1.02, 1.91]; P = .04) or operative parameters (model 3) (HR = 1.38, with 95% CI [1.01, 1.88]; P = .046) did not alter the association. The 1:1 matched-cohort analysis confirmed the increased risk associated with PCI-S (HR = 1.61, with 95% CI [1.03, 2.51]; P = .037)., Conclusions: Patients who have both diabetes and triple-vessel disease, and have undergone prior PCI-S, have poorer long-term outcomes after CABG compared with those who have had no prior PCI-S., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)