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To examine the association/effect of intraoperative cerebral oximetry (CeOx) on major organ morbidity and mortality (MOMM) after adult cardiac surgery.A retrospective, multicenter cohort study.Patients treated at any hospital within the Society of Thoracic Surgeons Adult Cardiac Surgery Database between July 1, 2011, and December 31, 2016, with a 30-day postoperative follow-up.Individuals ≥18 years old undergoing isolated coronary artery bypass graft (CABG) or valve repair or replacement, or any combination of procedures with cardiopulmonary bypass.Intraoperative CeOx.MOMM includes operative mortality, stroke, renal failure, prolonged mechanical ventilation, deep sternal wound infection, or reoperation for any reason within 30 days. Of 1.19 million patients who met inclusion criteria within 1,180 facilities, ∼30% (n = 361,124) received CeOx versus nonrecipients (n = 838,675) with similar baseline patient characteristics. Using a propensity score-based 1:1 greedy matching method, 99.7% of CeOx recipients (n = 360,285) were matched with nonrecipients. The rates of MOMM were lower with versus without CeOx. The absolute risk reduction translated to a number needed to treat of 227 patients (95% CI: 166-363, p0.0001). In sensitivity analyses of prespecified subgroups, the benefit was strongest among patients undergoing aortic valve repair or replacement ± CABG (more than 7 fewer MOMM events per 1,000, p0.0001). However, intensive care unit stay72 hours was higher with CeOx.Intraoperative cerebral oximetry is associated with less major organ morbidity and mortality after adult cardiac surgery. A large-scale clinical trial is warranted, given that desaturation is common and correctable.

Cardiac surgery-associated acute kidney injury (CS-AKI) is common and is associated with increased risk for postoperative morbidity and mortality. Our recent survey of the Society of Cardiovascular Anesthesiologists (SCA) membership showed 6 potentially renoprotective strategies for which clinicians would most value an evidence-based review (ie, intraoperative target blood pressure, choice of specific vasopressor agent, erythrocyte transfusion threshold, use of alpha-2 agonists, goal-directed oxygen delivery on cardiopulmonary bypass [CPB], and the "Kidney Disease Improving Global Outcomes [KDIGO] bundle of care"). Thus, the SCA's Continuing Practice Improvement Acute Kidney Injury Working Group aimed to provide a practice update for each of these strategies in cardiac surgical patients based on the evidence from randomized controlled trials (RCTs). PubMed, EMBASE, and Cochrane library databases were comprehensively searched for eligible studies from inception through February 2021, with search results updated in August 2021. A total of 15 RCTs investigating the effects of the above-mentioned strategies on CS-AKI were included for meta-analysis. For each strategy, the level of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Across the 6 potentially renoprotective strategies evaluated, current evidence for their use was rated as "moderate," "low," or "very low." Based on eligible RCTs, our analysis suggested using goal-directed oxygen delivery on CPB and the "KDIGO bundle of care" in high-risk patients to prevent CS-AKI (moderate level of GRADE evidence). Our results suggested considering the use of vasopressin in vasoplegic shock patients to reduce CS-AKI (low level of GRADE evidence). The decision to use a restrictive versus liberal strategy for perioperative red cell transfusion should not be based on concerns for renal protection (a moderate level of GRADE evidence). In addition, targeting a higher mean arterial pressure during CPB, perioperative use of dopamine, and use of dexmedetomidine did not reduce CS-AKI (a low or very low level of GRADE evidence). This review will help clinicians provide evidence-based care, targeting improved renal outcomes in adult patients undergoing cardiac surgery.

One of the primary reasons for intensive care admission is shock. Identifying the underlying cause of shock (hypovolemic, distributive, cardiogenic, and obstructive) may lead to entirely different clinical pathways for management. Among patients with hypovolemic and distributive shock, fluid therapy is one of the leading management strategies. Although an appropriate amount of fluid administration might save a patient's life, inadequate (or excessive) fluid use could lead to more complications, including organ failure and mortality due to either hypovolemia or volume overload. Currently, intensivists have access to a wide variety of information sources and tools to monitor the underlying hemodynamic status, including medical history, physical examination, and specific hemodynamic monitoring devices. Although appropriate and timely assessment and interpretation of this information can promote adequate fluid resuscitation, misinterpretation of these data can also lead to additional mortality and morbidity. This article provides a narrative review of the most commonly used hemodynamic monitoring approaches to assessing fluid responsiveness and fluid tolerance. In addition, we describe the benefits and disadvantages of these tools.

PURPOSE OF REVIEW Ideal fluid management of critically ill patients is maintaining an adequate perfusion pressure but avoiding venous congestion. Venous excess ultrasound score (VExUS) quantifies venous congestion to guide the management of fluid balance. RECENT FINDINGS VExUS of abdominal veins measures fluid tolerance and helps clinicians avoid congestion. VExUS scoring predicts the development of acute kidney injury (AKI) that is a common hospital problem resulting in higher mortality and morbidity. VExUS can predict patients at risk of developing AKI post cardiac surgery. VExUS has been associated with an increase in adverse outcomes in a general intensive care population. Hepatic vein ultrasound can manifest as a sequela of right heart failure and pulmonary hypertension. Intrarenal congestion suggests poorer prognosis in heart failure patients. VExUS score has been used in decision-making to remove fluid in patients with cardiorenal syndrome. VExUS scoring may help curtail overly aggressive fluid resuscitation for patients with septic shock and help avoid iatrogenic 'salt water drowning'. SUMMARY We summarize the technique and clinical practice of VExUS to help guide fluid balance across different populations of critically ill patients.

Kidney disease is an important public health problem. Both acute kidney injury (AKI) and chronic kidney disease have been well defined and classified, leading to improved research efforts and subsequent management strategies and recommendations. For those patients with abnormalities in kidney function and/or structure who meet neither the definition of AKI nor chronic kidney disease, there remains a gap in research, care, and guidance. The term acute kidney diseases and disorders, abbreviated to acute kidney disease (AKD), has been introduced as an important construct to address this. To expand and harmonize existing definitions and to ultimately better inform research and clinical care, Kidney Disease: Improving Global Outcomes (KDIGO) organized a consensus workshop. Multiple invitees from around the globe, representing both acute and chronic kidney disease researchers and experts, met virtually to examine existing data, and discuss key concepts related to AKD. Despite some remaining unresolved questions, conference attendees reached general consensus on the definition and classification of AKD, management strategies, and research priorities. AKD is defined by abnormalities of kidney function and/or structure with implications for health and with a duration of ≤3 months. AKD may include AKI, but, more importantly, also includes abnormalities in kidney function that are not as severe as AKI or that develop over a period of >7 days. The cause(s) of AKD should be sought, and classification includes functional and structural parameters. Management of AKD is currently based on empirical considerations. A robust research agenda to enable refinement and validation of definitions and classification systems, and thus testing of interventions and strategies, is proposed.

Objectives The authors sought to (1) characterize the rationale underpinning anesthesiologists’ use of various perioperative strategies hypothesized to affect renal function in adult patients undergoing cardiac surgery, (2) characterize existing belief about the quality of evidence addressing the renal impact of these strategies, and (3) identify potentially renoprotective strategies for which anesthesiologists would most value a detailed, evidence-based review. Design Survey of perioperative practice in adult patients undergoing cardiac surgery. Setting Online survey. Participants Members of the Society of Cardiovascular Anesthesiologists (SCA). Interventions None. Measurements & Main Results The survey was distributed to more than 2,000 SCA members and completed in whole or in part by 202 respondents. Selection of target intraoperative blood pressure (and relative hypotension avoidance) was the strategy most frequently reported to reflect belief about its potential renal effect (79%; 95% CI: 72-85). Most respondents believed the evidence supporting an effect on renal injury of intraoperative target blood pressure during cardiac surgery was of high or moderate quality. Other factors, including a specific nonrenal rationale, surgeon preference, department- or institution-level decisions, tradition, or habit, also frequently were reported to affect decision making across queried strategies. Potential renoprotective strategies most frequently requested for inclusion in a subsequent detailed, evidence-based review were intraoperative target blood pressure and choice of vasopressor agent to achieve target pressure. Conclusions A large number of perioperative strategies are believed to variably affect renal injury in adult patients undergoing cardiac surgery, with wide variation in perceived quality of evidence for a renal effect of these strategies.

The administration of fluids is one of the most common interventions in the intensive care unit. The effects and side effects of intravenous fluids depend on the amount administered and their specific composition. Intravenous fluid solutions are either considered crystalloids (for example 0.9% saline, lactated Ringer's solution) or colloids (artificial colloids such as gelatins, and albumin). This narrative review summarizes the physiological principles of fluid therapy and reviews the most important studies on crystalloids, artificial colloids and albumin in the context of critically ill patients.

Purpose Bevacizumab is a recombinant humanized monoclonal antibody that inhibits vascular endothelial growth factor-specific angiogenesis in some cancers. MYL-1402O is a proposed bevacizumab biosimilar. Methods The primary objective of this single-center, randomized, double-blind, three-arm, parallel-group, phase 1 study in healthy male volunteers was to evaluate bioequivalence of MYL-1402O to EU and US-reference bevacizumab, and EU-reference bevacizumab to US-reference bevacizumab. The primary pharmacokinetic parameter was area under the serum concentration–time curve from 0 extrapolated to infinity (AUC0–∞). Pharmacokinetic parameters were analyzed using general linear models of analysis of variance. Secondary endpoints included safety and tolerability. Results Of 111 enrolled subjects, 110 were included in the pharmacokinetic analysis (MYL-1402O, n = 37; EU-reference bevacizumab, n = 36; US-reference bevacizumab, n = 37). Bioequivalence was demonstrated between MYL-1402O and EU-reference bevacizumab, MYL-1402O and US-reference bevacizumab, and between EU- and US-reference bevacizumab where least squares mean ratios of AUC0–∞ were close to 1, and 90% CIs were within the equivalence range (0.80–1.25). Secondary pharmacokinetic parameters (AUC from 0 to time of last quantifiable concentration [AUC0–t], peak serum concentration [Cmax], time to Cmax, elimination rate constant, and elimination half-life) were also comparable, with 90% CIs for ratios of AUC0–t and Cmax within 80–125%. Treatment-emergent adverse events were similar across all three treatment groups and were consistent with clinical data for bevacizumab. Conclusion MYL-1402O was well tolerated and demonstrated pharmacokinetic and safety profiles similar to EU-reference bevacizumab and US-reference bevacizumab in healthy male volunteers. No new significant safety issues emerged (ClinicalTrials.gov, NCT02469987; ClinicalTrialsRegister.eu EudraCT, 2014-005621-12; June 12, 2015).

BACKGROUND Postoperative hypotension (POH) is associated with major adverse events. However, little is known about the association of blood pressure thresholds and outcomes in postoperative patients without intraoperative hypotension (IOH) on the general-care ward. We evaluated the association of POH with major adverse cardiac or cerebrovascular events (MACCE) in patients without IOH. METHODS This retrospective analysis included 67,968 noncardiac patient-procedures (2008-2017) for patients discharged to the ward with postoperative mean arterial pressure (MAP) readings, managed for ≥48 hours postsurgery, with no evidence of IOH. The primary outcome was 30-day MACCE evaluated by postoperative MAP thresholds: ≤75, ≤65, and ≤55 mm Hg (POH defined as a single measurement below threshold). Secondary outcomes included all-cause mortality (30-/90-day), 30-day acute myocardial infarction, 30-day acute ischemic stroke, 30-day readmission, 7-day acute kidney injury, and 30-day readmission. Associations between POH and adverse events were also evaluated in a cohort (#2) of 16,034 patient-procedures with IOH (intraoperative MAP ≤65 mm Hg). RESULTS In patients without IOH, exposure to POH was not associated with MACCE at any investigated MAP threshold (P < .016 was considered significant: ≤75 mm Hg, hazard ratio [HR] 1.18 [98.4% confidence interval {CI} 0.99-1.39], P = .023; ≤65 mm Hg, HR 1.18 [0.99-1.41], P = .028; ≤55 mm Hg, HR 1.23 [0.90-1.71], P = .121); however, associations were observed at all MAP thresholds for secondary outcomes of acute kidney injury and 30-day readmission, for 30-/90-day mortality for MAP ≤65 mm Hg, and 90-day mortality for MAP ≤55 mm Hg, compared to those without POH. No associations were detected between POH and secondary outcomes of acute ischemic stroke or acute myocardial infarction at any MAP threshold. No interaction between POH and IOH was found when we evaluated the association of POH on outcomes in the data set including all patients, regardless of IOH status (P values for interaction terms nonsignificant). When the interaction term was utilized, the association between POH without IOH and MACCE was significant for MAP ≤75 mm Hg (HR 1.20 [1.01-1.41]) and MAP ≤65 mm Hg (HR 1.21 [1.02-1.45]), but not MAP ≤55 mm Hg. Cohort #2 (POH with IOH) showed largely similar results for MACCE: not significant for MAP ≤75 and ≤65 mm Hg, but significant for MAP ≤55 mm Hg (HR 1.53 [1.05-2.22], P = .006). CONCLUSIONS POH in patients without IOH was not associated with MACCE at any MAP investigated. No interaction was identified between POH and IOH. Large prospective randomized trials are necessary to develop better evidence and inform clinicians the value of postoperative blood pressure management.

Advances in cardiac surgical operative techniques and myocardial protection have dramatically improved outcomes in the past two decades. An unfortunate and unintended consequence is that 80% of the preventable morbidity and mortality following cardiac surgery now originates outside of the operating room. Our hope is that a renewed emphasis on evidence-based best practice and standardized perioperative care will reduce overall morbidity and mortality and improve patient-centric care. The Perioperative Quality Initiative (POQI) and Enhanced Recovery After Surgery–Cardiac Society (ERAS® Cardiac) have identified significant evidence gaps in perioperative medicine related to cardiac surgery, defined as areas in which there is significant controversy about how best to manage patients. These five areas of focus include patient blood management, goal-directed therapy, acute kidney injury, opioid analgesic reduction, and delirium.

BackgroundThe postoperative period is critical for a patient’s recovery, and postoperative hypotension, specifically, is associated with adverse clinical outcomes and significant harm to the patient. However, little is known about the association between postoperative hypotension in patients in the intensive care unit (ICU) after non-cardiac surgery, and morbidity and mortality, specifically among patients who did not experience intraoperative hypotension. The goal of this study was to assess the impact of postoperative hypotension at various absolute hemodynamic thresholds (≤ 75, ≤ 65 and ≤ 55 mmHg), in the absence of intraoperative hypotension (≤ 65 mmHg), on outcomes among patients in the ICU following non-cardiac surgery.MethodsThis multi-center retrospective cohort study included specific patient procedures from Optum® healthcare database for patients without intraoperative hypotension (MAP ≤ 65 mmHg) discharged to the ICU for ≥ 48 h after non-cardiac surgery with valid mean arterial pressure (MAP) readings. A total of 3185 procedures were included in the final cohort, and the association between postoperative hypotension and the primary outcome, 30-day major adverse cardiac or cerebrovascular events, was assessed. Secondary outcomes examined included all-cause 30- and 90-day mortality, 30-day acute myocardial infarction, 30-day acute ischemic stroke, 7-day acute kidney injury stage II/III and 7-day continuous renal replacement therapy/dialysis.ResultsPostoperative hypotension in the ICU was associated with an increased risk of 30-day major adverse cardiac or cerebrovascular events at MAP ≤ 65 mmHg (hazard ratio [HR] 1.52; 98.4% confidence interval [CI] 1.17–1.96) and ≤ 55 mmHg (HR 2.02, 98.4% CI 1.50–2.72). Mean arterial pressures of ≤ 65 mmHg and ≤ 55 mmHg were also associated with higher 30-day mortality (MAP ≤ 65 mmHg, [HR 1.56, 98.4% CI 1.22–2.00]; MAP ≤ 55 mmHg, [HR 1.97, 98.4% CI 1.48–2.60]) and 90-day mortality (MAP ≤ 65 mmHg, [HR 1.49, 98.4% CI 1.20–1.87]; MAP ≤ 55 mmHg, [HR 1.78, 98.4% CI 1.38–2.31]). Furthermore, we found an association between postoperative hypotension with MAP ≤ 55 mmHg and acute kidney injury stage II/III (HR 1.68, 98.4% CI 1.02–2.77). No associations were seen between postoperative hypotension and 30-day readmissions, 30-day acute myocardial infarction, 30-day acute ischemic stroke and 7-day continuous renal replacement therapy/dialysis for any MAP threshold.ConclusionsPostoperative hypotension in critical care patients with MAP ≤ 65 mmHg is associated with adverse events even without experiencing intraoperative hypotension.

Background Intraoperative hypotension (IOH) occurs frequently during surgery and may be associated with organ ischemia; however, few multicenter studies report data regarding its associations with adverse postoperative outcomes across varying hemodynamic thresholds. Additionally, no study has evaluated the association between IOH exposure and adverse outcomes among patients by various age groups. Methods A multicenter retrospective cohort study was conducted between 2008 and 2017 using intraoperative blood pressure data from the US electronic health records database to examine postoperative outcomes. IOH was assessed in 368,222 noncardiac surgical procedures using 5 methods: (a) absolute maximum decrease in mean arterial pressure (MAP) during surgery, (b) time under each absolute threshold, (c) total area under each threshold, (d) time-weighted average MAP under each threshold, and (e) cumulative time under the prespecified relative MAP thresholds. MAP thresholds were defined by absolute limits (≤75, ≤65, ≤55 mm Hg) and by relative limits (20% and 40% lower than baseline). The primary outcome was major adverse cardiac or cerebrovascular events; secondary outcomes were all-cause 30- and 90-day mortality, 30-day acute myocardial injury, and 30-day acute ischemic stroke. Residual confounding was minimized by controlling for observable patient and surgical factors. In addition, we stratified patients into age subgroups (18-40, 41-50, 51-60, 61-70, 71-80, >80) to investigate how the association between hypotension and the likelihood of major adverse cardiac or cerebrovascular events and acute kidney injury differs in these age subgroups. Results IOH was common with at least 1 reading of MAP ≤75 mm Hg occurring in 39.5% (145,743) of cases; ≤65 mm Hg in 19.3% (70,938) of cases, and ≤55 mm Hg in 7.5% (27,473) of cases. IOH was significantly associated with the primary outcome for all age groups. For an absolute maximum decrease, the estimated odds of a major adverse cardiac or cerebrovascular events in the 30-day postsurgery was increased by 12% (95% confidence interval [CI], 11-14) for ≤75 mm Hg; 17.0% (95% CI, 15-19) for ≤65 mm Hg; and by 26.0% (95% CI, 22-29) for ≤55 mm Hg. Conclusions IOH during noncardiac surgery is common and associated with increased 30-day major adverse cardiac or cerebrovascular events. This observation is magnified with increasing hypotension severity. The potentially avoidable nature of the hazard, and the extent of the exposed population, makes hypotension in the operating room a serious public health issue that should not be ignored for any age group.

Some neurological complications following surgery have been related to a mismatch in cerebral oxygen supply and demand that may either lead to more subtle changes of brain function or overt complications like stroke or coma. Discovery of a perioperative neurological complication may be outside the treatment window, thereby making prevention an important focus. Early commercial devices used differential spectroscopy to measure relative changes from baseline of 2 chromophores: oxy- and deoxyhemoglobin. It was the introduction of spatially resolved spectroscopy techniques that allowed near-infrared spectroscopy (NIRS)-based cerebral oximetry as we know it today. Modern cerebral oximeters measure the hemoglobin saturation of blood in a specific "optical field" containing arterial, capillary, and venous blood, not tissue oxygenation itself. Multiple cerebral oximeters are commercially available, all of which have technical differences that make them noninterchangeable. The mechanism and meaning of these measurements are likely not widely understood by many practicing physicians. Additionally, as with many clinically used monitors, there is a lack of high-quality evidence on which clinicians can base decisions in their effort to use cerebral oximetry to reduce neurocognitive complications after surgery. Therefore, the Sixth Perioperative Quality Initiative (POQI-6) consensus conference brought together an international team of multidisciplinary experts including anesthesiologists, surgeons, and critical care physicians to objectively survey the literature on cerebral oximetry and provide consensus, evidence-based recommendations for its use in accordance with the GRading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria for evaluating biomedical literature. The group produced the following consensus recommendations: (1) interpreting perioperative cerebral oximetry measurements in the context of a preinduction baseline value; (2) interpreting perioperative cerebral oximetry measurements in the context of the physiologic variables that affect them; (3) using caution in comparing cerebral oximetry values between different manufacturers; (4) using preoperative cerebral oximetry to identify patients at increased risk of adverse outcomes after cardiac surgery; (5) using intraoperative cerebral oximetry indexed to preinduction baseline to identify patients at increased risk of adverse outcomes after cardiac surgery; (6) using cerebral oximetry to identify and guide management of acute cerebral malperfusion during cardiac surgery; (7) using an intraoperative cerebral oximetry-guided interventional algorithm to reduce intensive care unit (ICU) length of stay after cardiac surgery. Additionally, there was agreement that (8) there is insufficient evidence to recommend using intraoperative cerebral oximetry to reduce mortality or organ-specific morbidity after cardiac surgery; (9) there is insufficient evidence to recommend using intraoperative cerebral oximetry to improve outcomes after noncardiac surgery.

Background: Accurately assessing the probability of significant respiratory depression following opioid administration can potentially enhance perioperative risk assessment and pain management. We developed and validated a risk prediction tool to estimate the probability of significant respiratory depression (indexed by naloxone administration) in patients undergoing noncardiac surgery. Methods: We studied n=63,084 patients (mean age 47.1±18.2 years; 50% male) who underwent emergency or elective noncardiac surgery between January 1st, 2007 and October 30th, 2017 at Vanderbilt University Medical Center. A derivation subsample reflecting two-thirds of available patients (n=42,082) was randomly selected for model development, and associations were identified between predictor variables and naloxone administration occurring within 5 days following surgery. The resulting probability model for predicting naloxone administration was then cross-validated in a separate validation cohort reflecting the remaining one-third of patients (n=21,002).Results: The rate of naloxone administration was identical in the derivation (n = 2,720 [6.5%]) and validation (n = 1,360 [6.5%]) cohorts. The risk prediction model identified female sex (Odds Ratio [OR]: 3.01; 95% confidence interval [CI]: 2.73-3.32), high-risk surgical procedures (OR: 4.16; 95% CI: 3.78-4.58), history of drug abuse (OR: 1.81; 95% CI: 1.52-2.16), and any opioids being administered on a scheduled rather than as-needed basis (OR: 8.31; 95% CI: 7.26-9.51) as risk factors for naloxone administration. Advanced age (OR: 0.40; 95% CI: 0.36-0.43), opioids administered via patient-controlled analgesia pump (OR: 0.55; 95% CI:0.49-0.62), and any scheduled non-opioids (OR: 0.63; 95% CI: 0.58-0.69) were associated with decreased risk of naloxone administration. An overall risk-prediction model incorporating the common clinically-available variables above displayed excellent discriminative ability both the derivation and validation cohorts (c-index = 0.820 and 0.814, respectively).Conclusion: Our cross-validated clinical predictive model accurately estimates the risk of serious opioid-related respiratory depression requiring naloxone administration in postoperative patients. In the precision medicine context, it may prove useful in facilitating selection of opioid-sparing pain management strategies for high-risk surgical patients.

In this study, we define and validate a state of postoperative systemic inflammatory dysregulation (PSID) based on postoperative phenotypic extremes of plasma C-reactive protein concentration following major abdominal surgery. PSID manifested clinically with significantly higher rates of sepsis, complications, longer hospital stays and poorer short, and long-term outcomes. We hypothesized that PSID will be associated with, and potentially predicted by, altered patterns of genome-wide peripheral blood mononuclear cell differential DNA methylation and gene expression. We identified altered DNA methylation and differential gene expression in specific immune and metabolic pathways during PSID. Our findings suggest that dysregulation results in, or from, dramatic changes in differential DNA methylation and highlights potential targets for early detection and treatment. The combination of altered DNA methylation and gene expression suggests that dysregulation is mediated at multiple levels within specific gene sets and hence, nonspecific anti-inflammatory treatments such as corticosteroids alone are unlikely to represent an effective therapeutic strategy.

To determine the incidence and predictive factors of acute kidney injury (AKI) after off-pump lung transplantation.A retrospective cohort study.The operating room and intensive care unit.Adult patients who underwent lung transplant without cardiopulmonary bypass or extracorporeal membrane oxygenator between 2006 and 2016 at the Vanderbilt University Medical Center.None.The presence of postoperative AKI was assessed by the Kidney Disease: Improving Global Outcomes criteria in the first seven postoperative days. Multivariate logistic regression analysis was used to determine the independent predictive factors of AKI. One hundred forty-eight patients were included in the final analysis, of whom 63 (42.6%) subsequently developed AKI: 43 (29.0%) stage 1, ten (6.8%) stage 2, and ten (6.8%) stage 3. Patients who had AKI had a longer hospital length of stay (12 days [interquartile range (IQR): 10-17] vs ten days [IQR: 8-12], p0.001). For every one-year increase in age, the odds of AKI decreased by 8% (odds ratio [OR] 0.92, 95% confidence interval [CI]: 0.87-0.98, p = 0.008). The odds of having AKI in patients with bilateral lung transplant was lower than patients with unilateral transplant (OR 0.09, 95% CI: 0.01-0.63, p = 0.015). Additionally, a diagnosis of chronic obstructive pulmonary disease increased the odds of AKI by four-fold compared with a diagnosis of idiopathic pulmonary fibrosis (OR 4.73, 95% CI: 1.44-15.56, p = 0.011).AKI is a common complication after off-pump lung transplantation and is associated with increased hospital length of stay. Younger age, unilateral lung transplant, and diagnosis of chronic obstructive pulmonary disease are independently associated with AKI.

Surgical care episodes place opioid-naïve patients at risk for transitioning to new persistent postoperative opioid use. With one of the central principles being the application of multimodal pain interventions to reduce the reliance on opioid-based medications, enhanced recovery pathways provide a framework that decreases perioperative opioid use. The fourth Perioperative Quality Initiative brought together a group of international experts representing anesthesiology, surgery, and nursing with the objective of providing consensus recommendations on this important topic. Fourth Perioperative Quality Initiative was a consensus-building conference designed around a modified Delphi process in which the group alternately convened for plenary discussion sessions in between small group discussions. The process included several iterative steps including a literature review of the topics, building consensus around the important questions related to the topic, and sequential steps of content building and refinement until agreement was achieved and a consensus document was produced. During the fourth Perioperative Quality Initiative conference and thereafter as a writing group, reference applicability to the topic was discussed in any area where there was disagreement. For this manuscript, the questions answered included (1) What are the potential strategies for preventing persistent postoperative opioid use? (2) Is opioid-free anesthesia and analgesia feasible and appropriate for routine operations? and (3) Is opioid-free (intraoperative) anesthesia associated with equivalent or superior outcomes compared to an opioid minimization in the perioperative period? We will discuss the relevant literature for each questions, emphasize what we do not know, and prioritize the areas for future research.

Persistent postoperative opioid use is thought to contribute to the ongoing opioid epidemic in the United States. However, efforts to study and address the issue have been stymied by the lack of a standard definition, which has also hampered efforts to measure the incidence of and risk factors for persistent postoperative opioid use. The objective of this systematic review is to (1) determine a clinically relevant definition of persistent postoperative opioid use, and (2) characterize its incidence and risk factors for several common surgeries. Our approach leveraged a group of international experts from the Perioperative Quality Initiative-4, a consensus-building conference that included representation from anesthesiology, surgery, and nursing. A search of the medical literature yielded 46 articles addressing persistent postoperative opioid use in adults after arthroplasty, abdominopelvic surgery, spine surgery, thoracic surgery, mastectomy, and thoracic surgery. In opioid-naive patients, the overall incidence ranged from 2% to 6% based on moderate-level evidence. However, patients who use opioids preoperatively had an incidence of >30%. Preoperative opioid use, depression, factors associated with the diagnosis of substance use disorder, preoperative pain, and tobacco use were reported risk factors. In addition, while anxiety, sex, and psychotropic prescription are associated with persistent postoperative opioid use, these reports are based on lower level evidence. While few articles addressed the health policy or prescriber characteristics that influence persistent postoperative opioid use, efforts to modify prescriber behaviors and health system characteristics are likely to have success in reducing persistent postoperative opioid use.

Factors contributing to development of complex regional pain syndrome (CRPS) are not fully understood. This study examined possible epigenetic mechanisms that may contribute to CRPS after traumatic injury. DNA methylation profiles were compared between individuals developing CRPS (n = 9) and those developing non-CRPS neuropathic pain (n = 38) after undergoing amputation following military trauma. Linear Models for Microarray (LIMMA) analyses revealed 48 differentially methylated cytosine-phosphate-guanine dinucleotide (CpG) sites between groups (unadjusted P's < 0.005), with the top gene COL11A1 meeting Bonferroni-adjusted P < 0.05. The second largest differential methylation was observed for the HLA-DRB6 gene, an immune-related gene linked previously to CRPS in a small gene expression study. For all but 7 of the significant CpG sites, the CRPS group was hypomethylated. Numerous functional Gene Ontology-Biological Process categories were significantly enriched (false discovery rate-adjusted q value

Background Perioperative arterial blood pressure management is a physiologically complex challenge influenced by multiple factors. Methods A multidisciplinary, international working subgroup of the Third Perioperative Quality Initiative (POQI) consensus meeting reviewed the (patho)physiology and measurement of arterial pressure as applied to perioperative medicine. We addressed predefined questions by undertaking a modified Delphi analysis, in which primary clinical research and review articles were identified using MEDLINE. Strength of recommendations, where applicable, were graded by National Institute for Health and Care Excellence (NICE) guidelines. Results Multiple physiological factors contribute to the perioperative physiological importance of arterial pressure: (i) arterial pressure is the input pressure to organ blood flow, but is not the sole determinant of perfusion pressure; (ii) blood flow is often independent of changes in perfusion pressure because of autoregulatory changes in vascular resistance; (iii) microvascular dysfunction uncouples microvascular blood flow from arterial pressure (haemodynamic incoherence). From a practical clinical perspective, we identified that: (i) ambulatory measurement is the optimal method to establish baseline arterial pressure; (ii) automated and invasive arterial pressure measurements have inherent physiological and technical limitations; (iii) individualised arterial pressure targets may change over time, especially in the perioperative period. There remains a need for research in non-invasive, continuous arterial pressure measurements, macro- and micro-circulatory control, regional perfusion pressure measurement, and the development of sensitive, specific, and continuous measures of cellular function to evaluate blood pressure management in a physiologically coherent manner. Conclusion The multivariable, complex physiology contributing to dynamic changes in perioperative arterial pressure may be underappreciated clinically. The frequently unrecognised dissociation between arterial pressure, organ blood flow, and microvascular and cellular function requires further research to develop a more refined, contextualised clinical approach to this routine perioperative measurement.

Background A multidisciplinary international working subgroup of the third Perioperative Quality Initiative consensus meeting appraised the evidence on the influence of preoperative arterial blood pressure and community cardiovascular medications on perioperative risk. Methods A modified Delphi technique was used, evaluating papers published in MEDLINE on associations between preoperative numerical arterial pressure values or cardiovascular medications and perioperative outcomes. The strength of the recommendations was graded by National Institute for Health and Care Excellence guidelines. Results Significant heterogeneity in study design, including arterial pressure measures and perioperative outcomes, hampered the comparison of studies. Nonetheless, consensus recommendations were that (i) preoperative arterial pressure measures may be used to define targets for perioperative management; (ii) elective surgery should not be cancelled based solely upon a preoperative arterial pressure value; (iii) there is insufficient evidence to support lowering arterial pressure in the immediate preoperative period to minimise perioperative risk; and (iv) there is insufficient evidence that any one measure of arterial pressure (systolic, diastolic, mean, or pulse) is better than any other for risk prediction of adverse perioperative events. Conclusions Future research should define which preoperative arterial pressure values best correlate with adverse outcomes, and whether modifying arterial pressure in the preoperative setting will change the perioperative morbidity or mortality. Additional research should define optimum strategies for continuation or discontinuation of preoperative cardiovascular medications.

Objectives: To determine the performance of a rapid fluorescent indicator technique for measuring plasma volume (PV). Methods: This was an open-label, observational evaluation of a two-component intravenous visible fluorescent dye technique to rapidly measure PV in 16 healthy subjects and 16 subjects with chronic kidney disease (8 stage 3 and 8 stage 4 CKD), at 2 clinical research sites. The method consisted of a single intravenous injection of 12 mg of a large 150-kDa carboxy-methyl dextran conjugated to a fluorescent rhodamine-derived dye as the PV marker (PVM), and 35 mg of a small 5-kDa carboxy-methyl dextran conjugated to fluorescein, the renal clearance marker. Dye concentrations were quantified 15 min after the injections for initial PV measurements using the indicator-dilution principle. Additional samples were taken over 8 h to evaluate the stability of the PVM as a determinant of PV. Blood volumes (BV) were calculated based on PV and the subject’s hematocrit. Pharmacokinetic parameters were calculated from the plasma concentration data taken over several days using noncompartmental methods (Phoenix WinNonlin®). Linear correlation and Bland-Altman plots were used to compare visible fluorescent injectate-measured PV compared to Nadler’s formula for estimating PV. Finally, 8 healthy subjects received 350 mL infusion of a 5% albumin solution in normal saline over 30 min and a repeat PV determination was then carried out. Results: PV and BV varied according to weight and body surface area, with PV ranging from 2,115 to 6,234 mL and 28.6 to 41.9 mL/kg when weight adjusted. Both parameters were stable for > 6 h with repeated plasma measurements of the PVM. There was no difference between healthy subjects and CKD subjects. Overall, there was general agreement with Nadler’s estimation formula for the mean PV in subjects. A 24-h repeat dose measurement in 8 healthy subjects showed PV variability of 98 ± 121 mL (mean = 3.8%). Additionally, following an intravenous bolus of 350 mL of a 5% albumin solution in normal saline in 8 healthy subjects, the mean (SD) measured increase in PV was 356 (±50.0) mL post-infusion. There were no serious adverse events reported during the study. Conclusions: This minimally invasive fluorescent dye approach safely allowed for rapid, accurate, and reproducible determination of PV, BV, and dynamic monitoring of changes following fluid administration.

ObjectivesAccurately assessing the probability of significant respiratory depression following opioid administration can potentially enhance perioperative risk assessment and pain management. We developed and validated a risk prediction tool to estimate the probability of significant respiratory depression (indexed by naloxone administration) in patients undergoing noncardiac surgery.DesignRetrospective cohort study.SettingSingle academic centre.ParticipantsWe studied n=63 084 patients (mean age 47.1±18.2 years; 50% men) who underwent emergency or elective non-cardiac surgery between 1 January 2007 and 30 October 2017.InterventionsA derivation subsample reflecting two-thirds of available patients (n=42 082) was randomly selected for model development, and associations were identified between predictor variables and naloxone administration occurring within 5 days following surgery. The resulting probability model for predicting naloxone administration was then cross-validated in a separate validation cohort reflecting the remaining one-third of patients (n=21 002).ResultsThe rate of naloxone administration was identical in the derivation (n=2720 (6.5%)) and validation (n=1360 (6.5%)) cohorts. The risk prediction model identified female sex (OR: 3.01; 95% CI: 2.73 to 3.32), high-risk surgical procedures (OR: 4.16; 95% CI: 3.78 to 4.58), history of drug abuse (OR: 1.81; 95% CI: 1.52 to 2.16) and any opioids being administered on a scheduled rather than as-needed basis (OR: 8.31; 95% CI: 7.26 to 9.51) as risk factors for naloxone administration. Advanced age (OR: 0.971; 95% CI: 0.968 to 0.973), opioids administered via patient-controlled analgesia pump (OR: 0.55; 95% CI: 0.49 to 0.62) and any scheduled non-opioids (OR: 0.63; 95% CI: 0.58 to 0.69) were associated with decreased risk of naloxone administration. An overall risk prediction model incorporating the common clinically available variables above displayed excellent discriminative ability in both the derivation and validation cohorts (c-index=0.820 and 0.814, respectively).ConclusionOur cross-validated clinical predictive model accurately estimates the risk of serious opioid-related respiratory depression requiring naloxone administration in postoperative patients.

Background Outcome selection underpins clinical trial interpretation. Inconsistency in outcome selection and reporting hinders comparison of different trials' results, reducing the utility of research findings. Methods We conducted an iterative consensus process to develop a set of Core Outcome Measures for Perioperative and Anaesthetic Care (COMPAC), following the established Core Outcome Measures for Effectiveness Trials (COMET) methodology. First, we undertook a systematic review of RCTs in high-impact journals to describe current outcome reporting trends. We then surveyed patients, carers, researchers, and perioperative clinicians about important outcomes after surgery. Finally, a purposive stakeholder sample participated in a modified Delphi process to develop a core outcome set for perioperative and anaesthesia trials. Results Our systematic review revealed widespread inconsistency in outcome reporting, with variable or absent definitions, levels of detail, and temporal criteria. In the survey, almost all patients, carers, and clinicians rated clinical outcome measures critically important, but clinicians rated patient-centred outcomes less highly than patients and carers. The final core outcome set was: (i) mortality/survival (postoperative mortality, long-term survival); (ii) perioperative complications (major postoperative complications/adverse events; complications/adverse events causing permanent harm); (iii) resource use (length of hospital stay, unplanned readmission within 30 days); (iv) short-term recovery (discharge destination, level of dependence, or both); and (v) longer-term recovery (overall health-related quality of life). Conclusions This core set, incorporating important outcomes for both clinicians and patients, should guide outcome selection in future perioperative medicine or anaesthesia trials. Mapping these alongside standardised endpoint definitions will yield a comprehensive perioperative outcome framework.

Postoperative hypotension (POH) is associated with major adverse events. However, little is known about the association of blood pressure thresholds and outcomes in postoperative patients without intraoperative hypotension (IOH) on the general-care ward. We evaluated the association of POH with major adverse cardiac or cerebrovascular events (MACCE) in patients without IOH.This retrospective analysis included 67,968 noncardiac patient-procedures (2008-2017) for patients discharged to the ward with postoperative mean arterial pressure (MAP) readings, managed for ≥48 hours postsurgery, with no evidence of IOH. The primary outcome was 30-day MACCE evaluated by postoperative MAP thresholds: ≤75, ≤65, and ≤55 mm Hg (POH defined as a single measurement below threshold). Secondary outcomes included all-cause mortality (30-/90-day), 30-day acute myocardial infarction, 30-day acute ischemic stroke, 30-day readmission, 7-day acute kidney injury, and 30-day readmission. Associations between POH and adverse events were also evaluated in a cohort (#2) of 16,034 patient-procedures with IOH (intraoperative MAP ≤65 mm Hg).In patients without IOH, exposure to POH was not associated with MACCE at any investigated MAP threshold (P.016 was considered significant: ≤75 mm Hg, hazard ratio [HR] 1.18 [98.4% confidence interval {CI} 0.99-1.39], P = .023; ≤65 mm Hg, HR 1.18 [0.99-1.41], P = .028; ≤55 mm Hg, HR 1.23 [0.90-1.71], P = .121); however, associations were observed at all MAP thresholds for secondary outcomes of acute kidney injury and 30-day readmission, for 30-/90-day mortality for MAP ≤65 mm Hg, and 90-day mortality for MAP ≤55 mm Hg, compared to those without POH. No associations were detected between POH and secondary outcomes of acute ischemic stroke or acute myocardial infarction at any MAP threshold. No interaction between POH and IOH was found when we evaluated the association of POH on outcomes in the data set including all patients, regardless of IOH status (P values for interaction terms nonsignificant). When the interaction term was utilized, the association between POH without IOH and MACCE was significant for MAP ≤75 mm Hg (HR 1.20 [1.01-1.41]) and MAP ≤65 mm Hg (HR 1.21 [1.02-1.45]), but not MAP ≤55 mm Hg. Cohort #2 (POH with IOH) showed largely similar results for MACCE: not significant for MAP ≤75 and ≤65 mm Hg, but significant for MAP ≤55 mm Hg (HR 1.53 [1.05-2.22], P = .006).POH in patients without IOH was not associated with MACCE at any MAP investigated. No interaction was identified between POH and IOH. Large prospective randomized trials are necessary to develop better evidence and inform clinicians the value of postoperative blood pressure management.

Mitali Stevens,1 Todd Davis,1 Sibyl H Munson,2 Apeksha V Shenoy,2 Boye LA Gricar,2 Halit O Yapici,2 Andrew D Shaw3 1Global Health Economics & Reimbursement, Edwards Lifesciences, Irvine, CA, USA; 2Department of Health Economics and Outcomes Research, Boston Strategic Partners, Inc., Boston, MA, USA; 3Department of Anaesthesiology and Pain Medicine, University of Alberta, Edmonton, Alberta, CanadaCorrespondence: Andrew D ShawDepartment of Anaesthesiology and Pain Medicine, University of Alberta, 8440 112 St NW, Edmonton, Alberta T6G 2G3, CanadaEmail ashaw2@ualberta.caObjective: A monitoring pulmonary artery catheter (PAC) is utilized in approximately 34% of the US cardiac surgical procedures. Increased use of PAC has been reported to have an association with complication rates: significant decreases in new-onset heart failure (HF) and respiratory failure (RF), but increases in bacteremia and urinary tract infections. We assessed the impact of increasing PAC adoption on hospital costs among cardiac surgery patients for US-based healthcare systems.Methods: An Excel-based economic model calculated annualized savings for a US hospital with various cardiac surgical volumes and PAC adoption rates. A second model, for an integrated payer-provider health system, analyzed outcomes/costs resulting from the cardiac surgical admission and for the treatment of persistent HF and RF complications in the year following surgery. Model inputs were extracted from published literature, and one-way and probabilistic sensitivity analyses were performed.Results: For an acute care hospital with 500 procedures/year and 34% PAC adoption, annualized savings equalled $61,806 vs no PAC utilization. An increase in PAC adoption rate led to increased savings of $134,751 for 75% and $170,685 for 95% adoption. Savings ranged from $12,361 to $185,418 at volumes of 100 and 1500 procedures/year, respectively. For an integrated payer-provider health system with the base-case scenario of 3845 procedures/year and 34% PAC adoption, estimated savings were $596,637 for the combined surgical index admission and treatment for related complications over the following year.Conclusion: PAC utilization in adult cardiac surgery patients results in reduced costs for both acute care hospitals and payer-provider integrated health systems.Keywords: heart failure, respiratory failure, economic evaluation, cost analysis, acute care hospital, integrated payer-provider

Whilst intraoperative hypotension is associated with postoperative acute kidney injury (AKI), the link between intraoperative hypotension and acute kidney disease (AKD), defined as continuing renal dysfunction for up to 3 months after exposure, has not yet been studied.We conducted a retrospective multicentre cohort study using data from noncardiac, non-obstetric surgery extracted from a US electronic health records database. Primary outcome was the association between intraoperative hypotension, at three MAP thresholds (≤75, ≤65, and ≤55 mm Hg), and the following two AKD subtypes: (i) persistent (initial AKI incidence within 7 days of surgery, with continuation between 8 and 90 days post-surgery) and (ii) delayed (renal impairment without AKI within 7 days, with AKI occurring between 8 and 90 days post-surgery). Secondary outcomes included healthcare resource utilisation for patients with either AKD subtype or no AKD.A total of 112 912 surgeries qualified for the study. We observed a rate of 2.2% for delayed AKD and 0.6% for persistent AKD. Intraoperative hypotension was significantly associated with persistent AKD at MAP ≤55 mm Hg (hazard ratio 1.1; 95% confidence interval: 1.38-1.22; P0.004). However, IOH was not significantly associated with delayed AKD across any of the MAP thresholds. Patients with delayed or persistent AKD had higher healthcare resource utilisation across both hospital and intensive care admissions, compared with patients with no AKD.Intraoperative hypotension is associated with persistent but not delayed acute kidney disease. Both types of acute kidney disease appear to be associated with increased healthcare utilisation. Correction of intraoperative hypotension is a potential opportunity to decrease postoperative kidney injury and associated costs.

Postoperative complications increase hospital length of stay and patient mortality. Optimal perioperative fluid management should decrease patient complications. This study examined associations between fluid volume and noncardiac surgery patient outcomes within a large multicentre US surgical cohort.Adults undergoing noncardiac procedures from January 1, 2012 to December 31, 2017, with a postoperative length of stay ≥24 h, were extracted from a large US electronic health record database. Patients were segmented into quintiles based on recorded perioperative fluid volumes with Quintile 3 (Q3) serving as the reference. The primary outcome was defined as a composite of any complications during the surgical admission and a postoperative length of stay ≥7 days. Secondary outcomes included in-hospital mortality, respiratory complications, and acute kidney injury.A total of 35 736 patients met the study criteria. There was a U-shaped pattern with highest (Q5) and lowest (Q1) quintiles of fluid volumes having increased odds of complications and a postoperative length of stay ≥7 days (Q5: odds ratio [OR] 1.51 [95% confidence interval {CI}: 1.30-1.74], P0.001; Q1: OR 1.20 [95% CI: 1.04-1.38], P=0.011) compared with Q3. Patients in Q5 had greater odds of more severe acute kidney injury compared with Q3 (OR 1.52 [95% CI: 1.22-1.90]; P0.001) and respiratory complications (OR 1.44 [95% CI: 1.17-1.77]; P0.001).Both very high and very low perioperative fluid volumes were associated with an increase in complications after noncardiac surgery.

Background The utility of pulmonary artery catheters (PACs) and their measurements depend on a variety of factors including data interpretation and personnel training. This US multi-center, retrospective electronic health record (EHR) database analysis was performed to identify associations between PAC use in adult cardiac surgeries and effects on subsequent clinical outcomes. Methods This cohort analysis utilized the Cerner Health Facts database to examine patients undergoing isolated coronary artery bypass graft (CABG), isolated valve surgery, aortic surgery, other complex non-valvular and multi-cardiac procedures, and/or heart transplant from January 1, 2011, to June 30, 2015. A total of 6844 adults in two cohorts, each with 3422 patients who underwent a qualifying cardiac procedure with or without the use of a PAC for monitoring purposes, were included. Patients were matched 1:1 using a propensity score based upon the date and type of surgery, hospital demographics, modified European System for Cardiac Operative Risk Evaluation (EuroSCORE II), and patient characteristics. Primary outcomes of 30-day in-hospital mortality, length of stay, cardiopulmonary morbidity, and infectious morbidity were analyzed after risk adjustment for acute physiology score. Results There was no difference in the 30-day in-hospital mortality rate between treatment groups (OR, 1.17; 95% CI, 0.65–2.10; p = 0.516). PAC use was associated with a decreased length of stay (9.39 days without a PAC vs. 8.56 days with PAC; p