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Some studies have found surgery and anesthesia in children to be associated with neurodevelopmental deficits, but specific reasons for this association have not been fully explored. This study evaluates intraoperative mean arterial pressure (MAP) during a single ambulatory procedure in children and subsequent mental disorder diagnoses.A retrospective observational study was performed including children ≥28 days and18 years of age with intraoperative electronic anesthetic records between January 1, 2009, and April 30, 2017, at our institution. Eligible children were categorized based on their mean intraoperative MAP relative to other children of the same sex and similar age: category 1 (very low): children with mean intraoperative MAP values below the 10th percentile, category 2 (low): mean MAP value ≥10th and25th percentiles, category 3 (reference): mean MAP value ≥25th and75th percentiles, category 4 (high): mean MAP value ≥75th and90th percentile, and category 5 (very high): mean MAP value ≥90th percentile. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) and ICD, Tenth Revision, Clinical Modification (ICD-10)-coded mental disorders were identified in hospital and outpatient claims, with a median duration of follow-up after surgery of 120 days (interquartile range [IQR], 8-774.5 days). Cox proportional hazards models evaluated the hazard ratio (HR) of time to first mental disorder diagnosis associated with intraoperative blood pressure category between the end of surgery and censoring, with the primary analysis adjusting for demographic, anesthetic, comorbidity, and procedure-type variables as potential confounders.A total of 14,724 eligible children who received general anesthesia for a single ambulatory surgical procedure were identified. After adjusting for all available potential confounders, when compared to the reference, there were no statistically significant differences in mental disorder diagnosis risk based on intraoperative mean MAP category. Compared to reference, children in the very low and low blood pressure categories reported HRs of 1.00 (95% confidence interval [CI], 0.74-1.35) and 1.10 (95% CI, 0.87-1.41) for a mental disorder diagnosis, respectively, and children in the high and very high categories reported HRs of 0.87 (95% CI, 0.68-1.12) and 0.76 (95% CI, 0.57-1.03), respectively.Presence in a predefined mean intraoperative MAP category was not associated with subsequent mental disorder diagnoses within our follow-up period. However, the limitations of this study, including uncertainty regarding what constitutes an adequate blood pressure in children, may limit the ability to form definitive conclusions.

Risk prediction models for postoperative mortality after intra-abdominal surgery have typically been developed using preoperative variables. It is unclear if intraoperative data add significant value to these risk prediction models.With IRB approval, an institutional retrospective cohort of intra-abdominal surgery patients in the 2005 to 2015 American College of Surgeons National Surgical Quality Improvement Program was identified. Intraoperative data were obtained from the electronic health record. The primary outcome was 30-day mortality. We evaluated the performance of machine learning algorithms to predict 30-day mortality using: 1) baseline variables and 2) baseline + intraoperative variables. Algorithms evaluated were: 1) logistic regression with elastic net selection, 2) random forest (RF), 3) gradient boosting machine (GBM), 4) support vector machine (SVM), and 5) convolutional neural networks (CNNs). Model performance was evaluated using the area under the receiver operator characteristic curve (AUROC). The sample was randomly divided into a training/testing split with 80%/20% probabilities. Repeated 10-fold cross-validation identified the optimal model hyperparameters in the training dataset for each model, which were then applied to the entire training dataset to train the model. Trained models were applied to the test cohort to evaluate model performance. Statistical significance was evaluated using P.05.The training and testing cohorts contained 4322 and 1079 patients, respectively, with 62 (1.4%) and 15 (1.4%) experiencing 30-day mortality, respectively. When using only baseline variables to predict mortality, all algorithms except SVM (area under the receiver operator characteristic curve [AUROC], 0.83 [95% confidence interval {CI}, 0.69-0.97]) had AUROC0.9: GBM (AUROC, 0.96 [0.94-1.0]), RF (AUROC, 0.96 [0.92-1.0]), CNN (AUROC, 0.96 [0.92-0.99]), and logistic regression (AUROC, 0.95 [0.91-0.99]). AUROC significantly increased with intraoperative variables with CNN (AUROC, 0.97 [0.96-0.99]; P = .047 versus baseline), but there was no improvement with GBM (AUROC, 0.97 [0.95-0.99]; P = .3 versus baseline), RF (AUROC, 0.96 [0.93-1.0]; P = .5 versus baseline), and logistic regression (AUROC, 0.94 [0.90-0.99]; P = .6 versus baseline).Postoperative mortality is predicted with excellent discrimination in intra-abdominal surgery patients using only preoperative variables in various machine learning algorithms. The addition of intraoperative data to preoperative data also resulted in models with excellent discrimination, but model performance did not improve.

BACKGROUND Aspects of intraoperative management (eg, hypotension) are associated with acute kidney injury (AKI) in noncardiac surgery patients. However, it is unclear if and how the addition of intraoperative data affects a baseline risk prediction model for postoperative AKI. METHODS With institutional review board (IRB) approval, an institutional cohort (2005-2015) of inpatient intra-abdominal surgery patients without preoperative AKI was identified. Data from the American College of Surgeons National Surgical Quality Improvement Program (preoperative and procedure data), Anesthesia Information Management System (intraoperative data), and electronic health record (postoperative laboratory data) were linked. The sample was split into derivation/validation (70%/30%) cohorts. AKI was defined as an increase in serum creatinine ≥0.3 mg/dL within 48 hours or >50% within 7 days of surgery. Forward logistic regression fit a baseline model incorporating preoperative variables and surgical procedure. Forward logistic regression fit a second model incorporating the previously selected baseline variables, as well as additional intraoperative variables. Intraoperative variables reflected the following aspects of intraoperative management: anesthetics, beta-blockers, blood pressure, diuretics, fluids, operative time, opioids, and vasopressors. The baseline and intraoperative models were evaluated based on statistical significance and discriminative ability (c-statistic). The risk threshold equalizing sensitivity and specificity in the intraoperative model was identified. RESULTS Of 2691 patients in the derivation cohort, 234 (8.7%) developed AKI. The baseline model had c-statistic 0.77 (95% confidence interval [CI], 0.74-0.80). The additional variables added to the intraoperative model were significantly associated with AKI (P < .0001) and the intraoperative model had c-statistic 0.81 (95% CI, 0.78-0.83). Sensitivity and specificity were equalized at a risk threshold of 9.0% in the intraoperative model. At this threshold, the baseline model had sensitivity and specificity of 71% (95% CI, 65-76) and 69% (95% CI, 67-70), respectively, and the intraoperative model had sensitivity and specificity of 74% (95% CI, 69-80) and 74% (95% CI, 73-76), respectively. The high-risk group had an AKI risk of 18% (95% CI, 15-20) in the baseline model and 22% (95% CI, 19-25) in the intraoperative model. CONCLUSIONS Intraoperative data, when added to a baseline risk prediction model for postoperative AKI in intra-abdominal surgery patients, improves the performance of the model.

BackgroundDespite 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.MethodsMajor 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).ResultsAmong 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.ConclusionsAdult 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.Editor’s PerspectiveWhat We Already Know about This TopicWhat This Article Tells Us That Is New

Study design Retrospective cohort. Objective To evaluate the effectiveness and safety of antifibrinolytic (AF) agents in reducing perioperative blood transfusion in pediatric patients undergoing spinal fusion. Summary of background data The potential for AF to decrease bleeding and reduce exposure to allogenic transfusions has led to widespread off-label use in a number of major pediatric surgical procedures. Recent reviews call for improving the body of evidence for their effectiveness and safety in pediatric spinal fusion. Methods Children undergoing spinal fusion were identified in the American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) 2016 and 2017 databases. Univariate analyses of patient and perioperative characteristics informed the creation of a propensity score model predicting treatment with AF, followed by 1:1 matching to allow comparison of allogenic red blood cell transfusion rates and secondary outcomes between treated and untreated patients. Results Of 6626 total patients, 5434 (81%) received AF and 1533 (23%) received a blood transfusion. Analysis of data for 1192 propensity score-matched pairs revealed that treatment with AF was associated with a statistically non-significant 16% reduction in perioperative transfusion (OR 0.84, 95% confidence interval 0.68-1.05, p = 0.119) and a statistically significant 43% reduction in postoperative transfusion (OR 0.57, 95% confidence interval 0.39-0.81, p = 0.002). No differences in the incidences of postoperative seizure or thrombosis were observed, with overall rates of 7.5 and 22.5 events per 10,000 patients, respectively. Conclusions AF agents appear to reduce postoperative allogenic transfusion in children undergoing spinal fusion surgery. Adverse drug effects such as thromboembolic complications and seizure were extremely rare and warrant continued monitoring, though this is the largest study to date providing evidence for the safety profile of these drugs. Level of evidence 3.

BACKGROUND: Unplanned postoperative intubation is an important quality indicator, and is associated with significantly increased mortality in children. Infant patients are more likely than older pediatric patients to experience unplanned postoperative intubation, yet the literature provides few characterizations of this outcome in our youngest patients. The objective of this study was to identify risk factors for unplanned postoperative intubation and to develop a scoring system to predict this complication in infants undergoing major surgical procedures. METHODS: In this retrospective cohort study, The National Surgical Quality Improvement Program-Pediatric database was surveyed for all infants who underwent noncardiac surgery between January 1, 2012 and December 31, 2015 (derivation cohort, n = 56,962) and between January 1 and December 31, 2016 (validation cohort, n = 20,559). Demographic and peri-operative clinical characteristics were examined in association with our primary outcome of unplanned postoperative intubation within 30 days of surgery. Risk factors were analyzed in the derivation cohort (2012–2015 data) using multivariable logistic regression with stepwise selection. Parameters from the final model were used to create a scoring system for predicting unplanned postoperative intubation. Data from the validation cohort were utilized to assess the performance of the scoring system using the area under the receiver operating characteristic curve. RESULTS: In the derivation cohort, 2.2% of the infants experienced unplanned postoperative intubation within 30 days of surgery. Of the 14 risk factors identified in multivariable analysis, 10 (age, prematurity, American Society of Anesthesiologists physical status, inpatient status, operative time >120 minutes, cardiac disease, malignancy, hematologic disorder, oxygen supplementation, and nutritional support) were included in the final multivariable logistic regression model to create the risk score. The area under the receiver operating characteristic curve of the final model was 0.86 (95% CI, 0.85–0.87) for the derivation cohort and 0.83 (95% CI, 82–0.85) for the validation cohort. CONCLUSIONS: About 1 in 50 infants undergoing major surgical procedures experiences unplanned postoperative intubation. Our scoring system based on routinely collected perioperative assessment data can predict risk in infants with good accuracy. Further investigation should assess the clinical utility of the scoring system for risk stratification and improvement in perioperative care quality and patient outcomes. (Anesth Analg XXX;XXX:00–00)

STUDY DESIGN Retrospective cohort. OBJECTIVE The purpose of the present study was to examine the incidence and risk factors for postoperative hematoma requiring reoperation in patients undergoing single-level lumbar fusion surgery. SUMMARY OF BACKGROUND DATA Postoperative hematoma can cause devastating neurological consequences after spine surgery. Risk factors for hematoma in specific spine procedures have not been well established. METHODS A cohort of patients undergoing single-level lumbar fusion surgery was constructed from the 2012 to 2013 American College of Surgeons National Surgical Quality Improvement Program dataset using Current Procedural Terminology codes (22533, 22558, 22612, 22630, and 22633). In cases requiring reoperation within 30 days after initial surgery, postoperative hematoma was identified using the ICD-9 code 998.1. Risk factors for postoperative hematoma were assessed with logistic regression modeling. RESULTS Of 5280 patients undergoing single-level lumbar fusion surgery, 27 patients (0.5%) developed a postoperative hematoma requiring reoperation for hematoma evacuation. A heightened incidence of postoperative hematoma was found in patients who were smokers (1.0% vs. 0.4% for nonsmokers, P = 0.016) or who had a diagnosis of bleeding disorder (3.8% vs. 0.5% for those without bleeding disorder, P = 0.007). Multivariate logistic regression analysis indicated that the adjusted odds ratios for postoperative hematoma associated with smoking and bleeding disorder were 3.34 (95% confidence interval, 1.15-9.71) and 10.2 (95% confidence interval, 1.9-54.8), respectively. CONCLUSION Smoking and bleeding disorder appear to be major risk factors for postoperative hematoma requiring reoperation after single-level lumbar fusion surgery. Intervention programs targeting patients with these risk factors are needed to reduce their excess risk of postoperative hematoma. LEVEL OF EVIDENCE 3.

Acute kidney injury (AKI), acute respiratory failure, and sepsis are distinct but related pathophysiologic processes. We hypothesized that these 3 processes may interact to synergistically increase the risk of short-term perioperative mortality in patients undergoing high-risk intraabdominal general surgery procedures.We performed a retrospective, observational cohort study of data (2005-2011) from the American College of Surgeons-National Surgical Quality Improvement Program, a high-quality surgical outcomes data set. High-risk procedures were those with a risk of AKI, acute respiratory failure, or sepsis greater than the average risk in all intraabdominal general surgery procedures. The effects of AKI, acute respiratory failure, and sepsis on 30-day mortality were assessed using a Cox proportional hazards model. Additive interactions were assessed with the relative excess risk due to interaction.Of 217,994 patients, AKI, acute respiratory failure, and sepsis developed in 1.3%, 3.7%, and 6.8%, respectively. The 30-day mortality risk with sepsis, acute respiratory failure, and AKI were 11.4%, 24.1%, and 25.1%, respectively, compared with 0.85% without these complications. The adjusted hazard ratios and 95% confidence intervals for a single complication (versus no complication) on mortality were 7.24 (6.46-8.11), 10.8 (8.56-13.6), and 14.2 (12.8-15.7) for sepsis, AKI, and acute respiratory failure, respectively. For 2 complications, the adjusted hazard ratios were 30.8 (28.0-33.9), 42.6 (34.3-52.9), and 65.2 (53.9-78.8) for acute respiratory failure/sepsis, AKI/sepsis, and acute respiratory failure/AKI, respectively. Finally, the adjusted hazard ratio for all 3 complications was 105 (92.8-118). Positive additive interactions, indicating synergism, were found for each combination of 2 complications. The relative excess risk due to interaction for all 3 complications was not statistically significant.In high-risk general surgery patients, the development of AKI, acute respiratory failure, or sepsis is independently associated with an increase in 30-day mortality. In addition, the development of 2 complications shows significant positive additive interactions to further increase the risk of mortality. Our findings suggest that interactions between these 3 perioperative complications increase the risk of mortality more than would be expected by the independent effects of each complication alone.