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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.

OBJECTIVES: To determine whether randomization of patients undergoing extracorporeal membrane oxygenation to either therapeutic or a low-dose anticoagulation protocol results in a difference in activated partial thromboplastin time and anti-Xa. DESIGN: Randomized, controlled, unblinded study. SETTING: Two ICUs of two university hospitals. PATIENTS: Patients admitted to the ICU, who required extracorporeal membrane oxygenation (venovenous or venoarterial) and who did not have a preexisting indication for therapeutic anticoagulation. INTERVENTIONS: Therapeutic anticoagulation with heparin (target activated partial thromboplastin time between 50 and 70 s) or lower dose heparin (up to 12,000 U/24 hr aiming for activated partial thromboplastin time < 45 s). MEASUREMENTS AND MAIN RESULTS: Thirty-two patients were randomized into two study groups that were not significantly different in demographics and extracorporeal membrane oxygenation characteristics. There was a significant difference in the daily geometric mean heparin dose (11,742 U [95% CI, 8,601-16,031 U] vs 20,710 U [95% CI, 15,343-27,954 U]; p = 0.004), daily geometric mean activated partial thromboplastin time (48.1 s [95% CI, 43.5-53.2 s] vs 55.5 s [95% CI, 50.4-61.2 s]; p = 0.04), and daily geometric mean anti-Xa (0.11 international units/mL [95% CI, 0.07-0.18] vs 0.27 [95% CI, 0.17-0.42]; p = 0.01). We found similar results when considering only venovenous extracorporeal membrane oxygenation episodes; however, no difference in daily geometric mean activated partial thromboplastin time between groups when considering only venoarterial extracorporeal membrane oxygenation episodes. CONCLUSIONS: Allocating patients on extracorporeal membrane oxygenation to two different anticoagulation protocols led to a significant difference in mean daily activated partial thromboplastin time and anti-Xa levels between groups. When considering subgroups analyses, these results were consistent in patients on venovenous extracorporeal membrane oxygenation. Our results support the feasibility of a larger trial in patients undergoing venovenous extracorporeal membrane oxygenation to compare different anticoagulation protocols; however, this study does not provide evidence on the optimal anticoagulation protocol for patients undergoing extracorporeal membrane oxygenation.

Background Perioperative hypothermia has been reported to increase the occurrence of cardiovascular complications. By increasing the activity of sympathetic nervous system, perioperative hypothermia also has the potential to increase cardiac injury and dysfunction associated with subarachnoid hemorrhage. Methods The Intraoperative Hypothermia for Aneurysm Surgery Trial randomized patients undergoing cerebral aneurysm surgery to intraoperative hypothermia (n = 499, 33.3 degrees +/- 0.8 degrees C) or normothermia (n = 501, 36.7 degrees +/- 0.5 degrees C). Cardiovascular events (hypotension, arrhythmias, vasopressor use, myocardial infarction, and others) were prospectively followed until 3-month follow-up and were compared in hypothermic and normothermic patients. A subset of 62 patients (hypothermia, n = 33; normothermia, n = 29) also had preoperative and postoperative (within 24 h) measurement of cardiac troponin-I and echocardiography to explore the association between perioperative hypothermia and subarachnoid hemorrhage-associated myocardial injury and left ventricular function. Results There was no difference between hypothermic and normothermic patients in the occurrence of any single cardiovascular event or in composite cardiovascular events. There was no difference in mortality (6%) between groups, and there was only a single primary cardiovascular death (normothermia). There was no difference between hypothermic and normothermic patients in postoperative versus preoperative left ventricular regional wall motion or ejection fraction. Compared with preoperative values, hypothermic patients had no postoperative increase in cardiac troponin-I (median change 0.00 microg/l), whereas normothermic patients had a small postoperative increase (median change + 0.01 microg/l, P = 0.038). Conclusion In patients undergoing cerebral aneurysm surgery, perioperative hypothermia was not associated with an increased occurrence of cardiovascular events.

ESPITE more than half a century of investigation,acute kidney injury (AKI) remains a major healthcareissue in medicine today. Reported to occur in 1–32% of allhospital admissions and 10–90% of intensive care unit ad-missions, the wide variation reflects different criteria used todefineAKI.However,independentofdefinition,adiagnosisof AKI is consistently associated with an increase in bothshort- and long-term morbidity and mortality. Even themildest forms of AKI are independently associated with in-creased early as well as long-term mortality, the risk increas-ing as severity of renal injury increases.

Background Although hypothermia and barbiturates improve neurologic outcomes in animal temporary focal ischemia models, the clinical efficacy of these interventions during temporary occlusion of the cerebral vasculature during intracranial aneurysm surgery (temporary clipping) is not established. Methods A post hoc analysis of patients from the Intraoperative Hypothermia for Aneurysm Surgery Trial who underwent temporary clipping was performed. Univariate and multivariate logistic regression methods were used to test for associations between hypothermia, supplemental protective drug, and short- (24-h) and long-term (3-month) neurologic outcomes. An odds ratio more than 1 denotes better outcome. Results Patients undergoing temporary clipping (n = 441) were assigned to intraoperative hypothermia (33.3 degrees +/- 0.8 degrees C, n = 208) or normothermia (36.7 degrees +/- 0.5 degrees C, n = 233), with 178 patients also receiving supplemental protective drug (thiopental or etomidate) during temporary clipping. Three months after surgery, 278 patients (63%) had good outcome (Glasgow Outcome Score = 1). Neither hypothermia (P = 0.847; odds ratio = 1.043, 95% CI = 0.678-1.606) nor supplemental protective drug (P = 0.835; odds ratio = 1.048, 95% CI = 0.674-1.631) were associated with 3-month Glasgow Outcome Score. The effect of supplemental protective drug did not significantly vary with temperature. The effects of hypothermia and protective drug did not significantly vary with temporary clip duration. Similar findings were made for 24-h neurologic status and 3-month Neuropsychological Composite Score. Conclusion In the Intraoperative Hypothermia for Aneurysm Surgery Trial, neither systemic hypothermia nor supplemental protective drug affected short- or long-term neurologic outcomes of patients undergoing temporary clipping.

Background: Smoking is considered to be a risk factor for patients undergoing surgery and anesthesia, but it is unclear whether this is applicable to patients undergoing ambulatory surgery. The aim of this study was to determine the risk of respiratory complications and wound infection among smokers. Methods: The authors studied a random selection of 489 adult patients undergoing ambulatory surgery. Smoking status was determined by self-report and confirmed with end-expired carbon monoxide analysis. The risk of respiratory complications (i.e., desaturation, cough, laryngospasm, bronchospasm, breath-holding, or apnea) and wound infection (i.e., wound redness or discharge positive microbial culture, requiring antibiotic therapy) in smokers versus nonsmokers was ascertained. Odds ratios were estimated from multivariable logistic regression and adjusted for age, gender, body mass index, partner’s smoking status, domiciliary smoking exposure, and extent and duration of surgery. Results: Most smokers continued to smoke up until the day of surgery. Smokers had a higher rate of respiratory complications (32.8% vs. 25.9%; adjusted odds ratio, 1.71; 95% confidence interval, 1.03‐2.84; P 0.038) and wound infection (3.6% vs. 0.6%; odds ratio, 16.3; 95% confidence interval, 1.58‐175; P 0.019). Odds ratios comparing current plus ex-smokers with nonsmokers were of similar magnitude for most of these complications. Conclusions: Smoking was associated with an increased risk of respiratory complications and postoperative wound infection in ambulatory surgery patients. These findings warrant increased efforts at promoting smoking avoidance and cessation. SMOKING is a major health risk, with just under 20% of all deaths in developed countries attributed to tobacco. 1 It is also generally accepted that smoking increases the risk of complications in patients undergoing anesthesia and surgery. 2–11 Despite this, it is our experience, and that of others, 12 that recommendations to stop smoking before elective surgery are rarely heeded. Most previous studies of perioperative risk associated with smoking were based on self-reporting and did not control for additional risk factors. Also, they may not represent current surgical and anesthetic practice. For example, there has been a marked increase in the proportion of surgery performed on an ambulatory (daystay) basis, and this important group has not been previously studied. We therefore studied a broad range of patients undergoing ambulatory surgery and confirmed their smoking status with end-expired carbon monoxide (COexp) analysis.

Background Aspirin administration before cardiac surgery represents a balance between preventing perioperative thrombotic events and promoting surgical bleeding. Clear evidence to guide the preoperative use of aspirin in patients undergoing cardiac surgery is lacking. This systematic review and meta-analysis was performed to evaluate the efficacy and safety of preoperative aspirin, in patients undergoing coronary artery surgery. Methods We conducted a systematic review and meta-analysis of randomized trials involving patients undergoing coronary artery surgery assigned to preoperative aspirin therapy or no aspirin/placebo. The MEDLINE and EMBASE databases and Cochrane Central Register of Controlled Trials were searched up to March 2014 without language restrictions. Two reviewers performed independent quality review and data extraction. Efficacy outcomes of myocardial infarction (MI) and mortality, and safety outcomes of blood loss, red cell transfusion, and surgical re-exploration were compared. Results In 13 trials (n=2399), preoperative aspirin therapy reduced the risk of MI (OR, 0.56; 95% CI, 0.33–0.96; P=0.03), without a reduction in mortality (OR, 1.16; 95% CI, 0.42–3.22; P=0.77). Preoperative aspirin increased postoperative chest tube drainage (mean difference 168 ml; 95% CI, 39–297 ml; P=0.01), red cell transfusion (mean difference 141 ml; 95% CI, 55–226; P=0.001) and need for surgical re-exploration (OR, 1.85, 95% CI, 1.15–2.96; P=0.01). Studies were of low methodological quality, with significant heterogeneity identified. Conclusions In patients undergoing coronary artery surgery, preoperative aspirin reduces perioperative MI, but at a cost of increased bleeding, blood transfusion, and surgical re-exploration.

Background:Survival and freedom from disability are arguably the most important patient-centered outcomes after surgery, but it is unclear how postoperative disability should be measured. The authors thus evaluated the World Health Organization Disability Assessment Schedule 2.0 in a surgical population.Methods:The authors examined the psychometric properties of World Health Organization Disability Assessment Schedule 2.0 in a diverse cohort of 510 surgical patients. The authors assessed clinical acceptability, validity, reliability, and responsiveness up to 12 months after surgery.Results:Criterion and convergent validity of World Health Organization Disability Assessment Schedule 2.0 were supported by good correlation with the 40-item quality of recovery scale at 30 days after surgery (r = −0.70) and at 3, 6, and 12 months after surgery with physical functioning (The Katz index of independence in Activities of Daily Living; r = −0.70, r = −0.60, and rho = −0.47); quality of life (EQ-5D; r = −0.57, −0.60, and −0.52); and pain interference scores (modified Brief Pain Inventory Short Form; r = 0.72, 0.74, and 0.81) (all P < 0.0005). Construct validity was supported by increased hospital stay (6.9 vs. 5.3 days, P = 0.008) and increased day 30 complications (20% vs. 11%, P = 0.042) in patients with new disability. There was excellent internal consistency with Cronbach’s α and split-half coefficients greater than 0.90 at all time points (all P < 0.0005). Responsiveness was excellent with effect sizes of 3.4, 3.0, and 1.0 at 3, 6, and 12 months after surgery, respectively.Conclusions:World Health Organization Disability Assessment Schedule 2.0 is a clinically acceptable, valid, reliable, and responsive instrument for measuring postoperative disability in a diverse surgical population. Its use as an endpoint in future perioperative studies can provide outcome data that are meaningful to clinicians and patients alike.