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Importance: Intraoperative handovers of anesthesia care are common. Handovers might improve care by reducing physician fatigue, but there is also an inherent risk of losing critical information. Large observational analyses report associations between handover of anesthesia care and adverse events, including higher mortality., Objective: To determine the effect of handovers of anesthesia care on postoperative morbidity and mortality., Design, Setting, and Participants: This was a parallel-group, randomized clinical trial conducted in 12 German centers with patients enrolled between June 2019 and June 2021 (final follow-up, July 31, 2021). Eligible participants had an American Society of Anesthesiologists physical status 3 or 4 and were scheduled for major inpatient surgery expected to last at least 2 hours., Interventions: A total of 1817 participants were randomized to receive either a complete handover to receive anesthesia care by another clinician (n = 908) or no handover of anesthesia care (n = 909). None of the participating institutions used a standardized handover protocol., Main Outcomes and Measures: The primary outcome was a 30-day composite of all-cause mortality, hospital readmission, or serious postoperative complications. There were 19 secondary outcomes, including the components of the primary composite, along with intensive care unit and hospital lengths of stay., Results: Among 1817 randomized patients, 1772 (98%; mean age, 66 [SD, 12] years; 997 men [56%]; and 1717 [97%] with an American Society of Anesthesiologists physical status of 3) completed the trial. The median total duration of anesthesia was 267 minutes (IQR, 206-351 minutes), and the median time from start of anesthesia to first handover was 144 minutes in the handover group (IQR, 105-213 minutes). The composite primary outcome occurred in 268 of 891 patients (30%) in the handover group and in 284 of 881 (33%) in the no handover group (absolute risk difference [RD], -2.5%; 95% CI, -6.8% to 1.9%; odds ratio [OR], 0.89; 95% CI, 0.72 to 1.10; P = .27). Nineteen of 889 patients (2.1%) in the handover group and 30 of 873 (3.4%) in the no handover group experienced all-cause 30-day mortality (absolute RD, -1.3%; 95% CI, -2.8% to 0.2%; OR, 0.61; 95% CI, 0.34 to 1.10; P = .11); 115 of 888 (13%) vs 136 of 872 (16%) were readmitted to the hospital (absolute RD, -2.7%; 95% CI, -5.9% to 0.6%; OR, 0.80; 95% CI, 0.61 to 1.05; P = .12); and 195 of 890 (22%) vs 189 of 874 (22%) experienced serious postoperative complications (absolute RD, 0.3%; 95% CI, -3.6% to 4.1%; odds ratio, 1.02; 95% CI, 0.81 to 1.28; P = .91). None of the 19 prespecified secondary end points differed significantly., Conclusions and Relevance: Among adults undergoing extended surgical procedures, there was no significant difference between the patients randomized to receive handover of anesthesia care from one clinician to another, compared with the no handover group, in the composite primary outcome of mortality, readmission, or serious postoperative complications within 30 days., Trial Registration: ClinicalTrials.gov Identifier: NCT04016454.

Monitors that estimate nociception during anesthesia may be used to guide opioid and other analgesics administration to optimize anesthesia care and possibly outcome. We reviewed the literature to evaluate current evidence of the effect of nociception-guided management over standard anesthesia practice during surgery. A systematic review of the literature on the effect of nociception monitoring on anesthesia practice was conducted. Reports were eligible if they compared nociception-guided anesthesia to standard practice during surgery. Primary endpoint of this review is intraoperative opioid consumption. Secondary endpoints included hemodynamic control, postoperative pain and pain treatment. We identified 12 randomized controlled trials that compared one of five different nociception monitoring techniques to standard anesthesia care. Most studies were single center studies of small sample size. Six studies reported intraoperative opioid consumption as primary outcome. There was considerable variability with respect to surgical procedure and anesthesia technique. For nociception monitors that were investigated by more than one study, analysis of the pooled data was performed. The surgical plethysmographic index was the only monitor for which an intra operative opioid sparing effect was found. For the other monitors, either no effect was detected, or pooled analysis could not be performed due to paucity of study data. On secondary outcomes, no consistent effect of nociception-guided anesthesia could be established. Although some nociception monitors show promising results, no definitive conclusions regarding the effect of nociception monitoring on intraoperative opioid consumption or other anesthesia related outcome can be drawn.Clinical trial number PROSPERO ID 102913.

Background: Volatile anesthetics potentially trigger malignant hyperthermia crises in susceptible patients. We therefore aimed to identify preparation procedures for the Draeger Primus that minimize residual concentrations of desflurane and sevoflurane with and without activated charcoal filtration., Methods: A Draeger Primus test workstation was primed with 7% desflurane or 2.5% sevoflurane for 2 hours. Residual anesthetic concentrations were evaluated with five preparation procedures, three fresh gas flow rates, and three distinct applications of activated charcoal filters. Finally, non-exchangeable and autoclaved parts of the workstation were tested for residual emission of volatile anesthetics. Concentrations were measured by multicapillary column-ion mobility spectrometry with limits of detection/quantification being <1 part per billion (ppb) for desflurane and <2.5 ppb for sevoflurane., Results: The best preparation procedure included a flushing period of 10 minutes between removal and replacement of all parts of the ventilator circuit which immediately produced residual concentrations <5 ppm. A fresh gas flow of 10 L/minute reduced residual concentration as effectively as 18 L/minute, whereas flows of 1 or 5 L/minute slowed washout. Use of activated charcoal filters immediately reduced and maintained residual concentrations <5 ppm for up to 24 hours irrespective of previous workstation preparation. The fresh gas hose, circle system, and ventilator diaphragm emitted traces of volatile anesthetics., Conclusion: In elective cases, presumably safe concentrations can be obtained by a 10-minute flush at ≥10 L/minute between removal and replacement all components of the airway circuit. For emergencies, we recommend using an activated charcoal filter., (© 2020 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Background: Operating room (OR) utilization generally ranges from 50% to 75%. Inefficiencies can arise from various factors, including prolonged anesthesia preparation time, defined as the period from induction of anesthesia until patients are considered ready for surgery. Our goal was to use patient-related and procedure-related factors to develop a model predicting anesthesia preparation time., Methods: From the electronic medical records of adults who had noncardiac surgery at the Cleveland Clinic Main Campus, we developed a model that used a dozen preoperative factors to predict anesthesia preparation time. The model was based on multivariable regression with "Least Absolute Shrinkage and Selection Operator" and 10-fold cross-validation. The overall performance of the final model was measured by R, which describes the proportion of the variance in anesthesia preparation time that is explained by the model., Results: A total of 43,941 cases met inclusion and exclusion criteria. Our final model had only moderate discriminative ability. The estimated adjusted R for prediction model was 0.34 for the training data set and 0.27 for the testing data set., Conclusions: Using preoperative factors, we could explain only about a quarter of the variance in anesthesia preparation time-an amount that is probably of limited clinical value.

Study Objective: To assess professionalism in anesthesiology residents, it is important to obtain evaluations from people with whom they interact on daily basis. The purpose of this study was to evaluate the effect of a Multisource feedback (MSF) on resident's professional behavior and to assess the effect of faculty feedback on resident performance., Design: This study was a two-group randomized clinical trial., Setting: Residents were recruited from Cleveland Clinic Children's Hospital., Patients: Participants included twenty eight residents doing a two-month rotation in Pediatric Anesthesia., Interventions: Multisource feedback questionnaires were developed and then validated using face and content validity. Residents were randomly assigned to a feedback group or a control group. Both groups received the MSF evaluation. Only the group assigned to feedback had a 'coaching meeting' every month creating strategies for improvement., Measurements: MSF questionnaires were validated using a face validation and expert content validity. The effect of MSF on a professionalism questionnaire was assessed using analysis of covariance and linear mixed effects regression models., Main Results: Observed test-retest agreement was greater than 0.90 for all items, with more than half of kappa statistics greater than 0.50. Cronbach's alpha was 0.71.The MSF increased the self-assessment score with an estimated effect of 0.21 (95% CI 0.06, 0.37), P=.015. There was no detected effect on patient family evaluation, with mean difference (CI) in change from baseline of 0.03 (-0.15, 0.21), P=.77, faculty evaluation, 0.21 (-0.02, 0.44), P=.08, or coworker evaluation 0.13 (-0.11, 0.37)., Conclusions: Our new multi-source feedback questionnaire to assess professionalism had good reliability and internal consistency. Using our validated questionnaire we assessed the effect of a monthly feedback to improve professionalism in anesthesia residents. While we did see improvement in anesthesiology residents' self-assessment, we did not see a similar effect on patient family, faculty or coworker evaluations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Prompt treatment of severe blood pressure instability requires both cognitive and technical skill. The ability to anticipate and respond to episodes of hemodynamic instability should improve with training. The authors tested the hypothesis that the duration of severe hypotension during anesthesia administered by residents correlates with concurrent adjusted overall performance evaluations by the Clinical Competence Committee and subsequent in-training exam scores., Methods: The authors obtained data on 70 first- and second-year anesthesia residents at the Cleveland Clinic. Analysis was restricted to adults having noncardiac surgery with general anesthesia. Outcome variables were in-training exam scores and subjective evaluations of resident performance ranked in quintiles. The primary predictor was cumulative systolic arterial pressure less than 70 mmHg. Secondary predictors were administration of vasopressors, frequency of hypotension, average duration of hypotensive episodes, and blood pressure variability., Results: The primary statistical approach was mixed-effects modeling, adjusted for potential confounders. The authors considered 15,216 anesthesia care episodes. A total of 1,807 hypotensive episodes were observed, lasting an average of 32 ± 20 min (SD) per 100 h of anesthesia, with 68% being followed by vasopressor administration. The duration of severe hypotension (systolic pressure less than 70 mmHg) was associated with neither Competence Committee evaluations nor in-training exam scores. There was also no association between secondary blood pressure predictors and either Competence Committee evaluations or in-training exam results., Conclusions: There was no association between any of the five blood pressure management characteristics and either in-training exam scores or clinical competence evaluations. However, it remains possible that the measures of physiologic control, as assessed from electronic anesthesia records, evaluate useful but different aspects of anesthesiologist performance.

Composite endpoints consisting of several binary events, such as distinct perioperative complications, are frequently chosen as the primary outcome in anesthesia studies (and in many other clinical specialties) because (1) no single outcome fully characterizes the disease or outcome of interest, and/or (2) individual outcomes are rare and statistical power would be inadequate for any single one. Interpreting a composite endpoint is challenging because components rarely meet the ideal criteria of having comparable clinical importance, frequency, and treatment effects. We suggest guidelines for forming composite endpoints and show advantages of newer versus conventional statistical methods for analyzing them. Components should be a parsimonious set of outcomes, which when taken together, well represent the disease of interest and are very plausibly related to the intervention. Adding components that are too narrow, redundant, or minimally influenced by the study intervention compromises interpretation of results and reduces power. We show that multivariate (i.e., multiple outcomes per patient) methods of analyzing a binary-event composite provide distinct advantages over standard methods such as any-versus-none, count of events, or evaluation of individual events. Multivariate methods can incorporate clinical importance weights, compensate for events occurring at varying frequencies, assess treatment effect heterogeneity, and are often more powerful than alternative statistical approaches. Methods are illustrated with an American College of Surgeons National Surgical Quality Improvement Program registry study that evaluated the effects of smoking on major perioperative outcomes, and with a clinical trial comparing the effects of crystalloids and colloids on major complications. Sample data files and SAS code are included for convenience.

BackgroundThe Hypotension Prediction Index (the index) software is a machine learning algorithm that detects physiological changes that may lead to hypotension. The original validation used a case control (backwards) analysis that has been suggested to be biased. We therefore conducted a cohort (forwards) analysis and compared this to the original validation technique.MethodsWe conducted a retrospective analysis of data from previously reported studies. All data were analysed identically with 2 different methodologies and receiver operating characteristic curves (ROC) constructed. Both backwards and forwards analyses were performed to examine differences in area under the ROC for HPI and other haemodynamic variables to predict a MAP < 65mmHg for at least 1 minute 5, 10 and 15 minutes in advance.ResultsTwo thousand and twenty-two patients were included in the analysis, yielding 4,152,124 measurements taken at 20 second intervals. The area-under-the-curve for the index predicting hypotension analysed by backward and forward methodologies respectively was 0.957 (95% CI, 0.947-0.964) vs 0.923 (95% CI, 0.912-0.933) 5 minutes in advance, 0.933 (95% CI, 0.924-0.942) vs 0.923 (95% CI, 0.911-0.933) 10 minutes in advance , and 0.929 (95% CI, 0.918-0.938) vs. 0.926 (95% CI, 0.914-0.937) 15 minutes in advance. No other variable had an area-under-the-curve > 0.7 except for MAP. Area-under-the-curve using forward analysis for MAP predicting hypotension 5, 10, and 15 minutes in advance was 0.932 (95% CI, 0.920-0.940), 0.929 (95% CI, 0.918-0.938), and 0.932 (95% CI, 0.921-0.940). The R 2 for the variation in the index due to MAP was 0.77.ConclusionUsing an updated methodology, we found the utility of the HPI index to predict future hypotensive events is high, with an area under the receiver-operating-characteristics curve similar to that of the original validation method.

IntroductionWe previously reported that a 6-day continuous peripheral nerve block reduces established postamputation phantom pain. To provide patients and providers with the information to best inform treatment decisions, here we reanalyze the data and present the results in a more patient-centered format. We also provide information on patient-defined clinically relevant benefits to facilitate evaluation of available studies and guide future trial design.MethodsThe original trial enrolled participants with a limb amputation and phantom pain who were randomized to receive a 6-day continuous peripheral nerve block(s) of either ropivacaine (n=71) or saline (n=73) in a double-masked fashion. Here we calculate the percentage of each treatment group that experienced a clinically relevant improvement as defined by previous studies as well as present what the participants of our study defined as small, medium, and large analgesic improvements using the 7-point ordinal Patient Global Impression of Change scale.ResultsAmong patients who were given a 6-day ropivacaine infusion, 57% experienced at least a 2-point improvement on the 11-point numeric rating scale in their average and worst phantom pain 4 weeks postbaseline as compared with 26% (p

BackgroundPostamputation phantom pain is notoriously persistent with few validated treatments. Cryoneurolysis involves the application of low temperatures to reversibly ablate peripheral nerves. The authors tested the hypothesis that a single cryoneurolysis treatment would decrease phantom pain 4 months later.MethodsThe authors enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. The primary outcome was the change in average phantom pain intensity between baseline and 4 months as measured with a numeric rating scale (0 to 10), after which an optional crossover treatment was offered. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction.ResultsPretreatment phantom pain scores were similar in both groups, with a median [quartiles] of 5.0 [4.0, 6.0] for active treatment and 5.0 [4.0, 7.0] for sham. After 4 months, pain intensity decreased by 0.5 [-0.5, 3.0] in patients given cryoneurolysis (n = 71) versus 0 [0, 3] in patients given sham (n = 73), with an estimated difference (95% CI) of -0.1 (-1.0 to 0.7), P = 0.759. Following their statistical gatekeeping protocol, the authors did not make inferences or draw conclusions on secondary endpoints. One serious adverse event occurred after a protocol deviation in which a femoral nerve cryolesion was induced just below the inguinal ligament-instead of the sensory-only saphenous nerve-which resulted in quadriceps weakness, and possibly a fall and clavicle fracture.ConclusionsPercutaneous cryoneurolysis did not decrease chronic lower extremity phantom limb pain 4 months after treatment. However, these results were based upon the authors' specific study protocol, and since the optimal cryoneurolysis treatment parameters such as freeze duration and anatomic treatment location remain unknown, further research is warranted.Editor’s perspective

BackgroundExcessive or inadequate fluid administration causes complications, but despite this, fluid administration during noncardiac surgery is highly variable. Goal-directed management helps optimize the amount and timing of fluid administration; however, implementation is difficult because algorithms are complex. The authors therefore tested the performance of the Acumen Assisted Fluid Management software (Edwards Lifesciences, USA), which is designed to guide optimal intravenous fluid administration during surgery.MethodsIn this multicenter, prospective, single-arm cohort evaluation, the authors enrolled 330 adults scheduled for moderate- to high-risk noncardiac surgery that required arterial catheter insertion and mechanical ventilation. Clinicians chose a fluid strategy based on a desired 10%, 15%, or 20% increase in stroke volume (SV) in response to a fluid bolus. Dedicated fluid management software prompted "test" or "recommended" boluses, and clinicians were free to initiate a "user" bolus of 100 to 500 ml of crystalloid or colloid. Clinicians were free to accept or decline the software prompts. The authors primarily compared the fraction of software-recommended boluses that produced suitable increases in SV to a 30% reference rate. On an exploratory basis, we compared responses to software-recommended and clinician-initiated boluses.ResultsFour hundred twenty-four of 479 (89%) software-recommended fluid boluses and 508 of 592 (86%) clinician-initiated fluid boluses were analyzed per protocol. Of those, 66% (95% CI, 62 to 70%) of delivered fluid boluses recommended by the software resulted in desired increases in SV, compared with the 30% reference rate, whereas only 41% (95% CI, 38 to 44%) of clinician-initiated boluses did (P < 0.0001). The mean ± SD increase in SV after boluses recommended by the software was 14.2 ± 13.9% versus 8.3 ± 12.1% (P < 0.0001) for those initiated by clinicians.ConclusionsFluid boluses recommended by the software resulted in desired SV increases more often, and with greater absolute SV increase, than clinician-initiated boluses. Automated assessment of fluid responsiveness may help clinicians optimize intraoperative fluid management during noncardiac surgery.Editor’s perspective

BackgroundPercutaneous peripheral nerve stimulation is an analgesic technique involving the percutaneous implantation of a lead followed by the delivery of electric current using an external pulse generator. Percutaneous peripheral nerve stimulation has been used extensively for chronic pain, but only uncontrolled series have been published for acute postoperative pain. The current multicenter study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent clinical trial and (2) estimate the treatment effect of percutaneous peripheral nerve stimulation on postoperative pain and opioid consumption.MethodsPreoperatively, an electrical lead was percutaneously implanted to target the sciatic nerve for major foot/ankle surgery (e.g., hallux valgus correction), the femoral nerve for anterior cruciate ligament reconstruction, or the brachial plexus for rotator cuff repair, followed by a single injection of long-acting local anesthetic along the same nerve/plexus. Postoperatively, participants were randomized to 14 days of either electrical stimulation (n = 32) or sham stimulation (n = 34) using an external pulse generator in a double-masked fashion. The dual primary treatment effect outcome measures were (1) cumulative opioid consumption (in oral morphine equivalents) and (2) mean values of the "average" daily pain scores measured on the 0 to 10 Numeric Rating Scale within the first 7 postoperative days.ResultsDuring the first 7 postoperative days, opioid consumption in participants given active stimulation was a median (interquartile range) of 5 mg (0 to 30) versus 48 mg (25 to 90) in patients given sham treatment (ratio of geometric means, 0.20 [97.5% CI, 0.07 to 0.57]; P < 0.001). During this same period, the average pain intensity in patients given active stimulation was a mean ± SD of 1.1 ± 1.1 versus 3.1 ± 1.7 in those given sham (difference, -1.8 [97.5% CI, -2.6 to -0.9]; P < 0.001).ConclusionsPercutaneous peripheral nerve stimulation reduced pain scores and opioid requirements free of systemic side effects during at least the initial week after ambulatory orthopedic surgery.Editor’s perspective

Phantom limb pain is thought to be sustained by reentrant neural pathways, which provoke dysfunctional reorganization in the somatosensory cortex. We hypothesized that disrupting reentrant pathways with a 6-day-long continuous peripheral nerve block reduces phantom pain 4 weeks after treatment. We enrolled patients who had an upper- or lower-limb amputation and established phantom pain. Each was randomized to receive a 6-day perineural infusion of either ropivacaine or normal saline. The primary outcome was the average phantom pain severity as measured with a Numeric Rating Scale (0-10) at 4 weeks, after which an optional crossover treatment was offered within the following 0 to 12 weeks. Pretreatment pain scores were similar in both groups, with a median (interquartile range) of 5.0 (4.0, 7.0) for each. After 4 weeks, average phantom limb pain intensity was a mean (SD) of 3.0 (2.9) in patients given local anesthetic vs 4.5 (2.6) in those given placebo (difference [95% confidence interval] 1.3 [0.4, 2.2], P = 0.003). Patients given local anesthetic had improved global impression of change and less pain-induced physical and emotional dysfunction, but did not differ on depression scores. For subjects who received only the first infusion (no self-selected crossover), the median decrease in phantom limb pain at 6 months for treated subjects was 3.0 (0, 5.0) vs 1.5 (0, 5.0) for the placebo group; there seemed to be little residual benefit at 12 months. We conclude that a 6-day continuous peripheral nerve block reduces phantom limb pain as well as physical and emotional dysfunction for at least 1 month.

BackgroundPercutaneous peripheral nerve stimulation (PNS) is an analgesic modality involving the insertion of a lead through an introducer needle followed by the delivery of electric current after needle withdrawal. This modality has been used extensively to treat chronic pain, but only small series have been published involving postoperative pain. The ultimate objective of this study is to determine the postoperative effects of percutaneous PNS following moderately to severely painful ambulatory surgery within a real-world clinical practice setting. The primary hypothesis is that surgical pain and opioid consumption during the initial 7 days after surgery will be reduced by percutaneous PNS compared with usual and customary analgesia (dual primary outcome measures).DesignA multicenter pragmatic effectiveness trial. We are randomizing participants having painful orthopedic surgical procedures of the upper and lower extremity to receive 14 days of either 1) electrical stimulation or 2) sham in a double-masked fashion. End points are being assessed at various time points over 12 postoperative months.SummaryThe postoperative experience will be much improved if percutaneous PNS provides potent analgesia while concurrently decreasing opioid requirements following painful surgery. Because this modality can be administered for up to 60 days at home, it may provide postoperative analgesia that outlasts surgical pain yet has relatively few risks and, unlike opioids, has no systemic side effects or potential for abuse, addiction, and overdose. Percutaneous PNS has the potential to revolutionize postoperative analgesia as it has been practiced for the past century. This study will inform key stakeholders regarding an evidence-based nonpharmacologic approach to the management of postoperative pain.

BackgroundIt remains unknown whether continuous or scheduled intermittent bolus local anesthetic administration is preferable for adductor canal perineural catheters. Therefore, we tested the hypothesis that scheduled bolus administration is superior or noninferior to a continuous infusion on cutaneous knee sensation in volunteers.MethodsBilateral adductor canal catheters were inserted in 24 volunteers followed by ropivacaine 0.2% administration for 8 hours. One limb of each subject was assigned randomly to a continuous infusion (8 mL/h) or automated hourly boluses (8 mL/bolus), with the alternate treatment in the contralateral limb. The primary end point was the tolerance to electrical current applied through cutaneous electrodes in the distribution of the anterior branch of the medial femoral cutaneous nerve after 8 hours (noninferiority delta: -10 mA). Secondary end points included tolerance of electrical current and quadriceps femoris maximum voluntary isometric contraction strength at baseline, hourly for 14 hours, and again after 22 hours.ResultsThe 2 administration techniques provided equivalent cutaneous analgesia at 8 hours because noninferiority was found in both directions, with estimated difference on tolerance to cutaneous current of -0.6 mA (95% confidence interval, -5.4 to 4.3). Equivalence also was found on all but 2 secondary time points.ConclusionsNo evidence was found to support the hypothesis that changing the local anesthetic administration technique (continuous basal versus hourly bolus) when using an adductor canal perineural catheter at 8 mL/h decreases cutaneous sensation in the distribution of the anterior branch of the medial femoral cutaneous nerve.

BackgroundWe tested the hypothesis that, following unicompartment knee arthroplasty, a continuous adductor canal block decreases the time to reach 4 discharge criteria compared with a continuous femoral nerve block.MethodsSubjects were randomized to either an adductor canal or femoral perineural catheter (2-day ropivacaine 0.2% infusion) in an unmasked fashion. The primary outcome was the time to attain 4 discharge criteria: (1) adequate analgesia; (2) intravenous opioid independence; (3) ability to independently stand, walk 3 m, return, and sit down; and (4) ambulate 30 m.ResultsSubjects with an adductor canal catheter (n = 15) reached all 4 criteria in a median of 35 hours (interquartile range, 24-43 hours), compared with 40 hours (interquartile range, 27-69 hours) for those with a femoral catheter (n = 15; Wilcoxon rank sum test: P = 0.46; log-rank test: P = 0.16). However, the percentages of subjects (adductor canal: femoral) who reached the 2 mobilization criteria were 27%:0% on postoperative day (POD) 0, 93%:53% on POD 1, and 100%:73% on POD 2. Of adductor canal subjects, 100% were discharge ready by POD 2, compared with only 73% of femoral subjects (P < 0.001).ConclusionsCompared with a continuous femoral nerve block, a continuous adductor canal block did not appreciably decrease the median number of hours to overall discharge readiness, yet did decrease the number of discrete days until discharge readiness. These results are applicable to only unicompartment knee arthroplasty and must be considered preliminary because of the limited sample size of this pilot study.

BackgroundThe authors conducted a randomized, controlled, parallel-arm, superiority study to test the hypothesis that a continuous adductor canal block decreases the time to attain four discharge criteria compared with a continuous femoral nerve block after tricompartment knee arthroplasty.MethodsSubjects undergoing tricompartment knee arthroplasty were randomized using computer-generated lists to either an adductor canal or femoral perineural catheter (3-day ropivacaine 0.2% infusion) in an unmasked manner. The primary outcome was the time to attain four criteria: (1) adequate analgesia; (2) intravenous opioids independence; (3) ability to stand, walk 3 m, return, and sit down; and (4) ambulate 30 m.ResultsSubjects with an adductor canal catheter (n = 39) reached all four criteria in a median of 55 h (interquartile, 42 to 63 h) compared with 61 h (49 to 69 h) for those with a femoral catheter (n = 41; 95% CI, -13 to 1 h; P = 0.12). The percentage of subjects who reached the two mobilization criteria on postoperative days 1 and 2 were 72 and 95% for those with an adductor canal catheter (n = 39), but only 27 and 76% in subjects with a femoral catheter (n = 41; both P < 0.001). Differences in pain scores at rest and intravenous opioid requirements were minimal, but femoral infusion improved dynamic analgesia (P = 0.01 to 0.02).ConclusionCompared with a continuous femoral nerve block, a continuous adductor canal block did not appreciably decrease the time to overall discharge readiness even though it did decrease the time until adequate mobilization, primarily because both groups experienced similar analgesia and intravenous opioid requirements that--in most cases--exceeded the time to mobilization.

BackgroundThe authors tested the hypotheses that, compared with an overnight continuous femoral nerve block (cFNB), a 4-day ambulatory cFNB increases ambulation distance and decreases the time until three specific readiness-for-discharge criteria are met after tricompartment total knee arthroplasty.MethodsPreoperatively, all patients received a cFNB (n = 50) and perineural ropivacaine 0.2% from surgery until the following morning, at which time they were randomly assigned to either continue perineural ropivacaine or switch to perineural normal saline. Primary endpoints included (1) time to attain three discharge criteria (adequate analgesia, independence from intravenous analgesics, and ambulation of at least 30 m) and (2) ambulatory distance in 6 min the afternoon after surgery. Patients were discharged with their cFNB and a portable infusion pump, and catheters were removed on postoperative day 4.ResultsPatients given 4 days of perineural ropivacaine attained all three discharge criteria in a median (25th-75th percentiles) of 25 (21-47) h, compared with 71 (46-89) h for those of the control group (estimated ratio, 0.47; 95% confidence interval, 0.32-0.67; P

Abstract Background The perioperative period is characterized by an intense inflammatory response. Perioperative inflammation promotes postoperative morbidity and increases mortality. Blunting the inflammatory response to surgical trauma might thus improve perioperative outcomes. We are studying three interventions that potentially modulate perioperative inflammation: corticosteroids, tight glucose control, and light anesthesia. Methods/Design The DeLiT Trial is a factorial randomized single-center trial of dexamethasone vs placebo, intraoperative tight vs. conventional glucose control, and light vs deep anesthesia in patients undergoing major non-cardiac surgery. Anesthetic depth will be estimated with Bispectral Index (BIS) monitoring (Aspect medical, Newton, MA). The primary outcome is a composite of major postoperative morbidity including myocardial infarction, stroke, sepsis, and 30-day mortality. C-reactive protein, a measure of the inflammatory response, will be evaluated as a secondary outcome. One-year all-cause mortality as well as post-operative delirium will be additional secondary outcomes. We will enroll up to 970 patients which will provide 90% power to detect a 40% reduction in the primary outcome, including interim analyses for efficacy and futility at 25%, 50% and 75% enrollment. Discussion The DeLiT trial started in February 2007. We expect to reach our second interim analysis point in 2010. This large randomized controlled trial will provide a reliable assessment of the effects of corticosteroids, glucose control, and depth-of-anesthesia on perioperative inflammation and morbidity from major non-cardiac surgery. The factorial design will enable us to simultaneously study the effects of the three interventions in the same population, both individually and in different combinations. Such a design is an economically efficient way to study the three interventions in one clinical trial vs three. Trial registration This trial is registered at Clinicaltrials.gov #: NTC00433251

Abstract Background Even the best cancer surgery is usually associated with minimal residual disease. Whether these remaining malignant cells develop into clinical recurrence is at least partially determined by adequacy of host defense, especially natural killer cell function. Anesthetics impair immune defenses to varying degrees, but nitrous oxide appears to be especially problematic. We therefore tested the hypothesis that colorectal-cancer recurrence risk is augmented by nitrous oxide administration during colorectal surgery. Methods We conducted a 4- to 8-year follow-up of 204 patients with colorectal cancer who were randomly assigned to 65% nitrous oxide (n = 97) or nitrogen (n = 107), balanced with isoflurane and remifentanil. The primary outcome was the time to cancer recurrence. Our primary analysis was a multivariable Cox-proportional-hazards regression model that included relevant baseline variables. In addition to treatment group, the model considered patient age, tumor grade, dissemination, adjacent organ invasion, vessel invasion, and the number of nodes involved. The study had 80% power to detect a 56% or greater reduction in recurrence rates (i.e., hazard ratio of 0.44 or less) at the 0.05 significance level. Results After adjusting for significant baseline covariables, risk of recurrence did not differ significantly for nitrous oxide and nitrogen, with a hazard ratio estimate (95% CI) of 1.10 (0.66, 1.83), P = 0.72. No two-way interactions with the treatment were statistically significant. Conclusion Colorectal-cancer recurrence risks were not greatly different in patients who were randomly assigned to 65% nitrous oxide or nitrogen during surgery. Our results may not support avoiding nitrous oxide use to prevent recurrence of colorectal cancer. Implications Statement The risk of colorectal cancer recurrence was similar in patients who were randomly assigned to 65% nitrous oxide or nitrogen during colorectal surgery. Trial Registration Current Controlled Clinical Trials NCT00781352 http://www.clinicaltrials.gov

Intraoperative mortality is now rare. In contrast, 30-day postoperative mortality remains common, with most deaths occurring during the initial hospitalisation. The legacy of anaesthesiology will be determined by our success in dealing with postoperative mortality, which is currently the major problem in perioperative medicine. Carpe diem! [ABSTRACT FROM AUTHOR]

Abstract Background Cuff pressure in endotracheal (ET) tubes should be in the range of 20–30 cm H2O. We tested the hypothesis that the tube cuff is inadequately inflated when manometers are not used. Methods With IRB approval, we studied 93 patients under general anesthesia with an ET tube in place in one teaching and two private hospitals. Anesthetists were blinded to study purpose. Cuff pressure in tube sizes 7.0 to 8.5 mm was evaluated 60 min after induction of general anesthesia using a manometer connected to the cuff pilot balloon. Nitrous oxide was disallowed. After deflating the cuff, we reinflated it in 0.5-ml increments until pressure was 20 cmH2O. Results Neither patient morphometrics, institution, experience of anesthesia provider, nor tube size influenced measured cuff pressure (35.3 ± 21.6 cmH2O). Only 27% of pressures were within 20–30 cmH2O; 27% exceeded 40 cmH2O. Although it varied considerably, the amount of air required to achieve a cuff pressure of 20 cmH2O was similar with each tube size. Conclusion We recommend that ET cuff pressure be set and monitored with a manometer.

Epidural analgesia is considered the standard of care but cannot be provided to all patients Liposomal bupivacaine has been approved for field blocks such as transversus abdominis plane (TAP) blocks but has not been clinically compared against other modalities. In this retrospective propensity matched cohort study we thus tested the primary hypothesis that TAP infiltration are noninferior (not worse) to continuous epidural analgesia and superior (better) to intravenous opioid analgesia in patients recovering from major lower abdominal surgery. 318 patients were propensity matched on 18 potential factors among three groups (106 per group): 1) TAP infiltration with bupivacaine liposome; 2) continuous Epidural analgesia with plain bupivacaine; and; 3) intravenous patient-controlled analgesia (IV PCA). We claimed TAP noninferior (not worse) over Epidural if TAP was noninferior (not worse) on total morphine-equivalent opioid and time-weighted average pain score (10-point scale) within first 72 hours after surgery with noninferiority deltas of 1 (10-point scale) for pain and an increase less of 20% in the mean morphine equivalent opioid consumption. We claimed TAP or Epidural groups superior (better) over IV PCA if TAP or Epidural was superior on opioid consumption and at least noninferior on pain outcome. Multivariable linear regressions within the propensity-matched cohorts were used to model total morphine-equivalent opioid dose and time-weighted average pain score within first 72 hours after surgery; joint hypothesis framework was used for formal testing. TAP infiltration were noninferior to Epidural on both primary outcomes (p<0.001). TAP infiltration were noninferior to IV PCA on pain scores (p = 0.001) but we did not find superiority on opioid consumption (p = 0.37). We did not find noninferiority of Epidural over IV PCA on pain scores (P = 0.13) and nor did we find superiority on opioid consumption (P = 0.98). TAP infiltration with liposomal bupivacaine and continuous epidural analgesia were similar in terms of pain and opioid consumption, and not worse in pain compared with IV PCA. TAP infiltrations might be a reasonable alternative to epidural analgesia in abdominal surgical patients. A large randomized trial comparing these techniques is justified. [ABSTRACT FROM AUTHOR]

Background: JM-1232(-) is a novel anesthetic agent which acts through gamma-aminobutyric acid receptors. Cerebral pial vascular effects of JM-1232(-) are unknown. We thus evaluated topical and intravenous effects of JM-1232(-) on cerebral pial microvessels in rabbits, and the extent to which carbon dioxide (CO2) reactivity is preserved. Methods: Closed cranial windows were used to visualize cerebral pial circulation in 29 Japanese white rabbits. In the first experiment, the cranial window was superfused with increasing concentrations of JM-1232(-): 10-11, 10-9, 10-7, 10-5 mol/L, n = 8 per concentration. In the second experiment, we examined the effects of an intravenous bolus of 1 mg/kg bolus of JM-1232(-), followed by the continuous infusion at 0.3 mg/kg/minute on cerebral pial vascular alteration (n = 9). In the third, we examined CO2 reactivity of cerebral pial vessels under JM-1232(-) (n = 6) or sevoflurane anesthesia (n = 6). Results: Topical application of JM-1232(-) did not change pial venular diameter, and constricted arterials only at the highest concentration. Intravenous administration of JM-1232(-) produced cerebral pial constriction which gradually diminished over time. Under intravenous administration of JM-1232(-) and inhaled sevoflurane, diameters of vessels increased in parallel with CO2 partial pressure. Slopes of linear regression and correlation coefficients in arterioles and venules were comparable for JM-1232(-) anesthesia and sevoflurane anesthesia. Conclusions: Topical application of JM-1232(-) had little effect on cerebral pial vessels. Intravenous administration produced vasoconstriction of cerebral pial arterioles and venules, however those changes were clinically unimportant. In addition, JM-1232(-) did not impair CO2 responsiveness. At least from the perspective of vascular reactivity, JM-1232(-) thus appears safe for neurosurgical patients. [ABSTRACT FROM AUTHOR]

Objective: To determine the effect of vitamin D on postoperative outcomes in cardiac surgical patients. Design: Retrospective study. Setting: Single institution-teaching hospital. Participants: Adult cardiac surgical patients with perioperative 25-hydroxyvitamin D measurements. Interventions: None. We gathered information from the Cardiac Anesthesiology Registry that was obtained at the time of the patients’ visit/hospitalization. Measurements and Main Results: We used data of 18,064 patients from the Cardiac Anesthesiology Registry; 426 patients with 25-hydroxyvitamin D measurements met our inclusion criteria. Association with Vitamin D concentration and composite of 11 cardiac morbidities was done by multivariate (i.e., multiple outcomes per subject) analysis. For other outcomes separate multivariable logistic regressions and adjusting for the potential confounders was used. The observed median vitamin D concentration was 19 [Q1-Q3∶12, 30] ng/mL. Vitamin D concentration was not associated with our primary composite of serious cardiac morbidities (odds ratio [OR], 0.96; 95% CI, 0.86–1.07). Vitamin D concentration was also not associated with any of the secondary outcomes: neurologic morbidity (P = 0.27), surgical (P = 0.26) or systemic infections (P = 0.58), 30-day mortality (P = 0.55), or length of initial intensive care unit (ICU) stay (P = 0.04). Conclusions: Our analysis suggests that perioperative vitamin D concentration is not associated with clinically important outcomes, likely because the outcomes are overwhelmingly determined by other baseline and surgical factors. [ABSTRACT FROM AUTHOR]

Background: Early predictors of morbidity after cardiac operations are lacking. Elevated lactate concentrations in the immediate postoperative period reflect unmet metabolic demand and may be associated with outcome. This study examined the association between early plasma lactate concentrations and outcome after cardiac operations. Methods: As a retrospective cohort investigation, patient information was obtained from the Cardiovascular Information and the Anesthesiology Institute''s patient registries. Inclusion criteria were all adult cardiac surgical patients undergoing isolated coronary artery bypass grafting or valve procedures, or coronary artery bypass grafting with a valve procedure, from January 1, 2008, to August 7, 2008 (arterial lactate values were added to the patient registry beginning January 1, 2008). Results: Lactate concentrations during the initial 12 postoperative hours of a patient''s stay in the cardiovascular intensive care unit were averaged (mean lactate concentration), and linear regression concentrations over time were used to predict when the lactate concentration would reach 1.5 mmol/L in individual patients (predicted lactate clearance time). We also considered the product of the mean and clearance (product value). Predicted lactate clearance time, mean lactate concentration, and product value were associated with any type of reoperation, death, and a set of composite outcomes (p < 0.001 for each). The accuracy of these indices was moderate to good, with the highest C statistic (for product value) being 0.82. Conclusions: Predicted lactate clearance time, mean lactate concentration, and product value are each associated with death, any type of reoperation, and a set of composite outcomes in patients undergoing coronary artery bypass grafting or valve operations, or both. Product value provided the best early prognostic guidance in individual patients. [Copyright &y& Elsevier]

Background: Gastrointestinal (GI) complications after coronary artery bypass graft surgery (CABG) are uncommon but associated with a disproportionate share of mortality. We thus identified variables associated with GI complications and analyzed their effect on postoperative mortality in patients undergoing isolated CABG. Methods: Information from patients who underwent isolated CABG at our institution during a 12-year period was obtained from the Anesthesiology Institute patient registry. Patients who experienced one or more postoperative GI complication(s) during their initial intensive care unit stay were identified. Multivariable logistic regression with backward variable selection was used to determine variables associated with GI complications and to evaluate their effect on mortality. Results: Among 16,043 patients who underwent isolated CABG, 213 (1.43%) had one or more GI complication(s). The main patient variables associated with postoperative GI complications included preoperative (odds ratio, 2.43; 95% confidence interval [CI], 1.39 to 4.23; p < 0.001) and intraoperative (odds ratio, 5.07; 95% CI, 3.08 to 8.35; p < 0.001) intraaortic balloon pump insertion, patient age (odds ratio, 1.65; 95% CI, 1.41 to 1.94; p < 0.001), intraoperative fresh-frozen plasma transfusion (odds ratio, 3.38; 95% CI, 2.12 to 5.41; p < 0.001), and cardiogenic shock (odds ratio, 3.04; 95% CI, 1.12 to 8.24). No difference was detected in complication rates between off-pump and on-pump CABG procedures (1.50% versus 1.30%, respectively; p = 0.63). Postoperative GI complication(s) after CABG was associated with a 12.98 times increase in mortality (p < 0.001). Conclusions: This single-center cohort study indicates that GI complications after isolated CABG remain rare with an incidence 1.43%. However, GI complications portend a significant mortality. The implications of intraoperative administration of fresh-frozen plasma and insertion of an intraaortic balloon pump deserve further investigation as they are associated with GI complications. [Copyright &y& Elsevier]

The author reflects on the long-term consequences of anesthetic management. He mentions the distinction between the classic definition of anesthetic complications and effects of anesthetic management on the period after surgery. He cites that the convincing evidences for long-term outcomes on anesthetic management were one that linked perioperative beta-blocker administration to myocardial infarction and another which showed that hypothermia increased the risk of surgical wound infection.

The author focuses on surgical site infections as a perioperative complication. He cites a study published in the issue which proposes the use of neuraxial rather than general anesthesia to prevent infection in patients undergoing hip and knee replacement. The author discusses mechanisms by which anesthesia could reduce infection and also discusses the study method.

The article offers information on the first Japanese Society of Anesthesiologists-Anesthesiology Symposium to be held at the 57th Annual Meeting of the Japanese Society of Anesthesiologists in Fukuoka, Japan on June 4, 2010.

The article focuses on a study which investigates the impact of the timing of coronary artery bypass graft surgery on outcomes. In this study, outcomes of coronary artery bypass graft surgery patients are analyzed based on the hour of the day or day of the workweek in which the surgery begins. These outcomes include in-hospital death, acute postoperative myocardial infarction and neurologic morbidity. It concludes that elective coronary artery bypass graft surgery can be scheduled throughout the workday or any day of the workweek without affecting the outcome.

The article reports on the result of the study which assesses the effectiveness of capnometer with oral guide nasal cannula in measuring end-tidal carbon dioxide pressure in obese and non-obese patients with and without obstructive sleep apnea (OSA) who were recovering from general anesthesia. The study was conducted to 20 healthy patients who were not obese and 20 obese patents with the sleep disorder where their end-tidal carbon dioxide pressure was monitored through the use of capnometer with oral guide nasal cannula, capnometer with standard nasal cannula, and capnometer with a nasal cannula and oral guide. It concludes that capnometry, along with oral guide, showed accuracy in measuring end-tidal carbon dioxide pressure in the two groups.

Study Objective: To investigate whether Type O blood group status is associated with increased intraoperative blood loss and requirement of blood transfusion in extensive spine surgery. Design: Retrospective comparative study. Setting: University-affiliated, non-profit teaching hospital. Measurements: Data from 1,050 ASA physical status 1, 2, 3, 4, and 5 patients who underwent spine surgeries involving 4 or more vertebral levels were analyzed. Patients with Type O blood were matched to similar patients with other blood types using propensity scores, which were estimated via demographic and morphometric data, medical history variables, and extent of surgery. Intraoperative estimated blood loss (EBL) was compared among matched patients using a linear regression model; intraoperative transfusion requirement in volume of red blood cells, fresh frozen plasma, platelet, cryoprecipitate, cell salvaged blood, volume of intraoperative infusion of hetastarch, 5% albumin, crystalloids, and hospital length of hospital (LOS) were compared using Wilcoxon rank-sum tests. Main Results: Intraoperative EBL and requirement of blood product transfusion were similar in patients with Type O blood group and those with other blood groups. Conclusion: There was no association between Type O blood and increased intraoperative blood loss or blood transfusion requirement during extensive spine surgery, with similar hospital LOS in Type O and non-O patients. [ABSTRACT FROM AUTHOR]

The article discusses a study which quantifies the change in initial postoperative core temperature happening during the emergence and transport and assesses the accuracy of noninvasive thermometers in the post-anesthesia care unit. Monitoring methods employed in this study, included oral, axillary and temporal artery. The study discovered that bladder temperature increased during transport and none of the tested noninvasive thermometers was within 0.5 degree Celsius of bladder temperature. It concluded that invasive temperature monitoring available postoperatively was more accurate than postoperative methods.