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Purpose: The extent to which postoperative hypotension contributes to renal injury remains unclear, much less what the harm thresholds might be. We therefore tested the primary hypothesis that there is an absolute hypotensive arterial pressure threshold for acute kidney injury during the initial seven days after noncardiac surgery., Methods: We conducted a single-centre historical cohort analysis of adults who had noncardiac surgery and had creatinine recorded preoperatively and postoperatively. Our exposure was the lowest postoperative mean arterial pressure, defined as the average of the three lowest postoperative pressure measurements. Our primary analysis was the association between the lowest mean arterial pressure and acute kidney injury, defined according to Kidney Disease: Improving Global Outcomes initiative criteria. Our analysis was adjusted for potentially relevant confounding factors including intraoperative hypotension., Results: Among 64,349 patients analyzed, 2,812 (4.4%) patients had postoperative acute kidney injury. Each 5-mm Hg decrease in the lowest mean arterial pressure was associated with a 28% (97.5% confidence interval [CI], 23 to 32; P < 0.001) increase in the odds of acute kidney injury for lowest mean arterial pressures < 80 mm Hg. Higher lowest pressures were not associated with acute kidney injury (odds ratio, 1.08; 97.5% CI, 0.99 to 1.17; P = 0.04) for each 5-mm Hg decrease in the lowest mean arterial pressure., Conclusion: Postoperative hypotension, defined as the lowest postoperative mean arterial pressure < 80 mm Hg, was associated with acute kidney injury after noncardiac surgery. A prospective trial will be required to determine whether the observed association is causal and thus amenable to modification., (© 2023. Canadian Anesthesiologists' Society.)

Background: The intravenous anesthetic propofol is a gamma-aminobutyric acid A receptor agonist. Propofol promotes analgesia by depressing nociceptive transmission in peripheral neurons, antagonizing N-methyl-D-aspartate receptors, and activating gamma-aminobutyric acid A receptors in dorsal root ganglion receptor cells. Nevertheless, it remains unclear whether intraoperative propofol causes clinically meaningful postoperative analgesia. We therefore tested the hypothesis that patients anesthetized with sevoflurane require a greater quantity of postoperative opioids (from the end of surgery until the next postoperative morning) than those anesthetized with propofol., Methods: With Institutional Review Board and EudraCT Number approval (2009-011038-82) and patients' informed consent, ninety patients scheduled for open vein stripping were randomized to either sevoflurane or propofol anesthesia at the Medical University of Vienna General Hospital and the Danube Hospital, the largest regional hospital in Vienna. Pain was treated with bolus piritramide and patient-controlled morphine hydrochloride. The primary outcome was total opioid use from the end of surgery until the first postoperative morning. For the initial four postoperative hours and on the first postoperative morning, a blinded investigator recorded pain scores on an 11-point Likert verbal response scale., Results: The median [interquartile range] morphine sulfate equivalents were 9.8 [4-19] mg in the sevoflurane group and 10 [6-20] mg in the propofol group. Sevoflurane was not superior to propofol on postoperative opioid consumption, giving a ratio of means of 0.91 (95% interim-adjusted confidence interval [CI], 0.33 to 2.45; P = 0.74). Additionally, no difference in pain scores was found over time between the two groups, with a mean difference on an 11-point scale of 0.20 (95% interim-adjusted CI, -0.36 to 0.73; P = 0.31)., Conclusion: Intraoperative sevoflurane did not reduce postoperative analgesia. This finding is consistent with the results in most previous reports. This trial was registered at ClinicalTrials.gov: NCT00712517.

Introduction: Double-lumen endotracheal tubes (DLTs), which are commonly used for single-lung ventilation during surgery, are difficult to insert. In addition, they often move during surgical lung manipulation which can cause life-threatening complications. Flexible bronchoscopy is used routinely to establish and confirm proper DLT placement. The newly designed VivaSight DLT has an integrated camera, allowing continuous visualization of its position in the trachea. We hypothesized that the time to intubation using the VivaSight DLT would be faster than with a conventional DLT., Methods: We enrolled 40 adults scheduled for thoracic surgery. Patients were randomized to conventional DLT (n = 20) or VivaSight DLT (n = 20). Time to intubation was our primary outcome. Secondary outcomes were insertion success without flexible bronchoscopy, frequency of tube displacement, ease of insertion, quality of lung collapse, postoperative complaints, and airway injuries., Results: Time [mean (SD)] to successful intubation was significantly faster with the VivaSight DLT [63 (58) sec] compared with the conventional DLT [97 (84) sec; P = 0.03]. The VivaSight DLTs were correctly inserted during all attempts. When malpositioning of the VivaSight DLT occurred, it was easily remedied, even in the lateral position. The devices were comparable with respect to postoperative coughing, hoarseness, and sore throat. Airway injuries tended to be more common with the VivaSight DLT, although this study was underpowered for airway injuries., Conclusion: The VivaSight DLT camera allowed faster insertion and facilitated initial positioning. It also confirmed proper tube positioning intraoperatively and facilitated repositioning when necessary. This trial was registered at clinicaltrials.gov: NCT01807676.

Background: Serum creatinine is the most commonly used indicator of renal function, but its derivative, estimated glomerular filtration rate (eGFR), has been shown to be superior in non-surgical settings. It remains unknown if eGFR better predicts postoperative mortality in non-cardiac surgical patients. We thus tested the hypothesis that eGFR predicts 30-day mortality after non-cardiac surgery better than serum creatinine., Methods: We evaluated patients who had inpatient non-cardiac surgery of at least one hour duration during January 2006 to December 2011 at the Cleveland Clinic Main Campus and whose preoperative serum creatinine was measured within 30 days before surgery. The eGFR was calculated using the Chronic Kidney Disease-Epidemiology Collaboration equation. Preoperative eGFR was compared in a multivariable analysis with preoperative serum creatinine (both assessed as continuous variables) on the ability to predict 30-day mortality in all patients. Secondarily, the comparison was made within subgroups based on amount of blood loss, blood transfusion, and sex., Results: There were 92,888 patients included in the final analysis. The eGFR was a modestly better discriminator of 30-day mortality than serum creatinine, with an estimated c-statistic (95% confidence interval) of 0.67 (0.65 to 0.68) for eGFR vs 0.61 (0.59 to 0.63) for serum creatinine (P < 0.001). Furthermore, the eGFR was consistently a better discriminator of 30-day mortality across blood loss, transfusion, and sex groups. Reclassification analyses suggested improved individual predictions of 30-day mortality using eGFR compared with serum creatinine. Nevertheless, a multivariable combination of baseline characteristics of American Society of Anesthesiologists physical status, age, and body mass index (all P < 0.001) discriminated 30-day mortality with a c-statistic of 0.850. Adding eGFR to the model improved the c-statistic to only 0.851, while separately adding serum creatinine did not change the c-statistic., Conclusion: The eGFR is a modestly better predictor of 30-day mortality than serum creatinine in patients having inpatient non-cardiac surgery. Given that eGFR is often reported by clinical laboratories and is otherwise easy to calculate, it should generally be used in preference to creatinine alone.

Purpose: To determine whether combining spinal or epidural anesthesia with general anesthesia (combined anesthesia) reduces major medical complications of elective surgery compared with general anesthesia alone., Methods: We conducted a propensity-matched population-based historical cohort study using large healthcare databases from Ontario, Canada. We identified patients undergoing 21 different elective procedures that were amenable to either combined anesthesia or general anesthesia alone in 108 hospitals from 2004 to 2011. We assessed the following four outcomes together as a composite and individually in the 30 days following surgery: acute kidney injury, stroke, myocardial infarction, and all-cause mortality., Results: Prior to matching, we identified 21,701 patients receiving general anesthesia and 8,042 patients receiving combined anesthesia. After matching, our cohort included 12,379 patients. Twenty-eight baseline characteristics were well-matched between the combined (n = 4,773) and general anesthesia groups (n = 7,606). Mean patient age was 66 yr. Relative to general anesthesia alone, combined anesthesia was not associated with a reduced risk for the composite outcome [104/4,773 (2.2%) vs 162/7,606 (2.1%); odds ratio (OR) 0.97; 95% confidence interval (CI) 0.75 to 1.24] or for any of the four component outcomes when examined separately: acute kidney injury (OR 0.93; 95% CI 0.58 to 1.51), stroke (OR 0.79; 95% CI 0.36 to 1.73), myocardial infarction (OR 1.04; 95% CI 0.69 to 1.57), and all-cause mortality (OR 0.91; 95% CI 0.59 to 1.42)., Conclusion: The addition of spinal or epidural anesthesia to general anesthesia was not associated with a reduced risk of major medical complications among 21 different elective procedures when compared with general anesthesia alone.

Background: The contribution of regional anesthesia with thoracic paravertebral blockade to postoperative analgesia remains unclear. We compared the effect of a combination of paravertebral blockade and propofol general anesthesia (GA) with sevoflurane GA and opioid analgesia on postoperative pain and opioid use for patients undergoing breast cancer surgery., Methods: Patients having breast cancer surgery were randomly assigned to paravertebral analgesia with propofol GA (PPA, n = 187) or sevoflurane GA with perioperative opioid analgesia (SOA, n = 199). The PPA and SOA groups were compared for opioid consumption and pain outcomes (on a 0-10 visual analogue scale [VAS]) at two hours postoperatively using superiority and inferiority statistics. We compared our results with previous publications in a meta-analysis., Results: Compared with the SOA group, the PPA group experienced reduced median [interquartile range] pain VAS scores (1 [1,3] vs 2.5 [1,4], respectively; median difference -1.0; 99% confidence intervals [CI]: -1.5 to -0.5) and required less intraoperative fentanyl (50 [0, 125] µg vs 200 [100, 300] µg, respectively; median difference -100; 99% CI: -150 to -100) and less long-acting opioid (0 [0, 0] mg vs 3.0 [0, 12] mg, respectively, morphine equivalents; median difference -3; 99% CI: -4 to -2). Thus, non-inferiority was detected for all the above outcomes, and superiority tests for each outcome were highly significant in the expected directions (P < 0.001). Meta-analysis, including the current study, estimated a reduction in worst pain of 2.3 points (95% CI: 1.8 to 2.8) on a 0-10 scale and a 72% reduction (95% CI: 42 to 87) in mean opioid consumption in the immediate two postoperative hours for PPA vs SOA., Conclusion: Our results were largely consistent with previous much smaller studies. Compared with sevoflurane GA with opioid analgesia, the combination of paravertebral analgesia with propofol GA provides an early clinical analgesic benefit in females having breast cancer surgery. This analysis is a substudy of an ongoing multicentre double-blinded randomized trial ( www.clinicaltrials.gov , NCT00418457) of cancer recurrence.

Background: Patients with dementia are thought to be more sensitive to anesthesia, although volatile anesthetic requirement has not specifically been evaluated in this population. We tested the hypothesis that patients with dementia having non-cardiac surgery have a lower ratio of bispectral index (BIS) to minimal alveolar concentration (MAC) during the five minutes immediately preceding incision, thus exhibiting deeper hypnotic levels at a given MAC fraction., Methods: We obtained records from our database registry on patients who had volatile general anesthesia during their most recent operation. We excluded patients premedicated with midazolam. Patients with dementia were identified and their diagnosis was confirmed by chart review. Each patient with dementia was successfully matched with a maximum of five patients without dementia using a multivariate nearest-neighbor distance-matching algorithm restricted to the following criteria: American Society of Anesthesiologists physical status, age, five-minute pre-incision time-weighted average (TWA) estimated effect-site concentration of propofol and fentanyl, and use of remifentanil. Our primary outcome was the TWA BIS-to-MAC ratio during the five minutes immediately preceding incision., Results: We analyzed 31 patients with dementia matched with 151 patients without dementia. Median [quartiles] TWA BIS-to-MAC ratios for the matched patients were 85 [73, 100] for the patients with dementia and 78 [73, 84] for the patients without dementia. The percent difference in mean BIS-to-MAC ratios between patients with dementia and patients without dementia was 9% (95% confidence interval: -9% to 29%) (P = 0.35, Wald test)., Conclusions: Our results do not support the hypothesis that patients with dementia are more sensitive to volatile anesthetics than patients without dementia.

Background: Massive transfusion is associated with high morbidity and mortality, yet existing reports of massive transfusion are limited. Our primary aim was to determine the incidence of complications and 30-day mortality among patients who received massive transfusions and to explore risk factors associated with 30-day mortality., Methods: We evaluated 971,455 patients from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We assessed the associations between 30-day mortality and baseline, intraoperative, and postoperative factors among 5,143 patients who received massive transfusions and for whom complete data were available., Results: The crude 30-day postoperative mortality of the non-transfused, low transfusion (1-4 units), and massive transfusion (≥ 5 units) patients in the NSQIP was 1.2%, 8.9%, and 21.5%, respectively. Of the 5,143 massive transfusion patients with non-missing covariable data, 17% (95% confidence interval [CI] 16% to 18%) died within 30 days of surgery, while 54% (95% CI 53% to 56%) had at least one non-fatal major complication. The following baseline and intraoperative variables were independently associated with 30-day mortality after adjusting for multiple testing: age, American Society of Anesthesiologists (ASA) physical status, emergency case, surgical types, coma > 24 hr before surgery, systemic sepsis, preoperative international normalized ratio of prothrombin time, the number of intraoperative transfusions, and requirement of postoperative transfusion., Conclusion: Massive transfusion is associated with substantial risk for respiratory and infectious complications and for mortality. Patients who died within 30 days of a massive perioperative transfusion were generally older, more likely to have vascular surgical procedure and abnormal international normalized ratio of prothrombin time, higher ASA physical status, preoperative coma and sepsis, and higher postoperative bleeding requiring transfusion, and they were likely given more intraoperative red cell units.

Introduction: The GlideScope(®) video laryngoscope has a 60° angled blade and the blade of the Truview PCD™ video laryngoscope has an optical lens that provides a 46° refraction of the viewing angle. Despite successful results using the GlideScope in adults, few studies have been published regarding its use in pediatric patients. We therefore tested our joint primary hypothesis that the GlideScope and the Truview PCD video laryngoscopes provide superior visualization to direct laryngoscopy and are non-inferior regarding time to intubation., Methods: One hundred thirty-four patients (neonate to ten years of age, American Society of Anesthesiologists physical status I-III) scheduled for general surgical procedures were randomized to tracheal intubation using the Truview PCD or GlideScope video laryngoscope or direct laryngoscopy (Macintosh blade). The laryngoscopic view was scored using the Cormack-Lehane scale. Time to intubation (defined as the time from the moment the device entered the patient's mouth until end-tidal CO2 was detected) and the number of attempts were recorded., Results: The Cormack-Lehane views attained using the GlideScope (P > 0.99) and Truview PCD (P = 0.18) were not superior to the views attained with direct laryngoscopy. Furthermore, the view attained using the GlideScope was significantly worse than that attained using direct laryngoscopy (P < 0.001). Fewer patients showed Cormack-Lehane grade I views with the GlideScope than with the Truview PCD (14% vs 82%, respectively; 95% confidence interval [CI] -91% to -46%). The observed median [Q1, Q3] times to intubation were: 39 [31, 59] sec, 44 [28, 62] sec, and 23 [21, 28] sec with the GlideScope, Truview PCD, and direct laryngoscopy, respectively, with median differences of 14 sec (95% CI 7 to 26, GlideScope - direct laryngoscopy) and 17 sec (95% CI 6 to 28, Truview PCD - direct laryngoscopy)., Conclusion: The Cormack-Lehane views attained using the GlideScope and the Truview PCD video laryngoscopes were not superior to views attained using direct laryngoscopy. Visualization with the GlideScope was significantly worse than with direct laryngoscopy. Use of the GlideScope and Truview PCD systems should be restricted to patients with specific indications.

Background: Preoperative chemotherapy is frequently given to shrink or decrease the chance of metastasis. However, chemotherapy has well-recognized side effects that may complicate the perioperative period. We therefore tested the hypotheses that chemotherapy within 30 days before cancer surgery is associated with an increased risk of mortality and with a composite of major morbidities within 30 postoperative days., Methods: We evaluated 971,455 patients from the American College of Surgeons National Surgical Quality Improvement Program database. Patients were defined as having chemotherapy when they were given any chemotherapy for malignancy within 30 days before surgery. We successfully matched 1,348 pairs of chemotherapy recipients and non-recipients., Results: Twenty-one of the 1,348 (1.6%) non-chemotherapy patients died within 30 days after surgery compared with 30 of the 1,348 (2.2%) chemotherapy patients. The odds of mortality were not statistically different between groups based on our logistic regression model [odds ratio (OR) = 1.47; 95% confidence interval (CI) 0.82 to 2.64; P = 0.19]. The most common complication observed was wound infection in 13.1% of non-chemotherapy patients compared with 14.2% of the chemotherapy patients. There was similarly no difference between groups for the collapsed composite of major morbidities [OR = 1.17; 95% CI 0.97 to 1.42; P = 0.09]., Conclusion: Preoperative use of neoadjuvant chemotherapy in cancer patients undergoing resection surgeries was not associated with a higher rate of early postoperative complications or mortality.

Background: One-third of surgical outpatients experience postoperative nausea and vomiting (PONV) during their hospital stay or post-discharge nausea and vomiting (PDNV) after hospitalization. We determined the incremental costs of PONV/PDNV in ambulatory patients with this time-and-motion study., Methods: In 100 ambulatory surgery patients, we evaluated the incidence of PONV, time staff spent with patients, use of PONV-related supplies, recovery duration, PONV rescue treatments, and quality-of-life through to the third postoperative morning. Patients with and without PONV/PDNV were compared in relation to PONV-related cost after adjusting for age, American Society of Anesthesiologists status, body mass index, and duration and complexity of surgery., Results: Thirty-seven percent of the patients experienced PONV during hospitalization; this increased to 42% by the first postoperative morning and increased further to 49% by the third postoperative morning. Patients with PONV spent one hour longer in the postanesthesia care unit than patients without PONV (median [interquartile range] 234 [188-287] min vs 171 [144-212] min, respectively; P = 0.001). The amount of nursing time required for patients with PONV was significantly greater than that required for patients without PONV (82 [63-106] min vs 68 [57-79] min, respectively; P = 0.02). The total cost of postoperative recovery was significantly greater for patients with PONV/PDNV than for those without (US$730 vs $640, respectively; P = 0.006). Postoperative nausea and vomiting/PDNV was associated with an adjusted incremental total cost of $75 (95% confidence interval $67 to $86). Postoperative nausea and vomiting was also associated with worsened postoperative quality of life (49% of patients with PONV/PDNV rated quality high in four domains vs 94% of patients without PONV/PDNV; P < 0.001)., Conclusion: Postoperative nausea and vomiting/PDNV were common; they impaired quality of life and imposed an incremental cost of $75 per patient. This incremental cost is comparable with the cost patients are willing to pay to avoid PONV.

Purpose: A safe and effective insulin infusion algorithm that achieves rigorous intraoperative glycemic control in noncardiac surgery has yet to be formally characterized and evaluated. We therefore report the validation of the DeLit Trial insulin infusion algorithm., Methods: Patients scheduled for major noncardiac surgery were randomized to a target intraoperative blood glucose concentration of 4.4-6.1 mmoL·L(-1) (80-110 mg·dL(-1)) intensive group or 10-11.1 mmoL·L(-1) (180-200 mg·dL(-1)) conventional group. Glucose was managed with a dynamic intravenous insulin infusion algorithm. We compared the randomized groups on glucose time-weighted average (TWA), proportion of time spent within target, number of severe (< 2.2 mmoL·L(-1) or < 40 mg·dL(-1)) or moderate (< 2.8 mmoL·L(-1) or < 50 mg·dL(-1)) hypoglycemic episodes, and within-patient variability in glucose concentrations expressed as standard deviation from the patient mean., Results: One hundred eighty-seven patients were assigned to intensive glucose control, and 177 patients were assigned to conventional glucose control. Median (lower quartile value [Q1], upper quartile value [Q3]) of intraoperative TWA for the intensive vs conventional groups was 6 [5.6, 6.7] mmoL·L(-1) vs 7.7 [6.9, 9.2] mmoL·L(-1), respectively; P < 0.001. The intensive group spent 49% (29, 71) of the time within target, substantially more time than the conventional group spent either within the intensive target or within its own target (both P < 0.001). The intensive group had slightly lower within-patient glucose variability than the conventional group (0.9 [0.7, 1.3] mmoL·L(-1) vs 1.3 [0.8, 1.8] mmoL·L(-1), respectively; P < 0.001). Three patients had moderate hypoglycemia (intensive group), but none experienced severe episodes., Conclusion: Tight intraoperative glucose control in noncardiac surgery can be maintained successfully without serious hypoglycemic episodes. (ClinicalTrials.gov number, NCT00433251).

Purpose: To compare distal oesophageal (reference) temperature with "deep-sternal," "deep-forehead," and tracheal temperatures, establishing the accuracy and precision of each., Methods: We studied 20 patients undergoing general anaesthesia for gynaecological surgery. Their lungs were mechanically ventilated with a circle system, at a fresh-gas flow rate of 6 L.min-1 Respiratory gases were not warmed or humidified. Tracheal temperatures were recorded from a Trachelon tube inserted approximately 21 cm. Deep-body temperatures were measured at the sternum and forehead using a Coretemp thermometer. The principle of the method is to null thermal flux through a cutaneous disk, thus obliterating thermal gradients between the sides of the disk, skin surface, and subcutaneous tissues. Distal oesophageal temperatures were measured from thermocouples incorporated into oesophageal stethoscopes. Tracheal and deep-tissue temperatures were compared with oesophageal temperature using regression and Bland and Altman analyses., Results: Tracheal, sternal, and forehead temperatures correlated similarly with distal oesophageal temperature, correlation coefficients (r2) being 0.7 in each case. The offset (oesophageal temperature minus study site) was considerably larger for tracheal temperature (0.7 degree C) than for the other sites (0.2 degree C). However, the precision was only 0.3 degree C at each site., Conclusion: Our data suggest that tracheal temperatures may not be an adequate substitute for conventional core-temperature monitoring sites. In contrast, the accuracy and precision of deep-tissue temperature monitoring at the sternum and forehead was sufficient for clinical use.