Association Between Preoperative Statin Use and Respiratory Complications After Noncardiac Surgery: A Retrospective Cohort Analysis.

BACKGROUND: Statins possess pleiotropic effects, which potentially benefit noncardiovascular conditions. Previous work suggests that statins reduce inflammation and prevent acute respiratory distress syndrome and infections. However, there is a paucity of data regarding potential benefits of statins on respiratory and infectious complications, particularly after noncardiac surgery. We therefore evaluated respiratory and other complications in noncardiac surgery patients taking or not taking statins preoperatively. METHODS: We obtained data from the Cleveland Clinic Perioperative Health Documentation System and evaluated medical records of 92,139 inpatients who had noncardiac surgery. Among these, 31,719 patients took statins preoperatively. Statin patients were compared to nonstatin patients on incidence of intraoperative use of albuterol and postoperative respiratory complications for primary analysis. Infectious complications, cardiovascular complications, in-hospital mortality, and duration of hospitalization were compared for secondary analyses, using inverse probability of treatment weighting to control for potential confounding. RESULTS: Statin use was associated with lower odds of intraoperative albuterol treatment (odds ratio [OR] = 0.89; 97.5% confidence interval [CI], 0.82-0.97; P = .001; number needed to treat [NNT] = 216). Postoperative respiratory complications were also less common (OR = 0.82; 98.75% CI, 0.78-0.87; P < .001). Secondarily, statin use was associated with lower odds of infections, cardiovascular complications, in-hospital mortality, and shorter duration of hospitalization. The interaction between statin use and sex was significant (with significance criteria P < .10) for all primary and secondary outcomes except intraoperative use of albuterol. CONCLUSIONS: Preoperative statin use in noncardiac surgical patients was associated with slightly reduced odds of postoperative respiratory, infectious, and cardiovascular complications. However, the NNTs were high. Thus, despite the fact that statins appeared to be associated with lower odds of various complications, especially cardiovascular complications, our results do not support using statins specifically to reduce noncardiovascular complications after noncardiac surgery.

Diagnosis of Sacroiliac Joint Pain: Predictive Value of Three Diagnostic Clinical Tests.

INTRODUCTION: To date, there have been no acceptable and accurate diagnostic criteria or standards of care for the management of sacroiliac joint (SIJ) pain. Several studies have yielded different contributions of clinical presentation, history, and physical examination in the diagnosis of SIJ pain. Our goal in this study was to assess the sensitivity and specificity of the diagnostic clinical tests and their predictive value in accurately diagnosing SIJ pain. METHODOLOGY: Upon enrolling 200 eligible patients with SIJ pain as their primary diagnosis, they were re-evaluated and their verbal rating scale (VRS) pain scores and demographic data were obtained. Thereafter, three SIJ diagnostic tests were performed: the thigh thrust test, the Patrick test, and a modified version of the Gaenslen test that is referred to as the Mekhail test. Subsequently, the patients were taken to the procedure room to undergo SIJ injection, for which a confirmative result was ≥50% pain relief. The physicians performing the procedure were blinded of the results of the 3 tests performed. Results from the 3 tests were incorporated with the procedure results, from which we drew statistical and medical conclusions determining their predictive value and degree of aid to physicians in diagnosing SIJ pain. RESULTS: We found that the cumulative effect of adding simultaneous tests increased the sensitivity of the testing but decreased the specificity, which generates a powerful screening tool. The combination of the Patrick and Mekhail tests demonstrated the best accuracy, with 94% sensitivity, 17% specificity, 81% positive predictive value, and 44% negative predictive value. The Patrick test was better than other tests for differentiating patients with SIJ pain from those with non-SIJ pain. No combination yielded both significant sensitivity and specificity. Generally, the overall predictive value of any of the tests on their own or their combination did not vary significantly from the predictive value of baseline demographics, including pre-injection pain score and pain referral diagram. CONCLUSION: In conclusion, our study results were similar to those of previous investigators who found that physical examination plays a limited role in diagnosing SIJ pain. Specifically, we found that the clinical tests and/or their combinations added no significant predictive capacity compared to patients' baseline characteristics in predicting the response to diagnostic SIJ injection, albeit the combination of the Mekhail and Patrick tests yielded high sensitivity (94%), making them viable for consecutive screening, possibly reducing the unnecessary costs of diagnostic SIJ injection procedures.

Deficit Accumulation and Phenotype Assessments of Frailty Both Poorly Predict Duration of Hospitalization and Serious Complications after Noncardiac Surgery.

BACKGROUND: Frailty is associated with adverse postoperative outcomes, but it remains unclear which measure of frailty is best. This study compared two approaches: the Modified Frailty Index, which is a deficit accumulation model (number of accumulated deficits), and the Hopkins Frailty Score, which is a phenotype model (consisting of shrinking, weakness, exhaustion, slowness, and low physical activity). The primary aim was to compare the ability of each frailty score to predict prolonged hospitalization. Secondarily, the ability of each score to predict 30-day readmission and/or postoperative complications was compared. METHODS: This study prospectively enrolled adults presenting for preanesthesia evaluation before elective noncardiac surgery. The Hopkins Frailty Score and Modified Frailty Index were both determined. The ability of each frailty score to predict the primary outcome (prolonged hospitalization) was compared using a ratio of root-mean-square prediction errors from linear regression models. The ability of each score to predict the secondary outcome (readmission and complications) was compared using ratio of root-mean-square prediction errors from logistic regression models. RESULTS: The study included 1,042 patients. The frailty rates were 23% (Modified Frailty Index of 4 or higher) and 18% (Hopkins Frailty Score of 3 or higher). In total, 12.9% patients were readmitted or had postoperative complications. The error of the Modified Frailty Index and Hopkins Frailty Score in predicting the primary outcome was 2.5 (95% CI, 2.2, 2.9) and 2.6 (95% CI, 2.2, 3.0) days, respectively, and their ratio was 1.0 (95% CI, 1.0, 1.0), indicating similarly poor prediction. Similarly, the error of respective frailty scores in predicting the probability of secondary outcome was high, specifically 0.3 (95% CI, 0.3, 0.4) and 0.3 (95% CI, 0.3, 0.4), and their ratio was 1.00 (95% CI, 1.0, 1.0). CONCLUSIONS: The Modified Frailty Index and Hopkins Frailty Score were similarly poor predictors of perioperative risk. Further studies, with different frailty screening tools, are needed to identify the best method to measure perioperative frailty.

Mild Acute Kidney Injury after Noncardiac Surgery Is Associated with Long-term Renal Dysfunction: A Retrospective Cohort Study.

BACKGROUND: Perioperative acute kidney injury is common. However, it is unclear whether this merely represents a transient increase in creatinine or has prognostic value. Therefore, the long-term clinical importance of mild postoperative acute kidney injury remains unclear. This study assessed whether adults who do and do not experience mild kidney injury after noncardiac surgery are at similar risk for long-term renal injury. METHODS: This study is a retrospective cohort analysis of adults having noncardiac surgery at the Cleveland Clinic who had preoperative, postoperative, and long-term (1 to 2 yr after surgery) plasma creatinine measurements. The exposure (postoperative kidney injury) and outcome (long-term renal injury) were defined and staged according to the Kidney Disease: Improving Global Outcomes (KDIGO) initiative criteria. The primary analysis was for lack of association between postoperative kidney injury (stage I vs. no injury) and long-term renal injury. RESULTS: Among 15,621 patients analyzed, 3% had postoperative stage I kidney injury. Long-term renal outcomes were not similar in patients with and without postoperative stage I injury. Specifically, about 26% of patients with stage I postoperative kidney injury still had mild injury 1 to 2 yr later, and 11% had even more severe injury. A full third (37%) of patients with stage I kidney injury therefore had renal injury 1 to 2 yr after surgery. Patients with postoperative stage I injury had an estimated 2.4 times higher odds of having long-term renal dysfunction (KDIGO stage I, II, or III) compared with patients without postoperative kidney injury (odds ratio [95% CI] of 2.4 [2.0 to 3.0]) after adjustment for potential confounding factors. CONCLUSIONS: In adults recovering from noncardiac surgery, even small postoperative increases in plasma creatinine, corresponding to stage I kidney injury, are associated with renal dysfunction 1 to 2 yr after surgery. Even mild postoperative renal injury should therefore be considered a clinically important perioperative outcome.

Multimodal Analgesic Regimen for Spine Surgery: A Randomized Placebo-controlled Trial.

BACKGROUND: Various multimodal analgesic approaches have been proposed for spine surgery. The authors evaluated the effect of using a combination of four nonopioid analgesics versus placebo on Quality of Recovery, postoperative opioid consumption, and pain scores. METHODS: Adults having multilevel spine surgery who were at high risk for postoperative pain were double-blind randomized to placebos or the combination of single preoperative oral doses of acetaminophen 1,000 mg and gabapentin 600 mg, an infusion of ketamine 5 µg/kg/min throughout surgery, and an infusion of lidocaine 1.5 mg/kg/h intraoperatively and during the initial hour of recovery. Postoperative analgesia included acetaminophen, gabapentin, and opioids. The primary outcome was the Quality of Recovery 15-questionnaire (0 to 150 points, with 15% considered to be a clinically important difference) assessed on the third postoperative day. Secondary outcomes were opioid use in morphine equivalents (with 20% considered to be a clinically important change) and verbal-response pain scores (0 to 10, with a 1-point change considered important) over the initial postoperative 48 h. RESULTS: The trial was stopped early for futility per a priori guidelines. The average duration ± SD of surgery was 5.4 ± 2.1 h. The mean ± SD Quality of Recovery score was 109 ± 25 in the pathway patients (n = 150) versus 109 ± 23 in the placebo group (n = 149); estimated difference in means was 0 (95% CI, -6 to 6, P = 0.920). Pain management within the initial 48 postoperative hours was not superior in analgesic pathway group: 48-h opioid consumption median (Q1, Q3) was 72 (48, 113) mg in the analgesic pathway group and 75 (50, 152) mg in the placebo group, with the difference in medians being -9 (97.5% CI, -23 to 5, P = 0.175) mg. Mean 48-h pain scores were 4.8 ± 1.8 in the analgesic pathway group versus 5.2 ± 1.9 in the placebo group, with the difference in means being -0.4 (97.5% CI; -0.8, 0.1, P = 0.094). CONCLUSIONS: An analgesic pathway based on preoperative acetaminophen and gabapentin, combined with intraoperative infusions of lidocaine and ketamine, did not improve recovery in patients who had multilevel spine surgery.

Saline versus Lactated Ringer's Solution: The Saline or Lactated Ringer's (SOLAR) Trial.

BACKGROUND: Both saline and lactated Ringer's solutions are commonly given to surgical patients. However, hyperchloremic acidosis consequent to saline administration may provoke complications. The authors therefore tested the primary hypothesis that a composite of in-hospital mortality and major postoperative complications is less common in patients given lactated Ringer's solution than normal saline. METHODS: The authors conducted an alternating cohort controlled trial in which adults having colorectal and orthopedic surgery were given either lactated Ringer's solution or normal saline in 2-week blocks between September 2015 and August 2018. The primary outcome was a composite of in-hospital mortality and major postoperative renal, respiratory, infectious, and hemorrhagic complications. The secondary outcome was postoperative acute kidney injury. RESULTS: Among 8,616 qualifying patients, 4,187 (49%) were assigned to lactated Ringer's solution, and 4,429 (51%) were assigned to saline. Each group received a median 1.9 l of fluid. The primary composite of major complications was observed in 5.8% of lactated Ringer's versus 6.1% of normal saline patients, with estimated average relative risk across the components of the composite of 1.16 (95% CI, 0.89 to 1.52; P = 0.261). The secondary outcome, postoperative acute kidney injury, Acute Kidney Injury Network stage I-III versus 0, occurred in 6.6% of lactated Ringer's patients versus 6.2% of normal saline patients, with an estimated relative risk of 1.18 (99.3% CI, 0.99 to 1.41; P = 0.009, significance criterion of 0.007). Absolute differences between the treatment groups for each outcome were less than 0.5%, an amount that is not clinically meaningful. CONCLUSIONS: In elective orthopedic and colorectal surgery patients, there was no clinically meaningful difference in postoperative complications with lactated Ringer's or saline volume replacement. Clinicians can reasonably use either solution intraoperatively.

McGrath Video Laryngoscope Versus Macintosh Direct Laryngoscopy for Intubation of Morbidly Obese Patients: A Randomized Trial.

BACKGROUND: Two-thirds of the US population is considered obese and about 8% morbidly obese. Obese patients may present a unique challenge to anesthesia clinicians in airway management. Videolaryngoscopes may provide better airway visualization, which theoretically improves intubation success. However, previous work in morbidly obese patients was limited. We therefore tested the primary hypothesis that the use of McGrath video laryngoscope improves visualization of the vocal cords versus Macintosh direct laryngoscopy (Teleflex, Morrisville, NC) in morbidly obese patients. METHODS: We enrolled 130 surgical patients, aged 18-99 years, with a body mass index ≥40 kg/m and American Society of Anaesthesiologists (ASA) physical status I-III. Patients were randomly allocated 1:1-stratified for patient's body mass index ≥50 kg/m-to McGrath video laryngoscope versus direct laryngoscopy with a Macintosh blade. The study groups were compared on glottis visualization, defined as improved Cormack and Lehane classification, with proportional odds logistic regression model. RESULTS: McGrath video laryngoscope provided significantly better glottis visualization than Macintosh direct laryngoscopy with an estimated odds ratio of 4.6 (95% confidence interval [CI], 2.2-9.8; P < .01). We did not observe any evidence that number of intubation attempts and failed intubations increased or decreased. CONCLUSIONS: McGrath video laryngoscope improves glottis visualization versus Macintosh direct laryngoscopy in morbidly obese patients. Large clinical trials are needed to determine whether improved airway visualization with videolaryngoscopy reduces intubation attempts and failures.

Predicting Right Ventricular Failure After LVAD Implantation: Role of Tricuspid Valve Annulus Displacement.

OBJECTIVES: Right ventricular failure after left ventricular assist device implantation increases postoperative morbidity and mortality. Whether intraoperative echocardiographic and hemodynamic measurements predict right ventricular failure is unclear. Speckle-tracking-derived tricuspid annulus displacement may provide a useful, effective, and straightforward predictor of severe right ventricular failure in patients having left ventricular device implantation. The aim of this study was to determine if intraoperative tricuspid annulus displacement is a stronger discriminator compared with the global longitudinal strain and modified tricuspid annular plane systolic excursion, the Michigan risk score, and pulmonary artery pulsatility index. DESIGN: Retrospective analysis. SETTING: A tertiary-care referral center. PARTICIPANTS: Patients scheduled for left ventricular assist device implantation from January 2010 to December 2017. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: The authors examined 86 patients undergoing left ventricular assist device implantation with adequate intraoperative echocardiographic images. The analyses did not demonstrate an association between tricuspid annulus displacement and severe right ventricular failure (univariate C-statistics <0.60 for all 4 echocardiographic measures). The discrimination ability was not significantly better than strain (DeLong test p = 0.44) and modified tricuspid annular plane systolic excursion (p = 0.89). The discrimination ability of tricuspid annulus displacement measurements was not better than the Michigan risk score (p = 0.65) and pulmonary artery pulsatility index (p = 0.73). CONCLUSIONS: Intraoperative echocardiographic parameters, including tricuspid annulus displacement, modified tricuspid annular plane systolic excursion, and strain, are poor discriminators of severe right ventricular failure after left ventricular assist device implantation. The preoperative Michigan risk-scoring system and intraoperative pulmonary artery pulsatility index are equally unreliable.

Effect of Intravenous Acetaminophen on Postoperative Hypoxemia After Abdominal Surgery: The FACTOR Randomized Clinical Trial.

Importance: Opioid-induced ventilatory depression and hypoxemia is common, severe, and often unrecognized in postoperative patients. To the extent that nonopioid analgesics reduce opioid consumption, they may decrease postoperative hypoxemia. Objective: To test the hypothesis that duration of hypoxemia is less in patients given intravenous acetaminophen than those given placebo. Design, Setting, and Participants: Randomized, placebo-controlled, double-blind trial conducted at 2 US academic hospitals among 570 patients who were undergoing abdominal surgery, enrolled from February 2015 through October 2018 and followed up until February 2019. Interventions: Participants were randomized to receive either intravenous acetaminophen, 1 g (n = 289), or normal saline placebo (n = 291) starting at the beginning of surgery and repeated every 6 hours until 48 postoperative hours or hospital discharge, whichever occurred first. Main Outcomes and Measures: The primary outcome was the total duration of hypoxemia (hemoglobin oxygen saturation [Spo2] <90%) per hour, with oxygen saturation measured continuously for 48 postoperative hours. Secondary outcomes were postoperative opioid consumption, pain (0- 10-point scale; 0: no pain; 10: the most pain imaginable), nausea and vomiting, sedation, minimal alveolar concentration of volatile anesthetic, fatigue, active time, and respiratory function. Results: Among 580 patients randomized (mean age, 49 years; 48% women), 570 (98%) completed the trial. The primary outcome, median duration with Spo2 of less than 90%, was 0.7 (interquartile range [IQR], 0.1-5.1) minutes per hour among patients in the acetaminophen group and 1.1 (IQR, 0.1-6.6) minutes per hour among patients in the placebo group (P = .29), with an estimated median difference of -0.04 (95% CI,-0.18 to 0.11) minutes per hour. None of the 8 secondary end points differed significantly between the acetaminophen and placebo groups. Mean pain scores within initial 48 postoperative hours were 4.2 (SD, 1.8) in the acetaminophen group and 4.4 (SD, 1.8) in the placebo group (difference, -0.28; 95% CI, -0.71 to 0.15); median opioid use in morphine equivalents was 50 mg (IQR, 18-122 mg) and 58 mg (IQR, 24-151 mg) , respectively, with a ratio of geometric means of 0.86 (95% CI, 0.61-1.21). Conclusions and Relevance: Among patients who underwent abdominal surgery, use of postoperative intravenous acetaminophen, compared with placebo, did not significantly reduce the duration of postoperative hypoxemia over 48 hours. The study findings do not support the use of intravenous acetaminophen for this purpose. Trial Registration: ClinicalTrials.gov Identifier: NCT02156154.

Vasopressor Infusion During Prone Spine Surgery and Acute Renal Injury: A Retrospective Cohort Analysis.

BACKGROUND: Hypotension is associated with acute kidney injury, but vasopressors used to treat hypotension may also compromise renal function. We therefore tested the hypothesis that vasopressor infusion during complex spine surgery is not associated with impaired renal function. METHODS: In this retrospective cohort analysis, we considered adults who had complex spine surgery between January 2005 and September 2014 at the Cleveland Clinic Main Campus. Our primary outcome was postoperative estimated glomerular filtration rate. Secondarily, we evaluated renal function using Acute Kidney Injury Network criteria. We obtained data for 1814 surgeries, including 689 patients (38%) who were given intraoperative vasopressors infusion for ≥30 minutes and 1125 patients (62%) who were not. Five hundred forty patients with and 540 patients without vasopressor infusions were well matched across 32 potential confounding variables. RESULTS: In matched patients, vasopressor infusions lasted an average of 173 ± 100 minutes (SD) and were given a median dose (1st quintile, 3rd quintile) of 3.4-mg (1.5, 6.7 mg) phenylephrine equivalents. Mean arterial pressure and the amounts of hypotension were similar in each matched group. The postoperative difference in mean estimated glomerular filtration rate in patients with and without vasopressor infusions was only 0.8 mL/min/1.73 m (95% CI, -0.6 to 2.2 mL/min/1.73 m) (P = .28). Intraoperative vasopressor infusion was also not associated with increased odds of augmented acute kidney injury stage. CONCLUSIONS: Clinicians should not avoid typical perioperative doses of vasopressors for fear of promoting kidney injury. Tolerating hypotension to avoid vasopressor use would probably be a poor strategy.

Methylprednisolone Does Not Reduce Acute Postoperative Pain After Cardiac Surgery: Subanalysis of a Randomized Clinical Trial.

BACKGROUND: Pain after cardiac surgery is largely treated with opioids, but their poor safety profile makes nonopioid medications attractive as part of multimodal pathways. Anti-inflammatory drugs reduce acute postoperative pain, but the role of steroids in reducing acute poststernotomy pain is unclear. We evaluated the association between the intraoperative administration of methylprednisolone and postoperative analgesia, defined as a composite of pain scores and opioid consumption, during the initial 24 hours after cardiac surgery. METHODS: We conducted a post hoc retrospective analysis of a large clinical trial in which adults having cardiac surgery were randomized 1:1 to receive 2 intraoperative doses of 250 mg IV methylprednisolone or placebo. Pain scores and opioid consumption were collected during the initial 24 hours after surgery. Methylprednisolone was considered to be associated with better pain control than placebo if proven noninferior (not worse) on both pain scores (defined a priori with delta of 1 point) and opioid consumption (delta of 20%) and superior to placebo in at least 1 of the 2 outcomes. This test was repeated in the opposite direction (testing whether placebo is better than methylprednisolone on postoperative pain management). RESULTS: Of 251 eligible patients, 127 received methylprednisolone and 124 received placebo. Methylprednisolone was noninferior to placebo on pain with difference in mean (CI) pain scores of -0.25 (-0.71 to 0.21); P < .001. However, methylprednisolone was not noninferior to placebo on opioid consumption (ratio of geometric means [CI]: 1.11 [0.64-1.91]; P = .37). Because methylprednisolone was not noninferior to placebo on both outcomes, we did not proceed to superiority testing based on the a priori stopping rules. Similar results were found when testing the opposite direction. CONCLUSIONS: In this post hoc analysis, we could not identify a beneficial analgesic effect after cardiac surgery associated with methylprednisolone administration. There are currently no data to suggest that methylprednisolone has significant analgesic benefit in adults having cardiac surgery.

Simulation Versus Problem Based Learning for Cerebrospinal Drainage Catheter Insertion and Management: A Randomized Trial in a Large Academic Anesthesiology Residency Program.

OBJECTIVE: Cerebrospinal fluid drainage catheter-related complications can be reduced by following strict guidelines during their introduction, maintenance, and removal. The authors therefore aimed to determine whether simulation-based learning would improve senior anesthesiology residents' patient care performance during the insertion and management of these catheters compared to interactive problem-based learning (PBL) using the Anaesthetists' Non-Technical Skills global rating scale (ANTS). DESIGN: Prospective randomized trial. SETTING: Vascular or hybrid operating rooms in a large academic tertiary care center. PARTICIPANTS: Senior anesthesia (categorical anesthesia-3) residents rotating through the vascular rotation at the Cleveland Clinic main campus in the period between December 2014 and June 2017. INTERVENTION: Simulation-based learning versus PBL. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the composite score (ANTS global rating scale) achieved by participating residents as evaluated by their supervising anesthesiologists. Out of 28 residents who completed the study, N = 13 were randomized to simulation-based learning and N = 15 residents to the PBL approach. The median (first quartile, third quartile) composite score was 16 (14, 16) and 16 (13, 16) for the simulation-based learning and PBL groups, respectively. There was no significant difference in staff evaluation of the 2 study groups (p = 0.48) with an estimated odds (95% confidence interval) of getting a better staff evaluation score of 1.9 (0.3-10.6) times higher comparing simulation versus traditional training groups. CONCLUSION: Compared to interactive PBL, simulation-based learning does not result in a statistically significant improvement in anesthesia resident performance during insertion and management of cerebrospinal fluid drainage catheters.

Heating and Cooling Rates With an Esophageal Heat Exchange System.

BACKGROUND: The Esophageal Cooling Device circulates warm or cool water through an esophageal heat exchanger, but warming and cooling efficacy in patients remains unknown. We therefore determined heat exchange rates during warming and cooling. METHODS: Nineteen patients completed the trial. All had general endotracheal anesthesia for nonthoracic surgery. Intraoperative heat transfer was measured during cooling (exchanger fluid at 7°C) and warming (fluid at 42°C). Each was evaluated for 30 minutes, with the initial condition determined randomly, starting at least 40 minutes after induction of anesthesia. Heat transfer rate was estimated from fluid flow through the esophageal heat exchanger and inflow and outflow temperatures. Core temperature was estimated from a zero-heat-flux thermometer positioned on the forehead. RESULTS: Mean heat transfer rate during warming was 18 (95% confidence interval, 16-20) W, which increased core temperature at a rate of 0.5°C/h ± 0.6°C/h (mean ± standard deviation). During cooling, mean heat transfer rate was -53 (-59 to -48) W, which decreased core temperature at a rate of 0.9°C/h ± 0.9°C/h. CONCLUSIONS: Esophageal warming transferred 18 W which is considerably less than the 80 W reported with lower or upper body forced-air covers. However, esophageal warming can be used to supplement surface warming or provide warming in cases not amenable to surface warming. Esophageal cooling transferred more than twice as much heat as warming, consequent to the much larger difference between core and circulating fluid temperature with cooling (29°C) than warming (6°C). Esophageal cooling extracts less heat than endovascular catheters but can be used to supplement catheter-based cooling or possibly replace them in appropriate patients.

Postoperative Hypotension and Surgical Site Infections After Colorectal Surgery: A Retrospective Cohort Study.

BACKGROUND: Hypotension compromises local tissue perfusion, thereby reducing tissue oxygenation. Hypotension might thus be expected to promote infection. Hypotension on surgical wards, while usually less severe than intraoperative hypotension, is common and often prolonged. In this retrospective cohort study, we tested the hypotheses that there is an association between surgical site infections and low postoperative time-weighted average mean arterial pressure and/or postoperative minimum mean arterial pressure. METHODS: We considered patients who had colorectal surgery lasting ≥1 hour at the Cleveland Clinic between 2009 and 2013. We defined blood pressure exposures as time-weighted average (primary) and minimum mean arterial pressure (secondary) within 72 hours after surgery. We assessed associations between continuous blood pressure exposures with a composite of deep and superficial surgical site infection using separate severity-weighted average relative effect generalized estimating equations models, each using an unstructured correlation structure and adjusting for potentially confounding variables. RESULTS: A total of 5896 patients were eligible for analysis. Time-weighted mean arterial pressure and surgical site infection were not significantly associated, with an estimated odds ratio (95% CI) of 1.03 (0.99-1.08) for a 5-mm Hg decrease (P = .16). However, there was a significant inverse association between minimum postoperative mean arterial pressure and infection, with an estimated odds ratio of 1.08 (1.03-1.12) per 5-mm Hg decrease (P = .001). CONCLUSIONS: Postoperative time-weighted mean arterial pressure was not associated with surgical site infection, but lowest postoperative mean arterial pressure was. Whether the relationship is causal remains to be determined.

A Randomized Trial of Continuous Noninvasive Blood Pressure Monitoring During Noncardiac Surgery.

BACKGROUND: Intraoperative hypotension is associated with postoperative mortality. Early detection of hypotension by continuous hemodynamic monitoring might prompt timely therapy, thereby reducing intraoperative hypotension. We tested the hypothesis that continuous noninvasive blood pressure monitoring reduces intraoperative hypotension. METHODS: Patients ≥45 years old with American Society of Anesthesiologists physical status III or IV having moderate-to-high-risk noncardiac surgery with general anesthesia were included. All participating patients had continuous noninvasive hemodynamic monitoring using a finger cuff (ClearSight, Edwards Lifesciences, Irvine, CA) and a standard oscillometric cuff. In half the patients, randomly assigned, clinicians were blinded to the continuous values, whereas the others (unblinded) had access to continuous blood pressure readings. Continuous pressures in both groups were used for analysis. Time-weighted average for mean arterial pressure <65 mm Hg was compared using 2-sample Wilcoxon rank-sum tests and Hodges Lehmann estimation of location shift with corresponding asymptotic 95% CI. RESULTS: Among 320 randomized patients, 316 were included in the intention-to-treat analysis. With 158 patients in each group, those assigned to continuous blood pressure monitoring had significantly lower time-weighted average mean arterial pressure <65 mm Hg, 0.05 [0.00, 0.22] mm Hg, versus intermittent blood pressure monitoring, 0.11 [0.00, 0.54] mm Hg (P = .039, significance criteria P < .048). CONCLUSIONS: Continuous noninvasive hemodynamic monitoring nearly halved the amount of intraoperative hypotension. Hypotension reduction with continuous monitoring, while statistically significant, is currently of uncertain clinical importance.

Brachial Arterial Pressure Monitoring during Cardiac Surgery Rarely Causes Complications.

BACKGROUND: Brachial arterial catheters better estimate aortic pressure than radial arterial catheters but are used infrequently because complications in a major artery without collateral flow are potentially serious. However, the extent to which brachial artery cannulation promotes complications remains unknown. The authors thus evaluated a large cohort of cardiac surgical patients to estimate the incidence of related serious complications. METHODS: The institutional Society of Thoracic Surgeons Adult Cardiac Surgery Database and Perioperative Health Documentation System Registry of the Cleveland Clinic were used to identify patients who had brachial artery cannulation between 2007 and 2015. Complications within 6 months after surgery were identified by International Classification of Diseases, Ninth Revision diagnostic and procedural codes, Current Procedural Terminology procedure codes, and Society of Thoracic Surgeons variables. The authors reviewed electronic medical records to confirm that putative complications were related plausibly to brachial arterial catheterization. Complications were categorized as (1) vascular, (2) peripheral nerve injury, or (3) infection. The authors evaluated associations between brachial arterial complications and patient comorbidities and between complications and in-hospital mortality and duration of hospitalization. RESULTS: Among 21,597 qualifying patients, 777 had vascular or nerve injuries or local infections, but only 41 (incidence 0.19% [95% CI, 0.14 to 0.26%]) were potentially consequent to brachial arterial cannulation. Vascular complications occurred in 33 patients (0.15% [0.10 to 0.23%]). Definitely or possibly related infection occurred in 8 (0.04% [0.02 to 0.08%]) patients. There were no plausibly related neurologic complications. Peripheral arterial disease was associated with increased risk of complications. Brachial catheter complications were associated with prolonged hospitalization and in-hospital mortality. CONCLUSIONS: Brachial artery cannulation for hemodynamic monitoring during cardiac surgery rarely causes complications.

Lack of Association between Blood Pressure Management by Anesthesia Residents and Competence Committee Evaluations or In-training Exam Performance: A Cohort Analysis.

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.

Long-Acting Patient-Controlled Opioids Are Not Associated With More Postoperative Hypoxemia Than Short-Acting Patient-Controlled Opioids After Noncardiac Surgery: A Cohort Analysis.

BACKGROUND: Opioids can contribute to postoperative desaturation. Short-acting opioids, titrated to need, may cause less desaturation than longer-acting opioids. We thus tested the primary hypothesis that long-acting patient-controlled intravenous opioids are associated with more hypoxemia (defined as an integrated area under a postoperative oxyhemoglobin saturation of 95%) than short-acting opioids. METHODS: This analysis was a substudy of VISION, a prospective cohort study focused on perioperative cardiovascular events (NCT00512109). After excluding for predefined criteria, 191 patients were included in our final analysis, with 75 (39%) patients being given fentanyl (short-acting opioid group) and 116 (61%) patients being given morphine and/or hydromorphone (long-acting opioid group). The difference in the median areas under a postoperative oxyhemoglobin saturation of 95% between short-acting and long-acting opioids was compared using multivariable median quantile regression. RESULTS: The short-acting opioid median area under a postoperative oxyhemoglobin saturation of 95% per hour was 1.08 (q1, q3: 0.62, 2.26) %-h, whereas the long-acting opioid median was 1.28 (0.50, 2.23) %-h. No significant association was detected between long-acting and short-acting opioids and median area under a postoperative oxyhemoglobin saturation of 95% per hour (P = .66) with estimated change in the medians of -0.14 (95% CI, -0.75, 0.47) %-h for the patients given long-acting versus short-acting IV patient-controlled analgesia opioids. CONCLUSIONS: Long-acting patient-controlled opioids were not associated with the increased hypoxemia during the first 2 postoperative days.

The Association Between Rheumatoid Arthritis and Adverse Postoperative Outcomes: A Retrospective Analysis.

BACKGROUND: Patients with rheumatoid arthritis have a high overall incidence of mortality, primarily because of cardiovascular complications. Thus, we tested the primary hypothesis that rheumatoid arthritis is independently associated with increased postoperative cardiovascular complications. Second, we determined whether rheumatoid arthritis is associated with increased thromboembolic complications, microcirculatory complications, and mortality. METHODS: We obtained censuses of 2009 to 2010 inpatient hospital discharge data across 7 states (Arizona, California, Florida, Iowa, Maryland, Michigan, and New Jersey). Rheumatoid arthritis was identified using the present-on-admission diagnosis code 714.0. Each rheumatoid arthritis discharge that had surgery was propensity matched to a control discharge. Multivariable logistic regression was used to compare matched rheumatoid arthritis and control patients on risk of in-hospital cardiovascular complications. RESULTS: Among 5.5 million qualifying discharges, the matching procedure yielded successful 66,886 matched pairs. One thousand ninety-five (1.64%) of the matched rheumatoid arthritis discharges and 1006 (1.50%) of the matched controls had in-hospital cardiovascular complications. The adjusted odds ratio (99% confidence interval) was estimated at 1.08 (0.96-1.21; P = 0.08). There were no significant differences in the odds of in-hospital thromboembolic complications (1.03 [0.93-1.15]; P = 0.42), in-hospital microcirculatory complications (0.94 [0.86-1.01]; P = 0.03), or in-hospital mortality (1.11 [0.98-1.25]; P = 0.04). CONCLUSIONS: Rheumatoid arthritis was not associated with an increased risk for postoperative cardiovascular complications.

Etomidate and the Risk of Complications After Cardiac Surgery: A Retrospective Cohort Analysis.

OBJECTIVE: To compare incidence of atrial arrhythmia, duration of care, and major complications after cardiac surgery between patients who received etomidate and those who received other induction agents. DESIGN: Retrospective cohort study utilizing propensity score matching. SETTING: A single academic, tertiary care hospital. PARTICIPANTS: Eight thousand nine hundred seventy-eight patients undergoing coronary artery bypass grafting (CABG), valve, or combined valve/CABG surgery requiring cardiopulmonary bypass between January 2005 and December 2010. INTERVENTIONS: Patients were divided into those who received etomidate at anesthetic induction and those who received another induction agent. Patients given etomidate were propensity-score matched to patients given other induction agents in a 2:1 ratio. MEASUREMENTS AND MAIN RESULTS: Of 8,978 patients who underwent CABG, valve, or combined valve/surgery, 6,313 received etomidate and 2,665 received other induction agents. Among these, the authors successfully matched 4,094 etomidate patients with 2,524 non-etomidate patients. The authors did not find a significant association between receiving etomidate and odds of experiencing postoperative atrial arrhythmia (odds ratio [98.3% confidence interval] of 1.07 [0.92, 1.23], p = 0.29). Etomidate was not associated significantly with either intensive care unit or hospital stay. Etomidate was associated significantly with use of packed red blood cells (odds ratio [99.6% confidence interval] of 1.32 [1.02, 1.70], p = 0.002), but not with use of fresh frozen plasma, platelets, or cryoprecipitate. None of the other complications differed significantly between the groups. CONCLUSIONS: Etomidate was not associated with increased incidence of postoperative atrial arrhythmia or increased intensive care unit or hospital stay.