Emine O. Bayman

Are anesthesia and surgery during infancy associated with altered academic performance during childhood

Background: Although studies in neonatal animals show that anesthetics have neurotoxic effects, relevant human evidence is limited. We examined whether children who had surgery during infancy showed deficits in academic achievement. Methods: We attempted to contact parents of 577 children who, during infancy, had one of three operations typically performed in otherwise healthy children. We compared scores on academic achievement tests with population norms. Results: Composite scores were available for 287 patients. The mean normal curve equivalent score was 43.0 ± 22.4 (mean ± SD), lower than the expected normative value of 50, P < 0.0001 by one-sample Student t test; and 35 (12%) had scores below the 5th percentile, more than expected, P < 0.00001 by binomial test. Of 133 patients who consented to participate so that their scores could be examined in relation to their medical records, the mean score was 45.9 ± 22.9, P = 0.0411; and 15 (11%) scored below the 5th percentile, P = 0.0039. Of 58 patients whose medical records showed no central nervous system problems/potential risk factors during infancy, 8 (14%) scored below the 5th percentile, P = 0.008; however, the mean score, 47.6 ± 23.4, was not significantly lower than expected, P = 0.441. Duration of anesthesia and surgery correlated negatively with scores (r = −0.34, N = 58, P = 0.0101). Conclusions: Although the findings are consistent with possible adverse effects of anesthesia and surgery during infancy on subsequent academic achievement, other explanations are possible and further investigations are needed.

Statistical Modeling of Average and Variability of Time to Extubation for Meta-analysis Comparing Desflurane to Sevoflurane

BACKGROUND: The recovery profile of an ideal anesthetic or technique would be fast (e.g., mean of 5 min from end of surgery to extubation) with little variability (e.g., always 4–7 min). We used anesthesia information management system (AIMS) data to learn how to model the time from end of surgery to extubation. We applied that knowledge for meta-analyses of trials comparing extubation times after use of desflurane and sevoflurane. METHODS: AIMS data studied were 32,792 cases performed by 95 surgeons that included tracheal intubation and extubation in the operating room (OR) and use of volatile anesthetic(s). Meta-analysis included the 29 randomized controlled trials through 2008 comparing extubation times with desflurane and sevoflurane. Percentage differences in means and standard deviations were studied using random effects meta-analysis and a Bayesian method. RESULTS: Times to extubation were better fit by (skewed) Weibull distributions than by (symmetric) normal distributions. Drug choice had nearly equally proportional effects on the means and standard deviations of extubation times, as shown by unchanged coefficients of variation (P > 0.10 for 26 of 29 studies) and nonsignificant pooled difference in the coefficient of variation (sevoflurane − desflurane = −1%, 95% confidence interval [CI] −3% to 1%, P = 0.22). Applying these findings, desflurane reduced the mean extubation time by 25% (95% CI 17%–32%, P < 0.0001) and standard deviation by 21% (95% CI 16%–26%). To value the intangible costs (e.g., frustrated waiting surgeons) of prolonged extubation times, we considered the 15% of AIMS cases with times >15 min. These cases averaged 4.9 min longer times from out of the OR to the start of surgery of the surgeons next case (95% CI 2.7–7.1 min, P < 0.0001). Reduction in the means and standard deviations by 20%–25% would likely reduce incidences of these prolonged extubation times by 71%–82% (95% CI 68%–84%). CONCLUSIONS: Desflurane reduces the average extubation time and the variability of extubation time by 20%–25% relative to sevoflurane. The principal economic value of these end points is their reductions of direct (labor) costs of OR time. However, reductions in intangible costs of prolonged extubation are real, being associated with subsequent delays. Reductions in the average and variance of times to extubation can be interpreted and monitored in terms of corresponding expected 75% reductions in the incidences of prolonged extubation times by using desflurane relative to sevoflurane.

Association Between Postoperative Acute Kidney Injury and Duration of Cardiopulmonary Bypass: A Meta-Analysis

OBJECTIVE This meta-analysis examined the association between cardiopulmonary bypass (CPB) time and acute kidney injury (AKI). DESIGN Meta-analysis of previously published studies. SETTING Each single-center study was conducted in a surgical intensive care unit and/or academic or university hospital. PARTICIPANTS Adult patients undergoing heart surgery with CPB. INTERVENTIONS A systematic literature review was conducted using PubMed, EMBASE, and Cochrane Library databases and Google Scholar from January 1980 through September 2009. Initial search results were refined to include human subjects, age >18 years, randomized controlled trials, and prospective and retrospective cohort studies, meet the Acute Kidney Injury Network definition of renal failure, and report times on CPB. MEASUREMENTS AND MAIN RESULTS The length of time on CPB has been implicated as an independent risk factor for development of AKI after CPB (AKI-CPB). The 9 independent studies included in the final meta-analysis had 12,466 patients who underwent CPB. Out of these, 756 patients (6.06%) developed AKI-CPB. In 7 of the 9 studies, the mean CPB times were statistically longer in the AKI-CPB cohort compared with the control group (cohort without AKI). The absolute mean differences in CPB time between the 2 groups were 25.65 minutes with the fixed-effects model and 23.18 minutes with the random-effects model. CONCLUSIONS Longer CPB times are associated with a higher risk of developing AKI-CPB, which, in turn, has a significant effect on overall mortality as reported by the individual studies.

Independent Associations Between Electrocardiographic Abnormalities and Outcomes in Patients With Aneurysmal Subarachnoid Hemorrhage: Findings From the Intraoperative Hypothermia Aneurysm Surgery Trial

Background and Purpose— Electrocardiographic abnormalities are common after subarachnoid hemorrhage, but their significance remains uncertain. The aim of this study was to determine whether any specific electrocardiographic abnormalities are independently associated with adverse neurological outcomes. Methods— This was a substudy of the Intraoperative Hypothermia Aneurysm Surgery Trial, which was designed to determine whether intraoperative hypothermia would improve neurological outcome in patients with subarachnoid hemorrhage undergoing aneurysm surgery. The outcome was the 3-month Glasgow Outcome Score treated as both a categorical measure (Glasgow Outcome Score 1 [good outcome] to 5 [death]) and dichotomously (mortality/Glasgow Outcome Score 5 versus Glasgow Outcome Score 1 to 4). The predictor variables were preoperative electrocardiographic characteristics, including heart rate, corrected QT interval, and ST- and T-wave abnormalities. Univariate logistic regression was performed to screen for significant electrocardiographic variables, which were then tested for associations with the outcome by multivariate logistic regression adjusting for clinical covariates. Results— The study included 588 patients, of whom 31 (5%) died. There was a significant, nonlinear association between heart rate and mortality such that lowest quartile (≤60 beats/min; OR, 6.5; P=0.027) and highest quartile (>80 beats/min; OR, 8.8; P=0.006) were associated with higher risk. There was also a significant association between nonspecific ST- and T-wave abnormalities and mortality (OR, 3.1; P=0.031). Conclusions— Bradycardia, relative tachycardia, and nonspecific ST- and T-wave abnormalities are strongly and independently associated with 3-month mortality after subarachnoid hemorrhage. Further research should be performed to determine whether there is a causal relationship between cardiac dysfunction and neurological outcome after subarachnoid hemorrhage.

Sexual problems in male ankylosing spondylitis patients: relationship with functionality, disease activity, quality of life, and emotional status

This study has focused on sexual problems of male ankylosing spondylitis (AS) patients. Initially, patients’ perceptions about the effects of disease on sexual intercourse were assessed. Secondly, we investigated the factors that relate to the disease and affect sexual intercourse negatively. Thirdly, we compared data from the patients whose sexual intercourse were affected negatively with of those whose sexual intercourse were unaffected. This is a cross-sectional and double-centered study. A total of 53 married or sexually active male patients, who were certainly diagnosed with AS according to modified New York criteria, were assessed. Twenty seven patients (50.94%) expressed that their sexual life was affected negatively by the AS in general (affected patients), and 26 patients (49.06%) expressed no negative effect (unaffected patients). Both affected and unaffected patients were compared with each other with regard to educational level, joint involvement, functionality, disease activity, quality of life, and depression status. Mean BASFI, BASDAI scores were worse in the affected group, and the difference was statistically significant (p = 0.012, p = 0.039, respectively). There were statistically significant differences between the groups with regard to lumbar column and hip involvement (p = 0.035, p = 0.021; respectively). The physical functioning, role limitations due to physical problems, vitality/energy/fatigue, general mental health, and general health perception subscale scores of SF-36 were worse in the affected group, and the differences were statistically significant (p = 0.027, p = 0.023, p = 0,013, p = 0.005, p = 0.045, respectively). Affected patients’ Beck Depression Inventory scores were worse than those of unaffected patients, and the difference between the groups was statistically significant (p = 0.039). Sexual problems are common in AS patients and might usually be associated with joint involvement, decreased functionality, increased disease activity, decreased health quality, and depression. Therefore, while examining AS patients and managing their treatments, special attention must be given to all domains of life instead of only physical problems.

Meta-analysis of average and variability of time to extubation comparing isoflurane with desflurane or isoflurane with sevoflurane.

BACKGROUND: We recently determined how to use anesthesia information management system data to model the time from end of surgery to extubation. We applied that knowledge for meta-analyses of trials comparing extubation times after maintenance with desflurane and sevoflurane. In this study, we repeated the meta-analyses to compare isoflurane with desflurane and sevoflurane. METHODS: A Medline search through December 2009 was used to identify studies with (1) humans randomly assigned to isoflurane or desflurane groups without other differences (e.g., induction drugs) between groups, and (2) mean and SD reported for extubation time and/or time to follow commands. The search was repeated for random assignment to isoflurane or sevoflurane groups. We considered extubation times >15 minutes (representing 15% of cases in the anesthesia information management system data) to be prolonged. RESULTS: Desflurane reduced the mean extubation time by 34% and reduced the variability in extubation time by 36% relative to isoflurane. These reductions would reduce the incidence of prolonged extubation times by 95% and 97%, respectively. Sevoflurane reduced the mean extubation time by 13% and reduced the SD by 8.7% relative to isoflurane. These reductions would reduce the incidence of prolonged extubation times by 51% and 35%, respectively. CONCLUSIONS: The pharmacoeconomics of volatile anesthetics are highly sensitive to measurement of relatively small time differences. Therefore, surgical facilities should use these values combined with their local data (e.g., mean baseline extubation times) when making evidence-based management decisions regarding pharmaceutical purchases and usage guidelines.

Incidence and Severity of Chronic Pain at 3 and 6 Months After Thoracotomy: Meta-Analysis

UNLABELLED This systematic review was performed to determine the incidence and the severity of chronic pain at 3 and 6 months after thoracotomy based on meta-analyses. We conducted MEDLINE, Web of Science, and Google Scholar searches of databases and references for English articles; 858 articles were reviewed. Meta-regression analysis based on the publication year was used to examine if the chronic pain rates changed over time. Event rates and confidence intervals with random effect models and Freeman-Tukey double arcsine variance-stabilizing transformation were obtained separately for the incidence of chronic pain based on 1,439 patients from 17 studies at 3 months and 1,354 patients from 15 studies at 6 months. The incidences of chronic pain at 3 and 6 months after thoracotomy were 57% (95% confidence interval [CI], 51-64%) and 47% (95% CI, 39-56%), respectively. The average severity of pain ratings on a 0 to 100 scale at these times were 30 ± 2 (95% CI, 26-35) and 32 ± 7 (95% CI, 17-46), respectively. Reported chronic pain rates have been largely stable at both 3 and 6 months from the 1990s to the present. PERSPECTIVE This systematic reviews findings suggest that reported chronic pain rates are approximately 50% at 3 and 6 months and have been largely stable from the 1990s to the present. The severity of this pain is not consistently reported. Chronic pain after thoracotomy continues to be a significant problem despite advancing perioperative care.

Estimating surgical case durations and making comparisons among facilities: identifying facilities with lower anesthesia professional fees.

Consumer-driven health care relies on transparency in cost estimates for surgery, including anesthesia professional fees. Using systematic narrative review, we show that providing anesthesia costs requires that each facility (anesthesia group) estimate statistics, reasonably the mean and the 90% upper prediction limit of case durations by procedure. The prediction limits need to be calculated, for many procedures, using Bayesian methods based on the log-normal distribution. Insurers and/or governments lack scheduled durations and procedures and cannot practically infer these estimates because of the large heterogeneities among facilities in the means and coefficients of variation of durations. Consequently, the insurance industry cannot provide the cost information accurately from public and private databases. Instead, the role of insurers and/or governments can be to identify facilities with significantly briefer durations (costs to the patient) than average. Such comparisons of durations among facilities should be performed with correction for the effects of the multiple comparisons. Our review also has direct implications to the potentially more important issue of how to study the association between anesthetic durations and patient morbidity and mortality. When pooling duration data among facilities, both the large heterogeneity in the means and coefficients of variation of durations among facilities need to be considered (e.g., using “multilevel” or “hierarchical” models).

Effect of Nitrous Oxide on Neurologic and Neuropsychological Function after Intracranial Aneurysm Surgery

Background:Laboratory studies suggest that nitrous oxide augments brain injury after ischemia or hypoxia. The authors examined the relation between nitrous oxide use and outcomes using data from the Intraoperative Hypothermia for Aneurysm Surgery Trial. Methods:The Intraoperative Hypothermia for Aneurysm Surgery Trial was a prospective randomized study of the impact of intraoperative hypothermia (temperature = 33°C) versus normothermia (temperature = 36.5°C) in patients with aneurysmal subarachnoid hemorrhage undergoing surgical clipping. Anesthesia was dictated by a limited-options protocol with the use of nitrous oxide determined by individual anesthesiologists. All patients were assessed daily for 14 days after surgery or until hospital discharge. Neurologic and neuropsychological testing were conducted at 3 months after surgery. Outcome data were analyzed via both univariate tests and multivariate logistic regression analysis correcting for factors thought to influence outcome. An odds ratio (OR) greater than 1.0 denotes a worse outcome in patients receiving nitrous oxide. Results:Outcome data were available for 1,000 patients, of which 373 received nitrous oxide. There was no difference between groups in the development of delayed ischemic neurologic deficit. At 3 months after surgery, there were no significant differences between groups in any outcome variable: Glasgow Outcome Score (OR, 0.84; 95% confidence interval [CI], 0.63–1.14; P = 0.268), National Institutes of Health Stroke Scale (OR, 1.29; 95% CI, 0.96–1.73; P = 0.087), Rankin Disability Score (OR, 0.84; 95% CI, 0.61–1.15; P = 0.284), Barthel Activities of Daily Living Index (OR, 1.01; 95% CI, 0.68–1.51; P = 0.961), or neuropsychological testing (OR, 1.26; 95% CI, 0.85–1.87; P = 0.252). Conclusions:In a population of patients at risk for ischemic brain injury, nitrous oxide use had no overall beneficial or detrimental impact on neurologic or neuropsychological outcomes.

First-Attempt Intubation Success of Video Laryngoscopy in Patients with Anticipated Difficult Direct Laryngoscopy: A Multicenter Randomized Controlled Trial Comparing the C-MAC D-Blade Versus the GlideScope in a Mixed Provider and Diverse Patient Population

BACKGROUND:Intubation success in patients with predicted difficult airways is improved by video laryngoscopy. In particular, acute-angle video laryngoscopes are now frequently chosen for endotracheal intubation in these patients. However, there is no evidence concerning whether different acute-angle video laryngoscopes can be used interchangeably in this scenario and would allow endotracheal intubation with the same success rate. We therefore tested whether first-attempt intubation success is similar when using a newly introduced acute-angle blade, that is an element of an extended airway management system (C-MAC D-Blade) compared with a well-established acute-angle video laryngoscope (GlideScope). METHODS:In this large multicentered prospective randomized controlled noninferiority trial, patients requiring general anesthesia for elective surgery and presenting with clinical predictors of difficult laryngoscopy were randomly assigned to intubation using either the C-MAC D-Blade or the GlideScope video laryngoscope. The hypothesis was that first-attempt intubation success using the new device (D-Blade) is no >4% less than the established device (GlideScope), which would determine noninferiority of the new instrument versus the established instrument. The secondary outcomes we observed included intubation success with multiple attempts and airway-related complications within 7 days of enrollment. RESULTS:Eleven hundred patients were randomly assigned to either video laryngoscope. Intubation success rate on first attempt was 96.2% in the GlideScope group and 93.4% in the C-MAC D-Blade group. Although the absolute difference between the 2 groups was only 2.8%, the 90.35% upper confidence limit of the difference exceeded the predefined margin (4.98%), indicating a rejection of the noninferiority hypothesis for first-attempt intubation success. For attending anesthesiologists, and upon multiple attempts, intubation success did not differ between systems. Pharyngeal injury was noted in 1% of the patients, and the incidence did not differ between interventional groups. CONCLUSIONS:Head-to-head comparison in this large multicenter trial revealed that the newly introduced C-MAC D-Blade does not yield the same first-attempt intubation success as the GlideScope in patients with predicted difficult laryngoscopy except in the hands of attending anesthesiologists. Additional research would be necessary to identify potential causes for this difference. Intubation success rates were very high with both systems, indicating that acute-angle video laryngoscopy is an exceptionally successful strategy for the initial approach to endotracheal intubation in patients with predicted difficult laryngoscopy.