Factors Associated with Prolonged Extubation after Total Intravenous Anesthesia in Patients Undergoing Vestibular Schwannoma Resection

Economic impact of prolonged tracheal extubation times on operating room time overall and for subgroups of surgeons: a historical cohort study

BACKGROUND

Prolonged tracheal extubation time is defined as an interval ≥ 15 min from the end of surgery to extubation. An earlier study showed that prolonged extubations had a mean 12.4 min longer time from the end of surgery to operating room (OR) exit. Prolonged extubations usually (57%) were observed during OR days with > 8 h of cases and turnovers, such that longer OR times from prolonged extubation can be treated as a variable cost (i.e., each added minute incurs an expense). The current study addressed limitations of the generalizability of these earlier investigations.

METHODS

The retrospective cohort study included cases performed at a university hospital October 2011 through June 2023 with general anesthesia, tracheal intubation and extubation in the OR where the anesthetic was performed, and non-prone positioning. The primary endpoint was the interval from end of surgery to OR exit. Mean OR time differences with/without prolonged extubation were analyzed pairwise by surgeon. The variance among surgeons was estimated using the DerSimonian-Laird method with Knapp-Hartung adjustment for the sample sizes of surgeons. Proportions were analyzed after arcsine transformation, and the inverse taken to report results.

RESULTS

There were prolonged extubations for 23% (41,768/182,374) of cases. Prolonged extubations had a mean 13.3 min longer time from the end of surgery to OR exit (95% confidence interval 12.8-13.7 min, P < 0.0001). That result was among the 71 surgeons each with ≥ 9 cases having prolonged extubation times and ≥ 9 cases with typical extubation times. Results were similar using a threshold of ≥ 3 cases, comprising 257 surgeons (13.2 min, P < 0.0001). Among the 71 surgeons with at least nine prolonged extubations, on most days with a prolonged extubation during at least one of their cases, there were > 8 h of cases and turnover times in the OR (77%, 73%-81%, P < 0.0001). Results were similar when analyzed for the 249 surgeons each with ≥ 3 cases with prolonged extubation (76%, P < 0.0001).

CONCLUSIONS

Matching earlier findings, prolonged tracheal extubation times are important economically, increasing OR time by 13 min and usually performed in ORs with lists of cases of sufficient duration to treat the extra time as a variable cost.

Lack of Validity of Absolute Percentage Errors in Estimated Operating Room Case Durations as a Measure of Operating Room Performance: A Focused Narrative Review

Commonly reported end points for operating room (OR) and surgical scheduling performance are the percentages of estimated OR times whose absolute values differ from the actual OR times by ≥15%, or by various intervals from ≥5 to ≥60 minutes. We show that these metrics are invalid assessments of OR performance. Specifically, from 19 relevant articles, multiple OR management decisions that would increase OR efficiency or productivity would also increase the absolute percentage error of the estimated case durations. Instead, OR managers should check the mean bias of estimated OR times (ie, systematic underestimation or overestimation), a valid and reliable metric.

Effects of intraoperative low-dose esketamine on postoperative pain after vestibular schwannoma resection: A prospective randomized, double-blind, placebo-controlled study

AIMS

Esketamine may reduce acute postoperative pain in several settings. However, the effects of low-dose esketamine on postoperative pain after vestibular schwannoma (VS) resection with propofol/remifentanil total intravenous anaesthesia (TIVA) are unclear. The aim of this study is to observe the effects of intraoperative low-dose esketamine on postoperative pain after vestibular schwannoma resection.

METHODS

This single-centre, randomized, placebo-controlled, double-blind trial included 90 adults undergoing VS resection via the retrosigmoid approach with TIVA. The patients were randomly allocated to two groups: esketamine or control (n = 45 in each group). Patients received low-dose esketamine (0.2 mg/kg) or a similar volume of normal saline after dural closure. The primary outcome was the pain score during movement (gentle head movement) at 24 h postoperatively. Secondary outcomes included recovery time, bispectral index (BIS) values and haemodynamic profiles during the first 30 min after esketamine administration, and adverse effects.

RESULTS

Low-dose esketamine did not reduce pain scores at rest (P > .05) or with movement (P > .05) within the first 24 h after surgery. Esketamine moderately increased BIS values for at least 30 min after administration (P < .0001) but did not affect heart rate (P = .992) or mean arterial blood pressure (P = .994). Esketamine prolonged extubation time (P = .042, 95% confidence interval: 0.08 to 4.42) and decreased the effect-site concentration of remifentanil at extubation (P = .001, 95% confidence interval: -0.53 to -0.15) but did not affect the time to resumption of spatial orientation. Postoperative nausea and vomiting rates did not differ between groups, and no hallucinations or excessive sedation was observed.

CONCLUSION

Intraoperative low-dose esketamine did not significantly reduce acute pain after VS resection with propofol/remifentanil TIVA. However, BIS values increased for at least 30 min after esketamine administration.

Inhalational Agent Dosing Behaviors of Anesthesia Practitioners Cause Variability in End-Tidal Concentrations at the End of Surgery and Prolonged Times to Tracheal Extubation

INTRODUCTION

Prolonged times to tracheal extubation are intervals from the end of surgery to extubation ≥15 minutes. We examined why there are associations with the end-tidal inhalational agent concentration as a proportion of the age‑adjusted minimum alveolar concentration (MAC fraction) at the end of surgery.

METHODS

The retrospective cohort study used 11.7 years of data from one hospital. All p‑values were adjusted for multiple comparisons.

RESULTS

There was a greater odds of prolonged time to extubation if the anesthesia practitioner was a trainee (odds ratio 1.68) or had finished fewer than five cases with the surgeon during the preceding three years (odds ratio 1.12) (both P<0.0001). There was a greater risk of prolonged time to extubation if the MAC fraction was >0.4 at the end of surgery (odds ratio 2.66, P<0.0001). Anesthesia practitioners who were trainees and all practitioners who had finished fewer than five cases with the surgeon had greater mean MAC fractions at the end of surgery and had greater relative risks of the MAC fraction >0.4 at the end of surgery (all P<0.0001). The source for greater MAC fractions at the end of surgery was not greater MAC fractions throughout the anesthetic because the means during the case did not differ among groups. Rather, there was substantial variability of MAC fractions at the end of surgery among cases of the same anesthesia practitioner, with the mean (standard deviation) among practitioners of each practitioner's standard deviation being 0.35 (0.05) and the coefficient of variation being 71% (13%).

CONCLUSION

More prolonged extubations were associated with greater MAC fractions at the end of surgery. The cause of the large MAC fractions was the substantial variability of MAC fractions among cases of each practitioner at the end of surgery. That variability matches what was expected from earlier studies, both from variability among practitioners in their goals for the MAC fraction given at the start of surgical closure and from inadequate dynamic forecasting of the timing of when surgery would end. Future studies should examine how best to reduce prolonged extubations by using anesthesia machines' display of MAC fraction and feedback control of end-tidal agent concentration.

Narrative Review of Prolonged Times to Tracheal Extubation After General Anesthesia With Intubation and Extubation in the Operating Room

This narrative review summarizes research about prolonged times to tracheal extubation after general anesthesia with both intubation and extubation occurring in the operating room or other anesthetizing location where the anesthetic was performed. The literature search was current through May 2023 and included prolonged extubations defined either as >15 minutes or at least 15 minutes. The studies showed that prolonged times to extubation can be measured accurately, are associated with reintubations and respiratory treatments, are rated poorly by anesthesiologists, are treated with flumazenil and naloxone, are associated with impaired operating room workflow, are associated with longer operating room times, are associated with tardiness of starts of to-follow cases and surgeons, and are associated with longer duration workdays. When observing prolonged extubations among all patients receiving general anesthesia, covariates accounting for most prolonged extubations are characteristics of the surgery, positioning, and anesthesia provider's familiarity with the surgeon. Anesthetic drugs and delivery systems routinely achieve substantial differences in the incidences of prolonged extubations. Occasional claims made that anesthesia drugs have unimportant differences in recovery times, based on medians and means of extubation times, are misleading, because benefits of different anesthetics are achieved principally by reducing the variability in extubation times, specifically by decreasing the incidence of extubation times sufficiently long to have economic impact (ie, the prolonged extubations). Collectively, the results show that when investigators in anesthesia pharmacology quantify the rate of patient recovery from general anesthesia, the incidence of prolonged times to tracheal extubation should be included as a study end point.

Systematic review with meta-analysis of relative risk of prolonged times to tracheal extubation with desflurane versus sevoflurane or isoflurane

The objective of this systematic review was to estimate the relative risk of prolonged times to tracheal extubation with desflurane versus sevoflurane or isoflurane. Prolonged times are defined as ≥15 min from end of surgery (or anesthetic discontinuation) to extubation in the operating room. They are associated with reintubations, naloxone and flumazenil administration, longer times from procedure end to operating room exit, greater differences between actual and scheduled operating room times, longer times from operating room exit to next case start, longer durations of the workday, and more operating room personnel idle while waiting for extubation. Published randomized clinical trials of humans were included. Generalized pivotal methods were used to estimate the relative risk of prolonged extubation for each study from reported means and standard deviations of extubation times. The relative risks were combined using DerSimonian-Laird random effects meta-analysis with Knapp-Hartung adjustment. From 67 papers, there were 78 two-drug comparisons, including 5167 patients. Studies were of high quality (23/78) or moderate quality (55/78), the latter due to lack of blinding of observers to group assignment and/or patient attrition because patients were extubated after operating room exit. Desflurane resulted in a 65% relative reduction in the incidence of prolonged extubation compared with sevoflurane (95% confidence interval 49% to 76%, P < .0001) and in a 78% relative reduction compared with isoflurane (58% to 89%, P = .0001). There were no significant associations between studies' relative risks and quality, industry funding, or year of publication (all six meta-regressions P ≥ .35). In conclusion, when emergence from general anesthesia with different drugs are compared with sevoflurane or isoflurane, suitable benchmarks quantifying rapidity of emergence are reductions in the incidence of prolonged extubation achieved by desflurane, approximately 65% and 78%, respectively. These estimates give realistic context for interpretation of results of future studies that compare new anesthetic agents to current anesthetics.