Bispectral Index Changes Following Boluses of Commonly Used Intravenous Medications During Volatile Anesthesia Identified From Retrospective Data.

BACKGROUND: Although patients are commonly monitored for depth of anesthesia, it is unclear to what extent administration of intravenous anesthetic medications may affect calculated bispectral (BIS) index values under general anesthesia. METHODS: In a retrospective analysis of electronic anesthesia records from an academic medical center, we examined BIS index changes associated with 14 different intravenous medications, as administered in routine practice, during volatile-based anesthesia using a novel screening approach. Discrete-time windows were identified in which only a single drug bolus was administered, and subsequent changes in the BIS index, concentration of volatile anesthetic, and arterial pressure were analyzed. Our primary outcome was change in BIS index, following drug administration. Adjusted 95% confidence intervals were compared to predetermined thresholds for clinical significance. Secondary sensitivity analyses examined the same outcomes, with available data separated according to differences in baseline volatile anesthetic concentrations, doses of the administered medications, and length of time window. RESULTS: The study cohort was comprised of data from 20,170 distinct cases, 54.7% of patients were men, with a median age of 55. In the primary analysis, ketamine at a median dose of 20 mg was associated with a median (confidence limits) increase in BIS index of 3.8 (2.5-5.0). Midazolam (median dose 2 mg) was associated with a median decrease in BIS index of 3.0 (1.5-4.5). Neither of these drug administrations occurred during time periods associated with changes in volatile anesthetic concentration. Analysis for dexmedetomidine was confounded by concomitant decreases in volatile anesthetic concentration. No other medication analyzed, including propofol and common opioids, was associated with a significant change in BIS index. Secondary analyses revealed that similar BIS index changes occurred when midazolam and ketamine were administered at different volatile anesthetic concentrations and different doses, and these changes persisted 11 to 20 minutes postadministration. CONCLUSIONS: Modest, but persistent changes in BIS index occurred following doses of ketamine (increase) and midazolam (decrease) during periods of stable volatile anesthetic administration.

Clinical Outcomes and Hospital Utilization Among Patients Undergoing Bariatric Surgery With Telemedicine Preoperative Care.

Importance: Bariatric surgery is the mainstay of treatment for medically refractory obesity; however, it is underutilized. Telemedicine affords patient cost and time savings and may increase availability and accessibility of bariatric surgery. Objective: To determine clinical outcomes and postoperative hospital utilization for patients undergoing bariatric surgery who receive fully remote vs in-person preoperative care. Design, Setting, and Participants: This cohort study comparing postoperative clinical outcomes and hospital utilization after telemedicine or in-person preoperative surgical evaluation included patients treated at a US academic hospital. Participants underwent laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy after telemedicine or in-person preoperative surgical evaluation between July 1, 2020, to December 22, 2021, or January 1, 2018, to December 31, 2019, respectively. Follow-up was 60 days from date of surgery. Exposures: Telemedicine-based preoperative care. Main Outcomes and Measures: Clinical outcomes, including operating room delay, procedure duration, length of hospital stay (LOS), and major adverse events (MAE), and postoperative hospital resource utilization, including emergency department (ED) visit or hospital readmission within 30 days of the surgical procedure. Results: A total of 1182 patients were included; patients in the telemedicine group were younger (mean [SD] age, 40.8 [12.5] years vs 43.0 [12.2] years; P = .01) and more likely to be female (230 of 257 [89.5%] vs 766 of 925 [82.8%]; P = .01) compared with the control group. The control group had a higher frequency of comorbidity (887 of 925 [95.9%] vs 208 of 257 [80.9%]; P < .001). The telemedicine group was found to be noninferior to the control group with respect to operating room delay (mean [SD] minutes, 7.8 [25.1]; 95% CI, 5.1-10.5 vs 4.2 [11.1]; 95% CI, 1.0-7.4; P = .002), procedure duration (mean [SD] minutes, 134.4 [52.8]; 95% CI, 130.9-137.8 vs 105.3 [41.5]; 95% CI, 100.2-110.4; P < .001), LOS (mean [SD] days, 1.9 [1.1]; 95% CI, 1.8-1.9 vs 2.1 [1.0]; 95% CI, 1.9-2.2; P < .001), MAE within 30 days (3.8%; 95% CI, 3.0%-5.7% vs 1.6%; 95% CI, 0.4%-3.9%; P = .001), MAE between 31 and 60 days (2.2%; 95% CI, 1.3%-3.3% vs 1.6%; 95% CI, 0.4%-3.9%; P < .001), frequency of ER visits (18.8%; 95% CI, 16.3%-21.4% vs 17.9%; 95% CI, 13.2%-22.6%; P = .03), and hospital readmission (10.1%; 95% CI, 8.1%-12.0% vs 6.6%; 95% CI, 3.9%-10.4%; P = .02). Conclusions and Relevance: In this cohort study, clinical outcomes in the telemedicine group were not inferior to the control group. This observation suggests that telemedicine can be used safely and effectively for bariatric surgical preoperative care.