Comparison of Emergence Delirium in Patients Undergoing Laparoscopic Cholecystectomy With High or Low Fresh Gas Flow During Anesthesia: A Prospective Randomized Double-Blind Study.

CONTEXT: Cause of "emergence delirium" (ED) after general anesthesia with volatile anesthetics in adults remains unclear. While low "fresh gas flow" (FGF) is integral to current anesthesia practice, there is limited literature about FGF's role in ED.

AIMS: To compare ED in patients receiving high or low FGF during anesthesia with sevoflurane while undergoing laparoscopic cholecystectomy for gallstone disease.

SETTINGS AND

DESIGN

Prospective randomized double-blind study.

METHODS AND MATERIALS: One hundred American Society of Anesthesiologists (ASA) I and II patients, aged 18-50 years, were randomized to a low FGF or high FGF group of 50 patients each. After preoxygenation with 100% oxygen for 3 min, patients were induced. The low FGF group received 4 L for 5 min, followed by 1 L till the end, while the high FGF group received 4 L throughout. Sevoflurane, nitrous oxide, and oxygen (N2O : O2 = 1 : 1) were used to maintain minimum alveolar concentration (MAC) value of ≥ 1.2. A blind independent observer assessed ED by Richmond agitation-sedation scale (RASS).

STATISTICAL ANALYSIS USED: Student's T-test, chi-square test, and Mann-Whitney U test.

RESULTS

Postoperative lactate was significantly higher in the low FGF group compared with the high FGF group (1.49 ± 0.69 vs. 1.05 ± 0.54 mmol/L, p ≤ 0.001). RASS scores were also higher with low FGF both immediately after PACU admission (median 1 [IQR 1-1] vs. -1 [IQR -2-0], p < 0.001) and at 10 min (median 0 [IQR 0-1] vs. 0 [IQR -1-0], p < 0.001), while scores at 20 and 30 min were comparable.

CONCLUSIONS

ED and lactate levels were significantly higher in patients receiving low FGF compared to high FGF during anesthesia.