The impact of anesthesia on glycine absorption in operative hysteroscopy: a randomized controlled trial.

Background: Operative hysteroscopy requires the use of a distension medium and its absorption can lead to serious consequences from intravascular volume overload and water intoxication. We compared the impact of 2 types of anesthesia (general anesthesia and local anesthesia with sedation) on the absorption of glycine solution in operative hysteroscopy.

Methods: A randomized controlled trial was conducted over a 17-month period. Eligible patients undergoing operative hysteroscopy for abnormal uterine bleeding were randomized in 2 groups: a general anesthesia group and a local anesthesia with sedation group. The primary outcome was the median absorption of the glycine solution (10th-90th percentile) measured with an automated tandem canister system. Secondary outcomes included incidence of absorption >1000 mL, discontinued surgery because of excessive absorption, median change in serum sodium, postoperative hyponatremia, and patients' postoperative quality of life at 24 hours (8-item Short Form Health Survey questionnaire). Nonparametric analyses (Mann-Whitney U test, χ(2) test, and Fisher exact test) were used.

Results: Of 142 eligible patients, 95 agreed to participate and were randomized. Women who underwent general anesthesia had a higher median absorption of the glycine solution (10th-90th percentile) compared with women who underwent local anesthesia with sedation (480 mL [76-1300 mL] vs 253 mL [70-728 mL]; P = 0.005). General anesthesia was also associated with a higher rate of glycine solution absorption (>1000 mL [20% vs 4%; P = 0.009]) and a more rapid rate of decrease in serum sodium (≥10 mEq/L [8% vs 0%; P = 0.005]) than local anesthesia with sedation. Postoperative quality of life measures as rated by the patients were comparable between the 2 groups.

Conclusion: Compared with general anesthesia, local anesthesia with sedation is associated with less glycine absorption and should be considered the preferred method of anesthesia for operative hysteroscopy.