An RCT: use of oxytocin drip during hysteroscopic endometrial resection and its effect on operative blood loss and glycine deficit

Abstract

Objective: To estimate the influence of oxytocin infusion on operative blood loss and glycine deficit during hysteroscopic transcervical endometrial resection (TCRE) for abnormal uterine bleeding (AUB).

Design: Prospective, randomized, placebo-controlled study (Canadian Task Force classification I).

Setting: Tertiary Care University Hospital.

Patients: Forty-eight women with abnormal uterine bleeding that was unresponsive to conservative medical management were randomly assigned to undergo hysteroscopic TCRE with either oxytocin infusion (group A) or saline (group B). Intravenous Ringer's lactate solution was used during surgery.

Interventions: TCRE was carried out with glycine 1.5% mixed with 2% ethanol as a distension medium. For group A: one ampoule of oxytocin (10 U/mL/amp) was added to 500 mL Ringer's lactate solution running at a rate of 400 mU/min during surgery. In group B, one ampoule of saline solution was added to the Ringer's solution and run at a similar rate. The amount of distension medium used, fluid deficit, blood levels of albumin and ethanol, hematocrit, hemoglobin, changes in serum sodium levels (Na+), and central venous pressure were compared between the groups.

Measurements and main results: The mean volume of distension fluid used and operating time were not significantly different in both groups (4.18 ± 0.2 vs 4.5 ± 0.5 L, and 28.3 ± 4.2 vs 27.5 ± 5.4 min, respectively). Although operating time, volume of distension fluid used, decrease in albumin level and hematocrit were less in the oxytocin than in the saline group, the differences were not statistically significant. The ethanol levels in blood, decrease in serum Na+, and glycine deficit were significantly lower in the oxytocin than in the saline group (17.4 ± 3.8 vs 25.3 ± 4.2 mg/ml, 6.7 ± 1.2 vs 9.1 ± 0.9 mEq/L, and 0.49 ± 0.08 vs 0.66 ± 0.05 L, respectively; p <.05). There was no significant difference in mean total uterine size, endometrial thickness, weight of resected tissue, and other demographic data between the study groups.

Conclusions: Oxytocin infusion combined with skillful surgical techniques may prevent fluid overload and glycine deficit during hysteroscopic TCRE for abnormal uterine bleeding. Although there is a trend toward a decrease in operative blood loss, further randomized trials are required to confirm this finding.