THE EFFECT OF INTRACERVICAL VASOPRESSIN ON THE SYSTEMIC ABSORPTION OFGLYCINE DURING HYSTEROSCOPIC ENDOMETRIAL ABLATION

Objective: To examine the effect of paracervical injection of vasopres sin on the absorption of glycine during transcervical endometrial abla tion. Methods: Thirty-three consecutive women scheduled for elective h ysteroscopic endometrial ablation were randomized to either the study or control group. All procedures were performed with a myoma resectosc opy using 1.5% glycine as the irrigating medium at a now rate of 100 m L/minute. In the study group, a solution of 0.2 mg vasopressin diluted with 20 mL saline was injected paracervically. Blood samples were obt ained through an indwelling intravenous catheter every 5 minutes until the completion of the operation. Serum sodium, potassium, and magnesi um levels were measured at 20-minute intervals. In addition, glycine c oncentrations were determined by both rapid screening and quantitative amino acid analysis. Results: Plasma glycine maximal concentrations w ere significantly lower (P < .001) in patients who received vasopressi n, compared with controls (8.8 +/- 4.5 versus 16.0 +/- 6.3 mmol/L, res pectively). The calculated extent of glycine absorption within the fir st 20 minutes of the procedure was 59.6 +/- 30.0 versus 179.8 +/- 66.2 mmol/L minute in the study and control groups, respectively (P < .001 ). The differences in plasma sodium, potassium, and magnesium levels w ere not significant. Conclusion: Intracervical vasopressin administrat ion significantly decreased systemic glycine absorption in patients un dergoing hysteroscopic endometrial ablation.