The effect of intracervical vasopressin on the systemic absorption of glycine during hysteroscopic endometrial ablation.

OBJECTIVE

To examine the effect of paracervical injection of vasopressin on the absorption of glycine during transcervical endometrial ablation.

METHODS

Thirty-three consecutive women scheduled for elective hysteroscopic endometrial ablation were randomized to either the study or control group. All procedures were performed with a myoma resectoscopy using 1.5% glycine as the irrigating medium at a flow rate of 100 mL/minute. In the study group, a solution of 0.2 mg vasopressin diluted with 20 mL saline was injected paracervically. Blood samples were obtained through an indwelling intravenous catheter every 5 minutes until the completion of the operation. Serum sodium, potassium, and magnesium levels were measured at 20-minute intervals. In addition, glycine concentrations were determined by both rapid screening and quantitative amino acid analysis.

RESULTS

Plasma glycine maximal concentrations were significantly lower (P < .001) in patients who received vasopressin, compared with controls (8.8 +/- 4.5 versus 16.0 +/- 6.3 mmol/L, respectively). The calculated extent of glycine absorption within the first 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 were not significant.

CONCLUSION

Intracervical vasopressin administration significantly decreased systemic glycine absorption in patients undergoing hysteroscopic endometrial ablation.