The effect of dilute vasopressin solution on blood loss during operative hysteroscopy: a randomized controlled trial.

OBJECTIVE: To assess the effect of intracervical injection of dilute (0.05 U/mL) vasopressin solution on blood loss during operative hysteroscopy.

METHODS: In a randomized, double-blind study, dilute vasopressin solution or placebo (normal saline) was injected into the cervical stroma of 106 women before dilation of the cervix in preparation for operative hysteroscopy. Intraoperative bleeding was calculated by dividing the number of red blood cells per milliliter of outflow distention fluid by the number of red blood cells per milliliter of the woman's blood immediately before the procedure and multiplying this quotient by the total amount of outflow fluid collected. Pressures were kept constant with a hysteroscopic infusion pump.

RESULTS: The mean (+/-standard error of the mean) intraoperative blood loss of the treated (vasopressin) and control (placebo) groups was 20.3 +/- 4.1 mL (range 0-135) and 33.4 +/- 5.4 mL (range 0-290), respectively. The volume of distention fluid intravasation in the treated and control groups was 448.5 +/- 47.0 mL (range 30-1410) and 819.1 +/- 79.7 mL (range 20-1977), respectively. The operating time in the treated and control groups was 31.1 +/- 1.2 minutes (range 18-52) and 34.1 +/- 1.3 minutes (range 19-65), respectively. For all three outcome measures, the differences between the two groups were statistically significant, but for visual clarity of the uterine cavity during surgery, the difference was not significant.

CONCLUSION: Administration of dilute vasopressin solution (0.05 U/mL) to the cervical stroma significantly reduces blood loss, distention fluid intravasation, and operative time during hysteroscopy. Further evaluation is required to determine the optimum dosage.