The Effect of Dilute Vasopressin Solution on Blood Loss During Operative Hysteroscopy.

A study was designed to assess the effect of intracervical injection of dilute vasopressin solution 0.05 U/ml on intraoperative blood loss during operative hysteroscopy. In a prospective, computer-randomized, double-blind study, vasopressin or placebo (normal saline) was injected into the cervical stroma of 108 women before dilatation of the cervix. Intraoperative bleeding was calculated by dividing the number of red blood cells/milliliter of outflow distention fluid by the number of red blood cells/milliliter of the patient's blood immediately before the procedure, and multiplying this quotient by the total amount of outflow fluid collected. Mean (± SEM) intraoperative blood loss of the placebo-treated group was 35 ± 6.5 ml (range 0-290 ml), and in the vasopressin-treated group was 18.2 ± 3.8 ml (range 0-135 ml), a 47.1% reduction (p <0.001). The visual clarity of the uterine cavity during surgery was not statistically different in the two groups. The concentration of vasopressin 50 U/ml may prove to be clinically significant to minimize the risk of cardiovascular morbidity, especially in women who are severely anemic and at risk for blood transfusion.