Cardiovascular Effects of Prostaglandin F_(2)α Injection to the Myometrium during Cesarean Section

Abstract

Background: Intramyometrial injection of prostaglandin F2 a (PGF2 a), in doses varying from 0.5 to 2 mg, has been used as a safe and effective method in the control of severe postpartum hemorrhage due to uterine atony which does not responding to conventional treatment. We earlier reported 8 cases of acute but transient hypertension after myometrial injection of PGF2 a. The purpose of the present study was to examine cardiovascular consequence of intramyometrial injection of PGF2 a and incidence of hypertension.

Methods: Forty full term pregnant women with no cardiovascular and respiratory diseases, who were scheduled for elective cesarean section under general anesthesia, were randomly grouped into two groups: control (pitocin) and experimental (PGF2 a) groups. Hypertension developed in five cases after PGF2 a intramyometrial injection, Thus PGF2 a group was divided into PGF2 a -normotension (PGF-N) and PGF2 a -hypertension (PGF-HS) groups, and 20 units of pitocin was infused intravenously in both groups after placental delivery. Twenty unit of pitocin in the control group and 2 mg of PGF2 a in the PGF2 a group were directly injected into myometrium, respectively Blood pressure (BP), heart rate (HR) and EKG were continuously monitored, and arterial blood was withdrawn for arterial blood gas analysis.

Results: The systolic BP was markedly increased in the PGF-HS group and slightly decreased in the PGF-N group (P<0.05). The diastolic BP was markedly increased in PGF-HS group, but decreased in the PGF-N and pitocin groups (P<0.05). The HR was increased at 2 min in the PGF-HS group (P<0.05). There was no significant difference in ABGA among the groups. Change of EKG occurred in 4 cases only in the PGF-HS group.

Conclusions: Only in the PGF-HS group, HR, systolic and diastolic BP are markedly increased and EKG changes are observed. These findings suggest that careful attention should be paid to toxemia as well as to healthy patients when PGF2 a is used. (Ajou Med J 1999; 4(1): 58-63)