Premedication with oral clonidine decreases intraoperative bleeding and provides hemodynamic stability in cesarean section

BACKGROUND: Intentional lowering of blood pressure helps to produce a desirably clean surgical field. Many drugs can be used to induce a hypotensive state, but due to their high potency and rapid effect, drugs that more easily and safely control the induction of hypotension are desirable. OBJECTIVES: To investigate the effects of premedication with oral clonidine on intraoperative bleeding and hemodynamic variables in patients undergoing cesarean sections. PATIENTS AND METHODS: A total of 110 patients classified as American Society of Anesthesiologists (ASA) physical status I and II and who were scheduled for elective cesarean section under general anesthesia were enrolled. The patients were randomized to receive either oral clonidine (0.2 mg) or identical-looking placebo tablets 90 minutes before arriving at the operating room. Induction of anesthesia was performed by the same standard protocol in all patients. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were recorded before and after induction; immediately after intubation; 5, 10, and 15 minutes thereafter; at the time of extubation; and one hour after the operation. The surgeons were asked to rate the quality of the operative field on a four-point scale that ranged from mild (1) to abundant bleeding (2). RESULTS: Intraoperative SBP was lower in the clonidine group. After both intubation and extubation, the increases in SBP, DBP, and HR in clonidine-treated subjects were significantly less than the changes in the control patients. The amount of fentanyl given to control blood pressure and HR was significantly less in the clonidine group (18 ± 38 vs. 39 ± 53 μg, P = 0.02). The responses to the four-point scale indicated that intraoperative bleeding in the clonidine group was less than in the placebo group (1.2 ± 0.4 vs. 1.7 ± 0.6, P < 0.05). CONCLUSIONS: Premedication with oral clonidine can improve the hemodynamic management of cesarean cases.