WHICH INDUCTION DRUG FOR CESAREAN-SECTION - A COMPARISON OF THIOPENTAL SODIUM, PROPOFOL, AND MIDAZOLAM

Study Objective: To determine maternal and neonatal effects of three d ifferent induction drugs (thiopental sodium, propofol, and midazolam) for cesarean section. Design: Randomized, double-blind study. Setting: Inpatient obstetric department at a general hospital Patients: 90 hea lthy patients undergoing elective cesarean section with general anesth esia. Interventions: 3 groups of 30 patients each receiving thiopental 5 mg/kg, Propofol 2.4 mg/kg, or midazolam 0.3 mg/kg for induction of anesthesia. Measurements and Main Results: Time to induce anesthesia, hemodynamic changes, depth of anesthesia, recovery after anesthesia, p lacental transfer, and neonatal outcome (Apgar and neurobehavioral exa minations) were studied. In the thiopental and midazolam groups, systo lic blood pressure and heart rate rose following endotracheal intubati on and skin incision (p < 0.001 and p < 0.0025, respectively), while i n the propofol group, there was significant hypotension after inductio n (p < 0.005). Electroencephalographic patterns showed a light depth o f anesthesia with propofol and midazolam between anesthesia induction and delivery, confirmed by the presence of clinical signs of light ane sthesia in 50% of propofol patients and 43% of midazolam patients. Tim e to induce anesthesia was longer with midazolam (p < 0.0001). Neonate s in the midazolam and Propofol groups had lower Apgar and neurobehavi oral scores than those in the thiopental group. Umbilical artery to um bilical vein ratios were above 1 in the propofol and midazolam groups. Conclusion: Thiopental still remains the first-choice induction drug for cesarean section. The slow induction time with midazolam may put t he mother at risk for pulmonary inhalation. A plane of anesthesia that may risk awareness and potential neonatal depression is the main draw back of the two newer induction drugs.