Costantino P

Which induction drug for cesarean section? a comparison of thiopental sodium, propofol, and midazolam

STUDY OBJECTIVE To determine maternal and neonatal effects of three different 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 healthy patients undergoing elective cesarean section with general anesthesia. 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, placental transfer, and neonatal outcome (Apgar and neurobehavioral examinations) were studied. In the thiopental and midazolam groups, systolic blood pressure and heart rate rose following endotracheal intubation and skin incision (p < 0.001 and p < 0.0025, respectively), while in the propofol group, there was significant hypotension after induction (p < 0.005). Electroencephalographic patterns showed a light depth of anesthesia with propofol and midazolam between anesthesia induction and delivery, confirmed by the presence of clinical signs of light anesthesia in 50% of propofol patients and 43% of midazolam patients. Time to induce anesthesia was longer with midazolam (p < 0.0001). Neonates in the midazolam and propofol groups had lower Apgar and neurobehavioral scores than those in the thiopental group. Umbilical artery to umbilical 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 the mother at risk for pulmonary inhalation. A plane of anesthesia that may risk awareness and potential neonatal depression is the main drawback of the two newer induction drugs.

Propofol and thiopentone for caesarean section revisited: maternal effects and neonatal outcome

In 56 women undergoing elective caesarean section, general anaesthesia was induced with either propofol 1% or thiopentone 2.5% followed by 50% nitrous oxide in oxygen and isoflurane 0.75% until delivery. In the thiopentone group the arterial pressure rose following tracheal intubation and skin incision, while in the propofol group there was a significant tendency to hypotension immediately following induction of anaesthesia. There were differences in electroencephalogram (EEG) between the groups, while laryngoscopy, intubation and surgical stimulation had no effect on EEG pattern. Recovery after anaesthesia did not differ between groups. None of the patients had recall of the intraoperative period, but 53% of patients induced with propofol showed signs of light anaesthesia between induction and delivery. Neonates in the propofol group had lower Apgar scores 1 min after birth than those in the thiopentone group, but these differences were no longer significant at 5 min. No differences were noted in neurobehavioural status at 1, 4 and 24 h.

Comparison of fentanyl with clonidine as adjuvants for epidural analgesia with 0.125% bupivacaine in the first stage of labor. A preliminary report

48 primiparae received epidural analgesia in labor with 10 ml of 0.125% bupivacaine with epinephrine 1:800 000, and then were divided in 4 equal groups (n = 12) to receive one of the following: 5 ml saline (B); 100 mug of fentanyl (BF); 150 microg of clonidine (BC); 75 microg of clonidine and 50 microg of fentanyl (BCF). All the patients had satisfactory analgesia. Onset was similar in the 4 groups but the duration of analgesia was significantly prolonged by the addition of either 100 microg of fentanyl or 150 microg of clonidine (respectively 89.8 min and 92.5 min vs 62.5 min) (P < 0.0001). The addition of both clonidine (75 microg) and fentanyl (50 microg) produced a considerably prolonged analgesia (177.5 min) (P < 0.0001). No episodes of bradycardia were observed. Hypotension, reversed by i.v. ephedrine, occurred in 2 patients of BCF group and in 1 patient of BF and BC groups. Only patients receiving fentanyl had pruritus. Both fentanyl and clonidine produced sedation, but both incidence and severity were greater with the mixture. No differences in neonatal outcome assessed by Apgar scores and NACS, were observed.