Anesthesia for cesarean section II: effects of the induction-delivery interval on the respiratory adaptation of the newborn in elective cesarean section.

Ten healthy mothers and their infants were studied in connection with elective cesarean section. Anesthesia was induced with 250-300 mg hexobarbitone followed by 100 mg succinylcholine for endotracheal intubation. The surgeon started the operation when the eyelid reflex disappeared, and delivered the baby as quickly as possible. Mean induction-delivery (I-D) interval was 2 min 45 s. Anesthesia was then deepened with further barbiturate, diazepam and methoxyflurane, and alcuronium used as muscle relaxant. The respiratory adaptation of the infant was studied by blood gas and acid-base measurements in repeated arterial samples during the first three hours of life. The mothers were interviewed after 3-12 months. A comparison was made with another barbiturate group with a longer I-D interval (x = 9 min 10 s). The present material showed initially higher PaO2 lower PaCO2, higher pH and less base deficit (BD), which relfected the maternal state at delivery. After 10-30 min, the results approached equivalence, though the babies in the short I-D group showed a tendency toward normalization of metabolic acidosis earlier. At the interviews, two mothers complained of pain during skin incision, and two of nightmares. Anesthesia with barbiturate for cesarean section with the I-D intervals studied in both groups allowed good respiratory adaptation in the infants. There is, neverless, the need for an adequate period of time between induction and the start of the operation in order to minimize the risk for maternal awareness.