[Clinical studies on prevention of spinal hypotension and aortocaval compression during elective cesarean section (author's transl)].

Maternal blood pressures, maternal and fetal blood-gas values, induction delivery intervals (I-D intervals) and Apgar scores were determined in 60 cases of elective cesarean section under spinal anesthesia. The procedures were as follows: In the right lateral position on an operating table, the intravenous drip infusion of 6 per cent hydroxyethyl starch solution (12 ml/kg) for 30 minutes prior to spinal anesthesia and the intramuscular injection of ephedrine (0.5 mg/kg) 15 minutes before spinal anesthesia were performed. Immediately after the anesthesia, on the left semilateral position the operation was started (group S). The same studies as group S were made in cases of no reduced blood pressure without ephedrine (group E), and cases of combined use of oxygen inhalation (group O and OII). No significant reduction of blood pressure was noted in group S and O. Fetal acid-base status and Apgar scores were favorable and had no correlation with I-D intervals in any groups. It is suggested that the uteroplacental circulation in group O and E was maintained more or less smoothly than that in group S. Oxygen inhalation led to a significant increase in fetal PO2 and the improvement of 5 minutes Apgar score. On performing elective cesarean section under spinal anesthesia, it may be advisable to take the procedures of group OII (Oxygen flow: 31/min., through a nasal cannula) and to make mother respire closing their mouths.