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

Comparison of thiopentone and diazepam as induction agents of anaesthesia for Caesarean section

Clinical effects of thiopentone (3 mg/kg body weight) and diazepam (0.3 mg/kg) were compared for elective caesarean sections in two groups of 43 and 39 women, respectively. They were given general anaesthesia in left lateral tilt. The systolic, diastolic and mean arterial pressures were moderately elevated at onset of surgery in both groups, probably indicating light anaesthesia. Later, a gradual decrease to the preinduction levels was observed. The mean injection-delivery (I-D) interval was 344 s in the thiopentone group and 339 s in the diazepam group. The I-D intervals were shorter than 10 min in 39 of the cases in the thiopentone group and 38 cases in the diazepam group. Low Apgar scores at 1 min (6 or less) occurred in five of the neonates in each group, while all had normal Apgar scores at 5 min ( 7 or mor) As judged by the Apgar scores and the acid-base status of umbilical cord blood, the effects of the induction agents on the neonatal condition were indistinguishable in the two groups. In the thiopentone group, unpleasant recollections were reported in 5 out of 40 patients (12.5%) compared to none in the diazepam group. Diazepam-nitrous oxide anaesthesia is well accepted by the mothers and is alternative to supplementing thiopentone induction with a volatile gas for patients who have previous experienced wakefulness or express fear of awareness. The main drawback with diazepam induction, however, is the slow induction of sleep. Harmful drug effects on the neonates must be expected if the dose has to be increased in order to ensure sleep.

Effects of delivery by caesarean section on lung mechanics and lung volume in the human neonate

Lung function tests were carried out in the first 6 hours of life on 26 babies born by vaginal delivery and 10 born by caesarean section. The babies born by caesarean section had a mean thoracic gas volume of only 19.7 ml/kg body weight compared with 32.7 ml/kg for the babies born vaginally. We conclude that this is owing to an excess of lung fluid in the babies born by caesarean section.

The effect of diazepam and lorazepam on awareness during anaesthesia for Caesarian section

One hundred-and-eighty-three patients having general anaesthesia for Caesarian section were given lorazepam or diazepam intravenously immediately following delivery. The incidence of unpleasant recall was comparable with the reports of other workers. There was no evidence of a specific retrograde amnesic effect by either drug. Neither agent appeared to affect cardiovascular stability, uterine contraction, the reversal of muscle relaxant or the time to recovery of protective reflexes. The patients tended to be drowsier after lorazepam but as safe as after diazepam so far as circulation, respiration and protective reflexes were concerned.

General anaesthesia or lumbar epidural block for caesarean section? Effects on the foetal heart rate

Caesarean section was performed in 10 patients under general anaesthesia and in 10 other patients under epidural block. The foetal heart rate was monitored continuously during anaesthesia and operation with a scalp electrode and a cardiotocograph. There was no major difference between the two anaesthetic techniques in their effect on the foetal heart rate. The most common finding was a reduction of the beat-to-beat variation. The operative time was longer in the epidural group than in the general anaesthesia group, due to a higher frequency of Pfannenstiel incisions and repeat caesarean sections in the epidural group. Clinically, all newborns seemed to be unaffected, with normal Apgar scores. Epidural block seems to be a good alternative to general anaesthesia for caesarean section, particularly when a long operative time is expected.

Anesthesia for cesarean section V: effects of enflurane anesthesia on the respiratory adaptation of the newborn in elective cesarean section

The new anesthetic inhalation agent, enflurane, is supposed to allow rapid induction and recovery. Experinece with this agent in obstetrics is limited. Enflurane was therefore studied in 14 pregnant women undergoing elective cesarean section. Its effects upon the respiratory adaptation of the newborn infants were followed during the first 3 hours, as judged by oxygen tensions and acid-base balance measurements in serial neonatal arterial samples. Results were compared with those from a previously studied group of women anesthetized with a barbiturate and nitrous oxide-oxygen. There were no differences with respect to oxygen tension. Carbon dioxide values in the enflurane group were higher than those in the barbiturate group. In comparison with the barbiturate group the enflurane group of babies had lower BD values, which is a sign of a better metabolic state post-partum. Mothers anesthetized with enflurane were satisfied with the method, especially for the post-operative period.

Anesthesia for cesarean section III: effects of epidural analgesia on the respiratory adaptation of the newborn in elective cesarean section

A rise in fetal Paco2 was observed after elective cesarean section in patients anesthetized both with a barbiturate and with nitrous oxide/oxygen. Epidural analgesia seemed to be a good alternative in order to attain better blood gas values in the newborn infant. Fourteen healthy mothers and their infants were studied in connection with elective cesarean section. Epidural analgesia with plain bupivacaine 0.75% was used. Doses varied between 90 and 120 mg. The time between the epidural injection and delivery was around 50 min. In six cases the fetal heart rate was registered continuously. Most of the mothers were sedated with diazepam intravenously or fully anesthetized, after delivery. The mothers were interviewed later. The respiratory adaptation of the infants was studied by blood gas and acid-base measurements in repeated arterial samples during the first 3 hours of life. A comparison was made with a group previously studied, where general anesthesia with a barbiturate, nitrous oxide/oxygen was the method used. The present material showed no differences concerning Pao2 and Paco2 but clearly indicated a tendency towards an earlier normalization of the initial metabolic acidosis. Mothers showed a respiratory alkalosis which was overcompensated by the metabolic component. Maternal blood pressure falls were observed in four cases, and fetal effects could be detected. Although epidural analgesia has a more favorable effect upon the newborn's metabolic component, both the compared methods allow good respiratory adaptation provided they are used correctly. Mothers can be given the opportunity to choose between being conscious or asleep when their child is delivered.