Time: An Important Variable at Caesarean Section

Abstract

Summary Biochemical evidence of fetal asphyxia (relative hypoxia with hypercapnia) and acidaemia has been found in the cord blood of infants delivered by Caesarean section in a series of patients who had been selected to exclude complications of pregnancy which prejudiced the fetal condition before or during anaesthesia. Further, the findings strongly suggest that fetal asphyxia develops progressively, and Apgar scores were lower as the duration of anaesthesia was extended. While changes with time in the general circulation and respiration of the mother could be excluded as the cause of fetal deterioration, local changes in the utero‐placental circulation, due to recumbency or surgical manipulation, and the effect of anaesthetic agents could not.

Human Umbilical Vessel Diameters and Blood Gas Tensions in the First Two Minutes after Delivery

“…A preliminary study showed that blood gas tension did not change significantly during 5-hour storage. K och [15] and L umley et al [18] have reported similar results. Heparin in the syringe dead space (0.1 ml) has been shown by Oliver et al [27] to have an insignificant effect on blood gas tension.…”

Survival, Growth and the Metabolic Response to Cold in Prematurely Delivered Lambs

“…The high perinatal mortality asso ciated with Caesarian delivery in man, appears to be due to the fact that Caesarian section is usually performed on babies that are already at high risk [8,14] but may also result from a delay in delivery following induc tion of maternal anaesthesia [11].…”

Fetal heart rate monitoring on the operating table immediately before delivery by cesarean section

“…Some authors [6,14] are in favor of a long induction-delivery-interval since the risk of depression of the newborn due to drugs Curriculum vitae MATTHIAS can be lessened through the exponential fall in barbiturate concentration in maternal and fetal plasma [3]. In some cases even when the mother is lying in a lateral position, a supine-hypotension-syndrome occurs leading to an increase in fetal impairment [2,8,11,15] during a prolonged inductiondelivery-interval. In 1970 SALING [12] suggested that another possible reason for the worsening in the fetal condition could be the loss of the oxygen conserving adaptation of the fetal circulation induced by barbiturates.…”

“…The chief factors causing biochemical depression are maternal hyperventilation [13], position of the mother during the operation and the duration of the induction-delivery-interval. Many authors [1,2,8,11,16] have pointed out how important the mother's position is during the operation, and how this influences the state of the newborn. In this way the frequency of fetal hazards caused by the supine hypotension vena cava-compression syndrome can be reduced by placing the mother in a lateral position of 15 ° deviation to the left.…”