Canadian Journal of Anesthesia, Vol 3, 97-101, Copyright © 1956 by Canadian Anesthesiologists' Society

Barbiturates in Obstetrics: Effects on the Newborn

¹ Department of Anaesthesiology, St. François d'Assise Hospital, Quebec City, Canada

1. The association of Demerol and hyoscine, which is largely used, has been the drug combination least detrimental to the foetus. It can be detrimental when it is repeated or used within one hour of the delivery Syncopal reactions are also possible which secondarily affect the child.

2. Barbiturates used in large doses, whether it be intravenously or rectally, have a striking or marked depressing effect on the newborn. A small amount (not over 250 mg of a 2 per cent solution of Pentothal) given intravenously not sooner than 5 minutes before the birth (as used in Caesarian sections) has a less deleterious effect than a larger dose given rectaLly.

3. The addition of a potent general anaesthetic like cyclopropane enhanced the danger of foetal asphyxia.

4. Spinal anaesthesia or N₂O alone or supplemented with trilene should be substituted whenever possible.

5. Decamethonium bromide, in spite of some reports, has seemed to affect the newborn.

6. Asphyxia neonotorum and its possible sequelae on the central nervous system is so often produced by barbiturates that their use in obstetrics should be restricted to a minimum. To expect the barbiturates to produce complete amnesia and analgesia for a number of hours and to have no ill effects on the baby is asking too much. Any hospital that wishes to diminish the neonatal mortality rate should, as a first step, banish the barbiturates, especially those given by intravenous and rectal administration, and be careful with curarising agents. These measures are already being applied in our medical group with undeniably good results.

Note:

Presented at the Annual Meeting of the Canadian Anaesthetists' Society, Toronto, June 20, 21 and 22, 1955.