Prophylactic intramuscular ephedrine before epidural anaesthesia for caesarean section: efficacy and actions on the fetus and newborn.

The authors studied the effectiveness of ephedrine given intramuscularly before epidural anaesthesia with bupivacaine 0.5 per cent in three groups of patients undergoing elective caesarean section. The patients received intramuscular saline as a placebo, ephedrine 25 mg or ephedrine 50 mg, 15 to 30 minutes before anaesthesia. The incidence of hypotension was 8 to 12 per cent in all three groups. Prophylactic intramuscular ephedrine did not lower the incidence of hypotension significantly. Intramuscular ephedrine 50 mg caused a persistent hypertension in eight out of 12 patients and was associated with an increase in umbilical artery [H+] (decrease in pH). No differences were observed in other indices of neonatal well-being. The prophylactic use of intramuscular ephedrine before epidural anaesthesia for caesarean section is not recommended.