Re-evaluation of i.m. ephedrine as prophylaxis against hypotension associated with spinal anaesthesia for Caesarean section.
OBJECTIVE
To assess the safety and efficacy of 37.5 mg ephedrine i.m. in preventing hypotension associated with spinal anaesthesia for Caesarean section.


METHODS
In a double-blind randomised controlled study, 40 patients (20 in each group) were given either 37.5 mg ephedrine or placebo i.m. The following parameters were recorded: (i) blood pressure; (ii) heart rate; (iii) ephedrine i.v. supplementation; (iv) umbilical venous blood gases and neonatal Apgar scores.


RESULTS
The incidence of hypertension in the study group was 30% compared with 20% for the control group (P:NS). There was no difference in mean highest blood pressure or mean highest heart rate between the groups. The incidence of hypotension was lower but not significantly lower in the study group (50%) than in the control group (80%) (P:NS). However, the incidence of delayed hypotension was only 10% in the study group patients compared with 50% in the control group patients (P < 0.05).


CONCLUSIONS
Giving 37.5 mg ephedrine i.m. prior to spinal anaesthesia was not associated with reactive hypertension or tachycardia. Intramuscular ephedrine provided more sustained cardiovascular support than intravenous ephedrine.
Webb
A A
AA
Department of Anaesthesiology, Chris Hani Baragwanath Hospital, Johannesburg, South Africa.
Shipton
E A
EA
D000773:Anesthesia, Obstetrical / Q000009:adverse effects*; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D002585:Cesarean Section; D004311:Double-Blind Method; D004809:Ephedrine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007022:Hypotension / Q000517:prevention & control*; D011247:Pregnancy; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
D014662:Vasoconstrictor Agents; D004809:Ephedrine