RESUMEN
Spinal anaesthesia [SA] for caesarean section [CS] is commonly associated with hypotension [HT]. This HT is treated commonly by vasopressor agents especially ephedrine. We aimed to study the effect of prophylactic ephedrine, injected intramuscularly or intravenously, on the incidence of maternal HT during SA. According to the route of ephedrine injection, forty ASAI singleton parturients who presented at term for elective CS under SA were randomly assigned into two groups, each consist of 20 patients: group [IM] received intramuscular ephedrine 30mg at 15 minutes before SA, and group [IV] received intravenous ephedrine 15 mg at the second minute after the SA. Patient's monitoring included continuous ECG, heart rate, non-invasive blood pressure, and peripheral arterial oxygen saturation. SA was performed at the level of L3/L4 using a G25 spinal needle. All patients were injected intrathecally with 2.5 ml of hyperbaric 0.5% bupivacaine using the midline approach. Three patients [15%] in group IM and five patients [25%] in group IV developed HT and treated with IV bolus doses of ephedrine for 5 and 10 occasions respectively. Total extradoses of ephedrine therapy required for treatment of hypotension were lower in IM group [14 mg +/- 9.16] than IV group [18 mg +/- 8.49], but the difference was statistically insignificant [P = 0.55]. IM is as similar as IV ephedrine for decreasing the incidence, maternal hypotension during SA. Regardless to the injection route, HT can not be completely eliminated by the prophylactic doses of ephedrine used in our study