Comparison of the Effect of Intravenous Bolus Norepinephrine and Ephedrine on Prevention of Post Spinal Hypotension in Cesarean Section: a Randomized Double-Blind Clinical Trial.

Currently, cesarean section is performed under spinal anesthesia. Hypotension is the most common complication of spinal anesthesia. This study aimed to compare the effect of intravenous bolus norepinephrine and ephedrine on prevention of post spinal hypotension in cesarean section. The present study was a double-blind clinical trial, in which 50 pregnant women aged 18-46 years, with ASA class I and II, were selected for cesarean section under spinal anesthesia and randomly assigned to two groups, one receiving norepinephrine (group A) and the other one ephedrine (group B). Immediately after spinal anesthesia, patients in group A received 5 μg of intravenous norepinephrine and those in group B 10 mg of intravenous ephedrine. The incidence of hypotension, bradycardia, mean systolic and diastolic blood pressure, and mean heart rate were recorded in a checklist. Patients with hypotension and bradycardia received 10 mg of ephedrine and 0.5 mg of atropine, respectively, and finally the amount of ephedrine and atropine was also recorded. Data were analyzed in SPSS, version 21 at a confidence level of 95%. Hypotension had a frequency of 24% and 40% (P = 0.364) and the dose of ephedrine used to treat that condition was 15.0±8.37 and 18.18±7.51 mg (P = 0.434) in the norepinephrine and ephedrine groups, respectively. The mean heart rate was significantly lower in the norepinephrine group than the ephedrine one (P <0.001). Both norepinephrine and ephedrine were effective in preventing hypotension during cesarean section under spinal anesthesia, but tachycardia was less common with norepinephrine. The present study was registered on 17 May 2019 in the Iranian Clinical Trial Center (https://www.irct.ir) Identifier: IRCT20120915010841N17.