Prophylactic co-administration of two different bolus doses of norepinephrine in spinal-induced hypotension during caesarean section: A prospective randomized double-blinded study

Abstract

Background: Vasopressors for prophylaxis and treatment of spinal hypotension have grown in popularity in recent years. Norepinephrine is now emerging as one of the feasible options for prevention as well as management of spinal-induced hypotension in caesarean section (CS). The aim of our study was to compare the efficacy of two different doses of norepinephrine as prophylaxis for spinal-induced hypotension during CS. Material and Methods: Total 110 patients were recruited in this prospective randomized double-blind study from December 2017 to June 2019. After fulfilling the inclusion and exclusion criteria, this study was conducted on 90 patients undergoing elective CS under spinal anesthesia, who were assigned into three groups of 30 patients each. Group N6received norepinephrine 6 μg as an intravenous bolus, group N4received norepinephrine 4 μg, and group C received normal saline simultaneously with subarachnoid block. Incidence of hypotension, requirement of rescue doses of norepinephrine, time of first rescue dose, hemodynamic parameters, adverse effects, and neonatal complications were assessed, compared and analyzed. Results: The incidence of post spinal hypotension was 63.33% in group N6, 80% in group N4, and 83.33% in group C (p = 0.155). Total rescue dose requirement of norepinephrine was significantly less in group N6(8.21 ± 2.97 μg) as compared to N4(9.00 ± 3.06 μg) and control group (11.00 ± 4.57 μg).(p = 0.011). The median time to first rescue dose requirement of norepinephrine was significantly delayed in group N6(6[8–4.5] min) and group N4(4[9–2.5] min) as compared to control group (4[5–2] min) (p = 0.004). Conclusion: Prophylactic intravenous bolus dose of 6 μg norepinephrine when co-administered with spinal anesthesia was found to be more effective than 4 μg norepinephrine in terms of decreasing total rescue dose requirement of vasopressor and delaying the time to first rescue dose, without significant change in the incidence of hypotension.