Prophylaxis against post-spinal hypotension in elective C-section: Efficacy of Norepinephrine

The objective of a study was to compare the effectiveness and safety of norepinephrine (NE) and phenylephrine (PE) infusions in preventing post-spinal hypotension during cesarean section (C-section) under spinal anesthesia (SA).

This was a randomized clinical trial that enrolled 164 ASA I and II parturients undergoing C-sections under SA. All participants were prophylactically administered NE (0.05 µg/kg/min) or PE (0.75µg/kg/min) infusions. The primary outcome was the incidence of post-spinal hypotension. Secondary outcomes included severe post-spinal hypotension, reactive hypertension, bradycardia, total vasopressor rescue doses, physician interventions, nausea and vomiting, and Apgar scores at 1 and 5 minutes.

The results indicated comparable incidences of post-spinal hypotension and severe post-spinal hypotension between NE and PE groups. The need for vasopressor rescue doses, incidence of bradycardia, and reactive hypertension were similar in both groups. Meanwhile, nausea and vomiting were low and comparable. However, the number of physician interventions was significantly higher in the PE group (39.02%) compared to the NE group (28.04%).

The findings showed that the hemodynamics were comparable with NE and PE infusions in preventing hypotension during elective C-section; NE was associated with a lower number of physician interventions compared to PE. The study suggests that NE may be a preferable option for preventing post-spinal hypotension in patients undergoing an elective C-section.

Source: Saharia HK, Barman RK, Mili T, Sarma A, Barman M, Saikia B, Rajbongshi A. The New Indian Journal of OBGYN. 2023; 10(1): 46-53.