Efficacy and Safety of Different Norepinephrine Regimens for Prevention of Spinal Hypotension in Cesarean Section: A Randomized Trial

Abstract

The aim of this paper is to evaluate the efficacy and safety of three different norepinephrine dosing regimens for preventing spinal hypotension in cesarean section. In this randomized double-blinded controlled study, 120 parturients scheduled for elective section delivery under spinal anesthesia were assigned to 1 of 4 groups. In the control group, patients received saline infusion. In three norepinephrine groups, the infusion dosage regimens were 5, 10, and 15 μg/kg/h, respectively. Hypotension was treated with a rescue bolus of 10 μg norepinephrine. The study protocol was continued until the end of surgery. The primary outcome was the proportion of participants that underwent hypotension. The proportion of hypotension participants was significantly reduced in the norepinephrine groups (37.9%, 20%, and 25%, respectively) compared to that in the control group (86.7%). However, the highest dose of norepinephrine (15 μg/kg/h) resulted in more hypertension episodes. In addition, blood pressure was better maintained in the norepinephrine 5 μg/kg/h and 10 μg/kg/h groups than in the control group and 15 μg/kg/h group. No significant differences in other hemodynamic variables, adverse effects, maternal and neonatal blood gases, or Apgar scores were observed among the groups. In summary, for patients who undergo cesarean delivery under spinal anesthesia, infusion of 5-10 μg/kg/h norepinephrine was effective to reduce hypotension incidence without significant adverse effects on maternal and neonatal outcomes. Clinical Trial Registration Number is ChiCTR-INR-16009452.

Figure 1

CONSORT flow chart.

Figure 2

Hemodynamic changes. Data are shown for five timepoints: baseline (T1), the highest level of sensory block (T2), delivery (T3), oxytocin administration (T4), and end of surgery (T5). Data are presented as mean (SD). Asterisks in the upper blank indicate overall significance of each timepoint. ^∗p < 0.05; ^∗∗p < 0.01. Post hoc multiple comparison results are shown in supplementary Table S2.