Norepinephrine versus colloid for preventing spinal anesthesia-induced hypotension and its impact on intracranial pressure in preeclamptic parturients: a randomized double-blind controlled trial.

Abstract

This study aims to evaluate the effects of two strategies for preventing hypotension after spinal anesthesia (prophylactic fluid loading and norepinephrine infusion) on intracranial pressure (ICP) in preeclamptic women by measuring the optic nerve sheath diameter (ONSD) using ultrasound. In this prospective, randomized, controlled trial, 60 healthy parturients and 60 preeclamptic parturients undergoing cesarean delivery under spinal anesthesia were enrolled. Normal parturients were randomly assigned to the infusion group (NA group, n = 30) and NE (norepinephrine) group (NB group, n = 30), while preeclamptic parturients were randomly assigned to the infusion group (PA group, n = 30) and NE group (PB group, n = 30). The primary outcome was bilateral ONSD values at baseline, pretreatment, 5 min after spinal anesthesia (Post-SA), and 5 min after fetal delivery (Post-birth). The secondary outcomes included maternal general characteristics, renal function indices, postoperative headache, fetal umbilical cord arterial blood gas indices, and Apgar scores. Pretreatment ONSD was significantly higher than baseline in both infusion groups, and baseline ONSD was higher in preeclamptic versus normal parturients (all P < 0.01). Among preeclamptic parturients, pretreatment ONSD was higher in the PA group than in the PB group (P < 0.01), with a similar difference (PA > PB) confirmed in normal parturients (P < 0.01). In addition, compared to the PA group, the PB group showed no significant differences in systolic blood pressure (SBP), diastolic blood pressure (DBP), or mean arterial pressure (MAP) at any time point in preeclamptic parturients (P > 0.05). Conversely, in normal parturients, post-birth SBP, DBP, and MAP were significantly higher in the NB than in the NA group (P < 0.01). Baseline hemodynamic values were higher in preeclamptic versus normal parturients (P < 0.01), and post-birth values decreased significantly from baseline in the PA and PB groups (P < 0.001). No significant intergroup differences were observed in maternal heart rate (HR), renal function indices, umbilical artery blood gas indices, Apgar scores, or the incidence of postpartum headache (all P > 0.05). For preeclamptic parturients, the risks induced by ICP increase should be noted. Compared to colloids, prophylactic infusion of NE was more effective and safer and did not increase ICP. This randomized controlled trial was registered on Chinese Clinical Trial Registry (ChiCTR2400092317; http://www.chictr.org.cn/) with the Clinical Trial Registry ({1}).