A comparative study of fractionated versus single dose injection for spinal anesthesia during cesarean section in patients with pregnancy-induced hypertension

Background: Local anesthetics for spinal anesthesia in one-single injection are known to induce more severe hypotension than a fractionated dose in healthy obstetric patients. Hypotension in obstetric patients with pregnancy-induced hypertension, including preeclampsia, during spinal anesthesia, could compromise fetal well-being. Objectives: This studyaimedtocomparethemeanarterial pressure (MAP), the total dose of ephedrine required, andlevel of sensory blockade between the fractionated-dose and single-dose spinal anesthesia injection in obstetric patients with pregnancy-induced hypertension who underwent a cesarean section. Methods: This single-blind randomized clinical trial was conducted from January to April 2018 after being approved by the Research Ethics Committee of Universitas Indonesia (No. 1174/UN2.F1/ETIK/2017) and recorded at ClinicalTrials.gov (NCT03693638). After obtaining informed consent, 42 parturients with hypertension in pregnancy (gestational hypertension or preeclampsia), ASA II-III, aged 18 - 40 years, and BMI of 18.5 - 35 kg/m² with singleton pregnancy, who were planned for spinal anesthesia for emergency or semi-emergency cesarean section with hyperbaric bupivacaine 0.5% (Marcaine^TM, Hospira) and fentanyl, were included in this study. All subjects were randomly divided into two groups including fractionated-dose (FD) and single-dose (SD). Results: There was no significant difference between the two groups in MAP in the first 15 minutes after anesthesia (P > 0.05) and median total dose of ephedrine required (10 (0 - 25) mg in the FD group vs. 15 (0 - 30) mg in the SD group, P = 0.30). However, in the FD group, MAP tended to be higher in the first three minutes compared to the SD group. The level of sensory blockade was mostly at T4, which was not significantly different between the groups (52.4% in FD vs. 42.9% in SD, P = 0.59). Conclusions: In obstetric patients with pregnancy-induced hypertension who underwent a cesarean section, the mean arterial pressure after spinal anesthesia was not significantly different between the fractionated dose of spinal anesthesia injection and single-dose injection. Total ephedrine required and levels of sensory blockade were not significantly different between the groups.