Prophylactic norepinephrine combined with 6% hydroxyethyl starch (130/0.4) co-load infusion for preventing postspinal anesthesia hypotension during cesarean section: a randomized, controlled, dose-finding trial

• Published in: Daru Vol. 32; no. 1; pp. 1 - 9
• Main Authors: Guo, Lei, Xiong, Xiangsheng, Qin, Rui, Li, Zhenzhou, Shi, Yongqiang, Xue, Wei, He, Ling, Ma, Shuqin, Chen, Yi
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-06-2024; Springer Nature B.V
• Subjects: Adult; Anesthesia, Obstetrical - adverse effects; Anesthesia, Obstetrical - methods; Anesthesia, Spinal - adverse effects; Biomedical and Life Sciences; Biomedicine; Blood Pressure - drug effects; Cesarean section; Cesarean Section - adverse effects; Dose-Response Relationship, Drug; Female; Humans; Hydroxyethyl Starch Derivatives - administration & dosage; Hypotension; Hypotension - etiology; Hypotension - prevention & control; Medicinal Chemistry; Norepinephrine - administration & dosage; Pharmaceutical Sciences/Technology; Pharmacology/Toxicology; Plasma Substitutes - administration & dosage; Pregnancy; Research Article; Young Adult; 6% hydroxyethyl starch (130/0.4); Norepinephrine; Postspinal anesthesia hypotension; Cesarean section; Co-load
• ISSN: 2008-2231; 1560-8115; 2008-2231
• DOI: 10.1007/s40199-023-00479-7

Purpose
Colloid and/or co-load may be more effective than crystalloid for preventing postspinal anesthesia hypotension. We tested five different prophylactic norepinephrine dosages combined with colloid co-load infusion in patients receiving cesarean section and spinal anesthesia.
Methods
Patients were randomly allocated to receive different prophylactic norepinephrine dosages (0 [NE 0 group], 0.025 [NE 25 group], 0.05 [NE 50 group], 0.075 [NE 75 group], or 0.1 [NE 100 group] µg/kg/min) combined with 500 mL 6% hydroxyethyl starch (130/0.4) immediately following spinal anesthesia (
n
 = 35 per group). The primary endpoint was the incidence of postspinal anesthesia hypotension (systolic blood pressure [SBP] < 80% of baseline). Secondary endpoints included severe hypotension, bradycardia, nausea or vomiting, hypertension, SBP stability control versus baseline, the 50% (effective dose, ED50) and 90% (ED90) dose effective for preventing postspinal anesthesia hypotension, Apgar scores, and umbilical cord blood gases.
Results
The incidence of postspinal anesthesia hypotension was 48.6%, 31.3%, 17.1%, 14.3%, and 5.7% in the respective groups. As the prophylactic norepinephrine dosage increased, the incidence of postspinal anesthesia hypotension declined (
p
 < 0.001), and SBP remained stable relative to baseline (median performance error [MDPE],
p
 < 0.001; median absolute performance error [MDAPE],
p
 = 0.001). The ED50 and ED90 values were -0.006 (95% CI -0.046—0.013) and 0.081 (95% CI 0.063—0.119) µg/kg/min. Other endpoints were comparable across the groups.
Conclusion
An initial prophylactic norepinephrine dosage of 0.05 µg/kg/min combined with 500 mL 6% hydroxyethyl starch (130/0.4) co-load infusion was optimal for preventing postspinal anesthesia hypotension during cesarean section.
Trial registration
NCT05133817, registration date: 12 Nov, 2021.