Norepinephrine vs. Phenylephrine for Hypotension in Low-Dose Spinal Anesthesia for Cesarean Delivery

Summary

This clinical trial was conducted to compare the effectiveness and safety of two medications, norepinephrine and phenylephrine, in preventing hypotension during low-dose spinal anesthesia for cesarean delivery (CD). Although low-dose spinal anesthesia combined with opioids is widely used to mitigate hypotension, the incidence remains unacceptably high. Thus, vasopressors remain essential in maintaining maternal blood pressure during these procedures. In this study, 100 women were initially assessed, with 2 excluded. The remaining 98 were randomly assigned to receive a continuous infusion of either norepinephrine or phenylephrine. During the follow-up process, 2 patients from each group were lost, resulting in 47 participants per group for final analysis. The results showed that norepinephrine was significantly more effective, with a lower incidence of hypotension (14.9% vs. 42.6%). It also provided more stable heart rates with fewer episodes of bradycardia and less need for rescue medications. Both treatments were safe for the babies with comparable Apgar scores. This study suggests that Norepinephrine infusion at 0.05 mcg/kg/min is more effective than phenylephrine at 0.25 mcg/kg/min in preventing hypotension during low-dose SA in CD, providing better hemodynamic stability and fewer episodes of bradycardia

Timeline

Start

2024-06-06

Primary completion

2025-10-04

Completion

2025-10-04

Publications

• Results 1. Afolabi BB, Lesi FEA. Regional versus general anaesthesia for caesarean section. Cochrane Database of Systematic Reviews. 2012(10). doi: 10.1002/14651858.CD004350.pub3. PubMed PMID: CD004350. 2. Vallejo MC, Attaallah AF, Elzamzamy OM, Cifarelli DT, Phelps AL, Hobbs GR, et al. An open-label randomized controlled clinical trial for comparison of continuous phenylephrine versus norepinephrine infusion in prevention of spinal hypotension during cesarean delivery. International journal of obstetric anesthesia. 2017;29:18-25. Epub 2016/10/11. doi: 10.1016/j.ijoa.2016.08.005. PubMed PMID: 27720613. 3. Klöhr S, Roth R, Hofmann T, Rossaint R, Heesen M. Definitions of hypotension after spinal anaesthesia for caesarean section: literature search and application to parturients. Acta anaesthesiologica Scandinavica. 2010;54(8):909-21. Epub 2010/05/12. doi: 10.1111/j.1399-6576.2010.02239.x. PubMed PMID: 20455872. 4. Herbosa GAB, Tho NN, Gapay AA, Lorsomradee S, Thang CQ. Consensus on the Southeast Asian management of hypotension using vasopressors and adjunct modalities during cesarean section under spinal anesthesia. Journal of Anesthesia, Analgesia and Critical Care. 2022;2(1):56. doi: 10.1186/s44158-022-00084-1. 5. Kinsella SM, Carvalho B, Dyer RA, Fernando R, McDonnell N, Mercier FJ, et al. International consensus statement on the management of hypotension with vasopressors during caesarean section under spinal anaesthesia. Anaesthesia. 2018;73(1):71-92. Epub 2017/11/02. doi: 10.1111/anae.14080. PubMed PMID: 29090733. 6. Allen TK, George RB, White WD, Muir HA, Habib AS. A double-blind, placebo-controlled trial of four fixed rate infusion regimens of phenylephrine for hemodynamic support during spinal anesthesia for cesarean delivery. Anesthesia and analgesia. 2010;111(5):1221-9. Epub 2010/05/25. doi: 10.1213/ANE.0b013e3181e1db21. PubMed PMID: 20495139. 7. Habib AS. A Review of the Impact of Phenylephrine Administration on Maternal Hemodynamics and Maternal and Neonatal Outc

Drugs

Indications