Phenylephrine Versus Noradrenaline for the Prevention and Treatment of Spinal-Induced Hypotension During Caesarean Section: A Literature Review

Spinal anaesthesia is the most commonly used anaesthetic technique for caesarean section due to its rapid onset, reliability, and favourable safety profile. Despite these advantages, spinal-induced hypotension remains a common complication with potential adverse effects on maternal and fetal well-being, including nausea, vomiting, dizziness, reduced cardiac output, and impaired uteroplacental perfusion. Phenylephrine remains the guideline-supported first-line vasopressor for spinal-induced hypotension during caesarean delivery because of its effectiveness in maintaining maternal blood pressure and its favourable fetal acid-base profile, including a lower risk of fetal acidosis compared with ephedrine. However, it may cause reflex bradycardia and reduced maternal cardiac output. Norepinephrine (noradrenaline) has emerged as a promising alternative because its α-adrenergic effects, combined with modest β1 activity, may better preserve maternal heart rate and cardiac output. A narrative literature review was conducted using PubMed/MEDLINE, Scopus, and Google Scholar. Studies were included if they evaluated maternal haemodynamic outcomes, adverse maternal effects, neonatal outcomes, or vasopressor efficacy during caesarean delivery under spinal anaesthesia. Recent trials and meta-analyses suggest that noradrenaline provides comparable efficacy to phenylephrine, with similar neonatal outcomes and potential maternal haemodynamic advantages. However, phenylephrine remains the current guideline-supported first-line agent, while noradrenaline requires further clarification regarding optimal dosing, safety, and routine first-line use. This review evaluates phenylephrine and noradrenaline for both prophylaxis and rescue treatment of spinal-induced hypotension during caesarean section.