Exploring Cardiac Effects After Oxytocin 2.5 I U or Carbetocin 100 μg: A Randomised Controlled Trial in Women Undergoing Planned Caesarean Delivery

Abstract

(Eur J Anaesthesiol. 2022;39:928–938) While oxytocin can be cardioprotective at physiologic levels, higher concentrations are used to prevent postpartum hemorrhage (PPH) and can induce hypotension, ST-depression, tachycardia, arrhythmias, and prolongation of the QTc interval. Further cardiovascular (CV) effects caused directly by oxytocin can result in fatalities in patients with underlying myocardial disease. Such acute risk for susceptible patients warrants characterization of CV changes induced by intravenous oxytocin and its commonly used analog carbetocin as administered to prevent PPH. While carbetocin has demonstrated comparable or improved effect for stimulating uterine contractions and has similar hemodynamic effects to oxytocin, the comparative prevalence of adverse cardiac events is unknown. Myocardial distress can be measured by the release of circulating troponin I (cTnI) and troponin T (cTnT), which are considered indirect indicators of ischemic heart damage. This exploratory Phase 4 randomized trial queried the difference in troponin release following oxytocin or carbetocin administration to approximate the incidence of cardiac adverse events when used to prevent PPH in women undergoing planned cesarean delivery (CD).