Comparison of the benefits and hemodynamic side effects of oxytocin between intravenous infusion with and without bolus injection during caesarean section.

The aim of this study was to compare the benefits and hemodynamic side effects of oxytocin between intravenous infusion with and without a bolus injection during a caesarean section. Women with singleton pregnancies who underwent caesarean sections under spinal anaesthesia were included. Oxytocin was administered by an iv bolus injection (5 U) followed by an intravenous infusion (10 U of oxytocin in 500 mL normal saline); this was switched to just an intravenous infusion. The amount of blood loss did not differ between the groups. In a multivariate analysis, the adjusted odds ratios for the risk of hypotension (≥20% reduction of systolic BP) and tachycardia (heart rate ≥100 bpm) were 4.5 (95% confidence interval [CI], 1.6-12.5) and 3.7 (95%CI 1.9-7.2) in the iv bolus group, respectively, compared with the just the infusion group. The oxytocin administration by iv bolus injection did not decrease blood loss and increased the rate of hemodynamic side effects.Impact statement