Uterotonic efficacy of oxytocin 2.5 versus 10 units during caesarean section at mulago hospital: a double blinded clinical trial.

Abstract

Introduction: Oxytocin is routinely administered during Caesarean section Delivery (C/S) to initiate and maintain adequate uterine tone (UT) and reduce blood loss after placenta delivery. Oxytocin is however associated with unwanted effects namely; tachycardia, hypotension, ECG changes, chest pain, nausea and vomiting. The magnitudes of these changes are dose dependant. In Uganda, 10 units of oxytocin is still being used, yet smaller doses have been shown to be effective at achieving adequate uterine tone and reducing blood loss with fewer side effects. Objective: To determine whether 2.5 International units of oxytocin gives adequate uterine tone and is safe as compared to 10 international units of oxytocin following caesarean section delivery at Mulago hospital. Methodology Study design: The study was a randomized double -blinded, clinical trial. Study population: Mothers undergoing both emergency and elective caesarean section delivery(C/S) in the obstetric theatres of Mulago hospital that fit the inclusion criteria and had consented to the study. 386 clients were recruited and randomized to receive 2.5 units or 10 units of Oxytocin after clamping of the umbilical cord. The primary out come: This was uterine tone (UT). The secondary out comes: These were heart rate (HR), NIBP, Blood Loss, MAP after administration of Oxytocin, as well as requirement of additional uterotonics.

Data Analysis Data was analysed using SPSS version 16. Categorical data was analysed using Fisher’s exact test. Mean (SD or median) was analysed using Kolmorgorov –Smirnov test. Data was analysed using ANOVA or Kruskal –Wallis test as appropriate. Results: 94.71% had adequate uterine tone after 2.5 units of oxytocin compared to 88.89% who received 10 units 2 minutes after injection. There was no statistical difference in requirement for additional uterotonics between groups ( p- value 0.119). There was also significant difference in blood loss. There was no significant difference in the frequency of vomiting (p=0.653), nausea (p=0.398), or chest pain (p=0.738) between the two treatment groups. The was no significant change in haemodynamics from the baseline mean values of MAP,SAP, HR in both groups. Conclusion; 2.5 International units of oxytocin give adequate uterine tone and is safe when compared to 10 international units of oxytocin following caesarean section delivery at Mulago hospital. Recommendation The routine use of 10 units of oxytocin for both elective and emergency caesarean section delivery should be revised as adequate uterine tone can be achieved with a lower dose of 2.5 units.