A comparison of the overall pain scores post elective caesarean section, when initial intraoperative analgesia is given intravenously (IV) versus per rectum (PR).

Currently, opinion amongst obstetric anaesthetists is divided as to whether an intravenous (IV) route is superior to the per rectum (PR) route for perioperative mangagement of post caesarean section pain. Recently, a prospective audit was conducted at the Northern Hospital. This audit assigned 50 women to receive IV analgesia and a further 50 women received PR analgesia post caesarean section, which was either an elective or an emergency procedure. Analysis of the data revealed that the group who had received IV analgesia had a lower 48 hour oxycodone usage of 148.9 +/- 36.7 compared to the PR analgesia group, which had a 48 hour oxycodone usage of 170.0 +/- 47.5 mg. This difference is a 12.4% reduction. Despite this apparent difference in opioid requirements, there did not appear to be a difference in pain scores as reflected by the fact that for three of the four pain questionnaires, all of which were unidimensional measurements of pain, there was no statistical difference between the two groups. For the fourth pain questionnaire, which measures the multidimensional aspect of pain, a statistical difference was found favouring the group who had received IV analgesia. Therefore, we wish to expand upon these findings and would like to propose a non-blinded randomised controlled trial comparing the IV route to the PR route. Based on data previously obtained, if the IV route provided better analgesia, we propose that there should be a 20% reduction in the total pain score as determined by the multidimensional pain questionnaire (SF-MPQ).