Effect of transversus abdominis plane block on post-operative morphine consumption in total abdominal hysterectomy patients

Abstract

Background and objectives Patients undergoing total abdominal hysterectomy experience moderate to severe post-operative pain. Peripheral nerve blocks such as the transversus abdominis plane block have been described to decrease post-operative pain in this population group. This study was conducted at the Rahima Moosa Mother and Child Hospital in Johannesburg, South Africa, amongst patients undergoing total abdominal hysterectomy. The primary aim was to assess the post-operative morphine consumption between patients who received a transversus abdominis plane (TAP) block, compared to those who did not receive a TAP block. In addition, pain scores and side effects were assessed between the TAP block and non-TAP block group. Methods One hundred and twenty six patient records were included in this retrospective study using a consecutive convenience sampling method. They were divided into the TAP block group and the non-TAP block group. Patient records assigned to the TAP block group had received TAP blocks by the anaesthetist after the induction of general anaesthesia, whilst the patient records assigned to the non-TAP block group only received a general anaesthetic. Both groups received intravenous analgesia as predetermined by the anaesthetist. Patients then received a patient controlled analgesia pump in the recovery room. The acute pain trainee documented the morphine consumption at Time 1, Time 2 and Time 3, the Numeric Rating Scale pain scores and any side effects experienced by the patient. Results There was no significant difference between the morphine consumption in the TAP block versus the non-TAP block groups at Time 1, Time 2 or Time 3. There was no significant difference of pain scores between the two groups. Conclusion TAP blocks did not decrease the amount of post-operative morphine consumed in patients who received a total abdominal hysterectomy, nor did it result in any differences in Numeric Rating Scale pain scores between the two groups