Efficacy of transversus abdominis plane blocks as part of a multimodal analgesia regime for total abdominal hysterectomies

Patients who undergo a total abdominal hysterectomy (TAH) experience a significant amount of pain postoperatively. Several multimodal pain regimes have been used in the past to manage these women’s pain. Neuraxial anaesthesia is usually not a feasible option in these cases, because of the risks involved. Limited resources with the lack of high care unit beds available when intrathecal opioids are given are also a problem. Effective analgesia includes both improved comfort and decreased opiate side-effects, if morphine requirements can be decreased. After approval from the University of Cape Town Human Research Ethics Committee, the trial was registered with the South African National Clinical Trial Register (DOH-27-0212-3945) and the South African National Human Research Ethics Council. All patients between the ages of 20-65 with an ASA score I-III were included in a prospective double-blind randomised controlled trial after obtaining written informed consent from them the day before their operation. Patients were excluded if they were allergic to any of the trial medication (morphine, bupivacaine), had a history of opioid addiction, coagulation disorders, infection at needle insertion site or were unable to give informed consent. If surgery did not for some reason proceed to a TAH, the patient was also excluded. The patients were visited in the ward the day before their operation to obtain informed consent. All the patients received a patient-controlled analgesia (PCA) pump and this as well as the visual analogue pain scale (VAS) were demonstrated and explained to them. This was done by the same person (principle investigator) for all the patients. Our aim with this double-blind randomised controlled trial was to study the efficacy of ultrasound-guided transversus abdominis plane blocks in patients undergoing total abdominal hysterectomy. We randomly allocated thirty patients to two groups, a transversus abdominis plane block group (n=15) and a placebo group (n=15). The transversus abdominis plane blocks were done with 0.25% bupivacaine. The placebo group received a sham block with normal saline post induction of anaesthesia. All patients received postoperative morphine patient-controlled analgesia. Pain scores and morphine consumption were assessed at 0, 6 and 24 hours postoperatively. Our trial showed a significant between-group difference in morphine requirements (5.2±3.9 vs. 9.7±4.3 mg [p=0.007], and 12.9±8.9 mg vs. 25±12.1 [p=0.006]) for the transversus abdominis plane- compared with placebo group at 6 and 24 hours respectively. There were no significant between-group differences in pain scores. There were no complications associated with any block. Ultrasound-guided transversus abdominis plane block is an effective addition to a multimodal postoperative analgesia regimen for abdominal hysterectomy.

Grantor dc:publisher.institution

Department of Anaesthesia

Year dc:date.issued

2014

Author dc:creator

• Marais, Adri

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/13314

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/13314