Intrathecal Morphine for Major Abdominal Surgery

Last week there was an anaesthesia clinical meeting at the Hospital of Miracles and Incurables. It included a presentation on anaesthesia for liver resection. A particular issue in Nick's excellent talk was postoperative analgesia for what is obviously an operation that needs it. While thoracic epidural analgesia is an effective tool, it is fraught by the deranged coagulation that occurs after liver resection, and which often persists until the time of desired removal. Despite this concern, Nick and his team in the UK used epidurals on many liver resection cases; effective analgesia without sequelae was the result in over 100 of them. The local team prefers to avoid epidurals, and it seems the patients kind of manage on "multimodal" intravenous analgesia, although the impression is that the postoperative period can be miserable for these patients. Unfortunately Nick didn't discuss intrathecal morphine through a preoperative single shot injection. This form of analgesia has been described and used in all manner of major operations and is widely used many in parts of the world, although not so much in Australia. However, there has, and is, a little hotbed of intrathecal morphine use, by yours truly. I have used it for several years, particularly for elderly women having major oncology surgery who seem particulary at risk of epidural haematoma because of osteoporotic spinal stenosis. And Di Pietri et al in Anesthesia Analgesia April 2006 find in their RCT on liver resection patients that the analgesia from 0.2 mg of intrathecal morphine and IVPCA is not inferior to thoracic epidural anlgesia. It is arguable to what extent a small spinal needle is less likely to cause haematoma than a large epidural needle and catheter, although it both plausible and supported by the prospective Swedish survey by Moen et al. Certainly the intrathecal technique avoids confusion about the cause of motor block and there is no need to be concerned about the timing of the withdrawal of a catheter. Respiratory depression seems only a remote possibility with a 0.2 mg dose. So it is a choice to be considered!