Effect of methadone as pain relief in day-surgery patients undergoing a laparascopic gynaecological procedure

Methadone is an opioid medication used as a pain reliever medication and as a way of reducing withdrawal symptoms for those patients addicted to opioids. It is in the same class of drugs as codeine, oxycodone, morphine and fentanyl. These drugs are commonly employed to manage acute pain, such as that inflicted by surgery. Due to opioids having significant side effects alongside addictive properties, reducing the dose of such potent drugs is important, especially to avoid patients becoming dependent on them. Such adverse effects range from nausea, constipation and sedation to respiratory suppression, overdose and death. Laparoscopic surgery is a minimally invasive, moderately painful procedure commonly employed in general and gynaecological cases. Such procedures, especially gynaecological surgeries can be notoriously difficult to manage post-operative pain where no ideal analgesic regimen has been established. Conventionally, potent opioids like fentanyl and morphine are employed during surgery with patients frequently requiring opioids in both the PACU, and after discharge. This carries substantial risks and adverse effects. Methadone may offer an appealing alternative to current strategies. If the amount of post-operative opioid required can be reduced, not only will patients benefit in terms of greater comfort and fewer dose-related opioid adverse effects, but recent concerns about overprescribing of discharge opioids may be alleviated Hypothesis This study hypothesises that intraoperative methadone use will reduce PACU opioid consumption. As a result, we also predict that we will be able to reduce opioid dose (in morphine equivalents) consumed after discharge, at one week.