RESUMO
Opioid-free anaesthesia (OFA) is a technique where no intraoperative systemic, neuraxial or intracavitary opioid is administered with the anaesthetic. Opioid-free analgesia similarly avoids opioids in the perioperative period. There are many compelling reasons to avoid opioids in the surgical population. A number of case reports and, increasingly, prospective studies from all over the world support its benefits, especially in the morbidly obese population with or without sleep apnoea. A derivative technique is opioid sparing, where the same techniques are used but some opioid use is allowed. This chapter is a review of the current knowledge regarding opioid-free or low-dose opioid anaesthetic and analgesic techniques for the following special populations: obesity, sleep apnoea, chronic obstructive pulmonary disease, complex regional pain syndromes, acute/chronic opioid addiction and cancer surgery. Practical aspects include sympatholysis, analgesia and Minimum Alveolar Concentration (MAC) reduction with dexmedetomidine; analgesia with low-dose ketamine and co-anaesthesia; and sympatholysis with intravenous lignocaine. Non-opioid adjuvants such as NSAIDS, paracetamol, magnesium, local anaesthetic infiltration and high-dose steroids are added in the perioperative period to further achieve co-analgesia. Loco-regional anaesthesia and analgesia are also maximised. It remains to be seen whether OFA and early postoperative analgesia, which similarly avoids opioids, can prevent the development of hyperalgesia and persistent postoperative pain syndromes.