Perioperative management of patients with opioid tolerance and misuse

Patients with opioid pretreatment can be divided into different groups.While patients after successful drug addiction treatment with or without drug replacement therapy usually not require an extensive perioperative pain therapy, patients with persistent chronic pain and patients with an existing opioid addiction regularly are challenging for the anesthetist. Important pathophysiological issues among the patients include opioid tolerance, opioid-induced hyperalgesia (OIH) as well as acute withdrawal symptomes. Pharmakokinetic properties of the opioid seems to be crucial the manifestation of an acute withdrawal syndrome following opioid administration, and thus the use of remifentanil has frequently been reported to induce withdrawal symptoms. While all established anesthetic procedures can be applied, regional anesthetic techniques should be included whenever possible. A common misstake when treating patients with a history of opioid abuse is an unwarranted restraint in using opioids. In patients with a ongoing opioid abuse, it may be efficient to apply methadone or buprenorphine even prior to surgery. While pregabalin and gabapentin are first line therapeutics for treatment of neuropathic pain, they also seem to be effective co-analgesics in patients suffering from chronic pain and undergo surgery. A similar statement applies to clonidine and dexmedetomidine, which probably induce analgesia by activation of the descending antinociceptive noradrenergic system. The intraoperative administration of S-ketamine is recommended for patients who either already have developed opioid tolerance or suffer from neuropathic pain, and by which postoperative pain is high and was already shown to be poorly adjusted. Other therapeutic options such as intraoperative administration of magnesium or lidocaine may be promising approaches.