Postoperative analgesia in patients with substance use disorders: Part II

The specific problems related to postoperative analgesia in patients with substance use disorders (SUD) concerning opioids, alcohol, benzodiazepines, barbiturates (Part I), cocaine, crack, amphetamines, amphetamine-like designer drugs (MDMA, ecstasy), LSD, and marijuana (Part II) are described. Whereas SUD with only one substance rarely occurs, the number of polysubstance abusers is increasing. Patients with SUD may have multiple organic diseases, impaired immune response psychiatric and behavioural abnormalities, and substance-induced disorders (intoxication, withdrawal, delerium, psychotic disorders), often associated with low compliance and craving behaviour.

The perioperative management should be focused on three problems: (1) on the prevention of physical withdrawal symptoms and stressful complications in patients with SUD using CNS-depressants, (2) on the symptomatic treatment of the predominant affective withdrawal symptoms in patients suffering from SUD with CNS-stimulants, and (3) on the effective pain treatment.

The analgesic therapy is often difficult and required for longer periods of time than in other patients. However, the principles of multimodal analgesia are as valid as in non-addicts. To be effective, systemic analgesia with paracetamol, NSAIDs and opioids has to be adapted as usual, but regional analgesia techniques should be preferred for postoperative pain relief.

Patients enrolled in preoperative maintenance programmes (methadone, buprenorphine) need their daily maintenance dosage as baseline. This baseline therapy does not, however, induce analgesia. Therefore, these patients need additional short-acting opioids which have to be administered at higher dosages than usual (which do not cause respiratory depression due to opioid tolerance). The additional opioid does not increase the risk of relapse into active SUD. On the other hand, regional analgesia in patients who are enrolled in a maintenance programme does not mean withdrawal prophylaxis. These patients have an excellent analgesia, but they need their previously used maintenance opioid to prevent withdrawal. Special considerations will have to be made in patients with naltrexone.

Recovering patients with a history of SUD have both an intensive fear of relapsing into the active SUD as well as fear of suffering from postoperative pain. These patients require an equally effective analgesia as other patients. Depending on the type of surgery and pain intensity they need atypical opioids (eg tramadol) or strong opioids (eg buprenorphine or morphine) as a part of balanced analgesia to the same degree as other patients. Withholding effective analgesic treatment can paradoxically lead to relapses in recovering patients. The common opinion of healthcare providers to withhold strong opioids from recovering patients with SUD is obsolete. However, in order to avoid psychotropic side effects the dosages of opioids, as well as the analgesic efficacy, should be monitored closely.