Substance abuse remains a major problem in the United States, and physicians can often encounter postsurgical patients who have addiction issues. Treating a patient with either acute intoxication or chronic use/abuse in the postoperative period can be quite challenging. Often, pain control can be hard to manage and could be misconstrued with drug-seeking behavior. Withdrawal symptoms should be monitored for and appropriately treated.

I. ALCOHOL

Alcohol is one of the most commonly abused substances in the United States. Up to 28% of surgical patients can have alcohol dependency.

A. Pharmacology

Alcohol is a term frequently used to refer to the substance ethanol. By binding to the γ-aminobutyric acid (GABA)_A receptor, ethanol affects the central nervous system (CNS) by increasing the inhibitory effects of the GABA neurotransmitter. Ethanol also inhibits N-methyl-D-asparate receptors and can lead to an upregulation of glutamate to maintain the CNS homeostasis. It is thought that both the decrease in both brain GABA levels and GABA-receptor sensitivity and the activation of glutamate systems have been implicated in the development of dependence, craving, and withdrawal.

B. Effects of Drug

Both acute intoxication and chronic alcohol use carry significant risks in the postoperative period. Patients who are acutely intoxicated in the postoperative setting can have increased sedation, impaired judgment, combativeness, and confusion. These patients are at increased risk for aspiration and can be at risk of injuring oneself or others. Chronic alcohol use can lead to liver disease, coagulapathies, immune deficiency, cardiomyopathy, increased risk for delirium, and electrolyte and glucose disturbances. Thus, they are at higher risk for postoperative bleeding, surgical wound infections, and electrolyte abnormalities, and they can be more susceptible to anesthetic side effects given impaired ability to metabolize these medications. Chronic alcoholics are also at increased risk for developing postoperative delirium.

C. Withdrawal Symptoms

Alcohol withdrawal onset occurs between 6 and 12 hours after ingestion of the last drink. Early symptoms include tremors, diaphoresis, nausea/vomiting, hypertension, tachycardia, hyperthermia, and tachypnea, but as the syndrome progress more serious complications can occur including visual and tactile disturbances, diffuse, tonic-clonic seizures, and fluctuating level of consciousness paired with severe autonomic symptoms known as delirium tremens (DT). Alcohol withdrawal symptoms can last up to 7 days and carry a 10% risk of mortality. It is important to consider that some agents commonly used for anesthesia
such as propofol and methohexital can increase GABA-mediated inhibitory tone in the CNS and postpone the onset of alcohol withdrawal.

D. Treatment

For sedated and combated patients who are acutely intoxicated, it is important to ensure that proper restraints and airway management equipment are available if needed. Treatment of alcohol withdrawal can be carried out with a combination of medications used to target the different symptoms associated with the syndrome. Benzodiazepines stimulate GABA receptors and are the gold standard agents in the management of alcohol withdrawal and prevention of complicated forms of it, with a reduction in the incidence of seizures, DT, and the associated risk of mortality. Recent clinical trials have found anticonvulsants such as carbamazepine and valproic acid, and barbiturates to also be efficacious in the treatment of alcohol withdrawal.

E. Potential Difficulties in Care Postoperatively

For chronic abusers of alcohol, alcohol withdrawal can be a life-threatening complication. The most dangerous complication of alcohol withdrawal is DT which can occur 2 to 4 days without alcohol. Seizures occurring during alcohol withdrawal are best treated with benzodiazepines. Agitation and hallucinations occurring during alcohol withdrawal should be treated with neuroleptics. Clonidine and β-blockers can serve as sympatholytics for controlling the autonomic manifestations of withdrawal. If clonidine and neuroleptics are used in conjunction, care must be taken to monitor QTc prolongation. Securement of the airway may be necessary when administering a large amount of sedatives to control symptoms.

II. HEROIN

Since 2007, the number of people who have started to use heroin has steadily risen. Part of the reason may be that heroin is more readily available and is cheaper than prescription opioids.

A. Pharmacology

Heroin is a drug of abuse that is a derivative of morphine. Users most often abuse the drug by injection, but it can also be administered by smoking, suppository (anal or vaginal insertion), insufflation (snorting), and ingestion (swallowing). Heroin, like all opioids, activate µ-, κ-, and δ-receptors. The µ-receptor is responsible for the reward and analgesic properties of opioids as well as the respiratory depression and constipation effects. Chronic use of opioids leads to up regulation of cyclic adenosine monophosphate along with gene transcription changes which may cause cellular tolerance.

B. Effects of Drug

Use of heroin can cause feelings of euphoria, sedation, and respiratory depression. People who use heroin on a long-term basis are at increased risk of addiction and infections from injection. The most dangerous complication of heroin use is overdose, which can lead to death.

C. Withdrawal Symptoms

Heroin withdrawal may present in the postoperative setting 6 to 24 hours after the last use of the substance. Symptoms may include nausea, dysphoria, anxiety, insomnia, rhinorrhea, gastrointestinal upset such as vomiting and diarrhea, and restlessness.

D. Treatment

Heroin withdrawal is not life-threatening, although it is unpleasant. Acute detoxification with long-acting agent methadone reduces symptoms dramatically. α₂-Agonists such as clonidine can also be used in suppressing autonomic symptoms, but should be used in conjunction with other drugs that can alleviate other withdrawal symptoms. However,
acute detoxification is rarely a sustainable solution, and people often relapse after completing it. Opioid replacement therapy has proven to be a more efficacious strategy reducing harm associated with heroin use; it consists of substituting heroin with noneuphoric agents such as methadone or buprenorphine. Psychosocial interventions need to be enacted and maintained to prevent relapse in the future.

E. Potential Difficulties in Care Postoperatively

Patients who are chronic users can be quite tolerant to opioids and typically need more medication to achieve the euphoric effects of opioid analgesics. Acute pain in the postoperative setting could be hard to treat. Quantification and conversion of a patient’s daily heroin use to opioid equivalents should be carried out. These patients should receive their baseline requirement in opioids minding that cross-tolerance between opioid agents is incomplete, hence adjustments are often needed to avoid accidental overdoses. Additionally, a short-acting opioids agents should be added for the treatment of acute pain postoperatively. Multimodal analgesics should also be added in order to achieve better pain control. Whenever possible, regional anesthesia should be implemented. A proper transition should occur between the acute postoperative pain management period and the discharge period. Appropriate follow-up after discharge should be coordinated.

III. RECOVERING/ABSTINENT HEROIN USERS

There may often be a fear to expose patients who are recovering or abstinent users to opioids in the postoperative setting. However, it is important to remember that increased pain without proper treatment could promote relapse after discharge from the hospital. Therefore, the appropriate course of action for these patients is treatment with short-acting opioid analgesics along with multimodal analgesics. After the acute pain management period, a taper plan for the opioids should be given and proper outpatient follow-up should be arranged to help prevent relapse.

IV. METHADONE

A. Pharmacology

Methadone is a long-acting µ-receptor agonist and N-methyl-D-aspartate antagonist that is used to treat patients with chronic pain or opiate abuse. Methadone has a half-life of 15 to 60 hours and its analgesic action can last between 6 and 8 hours.

B. Effects of Drug

Methadone’s effects are similar to those of other opioids. Other effects that methadone have include dizziness, vomiting, and sleep problems. Methadone can prolong QTc and cause heart arrhythmias. If used in conjunction with other QTc prolonging medications, frequent electrocardiography should be done to monitor for prolonged QT.

C. Withdrawal Symptoms

Methadone withdrawal presents similarly to withdrawal from other opioids. It usually begins 24 hours after the patient’s last dose. Common symptoms include chills, sweating, cravings, diarrhea, tachycardia, anxiety, irritability, insomnia, nausea, and vomiting.

D. Treatment

If a patient is withdrawing from methadone, he or she should be given the usual home dose of methadone. If the health care provider wants to ultimately have the patient come off of methadone, a strict taper schedule should be implemented. Psychosocial follow-up should be provided.

E. Potential Difficulties in Care Postoperatively

Patients on methadone may have a resistance to the euphoric effects of intravenous narcotics. Cross-tolerance with methadone does not occur; thus, these patients may need higher doses of pain medication
than would be required of patients who are not on methadone. When indicated, opioid analgesics should be given for pain in the postoperative setting in addition to the usual dose of maintenance methadone therapy. For patients on methadone maintenance therapy, the usual dosage of methadone should be continued after confirmation with the patient’s prescriber. If patients are not yet taking medications by mouth after surgery, parenteral methadone can be administered after the appropriate dose conversion.

V. BUPRENORPHINE