Substance abuse among patients presenting for surgery is a significant concern for anesthesia providers due to the complex interactions between the substances of abuse and anesthetic drugs, as well as the physiological and psychological changes these substances cause. Effective preoperative management of such patients requires a detailed understanding of the specific substances abused, their effects on the body, and the potential risks and challenges they pose during anesthesia.
Alcohol
Alcohol is one of the most frequently abused substances in patients presenting for surgery. Chronic alcohol use is associated with multiple systemic effects, including liver dysfunction, cardiovascular instability, respiratory compromise, and immunosuppression. Acute intoxication, on the other hand, presents an immediate risk of aspiration due to reduced lower esophageal sphincter tone and impaired airway reflexes. Alcohol withdrawal, characterized by symptoms ranging from mild tremors and anxiety to severe delirium tremens, poses a significant perioperative risk due to its potentially life-threatening complications, including seizures, electrolyte disturbances, and hemodynamic instability.
Preoperative management should involve screening and assessment using validated tools such as the AUDIT (Alcohol Use Disorders Identification Test) or CAGE questionnaire. Patients should be evaluated for alcohol-related organ damage, such as liver cirrhosis, cardiomyopathy, and coagulation disorders. Preventing withdrawal is crucial and may include the use of benzodiazepines for symptom-triggered or scheduled dosing. Patients with liver dysfunction may require vitamin K or fresh frozen plasma to correct coagulopathy, and fluid and electrolyte imbalances should be corrected preoperatively.
Benzodiazepines
Benzodiazepines are commonly prescribed for anxiety, insomnia, and other psychiatric disorders. Chronic use can lead to physical dependence, and abrupt cessation may result in withdrawal symptoms, which can range from mild anxiety and insomnia to severe seizures. Overdose or co-ingestion with other central nervous system depressants can result in profound respiratory depression, hypotension, and coma.
Preoperative management should include a thorough history of benzodiazepine use and continuation of therapy to prevent withdrawal. For patients at risk of benzodiazepine withdrawal, a long-acting benzodiazepine may be used for symptom-triggered or scheduled tapering. Anesthetic agents that potentiate the effects of benzodiazepines should be used cautiously, and intraoperative monitoring of respiratory function is essential.
Stimulants (Cocaine and Methamphetamines)
Stimulants such as cocaine and methamphetamines are associated with significant cardiovascular risks, including tachycardia, hypertension, arrhythmias, myocardial ischemia, and cardiomyopathy. Cocaine use may also cause nasal septal perforation and pulmonary complications, while methamphetamine use is associated with severe dental decay ("meth mouth") and airway challenges.
Preoperative management includes a thorough cardiovascular assessment and, if possible, postponement of surgery until acute effects have subsided. Patients should be closely monitored for signs of cardiovascular instability, and airway management should be planned carefully, especially if there is significant nasal damage.
Opioids
Opioid use, both therapeutic and illicit, is increasingly prevalent. Chronic opioid use leads to tolerance, physical dependence, and hyperalgesia, complicating perioperative pain management. Heroin users may have coexisting infections and difficulties with venous access, while methadone or buprenorphine maintenance therapy is common in patients recovering from opioid addiction.
Preoperative management should continue opioid therapy up to the day of surgery to prevent withdrawal. Multimodal analgesia strategies should be employed, and patients should be monitored closely for signs of respiratory depression.
Marijuana
Marijuana is the most commonly abused illicit drug and is now legal for medical or recreational use in many regions. While marijuana has relatively mild respiratory effects compared to tobacco, chronic use can lead to airway hyperreactivity, chronic cough, and mild airflow obstruction.
Preoperative management includes a detailed history of marijuana use and careful monitoring for potential interactions with anesthetic drugs. Airway management should consider the possibility of bronchospasm, especially during induction of anesthesia.
Club Drugs and Designer Drugs
Club drugs and designer drugs, such as ecstasy, LSD, PCP, ketamine, flunitrazepam, GHB, bath salts, and spice, have a wide range of effects on the central nervous system and other organ systems. These substances can cause severe hyperthermia, hyponatremia, rhabdomyolysis, cardiac complications, dissociative effects, agitation, and respiratory depression.
Preoperative management focuses on supportive care, including stabilization of vital signs and correction of electrolyte abnormalities. Continuous monitoring of vital signs, oxygen saturation, and cardiac rhythm is essential due to the unpredictable effects of these substances.
| Substance | Principal perioperative risks | Preoperative management |
|---|---|---|
| Alcohol | Liver dysfunction, cardiovascular instability, respiratory compromise, and immunosuppression; aspiration risk with acute intoxication; withdrawal up to delirium tremens | Screen with AUDIT or CAGE; evaluate for cirrhosis, cardiomyopathy, and coagulation disorders; benzodiazepines to prevent withdrawal; vitamin K or fresh frozen plasma for coagulopathy; correct fluid and electrolyte imbalances |
| Benzodiazepines | Withdrawal ranging from anxiety and insomnia to seizures; profound respiratory depression, hypotension, and coma with overdose or co-ingestion | Take a thorough use history and continue therapy; a long-acting benzodiazepine for symptom-triggered or scheduled tapering; use potentiating anesthetics cautiously with intraoperative respiratory monitoring |
| Stimulants (cocaine, methamphetamine) | Tachycardia, hypertension, arrhythmias, myocardial ischemia, and cardiomyopathy; nasal septal perforation and pulmonary complications; severe dental decay and airway challenges | Thorough cardiovascular assessment; postpone surgery until acute effects subside if possible; monitor for cardiovascular instability; plan airway management around significant nasal damage |
| Opioids | Tolerance, physical dependence, and hyperalgesia; coexisting infections and difficult venous access in heroin users | Continue opioid therapy up to the day of surgery to prevent withdrawal; multimodal analgesia; monitor closely for respiratory depression |
| Marijuana | Airway hyperreactivity, chronic cough, and mild airflow obstruction | Detailed use history; watch for interactions with anesthetic drugs; consider the possibility of bronchospasm during induction |
| Club and designer drugs | Hyperthermia, hyponatremia, rhabdomyolysis, cardiac complications, dissociative effects, agitation, and respiratory depression | Supportive care with stabilization of vital signs and correction of electrolyte abnormalities; continuous vital sign, oxygen saturation, and cardiac rhythm monitoring |
