Clinical twisters: Drug abuse can affect surgery

July 25, 2005

A 30-year-old African-American, B.H., is scheduled for hernia repair surgery at your hospital. In his admitting medical history, he acknowledges to your student that he is a heavy drinker and uses marijuana recreationally. Your student is suspicious that his recreational drug use may extend beyond marijuana. Will you recommend any modifications to your standard premedication/ anesthesia/postsurgery protocol?

A 30-year-old African-American, B.H., is scheduled for hernia repair surgery at your hospital. In his admitting medical history, he acknowledges to your student that he is a heavy drinker and uses marijuana recreationally. Your student is suspicious that his recreational drug use may extend beyond marijuana. Will you recommend any modifications to your standard premedication/ anesthesia/postsurgery protocol?

The first step is a frank discussion with the patient about the type and extent of substance abuse. If abuse is extensive, I'd recommend elective surgery be postponed until the patient undergoes detoxification. If surgery is of an emergent nature, prevention and treatment of an abstinence syndrome for all of the substances used becomes paramount. Treatment of withdrawal depends on the patient's specific drug use.

Supportive care and benzodiazepines may be used to manage alcohol withdrawal symptoms. Patients should also receive parenteral thiamine followed by oral thiamine to prevent Wernicke's encephalopathy secondary to administration of intravenous glucose solutions.

Ann M. Rule, Pharm.D.Assistant Professor of Pharmacy PracticeSchool of Pharmacy and Health SciencesCreighton UniversityOmaha

First, we need an accurate history. Generally, patients will tell the truth if they know you're not judgmental but just need accurate information for dosing pain medication. When drug abuse is suspected, I recommend a drug screen, especially in elective surgeries. Alcohol withdrawal can be prevented by benzodiazepine use postsurgically-but benzodiazepines can complicate opiate analgesic dosing, increasing the potential for sedation and respiratory suppression.

Whether or not marijuana poses postoperative problems depends on its quality and frequency of use. Intraoperatively, heavy marijuana users can pose an anesthetic dilemma: They can emerge from anesthesia prematurely or experience pain before completion of surgery. Restlessness produced by marijuana abstinence can be managed with a benzodiazepine or dronabinol (Marinol, Unimed). Unless withdrawal symptoms are managed, a patient can complain of uncontrolled pain despite adequate opiate analgesia.

Mixed drug withdrawal can also occur, exacerbating the patient's pain perception and reducing his ability to cope. Careful monitoring, vigilant assessment, and reassessment are essential to manage withdrawal symptoms and alleviate unnecessary pain and suffering.

Peter J. S. Koo, Pharm.D.Associate Clinical Professor of PharmacyPharmacist Specialist, Pain ManagementDepartment of Clinical Pharmacyand Pharmaceutical ServicesUniversity of California, San Francisco