Question 1
A 45-year-old patient with a history of daily heavy alcohol consumption is undergoing an exploratory laparotomy. During induction, the anesthesia provider notes inadequate sedation despite standard weight-based dosing of propofol. The perioperative nurse anticipates which physiological mechanism?
▸ Why C is the answer
Patients with chronic alcohol use disorder frequently develop cross-tolerance to anesthetic agents that act on similar neurotransmitter pathways. Alcohol and drugs like propofol or benzodiazepines both enhance inhibitory signaling at GABA receptors. When a patient drinks heavily on a daily basis, their receptors downregulate, meaning standard weight-based doses of anesthetics will often provide inadequate sedation. You can rule out synergistic central nervous depression because that would cause profound sedation rather than inadequate sedation, which typically happens during acute intoxication rather than chronic tolerance. Decreased hepatic enzyme induction is incorrect because chronic alcohol use actually induces, rather than decreases, hepatic enzymes, leading to faster drug metabolism. Accelerated renal clearance mechanisms do not primarily drive the resistance to lipid-soluble anesthetics like propofol, making cross-tolerance the most accurate physiological explanation for this clinical presentation.
🔑 Key takeaway
Chronic alcohol use causes cross-tolerance to anesthetics that act on GABA receptors, requiring higher induction doses.
