In 2017, 86.3 percent of adults in the United States reported that they drank alcohol at some point in their lifetimes. In some cases, adults may develop alcohol use disorder (AUD), which—according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA)—is a “chronic relapsing brain disease characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences.”1 Because of the effects alcohol can have on physical and mental health and mortality, health professionals should consider a patient’s alcohol consumption when providing care. In particular, anesthesia providers must factor acute and chronic alcohol use into their practice to ensure patient safety.2
Acute alcohol use or intoxication can affect the risks of anesthesia induction.2 In order to prevent complications, the anesthesiology practitioner will conduct a preoperative evaluation of the patient’s level of intoxication. This includes assessment of confusion, aggression and psychomotor impairments.2 Blood alcohol concentration (BAC) may also be useful in diagnosing acute alcohol intoxication, but it may be inaccurate in up to 45 percent of trauma patients with a history of alcohol misuse.3 Also, consent can be difficult to obtain if the procedure must be performed while the patient is still intoxicated. An intoxicated patient may have to be treated as if lacking the capacity to make an informed decision.2 If the anesthesia provider decides to proceed, the intoxicated patient may be at risk for complications. For one, the increased risk of vomiting while intoxicated means rapid intubation will be necessary for anesthesia induction.2 Also, acute alcohol intake changes the balance between proinflammatory and anti-inflammatory immune cells, ultimately predicting an increased postoperative infection rate.3 Furthermore, alcohol—which itself has served as an anesthetic historically4—has a similar mechanism of action to various anesthetic drugs.3 Thus, alcohol intoxication can enhance the effects of sedatives and depressants used during anesthesia, such as opioids, propofol and thiopentone.3 An anesthesiologist must account for these lower dosing requirements when inducing anesthesia in an intoxicated patient.3 Alcohol and anesthetic drugs can even interact after the procedure has long been completed, though data on the extent of interaction remain unclear. While one study found that drinking alcohol four hours after thiopental injection increased psychomotor impairments,5 another showed that alcohol consumption four hours after a midazolam injection did not exacerbate any side effects.5 Regardless, acute alcohol intake has a profound effect on perioperative patient care.
Even without acute intoxication, chronic alcohol use can also influence an anesthesiologist’s practice.6 A patient who formerly had AUD may be at risk for relapse and alcohol craving after exposure to depressant drugs throughout the perioperative period.6 Patients may also show tolerance and decreased sensitivity to anesthetic drugs, creating a need for higher dosing.7 For patients who currently have AUD, life-threatening alcohol withdrawal can occur after six to 24 hours without alcohol.2 Symptoms of alcohol withdrawal include tremor, gastric upset, sweating, hypertension, hyper-reflexia, anxiety and agitation progressing to delirium, hallucinations, seizures and even death.2 An anesthesia provider must monitor the patient for signs of withdrawal and treat the patient prophylactically or during the procedure, usually with benzodiazepines or clomethiazole.2 Also, chronic alcohol use, whether current or past, can cause a variety of health conditions that may require vigilant monitoring by the anesthesiologist.3 These include—but are not limited to—high cholesterol, obesity, heart failure, hypertension, vitamin deficiencies, myopathy, osteoporosis, liver disease and gastritis.2 A study by Hudetz et al. found that patients with a history of alcohol abuse showed postoperative cognitive dysfunction after general anesthesia.8 Thus, even if patients are not currently using alcohol, the anesthesiology practitioner must be aware of their drinking histories and make appropriate adjustments.
Given the ubiquity of alcohol use and AUD, anesthesiologists must consider a patient’s current intoxication and past alcohol use when providing medications. While acute intoxication can exacerbate the effects of anesthetic drugs, chronic alcohol users may show tolerance to such drugs along with other health problems. In order to prepare anesthesia providers for alcohol-related issues, such as consent and withdrawal syndrome, medical schools should create standardized curricula on alcohol use for students and faculty alike.
1. National Institute on Alcohol Abuse and Alcoholism. Alcohol Facts and Statistics. Alcohol Facts and Statistics December 2019; https://www.niaaa.nih.gov/publications/brochures-and-fact-sheets/alcohol-facts-and-statistics.
2. Chapman R, Plaat F. Alcohol and anaesthesia. Continuing Education in Anaesthesia Critical Care & Pain. 2009;9(1):10–13.
3. Adams C. Anaesthetic implications of acute and chronic alcohol abuse. Southern African Journal of Anaesthesia and Analgesia. 2010;16(3):42–49.
4. Dundee JW, Isaac M, Clarke RSJ. Use of Alcohol in Anesthesia. Anesthesia & Analgesia. 1969;48(4):665–669.
5. Lichtor JL, Zacny JP, Coalson DW, et al. The interaction between alcohol and the residual effects of thiopental anesthesia. Anesthesiology. 1993;79(1):28–35.
6. May JA, White HC, Leonard-White A, Warltier DC, Pagel PS. The Patient Recovering from Alcohol or Drug Addiction: Special Issues for the Anesthesiologist. Anesthesia & Analgesia. 2001;92(6):1601–1608.
7. Loft S, Jensen V, Røsgaard S, Dyrberg V. Influence of Moderate Alcohol Intake on Thiopental Anesthesia. Acta Anaesthesiologica Scandinavica. 1982;26(1):22–26.
8. Hudetz Judith A, Ph.D., Iqbal Z, M.D., Gandhi Sweeta D, M.D., et al. Postoperative Cognitive Dysfunction in Older Patients with a History of Alcohol Abuse. Anesthesiology: The Journal of the American Society of Anesthesiologists. 2007;106(3):423–430.