Alcohol intoxication

Alcohol intoxication is a temporary condition in which excessive consumption of alcohol alters consciousness, cognition, perception, judgment, affect, and/or behavior. Diagnosis is usually clinical, but diagnostic studies are indicated in clinical uncertainty or to identify alternative diagnoses and/or complications. Management is supportive: Most patients only require observation, but severely intoxicated patients may require management of agitation or respiratory support. Patients with a history of regular heavy alcohol use may require treatment for alcohol-related complications (e.g., Wernicke encephalopathy). Patients may be discharged when they are hemodynamically stable, motor and cognitive function has improved, and there is minimal risk of harm to themselves and others. Prior to discharge, patients should undergo screening for unhealthy alcohol use and appropriate follow-up provided if screening is positive.

For poisoning of unknown cause, see “Approach to the poisoned patient.”

• Mechanism: GABA-A receptor agonist
• Absorption: The majority of alcohol consumed is absorbed by the proximal small intestine; only a small amount of alcohol is absorbed by the oral, esophageal, and/or gastric mucosa. ^[1][2]

• Alcohol-related incidents represent ∼ 2% of all emergency department visits. ^[3]
• Alcohol intoxication accounts for ∼ 2,200 deaths in the US every year. ^[4]
  • Mortality is most common among men aged 35–64 years. ^[5]
  • Alcohol-impaired driving accounts for ∼ 30% of driving fatalities in the US. ^[6]
  • The all-cause mortality rate in individuals with ≥ 2 alcohol-related emergency department visits in ≤ 12 months is 5.4%. ^[7]

Epidemiological data refers to the US, unless otherwise specified.

• The manifestation, peak severity, and duration of symptoms depend on individual factors, e.g. : ^[8][9][10]
  • Genetics (e.g., ALDH2 deficiency) ^[11]
  • Alcohol absorption (e.g., alcohol concentration, rate of ingestion)
  • Alcohol metabolism (e.g., history of liver disease or gastric bypass, heavy drinking) ^[11][12]
  • Concurrent use of recreational drugs
• In individuals who do not have a history of long-term or heavy alcohol use, clinical features generally correlate with blood alcohol concentration (BAC). ^[8]

Motor vehicle drivers with a BAC ≥ 0.08 g/dL are considered to be alcohol-impaired and are at risk for injury and death. ^{[6][14] [10]}

Life-threatening features of alcohol intoxication (e.g., coma) and death can occur at BAC ≥ 250 mg/dL in individuals who do not have substance tolerance. ^[8][9][13]

Signs of decreased cardiac output (e.g., hypotension) may be seen in individuals with preexisting cardiac disease. ^[11]

See “Etiologies of altered mental status and coma.”

The differential diagnoses listed here are not exhaustive.

Most patients can be managed with simple observation in the emergency department. ^[11]

Approach ^[9][11]

• Perform an ABCDE survey to assess hemodynamic and respiratory stability. ^[7]
• Check vital signs and POC glucose; treat hypoglycemia if present. ^[7]
• Assess for concomitant conditions.
  • Look for signs of trauma and maintain a low threshold for imaging, as intoxication can reduce clinical features of trauma. ^[11]
  • Administer naloxone for opioid overdose if co-ingestion is suspected.
• Provide supportive care for alcohol intoxication when appropriate, e.g.: ^[13]
  • Respiratory support
  • Management of dehydration and hypovolemia
  • Prophylactic dose of thiamine supplementation (for Wernicke encephalopathy)
  • Electrolyte repletion
• Manage agitation as needed to facilitate care. ^[7][13]
  • Start with de-escalation techniques. ^[8]
  • For refractory agitation, use calming medications (e.g., benzodiazepines or haloperidol).
  • Monitor patients for associated respiratory depression; and initiate airway management for agitated patients if required.
• Regularly review patients; obtain diagnostic studies for alcohol intoxication if:
  • There is diagnostic uncertainty
  • The patient does not respond to treatment of intoxication
• Assess patients for indications for hospital admission and admit if present; consult specialists when appropriate.
• Ensure all patients have undergone screening for unhealthy alcohol use prior to discharge.

Do not assume agitation is caused by alcohol alone until other causes of agitation, such as injury or illness, have been excluded. ^[15]

Methods for gastrointestinal decontamination and enhanced elimination are generally discouraged because of the rapid absorption of alcohol, risk of complications (e.g., upper airway trauma with induction of emesis), and poor efficacy. ^[9][13]

Respiratory support ^[7][8]

• Select the degree of respiratory support based on clinical evaluation.
• Avoid using confirmatory studies (e.g., BAC level) to determine the patient's risk for respiratory instability. ^[9]

Fluid and electrolyte management ^[7][9][11]

• Most patients do not require fluid management.
• If clinical features of dehydration or hypovolemia are present, give oral or IV fluid therapy to manage dehydration and hypovolemia.
• Routine electrolyte repletion is not recommended. ^[7]

Do not use IV fluid therapy and diuresis to eliminate alcohol from the body as these are considered ineffective and can worsen complications of alcohol intoxication (e.g., electrolyte abnormalities). ^[7]

Vitamin supplementation ^[7][9][11]

• Suspected long-term alcohol use or evidence of malnutrition: Give thiamine to reduce the risk of Wernicke encephalopathy. ^[8][11][13]
• Avoid fixed-dose combined vitamin and mineral replacement (i.e., the “banana bag” approach). ^[7]

Do not delay glucose administration until thiamine has been given, because the risk of complications of hypoglycemia is greater than the risk of precipitating an acute thiamine deficiency. ^[7]

General principles

Diagnostic tests are not routinely required but should be considered for:

• Confirming the diagnosis if patients are either:
  • Unable to provide a history
  • Not responding to management of alcohol intoxication
• Identifying common complications of alcohol use
• Ruling out differential diagnoses of altered mental status in clinical uncertainty

Confirmatory studies

• Rapid tests (breath or saliva): usually used prehospital to estimate BAC ^[7][9][16]
• Blood alcohol concentration
  • Can detect alcohol up to 12 hours since the last alcoholic drink ^[12]
  • Expressed in mg/dL or as a percentage
  • See “Clinical features of alcohol intoxication” for expected presentation at specific levels.

Smelling alcohol on the breath is not a reliable method for confirming alcohol intoxication. ^[9]

Tests for ethanol metabolites detect alcohol up to 5 days since the last alcoholic drink; they are rarely used to assess for intoxication but may be useful to assess for abstinence (e.g., for liver transplant patients). ^[9]

Assessment for complications of alcohol use ^[7][9][11]

• Suspected long-term unhealthy alcohol use: diagnostic studies for alcohol-related complications
• Severe upper abdominal pain: lipase to rule out acute pancreatitis
• Symptoms of alcoholic hepatitis: liver chemistries
• Clinical features of alcoholic ketoacidosis
  • Blood gas
  • If an anion gap metabolic acidosis is identified: ^[7]
    • Serum osmolality, acetone, and/or lactate
    • Ketones (serum or urine)
• Tachycardia or chest pain: ECG to check for alcohol-induced atrial arrhythmia or ischemic ECG changes ^[7]
• Signs of respiratory distress: chest x-ray to rule out aspiration pneumonia or alcohol-induced cardiomyopathy

Exclusion of differential diagnoses of altered mental status ^[11]

• Ensure glucose levels are recorded in all patients.
• Obtain a CT head without contrast for patients with any of the following: ^[7][9][11]
  • Symptoms that are not explained by results of confirmatory testing (e.g., severe symptoms in a patient with BAC ≤ 300 mg/dL)
  • Patients with severe intoxication (e.g., BAC ≥ 300 mg/dL) and minimal clinical improvement after treatment
  • Concomitant head trauma or seizures ^[11]
• Consider urine drug screening if co-ingestion of other substances is suspected. ^[8]

Forensic medicine ^[7]

• Law enforcement may request a serum BAC for forensic purposes.
• If the patient is alert and able to provide consent, the clinician can take a sample.
• If the patient is unconscious or withholds consent, clinicians should defer to state law.

Reporting ^[7]

• Driving while intoxicated
  • State laws vary on the clinician reporting of intoxicated drivers.
    • In some states, reporting is mandatory; in others, it is not considered a reason to breach confidentiality.
    • If a passenger is a minor, there may be additional reporting requirements, e.g., to child protective services (CPS).
  • In all cases, discuss harm reduction strategies to reduce the risk of further incidents.
• Minors and alcohol intoxication: Check local laws, as mandatory reporting obligations may vary.
  • Intoxicated minors: Consider referral to social services.
  • Intoxicated adults in charge of minors ^[17]
    • Child in acute danger : Contact law enforcement and/or CPS.
    • Child not in acute danger: Consider referral to CPS based on the situation and mandatory reporting laws.

Indications for hospital admission ^[9][11]

• For medical care: Consult specialists (e.g., critical care) early, if indicated.
  • Hemodynamic instability
  • Respiratory depression
  • Altered mental status or coma
  • Impaired cognition or motor activity that impacts function
  • Evidence of trauma (see “Management of trauma” for further details)
  • Red flags for alcohol withdrawal
• For psychiatric care
  • Self-harm and/or suicide risk ^[7]
  • Substance-induced psychosis
• For social admission
  • Patients with barriers to care (e.g., homelessness, lack of transportation, discharge at night) ^[7]
  • Minors, to ensure appropriate psychosocial support ^[11]

Discharge from hospital setting ^[7][9][11]

• For patients with clinical features of alcohol intoxication: Discourage attempts to leave against medical advice. ^[7][9]
• Consider discharge in patients with all of the following:
  • Hemodynamic stability
  • Improved cognition and motor activity (e.g., able to function independently, steady gait) ^[7][11]
  • Minimal risk of harm to self and/or others
  • A safe method of getting home
• Using BAC to determine discharge is usually not recommended. ^[7]

Ethanol metabolism varies significantly, with elimination rates ranging from 10–35 mg/dL/hour. Base the decision to discharge on clinical intoxication and not a predicted BAC level. ^[7][18]

Ongoing care

• Screen for unhealthy alcohol use and provide the following prior to discharge: ^[7][9][11]
  • Education on harm reduction strategies ^[7][11]
    • Advise adequate micronutrient intake.
    • Caution against drinking and driving.
    • Encourage low risk drinking for patients who do not wish to be abstinent.
  • Resources for social support (e.g., Alcoholics Anonymous), especially for individuals with ≥ 2 alcohol-related emergency department visits in a year ^[7]
  • Referrals to psychiatry and/or alcohol rehabilitation or detoxification programs, if indicated ^[9]
• If possible, the patient should be monitored by a responsible adult for 24–48 hours. ^[11]
• Recommend outpatient follow-up with a primary care clinician to: ^[11]
  • Repeat screening for unhealthy alcohol use and reiterate patient education.
  • Review any new medications started in the ED.
  • Re-offer referrals for social support or rehabilitation.