eMedicine Specialties > Emergency Medicine > Toxicology

Withdrawal Syndromes: Differential Diagnoses & Workup

Author: Nathanael J McKeown, DO, Assistant Professor, Oregon Health and Science University; Medical Toxicologist, Oregon Poison Center; Attending Physician, Emergency Medicine, Portland Veteran Affairs Medical Center, Oregon Health and Science University
Coauthor(s): Patrick L West, MD, Clinical Instructor, Medical Toxicology Fellow, Department of Emergency Medicine, Oregon Health and Sciences University; Staff Physician, Department of Emergency Medicine, Portland Veterans Affairs Medical Center
Contributor Information and Disclosures

Updated: Oct 27, 2009

Differential Diagnoses

Workup

Laboratory Studies

• Serum glucose or finger-stick glucose test is indicated.
  • Patients with liver disease due to alcoholism have reduced glycogen stores, and ethanol impairs gluconeogenesis. As a consequence, these patients are susceptible to hypoglycemia.
  • Patients in alcohol withdrawal develop anxiety, agitation, tremor, seizure, and diaphoresis, all of which can occur with hypoglycemia.
• Analysis of arterial blood gases may be indicated.
  • Mixed acid-base disorders are common and usually result from AKA, volume-contraction alkalosis, and respiratory alkalosis.
  • Patients with these disorders may have hypoxia due to aspiration pneumonitis.
• Chemistry panel analysis is indicated.
  • A CHEM-7 analysis or its equivalent is indicated to look for acidosis, dehydration, concurrent renal disease, and other abnormalities that can occur in patients with chronic alcoholism. It also provides data needed to calculate anion and delta gaps, which are helpful in differentiating mixed acid-base disorders.
  • A low BUN value is expected in alcoholic liver disease. Obtain lipase levels if pancreatitis is suspected. Obtain the blood ammonia level if hepatic encephalopathy is suspected.
  • Determination of magnesium and calcium levels and liver function tests (LFTs) may be indicated because patients with chronic alcoholism usually have dietary magnesium deficiency and possibly concurrent alcoholic hepatitis. Alcoholic pancreatitis may cause hypocalcemia.
• Urinalysis is indicated.
  • Routinely check for ketones, as patients may have associated AKA.
  • Ketonuria without glycosuria must be investigated further to exclude AKA and the ingestion of isopropyl alcohol.
  • Myoglobinuria from rhabdomyolysis may first be suspected when hematuria is noted on urinalysis.
• CBC determination is recommended.
  • Long-term alcohol ingestion leads to myelosuppression with a slight reduction in all cell lines. Thrombocytopenia is common.
  • Blood loss from the GI tract and nutritional deficiencies producing anemia are common in alcohol withdrawal.
  • Many patients have dehydration, and hemoconcentration and anemia may become apparent only when rehydration is accomplished.
  • Megaloblastic anemia is observed in people with alcoholism and based on a dietary deficiency of vitamin B-12 and folate. Increased mean corpuscular volume suggests this condition.
• Cardiac markers may be indicated.
  • Elevated CK and cardiac troponin levels may indicate myocardial infarction resulting from increased demands placed on the heart from hypertension associated with alcohol withdrawal or from hypertension produced by cocaine intoxication prior to the patient's presentation.
  • Elevated CK level can also be from rhabdomyolysis, which may be associated with significant adrenergic hyperactivity from alcohol withdrawal or from myonecrosis in immobile patients.
• Measurement of prothrombin time may be indicated.
  • The prothrombin time (PT) is a useful index of liver function; patients with cirrhosis are at risk for coagulopathy.
  • PT should be considered in a patient with active bleeding in the GI tract or CNS.
• Toxicology screening may be indicated.
  • Consider measuring serum osmolality and screening for toxic alcohols if the patient is severely acidemic.
  • The ethanol concentration is frequently zero. However, some patients that are habituated to alcohol can be in severe alcohol withdrawal even if ethanol levels are clinically significant.
  • Send urine samples for drug toxicology screening because co-ingestion of other medications (eg, psychiatric medications) and use of other recreational drugs are common.
  • GHB, ketamine, fentanyl, and many other drugs of abuse are not included in routine urine drug screening, and a special request may be required if use of these drugs is suspected.

Imaging Studies

Imaging studies should be directed to the patient's clinical course.

• Chest radiography
  • Aspiration pneumonia is common among patients with alcohol withdrawal syndrome.
  • People with chronic alcoholism may have cardiomyopathy and CHF.
  • Patients using intravenous drugs are at increased risk for immunosuppression and consequently prone to pneumonia.
• Head CT scanning
  • Patients with alcohol withdrawal syndrome are at risk for intracranial bleeding because of cortical atrophy and coagulopathy.
  • Consider obtaining a head CT in patients with an inappropriate level of consciousness, in those with multiple seizures, in those with signs of head trauma, and in those with an unexpected failure to respond to treatment.
  • Cocaine can cause intracerebral bleeding due to hypertension. The symptoms may closely resemble those of the cocaine wash-out syndrome.
• Abdominal CT scanning: Patients with a history of intravenous drug abuse and unexplained hip pain may have intra-abdominal pathology, including psoas abscess, which may be seen on abdominal CT scan or ultrasonography.
• Spinal MRI: In patients with unexplained back pain, intravenous drug abuse, and fever, spinal MRI may be required to rule out epidural abscess, particularly if focal neurologic deficits are also present.
• Other imaging may be indicated if trauma or other associated conditions are suspected.

Other Tests

• Electrocardiography
  • Adrenergic storm produced by alcohol withdrawal increases demands on the heart and may precipitate infarction in susceptible individuals.
  • A prolonged QTc interval has been described in patients with alcohol withdrawal syndrome.⁴ The interval gradually reverts to normal as withdrawal symptoms remit.
• Lumbar puncture: One should have a low threshold for lumbar puncture and spinal-fluid analysis to rule out meningitis or subarachnoid hemorrhage because individuals in withdrawal are at increased risk.
• Blood cultures may also be indicated if sepsis or endocarditis is suspected in this group of often immunosuppressed patients.
• Additional tests may be indicated based on a patient's presentation.

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