Does ethanol explain the acidosis commonly seen in ethanol-intoxicated patients?

OBJECTIVE: Emergency physicians frequently treat ethanol-intoxicated trauma patients. In patients with apparently minor injuries, the presence of metabolic acidosis is often attributed to serum ethanol. We tested whether there is justification for the bias that ethanol reliably explains the acidosis commonly seen in alcohol-intoxicated patients.
METHODS: Prospective, observational. INCLUSION CRITERIA: Ethanol-intoxicated patients admitted to the emergency department (ED) following significant trauma mechanisms, in whom diagnostic evaluation revealed only minor injury. EXCLUSION CRITERIA: Major trauma (blood transfusions, drop in Hct > 10 points over 24 h, or Injury Severity Score [ISS] >5) or positive urine toxicology screen. DEFINITIONS: Ethanol Intoxication: (Blood Alcohol Level (BAL) > or =80 mg/dl), Acidosis: BD < or = -3.0 mMol/L; Lactic Acidosis (LAC >2.2 mMol/L). Data were reported as mean+/-SD. Data were compared by t-tests or Fishers exact test as appropriate (alpha= 0.05, 2 tails) and correlations by Pearson correlation coefficient.
RESULTS: 192 patients were studied (84% male) with a mean age of 31.7+/-15.6 years. Acidosis was observed in 19.3% (CI 95%, 14.5% to 25.0%) of all study patients. We observed significant (p<0.001) difference in prevalence of acidosis in ethanol intoxicated (42%) compared to nonintoxicated (1%) patients. Comparing the two study groups, patients with ethanol intoxication had lower BD (-2.24+/-2.74 vs. -0.05+/-2.35, p<0.001) and higher LAC (2.69+/-1.48 vs. 2.00+/-1.78, p=0.02). However, ethanol levels did not correlate significantly with BD (p=0.50) or LAC (p=0.14).
CONCLUSION: Ethanol intoxication is associated with acidosis, which does not correlate with BD or LAC. The complexity of pathogenesis of acidosis in ethanol intoxication justifies further diagnostic evaluation of these patients in order to rule out other causes of acidosis.