It is not practical to draw a blood alcohol level on every patient who presents to the emergency department with suspected alcohol consumption. In patients simply suspected of consuming alcohol, a clinical assessment by history and physical exam with particular focus on mental status and neurologic exam is sufficient. A determination of alcohol level is not necessary. It is acceptable to simply observe patients who are intoxicated and lack signs of trauma, focal neurologic deficit, or other problems for several hours without an alcohol level. These patients require serial exams to establish clinical improvement of mental status over time. For clinical purposes a blood alcohol level has little utility in knowing an actual numerical value. If the patient does not deny alcohol intake, the patients clinical capacity is more important than the specific level of alcohol. A low blood alcohol level does not guarantee competence. Other variables may not have been measured, such as drugs ingested, hypoglycemia, medical illness, blood loss etc.

Those patients who are comatose, in respiratory distress, have a severely altered mental status, or an altered mental status with signs of trauma a determination of alcohol level is indicated. In patients with signs of minor trauma alone, a determination of alcohol level should be based on the case history and physical exam, particularly the mental status and neurologic exam. In the patient who did not receive an initial level and then fails to clinically improve over time or whose condition deteriorates an alcohol level is required.