Q. Patient was brought in unconscious from an alleyway. Upon initial examination, there was no clear evidence of physical foul play due to a lack of surface blood or abrasions. After being admitted into the ED, patient remained completely unresponsive. An ID was found, but the patient was unable to communicate coherently to give any background information. Physicians then took vitals, checked airways, and ordered a head CT and labs (blood platelet count, electrolytes, etc.). Labs later showed a BAC of .415, over 5 times the legal limit. How long will it take the patient’s BAC to return to legal levels?
A. Regardless of how much alcohol an individual consumes, the liver is only able to metabolize a certain amount of alcohol every hour. This amount varies from person to person and is largely dependent on liver size and body mass. Generally, however, the liver is able to metabolize .01-.02 BAC per hour, meaning that it will likely take around 17 hours for the patient’s BAC to return to the legal limit of .08. I was also curious about whether or not there were changes in the rate of metabolism of alcohol — ie. would the liver work at a faster rate the first few hours, and then slow down? From Dr. Ramsey I found that the rate is 0th order, meaning that regardless of the time, the rate of metabolism will remain constant and linear. Resources: http://pubs.niaaa.nih.gov/publications/AA72/AA72.htm