Sleep deprivation does not mimic alcohol intoxication on field sobriety testing

Previous research shows that sleep deprivation (SD) produces cognitive impairment similar to that caused by alcohol intoxication. Individual studies suggest that SD also causes deficits in motor skills that could be mistaken for intoxication. Consequently, SD often is used as a defense when an impaired driver is charged with driving while intoxicated. Twenty-nine adult subjects participated in two test sessions each, one after a full night's rest and the other after wakefulness of at least 24 h. Subjects consumed prescribed amounts of alcohol during each session. Law enforcement officers conducted field sobriety tests identical to those with which a driver would be assessed at roadside. Researchers also measured clinical responses of visual function and vital signs. The presence and number of validated impairment clues increase with increasing blood alcohol concentration but not with SD. Thus, SD does not affect motor skills in a manner that would lead an officer to conclude that the suspect is intoxicated, unless intoxication also is present.     

Butalbital and Driving Impairment

Butalbital (Fiorinal^®), used in the treatment of migraines and muscle pain, is the most commonly encountered barbiturate in impaired driving cases. It has central nervous system (CNS) depressant properties, including sedation, drowsiness, and feelings of intoxication, which can contribute to driving impairment. Twenty‐six driving under the influence cases are reviewed including results from field sobriety tests and toxicology testing. Blood samples were screened using enzyme multiplied immunoassay technique immunoassay, and the presence of butalbital was confirmed and quantified using gas chromatography/mass spectrometry, gas chromatography with flame ionization detection, or gas chromatography nitrogen/phosphorus detection. Butalbital concentrations ranged from 1.0 to 30.2 mg/L, with a mean and median of 16.0 mg/L. General impairment indicators in these cases included horizontal and vertical nystagmus, lack of convergence, poor motor coordination, and balance and speech problems, which are common to CNS depressant intoxication, similar to that associated with alcohol. These findings indicate the importance of toxicological testing for butalbital in cases where CNS depressants are indicated.