Gaze nystagmus and blood alcohol.

Forty-six patients in an emergency room (ER) setting and 159 people suspected of driving while intoxicated (DWI) had their blood alcohol concentrations estimated by the angle of onset of horizontal gaze nystagmus and confirmed by blood alcohol analysis or breath-alcohol analysis (BAA) tests. In the ER group, 25/26 (96%) of legally intoxicated patients (blood alcohol concentration greater than or equal to .10% w/v) had an estimation consistent with intoxication. There were no cases in which the blood alcohol concentration (BAC) was incorrectly estimated to be greater than .10% w/v in the absence of other drugs. In DWI suspects there was a correlation of .878 between estimated BAC and BAA results. Three subjects were incorrectly classified as intoxicated. No subjects with estimated BAC less than .10% w/v were legally intoxicated by BAA testing. Alcohol gaze nystagmus is presented as an effective tool for estimating the BAC in pure alcoholic intoxication.