Roadside detection of impairment under the influence of ketamine--evaluation of ketamine impairment symptoms with reference to its concentration in oral fluid and urine.
Forensic science international July 20, 2007 Wing-Chi Cheng, Kin-Man Ng, Ka-Keung Chan et al.
A roadside testing protocol using field impairment tests (FIT) can detect ketamine-impaired drivers with over 90% accuracy when salivary ketamine concentrations exceed 300 ng/mL. Among 62 volunteers exiting discos in Hong Kong, 39 had ketamine in their oral fluid. Of 21 ketamine-only users, 71% were identified by FIT. Typical signs of ketamine impairment include lack of convergence, horizontal gaze nystagmus, elevated pulse rate, and poor performance on divided attention tests, particularly walk-and-turn and one-leg stand.