

Can someone balance on one leg when they are high on the anesthetic ketamine? This was the central question of a research paper written by government researchers in Hong Kong.

To find an answer, a team of social workers and scientists stood outside of two different nightclubs and asked 62 people to perform a series of sobriety tests in the parking lot or a nearby playground.

The team also checked their volunteers' vital signs including: pupil dilation, heart rate, body temperature, and blood pressure. Rather than relying on the partygoers to be honest about which drugs they had been using, the researchers collected saliva and urine samples form each one of them and analyzed those samples in a crime lab. At least 39 of them had gotten buzzed on the anesthetic that night. Only seven of them were sober.

Ketamine is one of the most popular club drugs in the massive Chinese city. There are no breathalyzer-style field tests to determine whether someone has been abusing the veterinary painkiller. Chinese cops want to know what behaviors are unique to ketamine so that they justifiably request the appropriate blood and urine tests.

According to the local law, cops can collect blood and urine samples if they suspect that a driver is drunk. The police want a similar ordinance for drug testing. Cops can't run around asking people to urinate in a jar without a good reason. Until they have developed an effective field test for ketamine abuse, it will be hard to pass a law that allows them to collect blood and urine samples for analysis in a crime lab.

Wing-Chi Cheng led the effort to develop criteria for an effective sobriety test. In the journal Forensic Science International, he concluded that ketamine users had normal body temperature and blood pressure, but some of them had a rather fast pulse. The best indicators of ketamine misuse are failures to complete two parts of a standard field test. To be more specific, 77 percent of the impaired volunteers could not walk in a straight line and turn on cue while distracted with questions and further instructions. The same number of ketamine users could not balance on one leg for 30 seconds.

The authors found the criteria that they wanted – failure to pass those simple divided attention tests would provide sufficient grounds for blood or urine drug testing. So partygoers that can't keep their balance at the end of the night may not have a legal leg to stand on.