The number of emergency department visits related to alcohol has risen dramatically in the United States in recent years. It can be challenging for ED doctors to quickly determine whether alcohol alone caused a patient's symptoms or whether other drugs are involved.

A new saliva test, described in the January issue of the Journal of Breath Research, may someday solve this problem.

Researchers at Loughborough University in the U.K. have developed a test they say can detect toxic chemicals commonly found in the "date rape drug" GHB (γ-hydroxybutyric acid). The saliva test can also detect cheap or fake alcohol.

The number of alcohol-related ED visits rose by 38 percent in both men and women from 2001-2002 and 2009-2010, according to the Centers for Disease Control and Prevention (CDC). An increasing number of these visits involve the presence of other compounds that patients did not know they had ingested.

Some of these patients have consumed drinks contaminated with methanol or ethylene glycol, which are cheap and sometimes lethal alternatives to ethanol. Others unintentionally ingested GHB, a potent colorless, tasteless and odor-free date rape drug slipped into a drink. GHB can cause drowsiness, relaxation, loss of consciousness, temporary memory loss, seizures and other effects that begin about 15 minutes after ingestion and last for 3-4 hours.

In current clinical settings, only blood tests can detect the presence of these compounds in a patient's system. This can delay diagnosis and timely treatment. Unintentional ingestion and intoxication from GHB and other sedatives can result in complications when the intoxication is mistaken for ethanol abuse, or when ethanol consumption masks signs of sedatives.

Faster point-of-care screening for methanol, ethanol, ethanol alternatives and GHB can shorten time to diagnosis and allow for prompt treatment. Quicker screening in clinical settings would also reduce the risk for complications resulting from alcohol combined with other chemical intoxicants.

To speed testing, the Loughborough University researchers developed a test that purportedly detects these chemicals in saliva. The research team added methanol, ethanol, GHB, ethylene glycol and propan 1,3 glycol to the fresh saliva of three study participants. The scientists used concentrations low enough to create realistic simulations of what a doctor might find in a clinical setting.

The researchers extracted the compounds with an oral sampler then used gas chromatography-differential mobility spectrometry to identify the compounds.

The presence of bacteria and their metabolites makes saliva particularly complicated to work with. Ammonia can also change the chemistry of the mouth. Detecting γ-hydroxybutyric acid can also be difficult in that it is both a polar and acidic molecule.

Despite these challenges, the researchers were able to detect γ-hydroxybutyric acid in saliva samples easily, even at low concentrations.

Based on their findings, the researchers may be on the verge of developing a simple saliva test practitioners can use to identify toxic compounds quickly in clinical settings.