Specimen collection for drug and alcohol testing is performed to identify a patient’s drug or alcohol use. It’s performed for several reasons, including obtaining evidence for a possible criminal charge (for instance, after an accident), helping to determine a cause of death, and screening for employment suitability or adherence to an ongoing drug addiction rehabilitation program. It’s also used to establish a differential diagnosis for a patient who’s experiencing an altered mental state or has such signs and symptoms as slurred speech, dizziness, confusion, blurred vision, anxiety, hallucinations, memory impairment, lack of muscle coordination, or hyperthermia. The collection method and source of the specimens vary, based on the reason for testing. Because of the variability in local and state laws, nurses must strictly follow all facility guidelines, policies, and procedures.

Drug testing that’s performed to determine employment suitability and rehabilitation program adherence usually involves a urine sample collected under highly controlled conditions. Although collection requirements may vary slightly, depending on the employer and type of employment or rehabilitation program, most include a designated collection site, security for the collection site, use of authorized personnel, privacy during collection, integrity and identity of the specimen, and chain-of-custody documentation. Some rehabilitation programs and employment circumstances may require the specimen collection to be observed. Testing is usually limited to five drug types: marijuana, cocaine, opiates, amphetamines, and phencyclidine. In the case of employment screening, if the results of the initial test are positive, a confirmatory test is performed using gas chromatography–mass spectrometry.

Depending on the reason for collection and your state laws, you should ensure that informed consent has been obtained from the patient or a family member before obtaining the sample. Consent may not be required if it’s an emergency, if results will be used only for a differential diagnosis in an acute crisis, or if the patient is not in a condition to grant permission. In a criminal case, a law enforcement officer can’t order blood to be drawn and doesn’t have the legal right to grant permission if the patient refuses consent.

Blood samples, when needed, are collected in 10-mL gray-top blood collection tubes that contain a preservative (100 mg of sodium fluoride) to help prevent deterioration of the specimen, including changes in alcohol concentration and the breakdown of cocaine, and an anticoagulant (20 mg of potassium oxalate) to prevent the sample from clotting. The integrity and identity of the specimen must be maintained and, if indicated, chain-of-custody documentation preserved.

In general, prescription and over-the-counter drugs can be detected in blood in 4 to 24 hours and in urine for 2 to 4 days. Detection times for alcohol and other drugs vary. (See Drug detection times.)

This procedure focuses on drug and alcohol specimen collection for medicolegal reasons. When specimens are collected for a patient who’s experiencing an altered mental state or other signs and symptoms, be sure to use the appropriate collection tubes. (See “Venipuncture,” page 781.)