what is the difference in a toxicology drug screen and a regular urine drug screen done in a hospital lab?

March 8, 2010

A toxicology screening is mostly performed on the blood or the urine but can even be done on the gastric contents like the vomit or the lavage fluids, if done shortly after the substance has been ingested. The nails or the hair can also be tested for any arsenic or for mercury.Blood is first drawn from the vein from the inner side of the person’s elbow or even the back of the person’s hand. The puncture area is cleaned thoroughly with antiseptic then an elastic band is tied around the upper portion of the arm to apply pressure and to help restrict blood flow passing through the vein. This causes the veins below the surface of the band to fill up with blood. A needle is then inserted into the person’s vein, and the blood is drawn into an air-tight syringe. The band is then removed to restore the circulation. Once the required blood has been filled, the needle is taken out, and the puncture area is taped to stop any further bleeding.

Urine sampling can be taken from a random sample where the patient is required to urinate into a vessel or container. In some circumstances, the person may need to take the urine sample in the nurse or technician’s presence to help verify that the sample came from him only and was not fouled or tampered with. This test is mainly done to evaluate any possible intentional or accidental overdose or even poisoning. This can be done when there is a requirement to evaluate the amount and the type of legal or illegal drugs that are used by the person. The test can also be performed to find the cause of acute drug toxicity, to monitor any drug dependency, or to find out if there are any substances present in the body. However the test as a drug screen has a finite time frame after ingestion of that the drug or before any of its various metabolites can then be detected.

Urine drug screening is defined as a process of chemical analysis that is designed to test people for drug abuse. It is also conducted to ensure that a person is substance-free prior to undergoing any medical procedure. This test involves the normal urination by a person. In the regular urine drug screening the tests are able to find out classes of compounds like barbiturates, amphetamines, opiates and the like. A person who is taking some heroin or codeine pills will cause the drug screen to be positive thus showing a false positive. Hence the urine drug test is done to mainly detect any illegal drugs or prescription drugs being present in the urine whereas the toxicology screening will help in detecting some specific drugs.

Submitted by M H on March 8, 2010 at 11:02

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