Blood and Alcohol Test – What Is It Used For?
25 October, 2023
Blood and Alcohol Tests help determine the alcohol consumption of an individual. Generally, healthcare professionals draw blood samples by using a needle in the arm. Afterwards, they store the sample in a vial and send it to a laboratory for analysis. Using specialised techniques provides accurate and reliable measurements of ethanol and its biomarkers in the blood. These results may be used for legal evidence, identifying those with alcohol use disorder, and for employment requirements.
Blood tests generally provide the most accurate results for substance use detection. However, other tests help verify a blood test result. This includes urine, hair, breath, and saliva testing. Additionally, it is crucial to use a reliable testing service to avoid sample contamination. This article will present how blood tests detect alcohol components, their accuracy and reliability, and how to understand the Blood Alcohol Concentration (BAC).
Blood and Alcohol Tests – How They Work to Detect Alcohol Components
Blood and alcohol tests are used to detect the presence of alcohol consumed by the individual. The blood samples are gathered by medical professionals depending on the type of blood test. Generally, a healthcare provider draws blood samples from the arm. However, pricking a finger will suffice for Phosphatidyelethanol (PEth) tests.
A blood test typically has a detection window of 6 to 12 hours after last consumption. Meanwhile, a Carbohydrate-Deficient Transferrin (CDT) test detects heavy alcohol consumption for up to two weeks. It is a type of blood test that detects the protein called transferrin. This protein is an indirect biomarker that increases after the consumption of alcohol.
Another type of blood test is the PEth test. It measures the level of the direct biomarker called PEth within two to four weeks of the last alcohol consumption. Examiners use specialised techniques such as liquid chromatography and mass spectrometry during lab testing. This helps determine the amount of alcohol consumed over a specific period. It identifies if the person engages in mild, moderate, or excessive drinking. Furthermore, this provides health professionals with information on their drinking habits and patterns.
Other Tests to Detect Alcohol Consumption
These are the other tests that detect alcohol consumption:
- Urine tests use urine samples to look for traces of alcohol. It has a detection window of 24 to 72 hours.
- Saliva or mouth swab tests use swab sticks to gather saliva samples from under the tongue or inside the cheek. It may detect substances for up to 12 hours.
- Hair follicle tests use hair strands to show a substance use history of up to 90 days. However, it does not show consumption seven days prior.
- Breath tests measure the Blood Alcohol Concentration (BAC) levels of an individual for up to 24 hours.
Blood and Alcohol Test – Accuracy and Reliability of the Procedure
Using blood and alcohol tests offers the most accurate results for detecting alcohol consumption. This is because alcohol directly enters the bloodstream after intake. Thus, blood tests are often used for legal reasons, such as evidence for Driving Under the Influence (DUI) cases.
In particular, PEth blood alcohol tests have a 99% sensitivity rate. This results in reliable results even with low alcohol consumption. Additionally, PEth tests provide a measurement of alcohol consumption. It is unlike most tests that only produce positive or negative results. This allows healthcare providers to identify those with Alcohol Use Disorder (AUD).
However, there are still risks of false positive results. Possible reasons are contamination of the sample or mishandling of the procedure. It is crucial to use a reliable testing service to avoid this. Furthermore, some may benefit from additional tests or retesting for more accurate results. Diversifying the tests taken by an individual may prevent the consequences of false positive or negative results.
Factors that May Influence the Result
Different factors may influence the result of a blood test. These may vary from person to person. Firstly, the amount of alcohol consumed affects the test results. Moreover, the time elapsed after the last alcohol consumption may exceed the detection window of some tests.
Furthermore, there are individual factors that affect how the liver metabolises alcohol. This includes gender, body weight, and age. Additionally, chronic alcohol consumption may hasten the processing of alcohol. However, liver damage from excessive alcohol intake may cause the body to metabolise it slowly. Lastly, medicines and illicit drug intake may decrease the alcohol elimination rate.
Blood and Alcohol Test – Understanding the BAC
Some blood and alcohol tests measure the amounts of alcohol in the blood or the Blood Alcohol Concentration (BAC). BAC is calculated as the weight of ethanol in grams in 100 millilitres of blood. Different levels of BAC have various effects on the individual. Heavy alcohol consumption leads to higher BAC levels. These higher levels result in more visible effects and impairment.
Those with a BAC of 0.05g often feel slight euphoria and become more relaxed and confident. Moreover, a BAC within 0.05g to 0.08g reduces inhibitions and impairs judgment. Furthermore, a BAC range between 0.08g and 0.15g results in slurred speech, slower reaction time, nausea, and vomiting. In addition, BAC levels within 0.15g to 0.30g cause inadequate breathing, loss of bladder control, and loss of consciousness. Lastly, exceeding 0.30g may result in alcohol poisoning, coma or death.
Thus, alcohol testing is done by healthcare providers to identify people who are misusing alcohol. Furthermore, police officers use tests to identify drivers who have exceeded the legal BAC limits.
Legal BAC Limits
Drink driving causes many accidents that result in injury and death. The legal BAC limits in Australia are set at 0.05% for most drivers. However, those with learner, provisional, and probationary licenses must follow the legal limit of zero BAC. In addition, public transportation drivers such as taxis, buses, and trams must have zero BAC.
Police officers conduct roadside tests to determine if drivers are engaging in drink driving. They have the authority to test the blood alcohol levels of individuals to ensure safety. Those caught exceeding the limits may face penalties. These include fines, license suspensions, vehicle impounding, alcohol interlock programs or imprisonment.
Blood and alcohol tests are accurate methods for determining alcohol consumption. Collecting blood samples is an invasive process using needles to gather blood from the arm or fingers. However, using CDT and PEth extends the detection window of blood tests to weeks. Additionally, these specific tests add to the accuracy and reliability of the results. Thus, blood test results are often used for legal proceedings, such as DUI cases.
Moreover, blood tests allow healthcare providers to gain information about the drinking pattern and history of the patient. High levels of BAC have many adverse health effects. Additionally, uncontrolled alcohol consumption may lead to death. This may be due to health conditions or risky behaviours like drink driving. Some people may benefit from owning personal breathalysers. It may help them limit and monitor their alcohol intake. BACtrack breathalysers from Breathalysers Australia provide reliable and accurate measurements of BAC levels.