Alcohol and Blood Tests: How They Work Together
04 October, 2023
Alcohol and blood tests are an important tool for assessing a person’s level of intoxication. A blood test can detect and measure the amount of alcohol in a person’s system. It uses advanced technology, like Phosphatidylethanol (PEth) to accurately identify the alcohol concentration in the bloodstream. The test works by detecting the biomarker of ethanol, the chemical compound found in alcoholic beverages. It also relies on alcohol metabolism and how long it stays in the system.
Testing for alcohol is a standard practice in many settings. It is common in roadside screening to determine if a person is legally intoxicated while driving. Similarly, workplaces conduct alcohol screening to monitor impairment. These help prevent accidents and injuries associated with alcohol use. In addition, there are several methods to detect alcohol, including breath, urine, saliva, and blood. This article will focus on blood testing and its procedures and results interpretation.
Alcohol and Blood Tests: How Long It Stays in the Blood
A reliable way to measure Blood Alcohol Concentration (BAC) is by understanding alcohol and blood tests. The rate at which the body processes alcohol plays a significant role. On average, the liver can metabolise one standard drink per hour. It produces biomarkers that enter the bloodstream, where they stay for a certain period of time. However, several factors can influence this, such as age, body weight, and overall health.
Secondly, the amount of alcohol consumed affects how long it remains in the bloodstream. Heavy alcohol consumption will result in a longer detection time. For example, a single standard drink may be eliminated from the blood within a few hours, while heavy drinking can extend to several days.
Generally, a blood test can detect alcohol within 6 to 12 hours after the last intake. The detection window may also vary depending on the type of test used. For example, PEth can trace the ethanol biomarkers up to four weeks prior to collection. Overall, the length of time alcohol stays in the blood can vary depending on several factors.
Reasons to Conduct a Test
- A blood alcohol test can determine if an individual has consumed alcohol recently.
- Measure the blood alcohol level for legal or medical purposes. It can provide evidence of alcohol use for drink driving cases or probations.
- Determine if alcohol contributed to an accident.
- Assess the impact of alcohol on liver function and overall health status.
- Monitor chronic alcohol use or identify potential alcohol abuse or addiction.
- Testing for potential alcohol poisoning. Hospital staff may employ a blood test during emergencies.
- Employers may test for alcohol before hiring a prospective employee to check whether they have a history of abuse or risky behaviour.
Alcohol and Blood Tests: Procedures
The procedures for alcohol and blood tests generally involve drawing a blood sample from the arm. Specific guidelines must be followed to ensure accurate results. Before administering the test, a trained medical professional must ensure the person being tested has not consumed alcohol or any substance that may interfere with the outcome.
Once ready, the test administrator draws the required amount of blood sample using a small needle. The sample is collected into a test tube or vial. The process usually takes less than five minutes. However, a person may feel a little sting from the procedure. The collector or test administrator forwards the sample to a laboratory for analysis.
Different settings can have different procedures. For example, law enforcement agencies may have specific protocols for conducting alcohol tests, while workplaces have different methods. Organisations administer alcohol screening according to established testing policies and in compliance with state or federal laws. Regardless of specific procedures, adherence to the general guidelines is crucial to obtaining accurate and reliable results.
How it Works
A blood test measures the blood alcohol content through various techniques. A common method is PEth. It traces the direct biomarker of ethanol, making it a reliable indicator of alcohol consumption. Another method is the Carbohydrate-deficient transferrin (CDT). It measures the percentage of transferrin in the blood.
Furthermore, the EtG (ethyl glucuronide) test is another reliable method for determining recent alcohol intake. It detects the presence of EtG, a metabolite produced when the body breaks down alcohol. Overall, if these biomarkers are outside the normal range, it may indicate excessive drinking. Direct biomarker testing is highly accurate as it detects ethanol byproducts only.
Alcohol and Blood Tests: Understanding the Results
Correct understanding and interpretation of the results of alcohol and blood tests is crucial. Positive test results can have legal consequences; therefore, it is vital to use reliable testing methods to avoid errors. Alcohol testing measures the BAC or levels of alcohol in the system. A positive BAC indicates recent consumption, usually within the past 12 to 24 hours.
Excessive alcohol consumption typically results in a high BAC level. This also puts a person exceeding the legal limit (0.05% BAC) for driving. Drivers that are over the BAC limit may face legal penalties, including heavy fines, license suspension, and jail terms. Thus, many use personal breathalysers to monitor their intake and stay within the legal limit.
Moreover, high-risk industries implement zero-tolerance for alcohol. This means an employee must not have any alcohol content while working. A person may face disciplinary actions if they return with even small amounts of alcohol in their system. Lastly, the results can show if a person has an alcohol use disorder.
Risks for False-Positives
Blood tests are accurate and reliable for detecting alcohol use. However, there are risks of false positives. This means the results indicate a person has consumed it when they have not. The common factors that may affect the test are certain medications and medical conditions. Diabetes and liver cirrhosis may cause elevated levels of the BAC.
The results can have drastic impacts on a person. It can affect their employment and ruin their reputation. Therefore, it is vital to conduct confirmatory laboratory tests before releasing the final results. A medical review officer may consider health conditions or other medical reasons in validating the test.
Alcohol and blood tests are essential to assess alcohol consumption in individuals. It involves analysing the blood sample to measure the percentage of alcohol in the system. It uses several techniques, such as PEth and EtG, to detect ethyl alcohol or alcohol metabolites. Hence, it can determine the person’s level of intoxication at the time of testing. It is also beneficial in medical settings for diagnosing if an individual has chronic alcohol abuse.
Excessive alcohol consumption can severely impair a person’s perception, judgment, and coordination. As a result, it poses safety risks when operating a motor vehicle or heavy machinery. Likewise, it may lead to long-term health issues, such as liver damage, cancer, and stroke. Therefore, it is vital to identify early signs and risk factors to prevent alcohol abuse. Reliable methods and procedures can ensure the accuracy and integrity of the tests to prevent or minimise the possibility of false positives.