- Alcohol level can be estimated in blood, breath and in saliva.
- When collecting blood then don’t clean the site with alcohol.
- A blood test is the best sample for the estimation of alcohol.
- Blood sample in living patient may be whole blood, serum or plasma.
- Serum and blood alcohol ratio is 1:14.
- Blood in a cadaver is taken from the aorta.
- The blood must be capped to avoid evaporation of alcohol.
- Collect blood in sodium fluoride or potassium oxalate.
Measurement can be done on following samples:
- Blood alcohol level tested in serum or plasma or whole blood.
- Breath alcohol where the blood: breath alcohol ratio is 2100:1.
- Urine alcohol level may be estimated.
- Quantitation of the alcohol level is done for therapeutic or legal purposes.
- Alcohol level is done to diagnose alcohol intoxication.
- Alcohol level may be done in cases of coma, cerebral trauma, and drug overdose.
- To differentiate alcoholic intoxication coma from diabetic coma.
- This test is also done for alcoholism.
- This test is done on the drivers.
- Alcohol is Ethanol and it is readily absorbed from the GI tract.
- Peak level is within 40 to 70 minutes after the intake.
- Ethanol is metabolized by the liver enzyme dehydrogenase into acetaldehyde 90% of alcohol is metabolized in the liver.
- This acetaldehyde is converted into acetic acid by the enzyme Aldehyde Dehydrogenase.
- Ethanol metabolite acetaldehyde leads to acidosis and ketosis called Alcoholic ketoacidosis.
- Once peak level is reached then it levels decreases.
- Ethanol depresses the CNS and ultimately may lead to coma and death.
- Alcohol is present in blood, urine, stomach contents, and breath.
- Saliva alcohol level is 9% higher than blood.
- Blood alcohol level of 50 to 100 mg/dL causes:
- Slowing of reflexes.
- Impaired vision.
- Blood alcohol level of >100 mg/dL causes:
- Signs of CNS depression seen.
- Blood alcohol level >300 mg/dl is usually associated with coma.
- Blood alcohol level of >400 mg/dL is fatal and death may occur.
- urine sample and blood alcohol levels are equal, while in the saliva will have 1.2 times of blood level.
- The blood alcohol level will be roughly 25 mg/dL when adult taking:
- An ounce of whiskey or.
- 12 ounce of the bear or.
- One glass of wine.
- Use of sedatives like barbiturates and benzodiazepines with alcohol is very dangerous and may lead to death by respiratory depression.
- Complication of chronic alcohol abuse:
- Cirrhosis of the liver.
- The degenerative changes in the brain.
- The degenerative changes in the skeletal muscles.
- Chronic alcoholics may have nutritional and vitamin deficiencies.
- Negative in the blood or any sample.
- <10 mg/dL = considered negative.
- <20 mg/dL = considered negative by the US transportation department.
- >40 mg/dL = considered positive.
- >80 mg/dL = considered drunk driver.
- Toxic level
- Toxic level of ethanol = > 100 mg/dL
- Toxic level of methanol = > 20 mg/dL.
- Toxic level of Isopropanol = > 40 mg/dL
- lower limit of detection is 10 mg/dL.
- >80 mg/dL is considered positive for driving under the influence in most of the states.
- >300 to 400 mg/dL is considered fatal.
|Blood alcohol level
|100 to 200 mg/dL
Patient has emotional instability and there is a loss of critical judgment
|200 to 300 mg/dL
Patient is confused impaired balance and disorientation.
|300 to 400 mg/dL
Patient is unable to walk or stand and is stuporous.
|More than 500 mg/dL
Patient is in a coma with depressed respiration and slow circulation.
|More than 1500 mg/dL
Patient condition is critical and may die due to respiratory paralysis.
|More than 2000 mg/mL
Death due to respiratory paralysis.
Clinical effect depending on the blood alcohol concentration:
|Blood alcohol concentration (%)
||Feels Soberness and calm
|0.05 to 0.1%
|0.1 to 0.2%
|0.2 to 0.3%
|0.3 to 0.4%
||Now is stuporous
||Goes into coma and death may occur
(modified from ASCP )
Possible References Used
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