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Test Name:
Volatiles, Blood
- SBMF No:
31035 - Performance Lab Name:
Toxicology - Test Mnemonic:
VOLAT - ABN:
Not required - CPT Code:
84600 - LOINC Code:
5568-1; 5643-2; 5693-7; 5669-7 - Test Includes:
Acetone
Ethanol
Isopropanol
Methanol - Also Known As:
Alcohol
Rubbing alcohol
Wood alcohol - Also See:
31134 – Acetone, by Gas Chromatography
23006 – Alcohol, Ethyl, Blood
31143 – Isopropanol, by Gas Chromatography (Includes Acetone)
31143 – Methanol, by Gas Chromatography - Spec Type:
Whole blood - Spec Container:
Gray top (fluoride/oxalate) tube - Alt Spec Type:
Serum - Alt Spec Container:
Red top (serum) tube - Pref Vol:
5.0 mL - Min Vol:
2.0 mL - Fasting:
No - Spec Collect:
Do not use gel-barrier tubes for specimen collection
Prep venipuncture site with non-alcohol containing prepping agent
Routine venipuncture
Fill collection tube to vacuum capacity to minimize evaporation of volatiles - Spec Process:
Do not centrifuge
Do not remove tube stopper (tube must remain tightly stoppered)
Do not remove serum or plasma from cells - Spec Store Transport:
Refrigerated - Spec Stability:
1 week refrigerated (2-8°C) - Methodology:
Gas Chromatography - Use:
Detect use
Evaluate toxicity - Clinical Significance:
Ethanol (Blood half life [T½] = 2-14 hours)
– Ethanol Levels up to 1.5 mg/dL are endogenous in the blood of man
– The state of Indiana has set 80 mg/dL (0.08 %) of ethanol via breath or blood to be legally intoxicated while driving a motor vehicle.
– One hour following ingestion of 100-proof whiskey, the following blood levels can be expected. Assume 70 kg male, with average alcohol distribution kinetics.
– Peak blood levels usually occur within 40-70 minutes on an empty stomach. Eating can prolong the peak level being reached by as much as 1-2 hours.
– After the peak blood concentration has been reached, the rate of disappearance is relatively linear and is referred to as the Widmark B Factor. The factor for adults is 15±5 mg/dL/hour (average 18 mg/dL/hour).
– As alcohol distributes freely through the total body water, it is possible to estimate the total body load of ethanol in the body. The distribution factor, referred to as the Widmark R Factor is 0.68 (average) for men and 0.55 (average) for women. The calculation is made by multiplying the body weight in grams by the blood alcohol level in g/100 by the distributive factor.
– The Otswald partition ratio is an expression relating weight of alcohol to volume of blood versus air. This ratio is 1:2100 and means that 1.0 mL of blood will contain the same weight of ethanol as 2100.0 mL of alveolar air. This implies that it would be almost impossible to become intoxicated by breathing ethanol fumes even at an irritating 9000 ppm.
– Urine/blood alcohol ratios are on the average 1.3:1. Since the kidneys have no ability to concentrate alcohol, one can conclude that at some time during the accumulation of urine the blood had a level of at least that calculated by the ratio.
– Serum/plasma results will be 14% higher than whole blood since the serum/plasma distribution of ethanol is on the average 14% higher than in the red blood cells. Therefore, the level reported should indicate what type of specimen the result was reported on.Methanol (Blood half life [T½] = 2-24 hours)In addition to widespread use as a solvent and gasoline additive, methanol is present in trace amounts in wines and liquors. Methanol ingested as part of a commercially available alcoholic beverage would result in a serum concentration below the detection limits of this method (less than 10 mg/dL) and would be accompanied by a high ethanol concentration. Methanol is metabolized, much more slowly than ethanol, probably by alcohol dehydrogenase (metabolism is inhibited by ethanol) to formaldehyde that is than oxidized to formic acid. Formic acid is further oxidized to carbon dioxide by a folate dependent pathway. Formic acid is 6 times more toxic than the parent methanol. The toxic symptoms of blindness and metabolic acidosis may not appear until 6-30 hours after ingestion of methanol. Treatment may include the early administration of ethanol to inhibit the methanol metabolism, administration of folate to induce formic acid detoxification, and hemodialysis for removal of methanol and formic acid. Blood methanol concentrations have been reported over a wide range in patients who have died during treatment. Concentrations of methanol greater than 40 mg/dL warrant dialysis. The acute ingestion of as little as 10.0 mL of methanol has caused permanent blindness.
Acetone (Blood half life [T½] = 3-5 hours)Acetone is a common industrial and home solvent. It is also found as a metabolite of isopropanol in humans. Normal endogenous acetone blood levels are less than 5 mg/dL in adults. During starvation, uncontrolled diabetes, or after prolonged and excessive vomiting, blood acetone concentrations may range up to 70 mg/dL and the urine specimen would be positive for ketones. An individual who ingested acetone and became lethargic was noted to have a blood acetone concentration of 250 mg/dL, which declined with a greatly extended half-life of 31 hours. Inhalation of acetone vapors in air at concentrations greater than 10,000 ppm has results in dizziness and muscular weakness. The current threshold limit value for industry is 1000 ppm.
Isopropanol (Blood half life [T½] = 2.5-3 hours)Isopropanol, or isopropyl alcohol, is commonly known as rubbing alcohol. Isopropanol is slowly metabolized, probably by alcohol dehydrogenase, to acetone. Both compounds are eliminated to a small degree from the lungs and in the urine. Acetone may be further oxidized to acetate, formate and carbon dioxide.
- Reference Range:
Ethanol:
– 20-100 mg/dL: may exhibit slight alcoholic influence
– 100-200 mg/dL: incoordination; decreased response to stimuli
– 200-300 mg/dL: staggering gait; slurred speech; delirium
– 250-400 mg/dL: severe incoordination; unconsciousness
– 350-500 mg/dL: may be comatose
Methanol:
– Toxic level: greater than 10 mg/dL
– Lethal level: greater than 40 mg/dL
– Lethal dose: 100-200 mL
Acetone:
– Toxic level: greater than 30 mg/dL
Isopropanol:
– Toxic level: greater than 40 mg/dL
– Lethal level: greater than 100 mg/dL
– Lethal dose: 250 mL - Day Run:
Mon-Fri - Time Run:
2:00 pm - Time Reported:
24 hours - Test Type:
TOX-TDM
