Complete Blood Count (CBC): Understanding This Common Blood Test and What Your Results Mean
This test detects the presence of barbital, a barbiturate medication, in your blood to monitor drug levels or check for poisoning.
{"Barbital is an older sedative-hypnotic drug rarely used today","The test checks if this medication is present in your serum or plasma","It may be used to monitor therapeutic levels or detect overdose","Blood sample is drawn from a vein in your arm","Results help doctors manage poisoning cases or medication safety"}
Key facts at a glance
- LOINC
- 14623-3
- Short code
- BARB
- Synonyms
- Barbital SerPl Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (no anticoagulant) or serum separator tube (SST) for serum; EDTA or heparinized tube for plasma
- Units
- N/A
- Ref low
- 0
- Ref high
- 0
- Critical range
- — – 20 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Gas Chromatography-Mass Spectrometry (GC-MS) or Immunoassay
- CPT
- 80101
- SNOMED
- 387458008
- Specimen volume
- 2-5 mL of blood (minimum 1 mL serum or plasma)
- Stability
- Serum/plasma stable at room temperature for 24 hours; refrigerated (2-8°C) for 7 days; frozen (-20°C or below) for 30 days
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 4–24 hours
- Order
- routine
A complete blood count, or CBC, is a routine blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets. It gives your healthcare provider a broad picture of your overall health and can help detect a wide range of conditions, such as anemia, infections, and blood clotting problems.
The Barbital [Presence] in Serum or Plasma test is a laboratory test that detects whether barbital, a type of barbiturate medication, is present in your blood. Barbiturates are sedative-hypnotic drugs that were commonly used in the past to treat anxiety, insomnia, and seizures. This test uses a sample of your serum (the liquid part of blood after it clots) or plasma (the liquid part of whole blood) to determine if barbital is present.
Your doctor may order this test as part of a routine checkup, or to help investigate symptoms like fatigue, weakness, fever, unexplained bruising, or weight loss. It is also used to monitor ongoing conditions such as anemia or infection, and to track how treatments like chemotherapy or certain medications are affecting your blood cells over time.
Your doctor may order this test for several reasons: (1) To monitor therapeutic drug levels if you are currently taking barbital for a medical condition, (2) To investigate suspected drug poisoning or overdose, especially if you have symptoms like extreme drowsiness, confusion, or breathing problems, (3) To detect accidental exposure to barbiturates, or (4) As part of a comprehensive toxicology screening when the cause of symptoms is unclear.
The test is performed with a simple blood draw, usually from a vein on the inside of your elbow or the back of your hand. A healthcare professional will clean the site, place a band around your upper arm, and collect a small sample into a tube. The procedure takes only a few minutes, and you can usually return to normal activities right afterward.
A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. The blood sample will be collected in a special tube and sent to a laboratory for analysis. The test detects the presence (qualitative) or sometimes amount (quantitative) of barbital in your blood. You do not need to fast or make any special preparations for this test, but you should inform your doctor about all medications you are currently taking.
Your results show whether your blood cell counts fall within normal ranges. A low red blood cell count may suggest anemia, while a high white blood cell count can point to infection or inflammation. Abnormal platelet levels may affect how well your blood clots. Many factors can influence the numbers, so your provider will interpret them alongside your symptoms, medical history, and other test results before making any diagnosis.
A positive result indicates that barbital is present in your blood. The significance of this finding depends on your medical history and why the test was ordered. If you are taking barbital as prescribed, therapeutic levels are expected. If you have not been prescribed this medication, the presence of barbital may indicate accidental exposure or intentional overdose. Your doctor will interpret the results in the context of your symptoms and overall health condition.
Reference range
Not detected (Negative). Therapeutic range: 5-15 mcg/mL; Toxic range: >20 mcg/mLN/A
No fasting required. Specimen should be collected prior to next dose when monitoring therapy. Avoid alcohol consumption prior to specimen collection as it may interact with barbiturates.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Barbital is one of the oldest barbiturate drugs and was historically used as a sedative, hypnotic, and anticonvulsant. While largely replaced by safer alternatives like benzodiazepines, it may still be encountered in certain clinical settings or in elderly patients who have long-term prescriptions. This test is clinically significant for: monitoring therapeutic drug levels to ensure effective yet safe dosing, diagnosing barbiturate poisoning which can cause respiratory depression, coma, or death, and forensic toxicology cases involving suspected drug intoxication. Barbiturate overdose requires immediate medical intervention and supportive care.
Frequently asked questions
Is barbital still commonly prescribed?
What are the symptoms of barbital overdose?
How long does barbital stay in the blood?
Will this test show other barbiturates?
Sources
- 1
- 2
- 3LOINC Code 14623-3Source
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy