Barbituratesgastqlscn

Published: August 9, 2026Updated: August 17, 2026

This test detects the presence of barbiturates, a class of sedative medications, in stomach fluid to help diagnose poisoning or drug exposure.

Quick summary

{"Barbiturates are sedative medications historically used for anxiety, sedation, and seizure control","This test checks if barbiturates are present in stomach fluid","It helps doctors diagnose accidental or intentional overdose","Results are typically available within a few days","Positive results may require additional blood tests to confirm"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC: 61096-4
Short code: BARBGAS
Synonyms: Barbiturates Gast Ql Scn
Category: chemistry
Sample: serum
Container: Sterile, leak-proof plastic container without preservative; no additive tube
Units: N/A
Ref low: 10
Ref high: 40
Critical range: — – 500 N/A
Fasting: false
Population: adult
Sex: all
Age range: 0–99 years
Method: screen
CPT: 80307
SNOMED: 16747691000119104
Specimen volume: 5-10 mL of gastric fluid
Stability: Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days
Hemolysis max: 500
Lipemia max: 1000
Icterus max: 500
TAT: 1–4 hours
Order: routine

What is this test?

The Barbiturates Screen test looks for barbiturates in your stomach fluid (gastric fluid). Barbiturates are a group of medications that slow down brain activity. They were historically prescribed for anxiety, sleep disorders, and seizure control, though they are less commonly used today due to safer alternatives. This test uses a screening method to detect whether these substances are present in the stomach contents.

Why might I need this test?

Your doctor may order this test if you have symptoms of barbiturate poisoning, such as extreme drowsiness, confusion, slow breathing, or unconsciousness. It is commonly used in emergency situations when someone has swallowed a large amount of medication, to help determine what was ingested and guide treatment. It may also be used in forensic or legal settings.

How is the sample collected?

A healthcare provider will collect a sample of stomach fluid using a nasogastric (NG) tube passed through the nose into the stomach, or during a procedure called gastric lavage (stomach pumping). The sample is then sent to a laboratory for analysis. In some cases, a blood test may also be ordered to confirm the results.

What do the results mean?

A positive result means barbiturates were detected in the stomach fluid, indicating recent ingestion. A negative result means no barbiturates were detected. However, this is a screening test, so if the result is positive, your doctor may order additional blood tests to confirm the findings and determine the level of medication in your bloodstream.

Are there any risks?

The risks of collecting gastric fluid are minimal but may include discomfort when the tube is inserted, minor nosebleeds, or rare complications such as injury to the throat or stomach. The test itself does not have significant risks.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special patient preparation required. Specimen is typically collected via gastric lavage or aspiration in cases of suspected overdose.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

How long does it take to get results?

Results are typically available within 1-3 days, though this may vary depending on the laboratory. In emergency situations, some facilities can provide preliminary results more quickly.

What happens if the test is positive?

If the test is positive, your healthcare team will likely order additional tests, including a blood test to measure the level of barbiturates in your bloodstream. Treatment will depend on the amount ingested and your symptoms, and may include monitoring, supportive care, and measures to help your body eliminate the medication.

Can this test detect all types of barbiturates?

This screening test can detect most common barbiturates, including phenobarbital, pentobarbital, and secobarbital. However, it is a qualitative test (yes/no) and does not identify the specific type or amount. Confirmatory testing may be needed for detailed information.

Do I need to prepare for this test?

No special preparation is needed for this test. Since it is typically performed in an emergency or clinical setting, your healthcare provider will handle all aspects of sample collection. If you are able to communicate, inform your doctor about any medications you have taken recently.

Is this test painful?

The collection of gastric fluid may cause some discomfort, especially when the tube is inserted through the nose. Your healthcare provider will use lubricant and may apply a numbing spray to minimize discomfort. The procedure is usually brief.

Sources

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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 17, 2026. · Read our editorial policy