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Phpcarstrip

Published: July 31, 2026Updated: August 16, 2026

A test that measures the acidity level of fluid collected from the sac surrounding the heart to help diagnose the cause of fluid buildup.

Quick summary

{"Measures pH (acid level) in fluid around the heart","Helps distinguish between different causes of pericardial effusion","Collected via a procedure called pericardiocentesis","Low pH may indicate inflammatory or infectious conditions","Results help doctors determine the best treatment approach"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
68382-1
Short code
PHPCF
Synonyms
pH Pcar Strip
Category
chemistry
Sample
serum
Container
Sterile collection tube or container, preferably with heparin anticoagulant for gas analysis
Units
not specified
Ref low
7.35
Ref high
7.45
Critical range
7.2 not specified – —
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
test-strip
CPT
83992
SNOMED
59408001
Specimen volume
1-3 mL minimum for test strip analysis; 2-5 mL preferred for comprehensive analysis
Stability
Analyze immediately (within 15-30 minutes) for accurate pH measurement. Do not refrigerate. Air exposure can alter pH readings
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
0–1 hours
Order
routine

What is this test?

The pericardial fluid pH test measures how acidic or alkaline the fluid is in the pericardium—the thin sac that surrounds your heart. Normally, pericardial fluid has a pH similar to blood, around 7.6-7.8. Changes in pH can provide important clues about what is causing fluid to accumulate around the heart, a condition called pericardial effusion.

How is the sample collected?

Pericardial fluid is not taken from your blood. Instead, it is collected using a procedure called pericardiocentesis. During this procedure, a doctor inserts a thin needle through your chest wall into the pericardial sac to withdraw the fluid. The procedure is usually done under local anesthesia and guided by ultrasound to ensure safety and accuracy. You may be asked to fast for several hours before the procedure.

What do the results mean?

A normal pericardial fluid pH is typically between 7.6 and 7.8. If the pH is lower (more acidic), it may suggest: inflammatory conditions such as pericarditis, bacterial or tuberculous infections, malignancy (cancer), or bleeding into the pericardial sac. A very low pH (below 7.2) is often associated with complicated or inflammatory effusions. Your doctor will interpret these results along with other test findings to determine the cause and appropriate treatment.

Are there any risks?

Pericardiocentesis is generally safe but carries some risks, including bleeding, infection, puncture of the heart or lungs, and irregular heartbeats. Your healthcare team will monitor you closely during and after the procedure. Contact your doctor immediately if you experience chest pain, difficulty breathing, or fever after the procedure.

Reference range

7.35-7.45not specified

Specimen: serum

No special preparation; specimen obtained by pericardiocentesis

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

pH-PCF

Frequently asked questions

Why is pericardial fluid pH tested instead of just blood pH?
Blood pH is tightly regulated by your body's buffering systems and may remain normal even when there is significant abnormality in the pericardial space. Measuring the pH directly in the pericardial fluid provides more specific information about the local environment around the heart and is more useful for diagnosing the cause of the effusion.
How long does it take to get results?
Results from the pH test are typically available within a few hours, as it is often performed at the bedside using test strips. However, if other tests (such as cell analysis, culture, or cytology) are ordered on the same fluid sample, it may take several days to get the complete results.
Does a low pH always mean cancer?
No, a low pH does not automatically mean cancer. While malignant effusions often have lower pH due to tumor metabolism and associated inflammation, many other conditions can cause acidic pericardial fluid, including bacterial infections, tuberculosis, and inflammatory conditions like pericarditis. Your doctor will consider your complete medical history and other test results to make an accurate diagnosis.
Will I need to have the fluid drained again after treatment?
This depends on the underlying cause and how well you respond to treatment. Some patients may require repeated drainage procedures if fluid re-accumulates. In cases of recurrent effusions, your doctor may discuss more permanent solutions such as a pericardial window (a surgical opening to allow continuous drainage) or sclerotherapy (a procedure to seal the pericardial space).
  1. 1
    Mayo Clinic - PericardiocentesisSource
  2. 2
    Cleveland Clinic - Pericardial EffusionSource
  3. 3
    American Heart Association - Pericardial DiseasesSource

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.

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 16, 2026. · Read our editorial policy