💧 Effusion / CSF Interpretation
Interpret pleural fluid by Light's criteria, ascites by SAAG and CSF by the cell/protein/glucose pattern. Browser-side reference.
After diuresis, a serum-fluid albumin gradient > 12 g/L suggests a pseudoexudate.
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When to use
Separate exudate from transudate, identify portal hypertension and give a first read of CSF; pairs with the Light and CSF-correction tools.
How it works
Light's exudate (any): fluid/serum protein > 0.5, fluid/serum LDH > 0.6, fluid LDH > ⅔ ULN. SAAG ≥ 11 g/L = portal hypertension.
Key points
- After diuresis, a serum-fluid albumin gradient > 12 g/L suggests a pseudoexudate.
- SAAG ≥ 11 g/L points to portal hypertension.
- Bacterial CSF: neutrophils, high protein, low glucose (CSF/blood < 0.4).
- Correct CSF WBC for a traumatic tap.
References
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| View | Pleural — Light's |
|---|
→InterpretationPleural effusion (Light's criteria)
- Exudate (any one)：Fluid/serum protein > 0.5, fluid/serum LDH > 0.6, fluid LDH > 2/3 of the upper normal limit (see 'Light's criteria')
- Transudate：None met: heart failure / cirrhosis / nephrotic syndrome
- Pseudoexudate：After diuresis → serum-to-fluid albumin gradient > 12 g/L suggests it is really a transudate
| View | CSF |
|---|
→InterpretationCerebrospinal fluid (CSF)
- Bacterial：Neutrophils ↑↑, protein ↑↑, glucose ↓ (CSF/blood glucose < 0.4), pressure ↑
- Viral：Lymphocytes ↑, protein normal/mildly ↑, glucose normal
- TB/fungal：Lymphocytes ↑, protein ↑↑, glucose ↓
Frequently asked questions
- What is Effusion / CSF Interpretation?
- Interpret pleural fluid by Light's criteria, ascites by SAAG and CSF by the cell/protein/glucose pattern. Browser-side reference.
- How is Effusion / CSF Interpretation calculated? What is the core formula?
- Light's exudate (any): fluid/serum protein > 0.5, fluid/serum LDH > 0.6, fluid LDH > ⅔ ULN. SAAG ≥ 11 g/L = portal hypertension.
- When is Effusion / CSF Interpretation used?
- Separate exudate from transudate, identify portal hypertension and give a first read of CSF; pairs with the Light and CSF-correction tools.
- What are the key clinical points for Effusion / CSF Interpretation?
- After diuresis, a serum-fluid albumin gradient > 12 g/L suggests a pseudoexudate. SAAG ≥ 11 g/L points to portal hypertension. Bacterial CSF: neutrophils, high protein, low glucose (CSF/blood < 0.4). Correct CSF WBC for a traumatic tap.
- What are the limits and cautions when using Effusion / CSF Interpretation?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is Effusion / CSF Interpretation calculated in practice? Can you show a worked example?
- Inputs: View Pleural — Light's → Result: Interpretation Pleural effusion (Light's criteria)（Exudate (any one): Fluid/serum protein > 0.5, fluid/serum LDH > 0.6, fluid LDH > 2/3 of the upper normal limit (see 'Light's criteria'), Transudate: None met: heart failure / cirrhosis / nephrotic syndrome, Pseudoexudate: After diuresis → serum-to-fluid albumin gradient > 12 g/L suggests it is really a transudate） Inputs: View CSF → Result: Interpretation Cerebrospinal fluid (CSF)（Bacterial: Neutrophils ↑↑, protein ↑↑, glucose ↓ (CSF/blood glucose < 0.4), pressure ↑, Viral: Lymphocytes ↑, protein normal/mildly ↑, glucose normal, TB/fungal: Lymphocytes ↑, protein ↑↑, glucose ↓）