Table 6-1.
Biochemical and Electrophoretic Tests Used to Evaluate Effusions
| Test | Use/Expected Result | Effusion |
|---|---|---|
| Creatinine/potassium | Fluid values are higher than those of serum creatinine and/or potassium | Uroperitoneum |
| Triglycerides | Fluids often contain triglycerides that exceed 100 mg/dL | Chylous |
| Cholesterol | Fluid level that is higher than that of serum cholesterol | Nonchylous |
| Bilirubin | Fluid level that is higher than serum bilirubin | Bile peritonitis/pleuritis |
| Lipase/amylase | Fluid values are higher than those of serum lipase and/or amylase | Pancreatitis |
| Protein electrophoresis | A:G ratio < 0.8 on the fluid is very suggestive for FIP | FIP infection |
| Lipoprotein electrophoresis | Presence of chylomicrons in fluid when triglyceride levels are equivocal | Chylous |
| pH | pH <7.0 may suggest benign or nonneoplastic conditions | Pericardial |
| pH, pCO2, glucose, lactate | Fluids with pH < 7.2, pCO2 > 55 mm Hg, glucose < 50 mg/dL, or lactate > 5.5 mmol/L are likely to have bacterial infection | Septic |
| Serum-effusion glucose | A difference of serum-effusion glucose of >20 mg/dL indicates bacterial infection | Septic peritonitis |
| Serum-effusion lactate | A difference in serum-effusion lactate of <−2.0 mmol/L (in dogs) indicates bacterial infection | Septic peritonitis |