Table 3. Reference intervals and differential limits for clinically useful analytes.
| Parameter | Normal SF | Inflammatory SF | Septic SF |
|---|---|---|---|
| Glucose (mmol/L) | 3.3–5.3 | 1.1–3.1 | 1.1–1.7 |
| Lactate (mmol/L) | 1.0–1.8 | Up to 6.8 | > 9.0 |
| Uric acid (mmol/L) | Equal to blood | Equal to blood | Equal to blood |
| Total proteins (g/L) | 11–22 | > 40 | 30–60 |
| RF | Negative | Positive/negative | Negative |
| LD (U/L) | < 280 | > 280 (to 750) | > 300 |
| WBC (x106/L) | < 200 | 2000–50,000 | 50,000 |
| %PMN | < 25 | > 50 | > 75 |
| Monosodium urate crystals | Negative | Positive | Negative |
| Calcium pyrophosphate crystals | Negative | Positive | Negative |
| SF – synovial fluid. RF – rheumatoid factor. LD – lactate dehydrogenase. WBC – white blood cell count. PMN – polymorphonuclear lymphocytes. Adapted from (2, 8, 10, 12, 13, 15, 19, 26). | |||