Laboratory parameters of the 1st order – obligatory laboratory tests.
- Small blood count
- Inflammatory parameters – CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
- Urine status (rapid test for: pH, leukocytes, nitrite, protein, blood), sediment, urine culture (pathogen detection and resistogram, that is, testing suitable antibiotics for sensitivity / resistance).
- Electrolytes – calcium
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance if necessary.
- Uric acid
- Urinalysis
- Microscopy (microhematuria/excretion of blood in urine not visible to the naked eye).
- Urine examination for dissolved substances such as calcium, uric acid, oxalate, citrate.
- Urine pH, specific gravity and urine volume.
- Urine pH values:
- Urine pH values in the daily pH profile (at least four measurements throughout the day) are usually between 4.5 and 8.0
- Urine pH values > 7.0 in the pH daily profile = indication of a urinary tract infection with urease-forming bacteria (risk of infection stone formation).
- Urine pH values constantly < 6 in the pH daily profile = “acidity of urine.” [favors cocrystallation of uric acid and calcium oxalate].
- Urine pH values constant > 5.8 in the pH daily profile = indication of an underlying renal tubular acidosis (RTA), provided that a urinary tract infection is excluded
- Specific gravity: urine density < 1.010 kg/l [for metaphylaxis/stone prophylaxis].
- Urine volume: 2.0-2.5 l /day [for metaphylaxis/stone prophylaxis].
- Urine pH values:
- Bacteriological urinalysis for pathogens.
- Stone analysis/urinary stone analysis – should be performed for any kidney or ureteral stone; this should also be done for any new stone episode.
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- 24h collection urine (volume, pH, ammonium, calcium, chloride, citrate, uric acid, sodium, potassium, magnesium, oxalate, phosphate and creatinine), twice – in high-risk patients.
- Hormone determinations such as:
- Parathyroid hormone (if calcium is elevated) and.
- Calcitonin (antagonist of parathyroid hormone, which lowers serum calcium levels) – in complicated course/high-risk patients.
After removal of the stone should always be performed a stone analysis (urinary stone analysis), which may provide clues to the origin and allows causal therapy
Reference values in the urinalysis (adults) due tometaphylaxis (prophylaxis) of urolithiasis.
| Parameters | Measured value | Assessment |
| pH value | see above | s. o. |
| Specific weight | > 1010 | Insufficient drinking quantity |
| Ammonium | > 50 mmol/d | Hyperammonuria |
| Inorganic phosphate | > 35 mmol/d | Hyperphosphaturia |
| Calcium | > 5.0 mmol/d | Metaphylaxis warranted |
| ≥ 8 mmol/d | Manifest hypercalciuria | |
| Oxalate | > 0.5 mmol/d | Hyperoxaluria |
| 0.45-0.85 mmol/d | Mild hyperoxaluria | |
| ≥ 1.0 mmol/d | Primary hyperoxaluria probable | |
| Uric acid | > 4.0 mmol/d | Hyperuricosuria |
| Magnesium | <3.0 mmol/d | Hypomagnesiuria |
| Citrate | <1.7 mmol/d | Hypocitraturia (hypocitraturia) |
| Cystine (Cystin) | > 0.8 mmol/d | Cystinuria (cystinuria) |