Laboratory parameters of the 1st order – obligatory laboratory tests.
- Small blood count
- Serum sodium and serum sodium osmolality.
- Total serum protein (serum protein)
- Urine osmolality
Interpretation
Isotonic dehydration
- Hb (hemoglobin), hematocrit, serum protein [↑]
NotesSerum sodium and serum osmolality is normal.Specific urine weight is increased with normal renal function.
Hypotonic dehydration
- Hb (hemoglobin), hematocrit, serum protein [↑]
- Serum sodium and serum sodium osmolality [↓]
- Urine Na+ (urinary sodium excretion).
- <20 mmol/l for extrarenal losses.
- > 20 mmol/l for renal losses
Hypertonic dehydration
- Hb (hemoglobin), hematocrit, serum protein [↑]
- Serum sodium and serum sodium osmolality [↑]
- Urine osmolality ↑ in patients with normal renal function.
- Urine osmolality ↓ in diabetes insipidus (in central diabetes insipidus, urine osmolality increases after ADH administration, but not in nephrogenic diabetes insipidus).
