Sample: Frozen plasma heparin 2.0 mL. Collect blood in ice immersed Lithium Heparin tube (serum is not suitable), without delay separate 2.0 mL of plasma in a refrigerated centrifuge and freeze immediately. Store frozen at -20°C. Transport frozen specimen to the laboratory in dry-ice following collection.
Take also a sample of Serum and/or Urine since Osmolality of the patient must be known in order to assess the ADH results.
Schedule: Three weeks
Status: UK Lab (Accredited)
Reference range: 1.0 - 5.0 (See Reference Chart below)
Factor: ADH pg/mL x 0,923 = pmol/L
Remarks: ADH (Vasopressin, Arginine-Vasopessin AVP) is used to differentiate diabetes insipidus due to imbalanced ADH production (and that produces polydipsia and polyuria) from nephrogenic diabetes insipidus due to the inability of renal tubules to respond to ADH. Also the test is use in the diagnosis of Inappropiate ADH (IADH), where release of ADH is disproportionate to a low serum Osmolality. This disorder results due to pulmonary disease, head trauma and cancer.