A 10 years old boy is having polyuria, polydipsia. Laboratory data showed (in meq/L): Na+ - 154, K+ - 4.5, HCO3- 22, S. Osmolality - 295, B. Urea - 50, Urine specific gravity - 1.005 What is the diagnosis?
High-Yield Explanation
The given child has presented with: Polyuria, polydipsia, hypernatremia, raised S. osmolality, raised B. urea, Normal K+ and HCO3- The given clinical and laboratory features are compatible with a diagnosis of diabetes insipidus (DI) DI is a disorder of water reabsorption, caused by resistance to the action of ADH on its receptor. Absorption of water in the distal tubules and collecting ducts is significantly impaired. Hypernatremia with low urine sodium is characteristic. S Serum chloride and serum osmolality are high. Urine osmolality is low. Treatment : Administration of hydrochlorothiazide alone or in combination with amiloride, increased fluid intake and sodiumrestriction. Other options in the question: Renal tubular acidosis- acidosis (low bicarboante), B. urea- normal, nephrocalcinosis Bater's syndrome- hypercalciuria, hyponatremia, hypokalemia, hypochloremic metabolic alkalosis