EpistemisPolyuria with clear urine and rapid weight loss in preschoolers
Specialty: Pediatrics.
Why it occurs
- Early onset Type 1 Diabetes Mellitus (absolute insulin deficiency due to autoimmune destruction of pancreatic beta cells, which produces hyperglycemia, glycosuria and massive osmotic diuresis)
- Central Diabetes Insipidus (deficiency in the synthesis or secretion of antidiuretic hormone or vasopressin due to idiopathic causes, pituitary tumors or trauma)
- Nephrogenic Diabetes Insipidus (renal resistance to the action of vasopressin due to genetic mutations linked to the X chromosome in the V2 receptor or aquaporin-2 receptor, or acquired by drugs or ionic disorders such as hypercalcemia)
- Primary or psychogenic polydipsia (excessive compulsive intake of water that saturates the kidney's ability to concentrate, more common in behavioral or neurodevelopmental disorders)
- Renal tubular acidosis or chronic interstitial nephropathy (loss of renal tubular concentrating capacity)
Initial workup
Immediate determination of capillary blood glucose and urine dipstick in the first available sample (to urgently evaluate the presence of massive glycosuria and ketonuria). Capillary or arterial blood gas (to assess plasma pH and bicarbonate, confirming ketoacidosis if pH < 7.3 or bicarbonate < 15 mEq/L). Complete ionogram (sodium, potassium, chloride, calcium), renal function (urea, creatinine) and plasma osmolarity. Determination of urinary density and urine osmolarity in a fresh sample (if the child has very dilute urine with a density < 1.005 in the presence of dehydration or high plasma osmolarity, this indicates diabetes insipidus).
red flags
Presence of rapid, deep and noisy breathing without apparent respiratory effort (Kussmaul respiration, cardinal sign of metabolic acidosis/diabetic ketoacidosis); breath that smells like fruit or rotten apples (acetone smell); progressive alteration of mental status, from extreme irritability to confusion, obtundation, drowsiness, or coma; severe dehydration with signs of hypovolemic shock despite continuous diuresis (the child continues to urinate profusely despite being severely dehydrated); repeated vomiting and absolute oral intolerance.
Standard management
- Rapid or regular insulin — of choice for the treatment and correction of diabetic ketoacidosis; continuous intravenous infusion at doses of 0.05 to 0.1 IU/kg/hour after rigorous initial expansion and hydration with 0.9% saline; The correction must be carried out under strict monitoring protocol to avoid cerebral edema
- Desmopressin or DDAVP — synthetic analogue of vasopressin indicated of choice in central diabetes insipidus; administered orally, sublingually or intranasally, individualized dose adjusting according to urine output and serum sodium levels
- 0.9% physiological saline solution (for initial volume replacement in case of hypovolemic shock).
Educational guidance for study. It is NOT a prescription recommendation. The actual choice depends on the cause, the patient, and current guidelines.
- Area
- Pediatrics
- Listed causes
- 5
- Treatment options
- 3