Polyuria : BASICS AND APPROACH
- 1. POLYURIA A P R O A C H Ahmad Soliyman Abdul Halim MD Lecture of paediatrics Faculty of medicine Benha university
- 3. BASICS Polyuria defined as urine out put is >3ml/kg/h
- 6. Hypertonic medulla Vasa recta TAL DT (urea) ADH effect Non Absorbable Pathophysiology of polyurea
- 7. CAUSES
- 8. Causes Acquired dysfunction of salt & water reabsorption • Obstructive uropathy • Osmotic diuresis • ATN (diuretic phase) • Tubulointerstial damage (CKD) • Drugs – diuretics – Corticosteroids – caffiene • Serious systemic infection • Hypercalciemia (↑13mg/dl ) • hypokalemia
- 9. Herediatry tubulopathies affecting salt reabsorption – RTA • Proximal (fanconi syndrome) • Distal (interstial nephritis) • Hyperkalemic, aldosterone defect (obstructive uropathy) – Bartter syndrome (AR) ADH abnormalities – Centeral DI – Nephrogenic DI Causes
- 11. ( January, 1900, - December 1969) Fuller Albright
- 12. Proximal RTA pathophysiology • Sodium loss • Bicarbonate loss • H+ retention
- 15. Renal tubular acidosis (the essentials ) • Failure to thrive • Chronic vomiting • Episodes of metabolic acidosis • Hypercholremic metabolic acidosis with NAG • Usually normal renal function • It is 4 types (proximal , distal , hyperkalemic & mixed)
- 16. Frederic Crosby Bartter (10 September 1914 – 5 May 1983)
- 18. Barrter (the essentials ) • Failure to thrive • Chronic vomiting • metabolic alkalosis • Hypocholremia • Hypokalemia • Elevated plasma renin and aldosterone
- 19. Thomas Willis (January 1621- November 1675)
- 20. Diabetes insipidus • Sever polyuria • Hypernatremia • Serum osmolarity >280 • Urine osmolarity <280 • Response to desmopressin (central type)
- 22. ASK FOR • Stress to confirm polyurea (Recurrent dehydration with no significant vomiting) • CKD • Diuretics or corticosteroids • Dark urine • Is the paient diabetic • Head trauma
- 23. Examine for • Urine volume • Hydration state • Acidotic breathing • Weight centile • Blood pressure • Racketic manifestations Evidence of CKD • Renal mass • Cushinoid features
- 24. Step 1: confirm polyurea Step 2: review your history and examination Exclude AQUIRED CAUSES at least Step3: initial investigations • Urine analysis (SG , glycosuria ) • Blood sugar level • Serum urea & creatnine • Serum electrolytes (calcium , potassium & sodium) • ABG • Abdominal US Step 4: Classify according ABG Metabolic acidosis Metabolic alkalosis No acidosis or alkalosis
- 25. Polyuria with metabolic acidosis Calculate anion gap Normal Wide Role out renal failure Dehydration Consider RTA Serum K Elevated Consider type IV Confirm by (TTKG) Investigate for aldosterone defect (pyleonephritis , obstructive uropathy ,addison,CAH) Normal or low Urine PH UAG NaHCO3 <5.5 Consider PRTA Investigate for fanconi syndrome (TYROSEMIA ,GALCTOSEMIA) >5.5Consider DRTA • SPORDIAC • INHERTIED • SYNDROMES (marfan ,wilson ) • Secondery(obst ,pyleonephritis , amphotricine B)
- 26. Polyuria with metabolic Alkalosis Role out loop diuretics and chronic vomiting Consider barrter syndrome Confirm Serum potassium (low) Serum renin and aldosterone (high)
- 27. Polyuria with no metabolic acidosis or alkalosis Role out acquired causes espically Hypercalcemia Hypokalemia Drugs Do serum & urine osmolarity Plasma osmalrity >280 Or Urine osmalrity <280 YES Diagnostic for DI (no need for WDT) DIFFERENCIATE BETWEEN CENTERAL & PREIPHERAL TYPES NO Water deprivation test