Polyuria Definition : Urine more than L/d Relatively common Causes and path physiology : A- Water diuresis (UoSm<250mosmol/kg of water) Appropriate : 1- Primary polydypsia 2- IV infusion of dilute solutions Inappropriate : 1- CDI 2- NDI

B- Solute diuresis (UoSm> 300 mosmol/kg of water) Appropriate : 1- Saline excess use 2- Diuresis after obstruction elimination Inappropriate : 1- Hyperglycemia 2- Excess proteion intake by gastric tube 3- Salt losing nephropathy

Approach : 1.Urine osmolality measurement (normal value in normal adult : mosmol/kg of water ) 2.Methods : 1- Sticks tapes 2- Frozen point depression (more accurate) Comparison between urine SP. GR and urine osmolality SP. GR Mosmol /kg

Diabetes Insipidus 1- Central or neurogenic DI (Complete and incomplete) 2- Nephrogenic DI Central DI Sign : Polyuria and polydypsia Abrupt onset of sign Near normal Serum Na Causes : 1- Idiopathic (75%), may be familial, nerve degeneration in hypothalamic nucleus 2- Neurosugical A- Craniopharingioma B- Trans-sphenoidal surgery

3- Head trauma 4- Ischemic encephalopathy or hypoxia A- Cadiopulmonary arrest B- Shock C- Sheehan syndrome 5-Neoplasma A- Primary : Craniopharingioma, pinealoma, cysts B- Metastatic : Breast or lung cancer 6- Miscelanous causes A- Histiocytosis B- Sarcoidosis C- Cerebral aneurism D- Meningitis and encephalitis E- Anorexia nervosa

Primary polypsia Hypotonic polyuric state Signs : Polyuria, polydysia Causes : 1- Psychologic disorder, delusion, depression, agitation, hysterical behavior. Water consuption :Irregular from hour to hour and from day to day. 2- Hypothalamic disorders (sarcoidosis ) Lab data : 1- Serum Na usually normal or slightly decreased. 2- Rare cases of lethal hyponatremia 3- After WDT : Urine osmolality = mosmol 4- After inhalation of dDAVP= <10% increase of urine osmolality.

Nephrogenic Diabetes Insipidus Pathophysiology : 1- Decrease of water reabsorption in distal tubule 2- Normal plasma AVP level Clinical sign :1- Polyuria 2- Polydypsia 3- Graual onset of sign and symptom Causes :1- Acquired (Frequently ) 2- Familial 3- Congenital

A- Acquired renal tubular disoeders : 1- Pyelonephritis 2- Analgesic nephropathy 3- M. M 4- Amyloidosis 5- Obstruction 6- Sarcoidosis 7- Hypercalcemia 8- Hypokalemia 9- Sicle cell anemia 10- Sjogren syndrome

B- Drugs and toxins 1- Lithium 2- Demeclocycline 3- Methoxyflurane 4- Ethanol 5- Diphenylhydantoine 6- Propoxiphen 7- Amphotricine

C- Congenital and heriditary 1- Polycyctic kidney 2- Medullary cyctic disease

Oliguria Definition : Urine < ml/day Pathogenesis : ARF and CRF Causes of ARF : 1- Pre-renal failure (55%) 2- Intra-renal failure (40%) 3- Post-renal failure Causes of pre-renal failure : 1- Cardiovascular shock 2- Blood volume depletion 3- Plasma volume depletion (vomiting, diarrhea) 4- Sepsis 5- Acute renal artery obstruction 6- NSAIDS 7- ACEI Causes of intra-renal failure : 1- Acute GN 2- Acute TIN 3- Renal vasculitis