Summary Nephrology Board Review

Osmolality - 2x sodium + glucose/18 + BUN/2.8 Osmotic demyelination syndrome RF - chronic hyponatremia, alcoholism, mal nutrition, liver disease, burns, hypokalemia, sodium less than 105 SiADH uric acid levels are... - Low, but could be misleading; Diuretic induced hyponatremia, beer potomania, Renal salt wasting, cirrhosis Response to sodium chloride in SiADH - Urine remains concentrated Urine sodium increases Response to sodium chloride in Edematous states - Urine remains concentrated Urine sodium remains low Edema worsens Response to sodium chloride in Hypovolemia - Urine becomes dilute Urine sodium increases Drug causes of SiADH - - ssri - ecstasy - carbamazepine - oxcarbazapime - ddavp - NSAIDs Cancers assoc with SiADH - - small cell lung - non small cell lung - head n neck Correction of hyponatremia - - if chronic, correct limited to 10 mEq/24 hours - correction by 4 to 6 mEq stops seizures - 240 mL of 3%nacl will correct sodium by 5 - the target correction at 8mEq - avoid correction greater than 18 Change in Na after 1 L of infusate = - (infusate Na - serum Na)/(TBW +1) Treat hyponatremia with aquaresis - Tolvaptan Rxn on HD w/in 5 min put on - Heparin sensitivity - itching sometimes type A reaction Rxn on HD w/in 10-30 min put on - Eto cleaner - removed with reprocessing; IgE mediated uriticaria Complement mediated - hypotension, Type B reaction Hypotension in HD pt 30-60 min - Pericardial tamponade - occurs after ultrafiltration Bradykinins in HD pts - Associate with acei Usu with PAN membranes not with cellulocic Hypotension, nv, muscle ache in HD pt - Acetate accumulation Fever hypotension, flush in HD pt later in day - Pyrogenic reaction - occurs late in day Due to unclean dialysate, bacterial contamination Tx with stopping HD Fluid replacement in hyponatremia (equation) - Want intake osm urine osm Urine osm = 2*(U na + U k) Intake = 154*2 =304 if NS So if lose 304 then will worsen [na] Methology in Acid-Base disorder - 1 look at bicarbonate and ph 2 look at pco2 change 3 calc anion gap; if low think mm or low albumin; delta gap should = delta bicarbonate; if delta gap delta bicarb then met alkalosis 4 if anon gap elev look at osmolal gap 5 if normal gap, calc urine gap (- is normal, + is RTA) 6 if pco2 elev response acidosis 7 if pco2 lower response alkalosis; think about shock or aspirin Ketoacidosis: gap or nongap acidosis - normal anion gap acidosis bc excrete ketones in urine Nitroprusside acetest Salicylate acid-base - Gap MA and response alkalosis (pure or mix) and then later accumulate lactate and salicylate Salicylate sign and symptom - Tinnitus, vertigo, nv, diarrhea; aloc, coma Salicylate treatment - charcoal, alkalinze plasma and urine, hd when drug level 100 Metabolic Alkalosis - Loss of hcl or chloride loss from GI or kidney