Nephrology Flashcards
causes of nephrogenic DI
hypokalemia
hypercalcemia
lithium toxicity
Tx. of central DI
Desmopressin
- prompt decrease in urine volume and increase in urine osmolality
tx. nephrogenic DI
correct underlying cause
thiazide diuretics
causes: hypervolemic hyponatremia
CHF
cirrhosis
nephrotic syndrome
causes: hypovolemic hyponatremia
GI losses - diarrhea, vomiting
skin loss of fluids - burns, sweating
diuretics
Tx. hypervolemic hyponatremia
fluid restriction
Tx. hypovolemic hyponatremia
NS
hyponatremia + hyperkalemia and mild metabolic acidosis
Addison’s disease
- tx. fludrocortisone
causes: euvolemic hyponatremia
SIADH
psychogenic polydipsia
hyperglycemia
effect of glucose on na level
every 100 mg increase in glucose drops Na by 1.6 points
Tx. hyponatremia 125-135
no tx or tx the cause
tx. hyponatremia 115-125
water restriction, if asymptomatic
Tx. mod -severe hyponatremia <115 or symptomatic hyponatremia
saline infusion
loop diuretics
appropriate rate of rise of Na in correction of hyponatremia
no more than 0.5 mEQ/L/hour (12 mEQ/L/day) in first 24 hours, no more than 18 in 48 hours
Tx. chronic SIADH ex from malignancy
demeclocycline
EKG changes in hyperkalemia
1) peaked T waves
2) loss of P waves
3) wide QRS complex
Tx. severe hyperkalemia
calcium gluconate - cardioprotective
insulin + glucose
causes of hypokalemia
diuretics Conns syndrome vomiting - metabolic alkalosis w/ cellular shifts proximal and distal RTA amphotericin Barter syndrome
Bartter syndrome
inability of the loop of henle to absorb NaCl which causes secondary hyperaldosteronism and renal potassium wasting
Tx. hypokalemia
replace K+ = no max rate on oral K+ replacement as bowel regulates absorption; you should avoid glucose containing fluids, which may worsen hypokalemia from cellular shifts
causes: hypermagnesemia
Mg containing laxatives
iatrogenic administration
rare unless underlying renal insufficiency
Tx. hyperMg
restrict intake
saline administration to promote diuresis
occasionally, dialysis
causes: hypomagnesemia
loop diuretics
alcohol withdrawl
gentamycin
cisplatin
fastest, single test to tell if patient’s hyperglycemia is life threatening
low serum bicarb
isoniazid toxicity
stop medication, move the clock forward
electrolyte disturbances with diarrhea
metabolic acidosis – increased loss of HCO3 from colon
hypokalemia
hyperchloremia - increased Cl- absorption
distal RTA (type 1)
inability to excrete H+ ions in distal tubule
- serum K+ low (K+ is cation that is excreted instead)
- serum HCO- low
- alkaline urine
test for distal RTA
IV acid (ammonium chloride) - should lower urinary pH secondary to H+ formation; in RTA, the pts urine stays basic
Tx distal RTA
Bicarb
proximal RTA (type 2)
inability to reabsorb bicarb in proximal tubule
- low urine pH
- osteomalacia
how do you test for proximal RTA
give bicarbonate
- urine pH will rise because unable to absorb the bicarb
Tx. proximal RTA
thiazide diuretic
large amts of bicarb
type IV RTA
decreased aldosterone production or effect
- hyperkalemia
- urine pH low
test: urine Na loss
Tx. type IV RTA
fludrocortisone
how do you distinguish from metabolic acidosis caused by diarrhea vs RTA
UAG = Urine Na - Urine Cl-
negative UAG = diarrhea
positive UAG = RTA
volume contraction
metabolic alkalosis –> secondary hyperaldosteronism (increased loss of urinary acid)
routine tests for HTN cases on CCS
EKG
urinalysis
eye exam for retinopathy
cardiac exam for murmur and gallop
most effective lifestyle modification for HTN
weight loss
first line therapy for HTN if lifestyle mods dont work
- thiazides
2. if diabetic - ACEI
coexisting conditions that you tx HTN with a BB
CAD
CHF
migraine
hyperthyroidism
in which conditions should you avoid BB for tx of HTN
asthma
depression
when should you investigate for 2ndary HTN
young 60 yo
failure to control pressure with 2 meds
specific findings on physical exam
you begin treating a pt with an ACEI, and on labs, their CR level rises - what should you suspect
renal artery stenosis
best initial test for renal artery stenosis
renal doppler usg
most accurate test for renal artery stenosis
renal angiogram
pt with varicocele with any of: bilateral, right sided or does not go away with supine position
needs further evaluation for obstruction of IVC
- order CT abdo
who gets tx for asymptomatic bacteriuria
pregnant pts
urologic intervetions
hip arthroplasty pts
clues that renal failure is short duration
normal size
normal hematocrit
normal calcium level
diagnostic features of prerenal failure
- BUN/Cr > 20:1
- U sodium LOW
- FE na < 1%
- Uosm >500
- hyaline casts
on CCS, all renal cases should have what three tests
urinalysis
chemistries
renal usg
Dx. postrenal azotemia
- obstruction of kidney (must be b/l)
- elevated BUN/Cr > 15:1
- clues:
- distended bladder
- large volume diuresis after cath
- b/l hydronephrosis on us
diagnostic features: intrarenal causes of RF
BUN/Cr ~ 10:1
U na > 40
U osm < 350
UA: muddy brown or granular casts
common toxins that cause renal failure
aminoglycosides - hypomagnesemia is suggestive
amphotericin
contrast agents
chemotherapy - cisplatin
pt on penicillin, develops rise in BUN/Cr with fever and rash - dx? best initial test?
allergic interstitial nephritis
best initial test: UA - increased WBCs
most accurate test for allergic interstitial nephritis
wright stain or hansel’s stain of urine
effect of cyclophosphamide on kidney
hemorrhagic cystitis - it does NOT cause renal failure
best initial test for rhabdo
UA - will see blood but no cells
most accurate test for rhabdo
urine myoglobin level
Dx. findings in rhabdo
UA - blood but no cells urine myoglobin + CPK elevated hyperkalemia hypocalcemia low serum bicarb
Tx. rhabdo
bolus NS
mannitol and diuresis
alkalinization of urine
first test to order in pt who you suspect has rhabdo
EKG - to r/o any arrhythmia secondary to hyperkalemia
envelope shaped urine crystals
calcium oxalate crystals
- ethylene glycol poisoning
best method to prevent contrast induced nephropathy
- IVF with NS
2. possibly bicarb, N acetylcysteine or both
best initial test: Goodpasture’s syndrome
anti-basement mb abs
most accurate test: Goodpasture’s syndrome
renal biopsy - shows linear deposits
Tx. goodpasture’s syndrome
plasmaphoresis
steroids
best initial test: churg strauss
CBC for eosinophil count
best initial therapy: churg strauss
steroids - prednisone
best initial test: Wegener’s
c-ANCA
best initial therapy: wegeners
cyclophosphamide
steroids
most accurate test for dx. polyarteritits
biopsy of sural N or kidney
best diagnostic test for dx. IgA nephropathy
biopsy
- no specific blood test or physical exam findings
Tx. IgA nephropathy
- steroids - for acute episodes
- ACEI
- fish oil - may delay progression
best initial test for Henoch Schonlein purpura
clinical presentation
Tx. Henoch Schonlein purpura
resolves spontaneously over time
best initial test for post-strep GN
ASLO, anti-DNAase B, antihyaluronidase
complement low
when should you do a biopsy with post-strep GN
- atypical course
- normal complement level
- sx > 2 months
- acute renal failure
pt with hepatitis C presents with joint pain and purpuric skin lesions. Exam shows LAD, hepatosplenomegaly and peripheral neuropathy. labs show hematuria, proteinuria and increased Cr. - Dx?
cryoglobulinemia
best initial test for cryoglobulinemia
serum cryoglobulin component levels
decreased C3, C4 and CH50
Tx. cryoglobulinemia
alpha interferon - alone, if renal dysfxn
+ ribavirin, if no renal dysfxn
and bocepravir or telaprevir