Nephrology Flashcards
What are the 3 GFR estimation equations? When do you use which? 1) best when GFR <60 2) best when near nromal GFR values 3) least accurate 4) which to use drug dosing
Cockcroft-Gault equation, Modification of Diet in Renal Disease (MDRD) study equation, CKD Epidemiology (CKD-EPO) collaboration equation
1) MDRD study
2) CKD-EPO
3) Cockcroft-Gault equation
4) Cockcroft-Gault equation
What is the BUN:Cr ratio for dehydration?
> 20:1
What is the only protein to be detected in dipstick?
albumin
What test can detect presence albumin and other proteins like urine light chains or immunoglobulins?
sulfosalicylic acid
What is the follow up test after detecting protein on a dipstick?
24 hour urine collection or protein/albumin creatine ratio
What is cutoff for protein Cr ratio for
1) tubulointerstitial or glomerular disease?
2) glomerular disease
1) >150mg/g but <200mg/g
2) >3500mg/g
When do you use albumin Cr ratio?
to measure diabetic kidney disease
What cut off is used for albumin cr ratio for
1) moderately increased albuminuria (microalbuminuria)
2) severely increased albuminuria (macroalbuminuria or overt proteinuria)
1) 30-300mg/g
2) >300mg/g
What findings in the urine can indicate glomerular disease? (2)
erythrocyte casts and dysmorphic erythrocytes (acanothcytes, RBCs with mickey mouse ears)
If there are no casts in urine, what other finding with hematuria can support glomerular cause or hematuria?
coexisting proteinuria
If hematuria is preserved morphology, what extraglumerular bleeding differential diagnosis can it indicate? (5)
GU cancer, kidney stones, infection, trauma, medications
What can sterile pyuria suggest? (3)
interstitial cystitis, interstitial nephritis, mycobacterium tuberculosis
What can eosinophiluria suggest? (5)
AIN, postinfectious GN, atheroembolic disease of kidney, septic emboli, small vessel vasculitis
What disorders are associated with the following casts:
1) erythrocyte casts
2) leukocyte casts
3) muddy brown casts
4) broad casts
1) glomerular disease
2) inflammation or infection of renal parenchyma
3) ATN
4) CKD
Casts=aggregates of Tamm-Horsfall mucoproteins that trap intraluminal contents
What imaging needs to be obtained to look for renal artery stenosis and renal vein thrombosis?
What is the risk if this imaging is used with CKD
MR with gadolinium (nongad for the thrombosis)
nephrogenic systemic fibrosis
What are 4 indications for renal biopsy?
glomerular hematuria, severely increased albuminuria, acute or CKD of unclear etiology kidney transplant dysfunction
What are 7 reasons not to do a kidney biopsy?
bleeding diatheses, severe anemia, UTI, hydronephrosis uncontrolled HTN, renal tumor, atrophic kidneys
What is the first thing to measure in hyponatremia?
What are 2 things that can cause pseudo hyponatremia and have a normal serum osm?
serum Osm–>hyper or hypo
severe hyperlipidemia and hyperproteinemia
What are 6 things that can cause hypertonic (hyperosm) hyponatremia?
glucose, BUN, alcohols, mannitol, sorbitol, glycine (used on bladder irrigation)
What is the next thing to look at when you have hypo-osmolar hyponatremia?
volume status
What are the following lab values for hypovolemia hypo-osmolar hyponatremia?
1) spot urine sodium
2) BUN/Cr ratio
What is the cause of this? (3)
1) <20mEq/L
2) >20:1
GI/kidney fluid losses, dehydration, mineralocorticoid insufficiency
What are the following spot urine sodium values for hypervolemia hypo-osmolar hyponatremia in
1) HF and cirrhosis in abscence of diuretic therapy
2) acute and chronic kidney failure
1) <20meq/L
2) >20meq/L
What is the following lab values for euvolemic hypo-osmolar hyponatremia due to SIADH, hypothyroidism, glucocorticoid deficiency (Addison disease)?
1) spot urine sodium
2) urine osm
1) >20mEq/L
2) >300mOsm/L
What is the following lab values for euvolemic hypo-osmolar hyponatremia due to compulsive water drinking?
1) spot urine sodium
2) urine osm
1) >20mEq/L
2) 50-100 mOsm/L
What are some medications that can cause SIADH? (6)
thiazides, SSRIs, TCAs, narcotics, phenothiazines, carbamazepine
What is the risk of overcorrection of hyponatremia?
central pontine myelinolysis; aim to correct 4-6mEq/L within the first 6 hours w/ 3% NaCl if symptomatic
How do you correct an overcorrection of hyponatremia?
desmopressin and D5W
How do you treat asymptomatic/minimally symptomatic outpatients with SIADH?
water restriction, loop with oral salt supplementation, demeclocycline
What is the treatment or euvolemic and hypervolemic hyponatremia
V1 and V2 receptor antagonist conivaptan and tolvaptan(reserve for Na <120)–not necessarily better than other conventional treatments
What are 5 reasons for hypernatremia?
inadequate access to water, defective thirst mechanism, kidney concentrating defect (with lithium), impared pituitary secretion of ADH (2/2 sarcoidosis), loss of hypotonic fluids
What is the formula for water deficit in hypernatremia?
(Na-140 divided by 140) x TBW
TBW=0.5 (in woman) or 0.6 (in men) x weight
What is treatment for hypernatremia due to central DI?
IN desmopressin
What are 5 causes of hyperkalemia?
hyporeniemic hypoaldosteronism, acute/chronic kidney failure, low urine flow states, meds, potassium shifts
What number is suggestive of excessive potassium urinary losses?
> 20
What number is suggestive of cellular shift, decreased intake or extrarenal losses of potassium?
<24 mEq/24 hours
What are 5 rare causes of hypokalemia?
1) primary aldosteronism
2) Bartter syndrome
3) Gitelman syndrome
4) inhalted beta2 agonists
5) hypokalemic periodic paralysis
What are the causes of hypokalemia?
1) HTN, urine Cl >40mEq/L, low plasma renin and elevated aldosterone?
2) normal BP, hypoK, metabolic alkalosis, elevated renin and aldosterone
3) normal BP, hypoK, hypoMg
1) primary aldosteronism
2) Bartter syndrome
3) Gitelman syndrome
What are the causes of hypokalemia?
-rare familial or acquired disorder characterized by flaccid generalized weakness from sudden shift precipitated by strenuous exercise or high CHO meal
- who do we see it in for inherited?
- what do we see it with if acquired?
hypokalemic periodic paralysis seen in Asian/Mexican men
if acquired, see with thyrotoxicosis
What are 4 symptoms of hypokalemia?
EKG findings?
ileus, muscle cramps, rhabdomyolysis, hypomagnesemia
EKG: U waves and flat/inverted T waves
What are two concurrent electrolyte/pH abnormalities with hypokalemia?
hypomag and metabolic alkalosis
What two electrolyte abnormalities are seen with hypomagnesemia?
hypocalcemia and hypokalemia
What are 4 medications associated with hypomagnesemia?
cisplatin, aminoglycosides, amphotericin B, cyclosporine
What does PTH do in phosphate regulation?
decreases phosphorus reabsorption and promotes kidney phosphate excretion
What does calcitriol do in phosphate regulation?
stimulates phosphate absorption in gut
What are 5 characteristic findings in severe hypophosphatemia?
HF, muscle weakness, rhabdo, hemolytic anemia, metabolic encephalopathy
What is the formula to calculate FEPO4?
(Urine PO4 x Cr serum x 100) / (serum PO4 x UCr)
What is the % of FEPO4 and renal phosphate excretion that indicates renal phosphate wasting?
> 5% and >100 mg/d
What are the 4 questions to ask when approaching acid/base problem?
1) what is primary disturbance
2) is the compensation appropriate
3) what is the anion gap
4) does the change in anion gap equal the change in serum bicarbonate concentration?
What is the compensation formula for metabolic acidosis?
1) acute
2) chronic
1) 1.5 (HCO3) +8 +/-2
2) HCO3 + 15
* if the pCO2 is higher than expected, then have a concomitant respiratory acidosis
* if the pCO2 is lower than expected, then have a concomitant respiratory alkalosis
What is the compensation formula for respiratory acidosis?
1) acute
2) chronic
1) 1 mEq/L increase in HCO3 for each 10mmHg increase in pCO2
2) 3.5 mEq/L increase in HCO3 for each 10mmHg increase in pCO2
* if HCO3 is lower than expected, then also have metabolic acidosis
* if HCO3 is higher than expected, then also have metabolic alkalosis
What is the compensation formula for metabolic alkalosis?
- 7 mmHg increase in pCO2 for each 1mEq/L increase in HCO3
* response is limited by hypoxemia
What is the compensation formula for respiratory alkalosis?
1) acute
2) chronic
1) acute: 2 mEq/L decrease in HCO3 for each 10 mmHg decrease in pCO2
2) chronic: 4mEq/L decrease in HCO3 for each 10 mmHg decrease in pCO2
* if HCO3 is higher than expected, there is also metabolic alkalosis
* if HCO3 is lower than expected, then there is also metabolic acidosis
What is the anion gap calculator? Which acid disturbance is this important for?
Na - Cl + HCO3
AG normal 10 +/-2
metabolic acidosis
What does a reduced anion gap <4 suggest? (2)
multiple myeloma or hypoalbuminemia
what are 6 reasons to have an elevated anion gap metabolic acidosis?
DKA, CKD, lactic acidosis, aspirin toxicity, alcoholic ketosis, methanol and ethylene glycol poisoning (also have osmolar gap)
What are 5 reasons to have a normal anion gap metabolic acidosis?
diarrhea (GI losses), ileal bladder/proximal RTA (kidney losses), reduced kidney H secretion (distal RTA, type IV RTA), fanconi syndrome (phosphaturia, glucosuria, uricosuria, aminoaciduria), carbonic anhydrase inhibitor use (acetazolamide and topiramate)
What is the urine anion gap calculation?
Na + K - Cl
What 2 situations is the urine anion gap calculation used?
1) normal anion gap metabolic acidosis when there is extra renal bicarb–>UAG will be very neg
2) type 1 RTA–>UAG will be positive
What is the expected ratio between the change in anion gap (normal - measured) and change in plasma HCO3 (normal - measured)
1-2
What if delta anion gap/delta HCO3 is <1?
What if delta anion gap/delta HCO3 is >2?
if <1–>concurrent normal anion gap acidosis
if >2–>concurrent metabolic alkalosis
Which RTA is this?
1) normal AGMA, hypoK, positive UAG, urine pH >5.5, serum bicarb=10
2) what are 4 associated findings?
3) treatment?
1) Distal (type 1) RTA
2) nephrolithiasis and nephrocalcinosis, autoimmune disorders, amphotericin B, urinary obstruction
3) bicarb
Which RTA is this?
1) normal AGMA, normal or negative UA, hypokalemia, urine PH <5.5, serum bicarb 16-18
2) what is associated finding?
3) treatment?
1) proximal (type 2) RTA
2) fanconi syndrome (glucosuria, phosphaturia, uricosuria, aminoaciduria, tubular proteinuria)
3) thiazide + potassium-sparing diuretic
Which RTA is this?
1) normal AGMA, hyperkalemia, positive UA, urine pH <5.5
2) what is 2 associated findings?
3) treatment?
1) type 4 RTA
2) DM, urinary tract obstruction
3) correct hyper K
How do you calculate osmol gap? What is the normal osmol gap?
2 x serum Na + BUN/2.8 + blood glucose/18
10 is normal
What osmol gap would you consider an alcohol poisoning? What is the most common alcohol poisoning?
> 10; ethanol
What alcohol would you suspect:
1) somnolence or coma and normal acid/base?
2) severe increased AGMA and acute visual symptoms or severe abdominal pain?
3) severe increased AGMA and AKI
4) increased AGMA and ketoacidosis that improves with NS and glucose
1) isopropyl alcohol
2) methanol (pancreatitis and retinal toxicity)
3) ethylene glycol (metabolizes to glycoxylate and oxalic acid–>nephrolithiasis and AKI)
4) ethanol
How do you treat the following alcohol poisonings?
1) mild isopropyl
2) severe isopropyl
3) methanol
4) ethylene glycol
5) alcoholic ketoacidosis
1) IV fluids, gastric lavage
2) HD
3) fomepizole and HD
4) fomepizole and HD
5) IV NS, glucose, thiamine
What is the treatment for the following RTAs?
1) distal (type 1)
2) proximal (type 2)
3) type 4
1) bicarb but correct K first
2) thiazide (volume depletion to lower GFR and decrease filtered load of bicarb); can also add Ksparing diuretic
3) correct hyperK
What are the 4 common causes of nephrotic syndrome?
membranous glomerular nephropathy, diabetic nephropathy, minimal change nephropathy, focal segmental nephropathy
1) What is the most common cause of nephrotic syndrome in blacks?
2) What are 2 things that are associated with it?
3) What is the treatment?
1) focal segmental glomerulosclerosis
2) HIV, morbid obesity
3) glucocorticoids or calcinurin inhibitors
1) What is the most common cause of nephortic syndrome in whites?
2) What antibody is positive?
3) What are 4 secondary causes
4) What is the treatment?
1) membranous glomerulopathy
2) phospholipase A2 receptor
3) infectious (hep B/C, malaria, syphilis), SLE, drugs (NSAIDs, gold slats), cancer (solid tumors, lymphoma)
4) spontaneous, glucocorticoids, cyclphospamide/calcineurin inhib
1) What is the most common cause of primary nephortic syndrome in children?
2) What is the treatment
minimal change
glucocorticoids
When do you measure albumin-creatinine ratio for diabetic nephropathy?
5 years after T1DM, at time of diagnosis for T2DM
What is the hallmark thing you see in the UA for nephritic syndrome?
dysmorphic erythrocytes
What is the most common cause of rapidly progressive GN in young/old?
young: anti GBM
old: pauci-immune
What GNs have normal complement? (4)
anti GBM, pauci-immune, IgA nephropathy, IgA vasculitis
What is the treatment for:
1) anti GBM?
2) pauci-immune?
3) IgA
4) lupus nephritis
1) cyclophosphamide and glucocorticoids with daily plasmapharesis
2) glucocorticoids and cyclophospamide/rituximab +/-plasmapharesis
3) spontaneous or ACEI/ARB
4) glucocorticoids with cyclophospamide/MMF
What GNs have decreased complement?
lupus, infection related, membranoproliferative glomerulonephritis, cryoglobulinemia, atheroembolic disease
What is membranoproliferative glomerulonephritis associated with? (3)
SLE, hep C, monoclonal gammopathy
Match the monoclonal gammopathies with the pathology:
1) apple green with congo red
2) congo red-negative light or heavy chain deposits
3) light chains in renal tubules or light chains absorbing and crystallizing in proximal tubular cells
4) vasculitis syndrome with GN with membranoproliferative features
1) amyloidosis
2) monoclonal immunoglobulin deposition disease
3) multiple myeloma
4) cryoglobulinemia
Which nephritic syndrome has low C4 only
cyroglobulinemia
How many cysts would give a diagosnis of ADPKD to a patient?
> 2 if under 60 yo
>4 if over 60 yo
What is the gene mutation in ADPKD?
PKD1 and PKD2
What abx should be used to treat cyst infection/pyelonephritis in ADPKD?
bactrim or fluroquinolones
What can be used to reduce the rate of increasing kidney size and loss of GFR in ADPKD? What is limiting its use?
Tolvaptan; drawbacks: hepatotoxicity and $$$
What is the most serious extrarenal complication of ADPKD?
intracranial cerebral aneurysm–need periodic MRAs especially if have family history
What are 2 findings classic for Alport syndrome?
sensorineural hearing loss and lenticonus
What type of AKI is the following?
1) BUN Cr >20:1, UOsm >500, UNa <20, FeNa <1%
2) BUN Cr 10:1, UOsm 300, UNa >40, FeNa >2%
3) BUN Cr >20:1, variable UOsm, UNa, FeNa
1) prerenal
2) ATN
3) post renal
What type of AKI is associated with the following UA findings?
1) normal or hyaline casts
2) muddy brown casts and tubular epithelial cells
3) mild proteinuria, leukocytes, erytheocytes, leukocyte casts, eosinophiluria
4) proteinuria, dysmorphic erythrocytes, erythrocyte casts
5) variable, bland
1) prerenal
2) ATN
3) AIN
4) acute GN
5) post renal
What are 2 medications that can be used to expulse stones?
tamsulosin and nifedipine
What is the minimum amount of fluid to ingest for someone who is prone for kidney stones?
> 2 L
What meds should someone be on if they are prone to the following stones:
1) calcium composite
2) large struvite
1) thiazide, allopurinol, citrate
2) percutaneous nephrostolithotomy and long term prophylactic antibiotics
What is the threshold for early microabluminuria?
spot albumin-creatin ratio 30-300mg/g
Which diuretic should be used in GFR<30?
loop
Yes/No: Treat patients on dialysis with statins
No
In CKD patients, if PTH elevated, what 2 medications can you use?
calcitriol to supress PTH and phosphate binders
In CKD, if patients who are receiving dialysis therapy who don’t respond to vit D analogues, calcium supplements and phosphate binders?
cinacalcet
How far in advance do you prep patients who are receiving:
1) peritoneal dialysis
2) HD
3) transplant
1) 1 month prior
2) AV fistula before eGFR drops below 15
3) refer once GFR<20
What are 2 calcineurin inhibitors? What are their side effects?
1) cyclosporine-HTN, decreased GFR, dyslipidemia, hirsutism
2) tacrolimus-DM, decreaseed GFR, HTN
what are 2 antimetabolite immunosuppressants and their side effects?
1) MMF-leukopenia, anemia
2) azathioprine-leukopenia
What are 2 mTOR inhibitors and their side effects?
sirolimus and everolimus–protinuria; dyslipidemia, DM, anemia, leukopenia
What is a glucocorticoid receptor agonist immunosuppressant?
prednisone–osteopenia, HTN, edema, DM
After kidney transplant, what is the most common complications:
1) in the 1st month (2)
2) 2 infections after the 1st month
3) BK virus causes 2 issues
4) most common malignancy
1) UTI, surgical wound
2) CMV–give prophy valganciclovir and bactrim against pneumocystis jirovecii
3) decrease immunosuppression, rise in serum creatinine
4) most common malignancy-cutaneous SCCs
What do you do if a kidney transplant recipient gets kaposi sarcoma?
reduce immunosuppression and switch to sirolimus-based immunosuppression
Posttransplant lymphoproliferative disease is associated with which infection? What do you do?
EBV–reduce immunosuppression and give rituximab if have CD20+ tumors
Which antacids do you not want to give to ESRD?
magnesium-based
In CKD, which renal osteodystrophy is caused by secondary hyperparathyroidism and has subperiosteal resorption of bone most prominently at the phalanges?
osteitis fibrosa cystica
In CKD, which renal osteodystrophy is caused by supresed levels of PTH or aggressive treatment with vit D analogues and has increased risk of fractures and made worse with bisphosphonate therapy?
adynamic bone disease
In CKD, which renal osteodystrophy is caused by vit D deficiency and has bone pain and fractures?
osteomalacia
Which CKD is this:
proteinuria, glycosuria, concentrating defect, sterile pyruria with leukocyte casts and papillary necrosis on US
tubulointerstitial disease
