Nephrology Flashcards
Which lab findings suggest that hematuria is caused by GN?
The presence of hematuria associated with red cell casts, dysmorphic red cells, or proteinuria suggest GN as a cause.
What are the causes of BUN:Cr ratio of >20?
BUN:Cr ratio >20 is caused by prerenal azotemia or increased protein breakdown.
What is the definition of oliguria? Anuria?
Oliguria is defined as urine output <0.5ml/kg/hour for at least 6 hours. Anuria is <50ml/day of urine output.
What is the underlying cause of prerenal kidney injury?
Prerenal kidney injury is due to underperfusion of the kidneys, either from true loss of volume or decreased effective arterial blood volume.
What causes do you consider in a patient with hypertension and hypokalemia?
Renal artery stenosis or fibromuscular dysplasia should be considered in a patient with hypertension and hypokalemia.
With postrenal AKI, how does the amount of urine produced relate to the degree of obstruction?
In patients with postrenal AKI, the amount of urine produced does not correlate to the degree of obstruction as some patients will have a postobstructive diuresis and in some patients with obstruction the chronic damage to the tubules impairs their ability to reabsorb water and solutes.
Drug-induced ATN is usually due to which 2 major nephrotoxins?
IV contrast, amphotericin, and aminoglycosides are major drug causes of ATN.
What are some manifestations of cholesterol emboli?
Clinical features of atheroembolic disease include livedo reticularis, eosinophilia, low complement levels, and a step-wise increase in creatinine.
What are Hollenhorst plaques?
Hollenhorst plaques are cholesterol emboli to the retinal arterioles. They appears as orange-white dots interrupting the circulation.
Characterize the clinical presentation of acute interstitial nephritis.
Acute interstitial nephritis is usually a drug hypersensitivity reaction leading to fever, eosinophilia and rash.
The biopsy picture of AIN due to NSAIDs resembles which glomerulonephropathy?
The biopsy picture of AIN due to NSAIDs resembles minimal change disease.
What is the definition of nephrotic range proteinuria?
Nephrotic range proteinuria is defined as >3.5 gm/day of proteinuria.
What are the systemic complications of nephrotic syndrome?
The complications of nephrotic syndrome include hypoalbuminemia, hypogammaglobulinemia, and hypercoagulability (due to loss of anti-thrombin III).
What are the complement levels in patients with PIGN?
Complement levels are low in patients with PIGN, and they remain low for 6-8 weeks.
Poststreptococcal GN can occur after streptococcal infection at which sites?
Poststreptococcal GN can follow streptococcal infection of the throat or skin.
Symptoms of GN due to streptococcal infection start how long after the initial infection?
Symptoms of PIGN start 1-6 weeks after infection. This contrasts to IgA nephropathy which begins concurrent with the pharyngitis (synpharyngitic).
What infections are associated with development of IC-mediated MPGN?
Hepatitis C and hepatitis B are associated with immune-complex mediated MPGN.
When does the GN due to IgA nephropathy present, relative to an inciting viral illness?
Glomerulonephritis due to IgA nephropathy presents concurrent with the viral illness.
What are the findings on renal biopsy in patients with IgA nephropathy?
Renal biopsy in IgA nephropathy shows deposition of IgA and complement in the mesangium and glomerular capillaries on immunofluorescence staining.
In addition to anti-GBM antibodies, which other feature defines Goodpasture syndrome?
In addition to anti-GBM antibodies, patients with Goodpasture syndrome also have pulmonary involvement often presenting with hemoptysis.
How are anti-GBM diseases diagnosed?
Anti-GBM antibodies in the serum establish a diagnosis of anti-GBM disease. Renal biopsy can also establish the diagnosis by revealing anti-GBM IgG deposited in a linear fashion along the glomerular basement membrane.
RPGN has which hallmark finding on renl biopsy?
The hallmark biopsy finding in RPGN is crescents from collapsing glomerulonephritis.
What are the 3 categories of RPGN, based on underlying mechanisms?
The 3 categories of RPGN include:
- Anti-GBM antibodies
- Immune complex deposition (IgA deposits, ANA, cryoglobulins, or antibodies against an infectious agent)
- No evidence of immune deposits (“pauci-immune”)
What is the empiric treatment for RPGN?
RPGN should be treated with high dose methylprednisolone followed by prednisone + cyclophosphamide +/- plasmapheresis (if pulmonary hemorrhage).
What drugs and diseases are associated with minimal change disease?
Most MCD is idiopathic, but it may also be associated with drugs (NSAIDs, lithium) and lymphomas.
“Maltese crosses” under polarized light are seen in the urine sediment of patients with what process?
“Maltese crosses” under polarized light microscopy represent oval fat bodies and are seen in nephrotic syndrome.
FSGS is found in what patient groups?
FSGS is the most common cause of nephrotic syndrome in African Americans. It is also associated with HIV, heroin use, obesity, sickle cell disease, and chronic vesicoureteral reflux.
Solid tumors are associated with which glomerular disease?
Solid tumors are associated with membranous nephropathy.
Which RTA is associated with diabetic nephropathy?
Diabetes is associated with type 4 RTA.
What is the classic finding seen on renal biopsy in a patient with diabetic nephropathy?
Renal biopsy in diabetic nephropathy shows expansion of the mesangium, thickening of the GBM, and sclerosis of the gloeruli (termed the Kimmelstiel-Wilson lesion).
What is the definition of microalbuminuria?
Microalbuminuria is low-grade proteinuria in the range of 30-300mg/dl.
When are glucocorticoids not used to treat nephrotic syndrome?
Glucocorticoids are useful in treatment of all types of nephrotic syndrome except those caused by diabetes and amyloidosis.
What is the definition of chronic kidney disease and what are its stages?
Chronic kidney disease is defined as either: 1. kidney damage >3 months, with or without decreased GFR, with either pathological abnormalities or markers of kidney damage or 2. GFR<60 for >3 months with or without kidney damage. Stages of CKD: Stage 1: GFR >90 but with microalbuminuria present Stage 2: GFR 60-89 Stage 3a: GFR 45-59 Stage 3b: GFR 30-44 Stage 4: GFR 15-29 Stage 5: GFR <15 or on dialysis
What is the effect of hyperphosphatemia in patients with CKD?
Hyperphosphatemia is associated with increased risk of death and heart disease, even in patients without CKD - but especially in those with stage 3-5 CKD.
Which bone disorders can be caused by CKD?
Patients with CKD can have 3 types of bone disease. 1. Osteitis fibrosa cystica due to secondary hyperparathyroidism (high bone turnover disease). 2. Adynamic bone disease dues to oversuppression of PTH release (low bone turnover disease) often caused by overtreated of #1. 3. Osteomalacia, a low bone turnover disease associated with unmineralized bone.
Which phosphate binders should be used in the hypercalcemic patient?
Non-calcium-based phosphate binders should be used in the hypercalcemic patient to prevent suppression of PTH and development of adynamic bone disease.
How is adynamic bone disease different from secondary hyperparathyroidism?
In adynamic bone disease the PTH is suppressed by hypercalcemia. In secondary hyperparathyroidism the hyperphosphatemia and normal/low calcium drive icnreased PTH release.
What are the signs/symptoms of uremia?
Signs and symptoms of uremia include anorexia, nausea/vomiting, pericardial and pleural effusions, hemorrhagic pericarditis, platelet dysfunction and bleeding, pruritis, sensory neuropathies, and CNS dysfunction.
How is normochromic-normocytic anemia in CKD treated?
Normochromic-normocytic anemia in CKD is treated with erythropoiesis stimulating agents if the Hgb is <10.
What is the risk of gadolinium use in the patient with CKD?
Use of gadolinium in CKD can cause nephrogenic systemic sclerosis, a devastating and irreversible condition.
When is dialysis initiated in a CKD patient?
Dialysis is initiated in a CKD patient when they have a GFR<15 and develop symptoms of uremia.
What is the most common cause of death in the dialysis patient?
The most common cause of death in a dialysis patient is cardiovascular disease. The second leading cause of death is infection.
What organisms are associated with peritonitis in the patient on CAPD?
Peritonitis in a CAPD patient is most commonly due to Gram-positive skin organisms (S. epidermidis and S. aureus) followed by Gram-negative organisms.
