Kidney Failure Flashcards
Sudden decrease in renal function
Renal function deterioration over hours to days
Acute Renal Failure
What is the most common cause of acute renal failure?
Hypoperfusion
What are the three mechanisms of renal failure? Which one is the most common?
Prerenal azotemia (most common)
Intrinsic renal failure
post-obstructive azotemia
What is the term for nitrogenous waste accumulation?
Azotemia
What are the signs of acute renal failure?
Rapidly rising creatinine
Electrolyte abnormalities
Acid/base alterations
Inability to excrete nitro wastes
BUN:Cr is a marker to help determine acute renal failure. What is the ratio that would indicate this?
BUN:Cr (increased >20:1)
This calculation is used to help differentiate between prerenal azotemia and ATN? What are the levels to differentiate?
FeNa
FeNa <1% ~ prerenal cause, volume depletion
FeNa >2% ~ ATN
What does FeNa stand for?
fractional excretion of sodium
What are the three main causes of intrinsic renal failure?
acute tubular necrosis
interstitial nephritis
glomerulonephritis
What is the most common cause of intrinsic renal failure?
Acute tubular necrosis – 85%
Prolonged ischemia – think “shock”
Nephrotoxic agents – contrast dye, ACE-Is, NSAIDs, aminoglycosides, amphotericin B, cyclosporine
Which cause of intrinsic renal failure is described below?
Muddy brown casts
Urine specific gravity <1.010 (very light, very dilute)
Hyperkalemia
Hyperphosphatemia
FeNa >1
BUN: Cr <20:1
Acute tubular necrosis
Which cause of intrinsic renal failure is described below?
Fever – 80%
Rash – 50%
Renal dysfunction
Pyuria
Arthralgias
Eosinophilia
UA: hematuria, WBC casts, pyuria (eosinophils)
Acute interstitial nephritis
Which cause of intrinsic renal failure is described below?
LE livedo reticularis or necrotic areas of the distal digits
Cholesterol emboli
Which cause of intrinsic renal failure is described below?
Occurs with hemolysis or rhabdomyolysis
Void of RBCs
Pigment-induced injury
What is the least common cause/mechanism of acute kidney failure?
Post-Obstructive
Progressive decline in renal function
GFR < 15
Rarely reversible
Affects 20 million in US
Chronic Renal Failure
What are the two most common causes of chronic renal failure?
AODM and HTN
List some broad categories of causes for chronic renal failure
Primary Glomerular disease (problem is within the glomerulus)
Secondary Glomerular disease (problem is outside of the glomerulus)
Tubulointerstitial nephritis (affects the tubules and interstium)
Hereditary disease
Vascular disease
Obstructive nephropathies
Which Primary Glomerular Disease is described below?
Usually presents with nephrotic syndrome
Can be primary renal or secondary to something else (ex: drug ingestion, systemic disease)
1/3 progress to ESRD and the remainder enter remission or have
slowly declining renal function
Histology - You’ll see thick capillary walls
Membranous Nephropathy
Which Primary Glomerular Disease is described below?
Primary renal disease of IgA deposition in the glomerular
mesangium
Most often idiopathic
Presentation: Asymptomatic hematuria with mild proteinuria or recurrent episodes of gross hematuria
May be concomitant with URI, GI symptoms, or viral illness
IgA Nephropathy
Which Secondary Glomerular Disease is described below?
Most common cause of ESRD in USA
Likely to have prior evidence of AODM > 10 years
Presentation - Albuminuria precedes the decline in GFR, Increased abnormal glycosylation of IgG
There is a predicable trajectory - Other end organ damage is common
Diabetic Nephropathy
Which Secondary Glomerular Disease is described below?
Presentation: Proteinuria, Glomerular hematuria
Usually follows a group A beta-hemolytic strep infection by 1-3
weeks
Usually self-limiting and resolves spontaneously
Post-infectious glomerulonephritis
Which Tubulointerstitial Nephritis Disease is described below?
Seen in persons who ingest large quantities of analgesic combinations
NSAIDS most common culprit
Analgesic Nephropathy
Which Tubulointerstitial Nephritis Disease is described below?
Significant cause of renal failure
Primarily a disorder of childhood - Patients are typically young,
hypertensive, and have a history of recurrent UTIs
Mild proteinuria is common
Reflux/Chronic Pyelonephritis
This disease is one of the most common hereditary diseases in the US
Polycystic kidney disease
In patients with polycystic kidney disease, what percentage will reach ESRD by age 60?
50%
What disease can you also see arterial aneurism of the circle of Willis?
Polycystic kidney disease
In patients with polycystic kidney disease, what percentage will have coexisting hepatic cysts?
25%
Which vascular disease is described below?
Vascular structure thickening and diminished perfusion
May have mild proteinuria and nocturia
1-5% will develop renal failure and azotemia
Hypertensive Nephrosclerosis
Which vascular disease is described below?
Produced by atherosclerotic occlusive disease or fibromuscular dysplasia
Acute kidney injury develops rapidly in patients started on ACE-I therapy (Creatinine will skyrocket)
May also present with new-onset HTN and poorly controlled HTN with pulmonary edema
Renal Artery Stenosis
In renal artery stenosis, what percentage of cases are caused by atherosclerotic occlusive disease versus fibromuscular dysplasia (F>M)
90% caused by atherosclerotic occlusive disease
10% fibromuscular dysplasia (F>M)
What is the most common demographic of patients that renal artery stenosis is seen in?
Most commonly found in >45 year olds with known atherosclerotic disease
What is the gold standard imaging for renal artery stenosis?
Renal angiography
This procedure is also called “renal replacement therapy”
Dialysis
What fistula is best in dialysis?
The artery-vein fistula
