Acute Tubular Necrosis/Acute Renal Failure Flashcards
Acute interstitial renal inflammation with eosinophils* in the urine?
Drug induced interstitial nephritis
Most drugs take _________ to develop Drug induced interstitial nephritis but NSAIDS take __________
1-2 weeks
Months
Acute generalized cortical infarction of both kidneys?
Diffuse cortical necrosis
MCC of acute injury in hospitalized patients?
Acute tubular necrosis (ATN)
With ATN, there will be increased?
FENa
What will you see in the urine? Why?
granular (“muddy brown”) casts
Tubular cells die and plug the nephron=>intrinsic azotemia=>granular casts
There are 3 stages to ATN; they are?
- Inciting event
- Maintenance phase—oliguric; lasts 1–3 weeks;
- Recovery phase—polyuric;
During the maintenance phase you could get?
Risk of hyperkalemia, metabolic acidosis,
uremia Why? there is oligouria
Low urine, low urine K+, Low urine H+ and Low urine Urea
During the Recovery phase you could get?
BUN and serum creatinine fall; risk of hypokalemia Why? there is polyuria
In ischemic tubular necrosis, what part of the kidney is most susceptible to injury?
PCT and thick ascending limb
In Toxic tubular necrosis, what part of the kidney is most susceptible to injury?
PCT=>lots to absorb
What are 3 common ways that Toxic tubular necrosis happens?
- Leukemia=>chemo
- Ethylene glycol=>oxalate crystals
- Crush Injury
How does a patient with leukemia get toxic tubular necrosis?
Leukemia=>chemo=>tumor lysis=>increased uric acid
After 4-6 weeks, ATN cells are able to regenerate. Why?
Tubular cells are stable cells (G0=>G1)
Hepatocytes and lymphocytes
Sloughing of necrotic renal papillae with gross hematuria and proteinuria? Dx?
Renal papillary necrosis
Renal papillary necrosis causes?
SAAD papa with papillary necrosis: Sickle cell disease or trait Acute pyelonephritis Analgesics (NSAIDs) Diabetes mellitus
What is acute renal failure?
Increased creatinine and BUN due to oligouria=>azotemia
Prerenal azotemia is due to?
=>decreased RBF=>Decreased GFR=>Increased renin=> More BUN is reabsorbed but creatinine is NOT
Prerenal azotemia what are the numbers
BUN: C=> 20:1
Urine Na+ b/c you are reabsorbing
FENab/c you are reabsorbing
Urine osmolarity= >500
500 20 1
Postrenal/Intrinsic azotemia what are the numbers?
Decreased tubular function
Urine Na+ >40
FENa >2
Urine osmolarity= 350
350 40 2
Postrenal vs Intrinsic Azotemia
Intrinisic BUN:C=
What is the problem in post renal azotemia?
There is backpressure, pushing BUN into the tubular cells but they are damaged
Another name for Intrisinic Azotemia?
Acute Tubular Necrosis
Tubular cells die=>cannot reabsorb
Consequences of Renal Failure?
Retention of everything
MAD HUNGER:
Metabolic Acidosis
Dyslipidemia (especially triglycerides)
Hyperkalemia
Uremia—clinical syndrome marked by
BUN:
Nausea and anorexia Pericarditis
Asterixis
Encephalopathy
Platelet dysfunction
Na+/H2O retention (HF, pulmonary edema, hypertension)
Growth retardation and developmental delay
Erythropoietin failure (anemia)
Renal osteodystrophy (Hyperphosphatemia)
