Flashcards in Kidney Deck (23):
Acute renal failure definition
The abrupt decrease of renal function sufficient enough to result in retention of nitrogenous waste products as well as loss of regulation of extracellular volume and electrolytes
How fast are ARF developed ?
Hours to days
ARF classic laboratory definition
- Cr increase of 0.5 mg/ dl
- Cr increase of more than 50%
- Decreased Cr clearance more than 50%
- Any decrease in renal function that requires dialysis
What is ADQI?
Acute dialysis quality initiative, RIFLE
What is the "R" in RIFLE?
Risk: Increased creatinine x 1,5 or GFR decrease of more than 25% or urine output less than 0,5ml/kg/h x 6h
What is the "I" in RIFLE?
Injury: Increased Cr x 2 or GFR decrease of more than 50% or urine output less than 0,5ml/kg/h x 12h
What is the "F" in RIFLE?
Failure: Increased Cr x 3 or GFR decrease of more than 75% or urine output less than 0,3 x 24h or anuria for 12h
What is the "E" in RIFLE?
ESRD, end-stage renal disease: Loss of renal function for more than 3 months
What is the "L" in RIFLE?
Loss: Persistent ARF = complete loss of renal function for more than 4 weeks
Which drugs may increase Cr w/out AKI?
Trimethoprim, Cimetidine and Probenecid
What may interfere w/ Cr assays in the lab (false elevation) ?
Glucose, acetoacetate, ascorbic acid, cefoxitin, flucytosine
What may cause an increase in BUN w/out AKI?
- Gi bleeding
- Catabolic states (prolonged ICU stay)
- Protein loads (TPN-Albumin infusion)
What are the alternatives to serum Cr?
- Urinary neutrophil gelatinase-associated lipocalin (NGAL)
- Urinary interleukin 18
- Urinary kidney injury molecule 1 (KIM-1)
What accounts for nearly 50% of all causes of AKI?
What are the symptoms and signs of renal failure in the means of retention of nitrogenous waste products?
- dry mouth
What are the symptoms and signs of renal failure in the means of salt and water retention?
- pulmonary edema
- peripheral edema
- pleural effusion
What are the symptoms and signs of renal failure in the means of potassium retention?
- ECG: tenting T-waves, widening QRS, increased PR interval,
- cardiac arrest
What are the symptoms and signs of renal failure in the means of retention of acid?
- Kussmaul respiration
What are the major disease categories causing AKI?
- Prerenal 40-80%
- Intrinsic 10-30%
- Postrenal <5%
What are the causes of prerenal AKI?
- Volume loss/sequestration
- Impaired cardiac output
- Hypotension (and potentially hypo-oncotic states)
Net result: hypoperfusion
What are the causes of intrinsic AKI?
- Vascular disorders
- Interstitial disorders: inflammation and intercalative
- Tubular necrosis: ischemia, toxin, pigmenturia
What are the causes of post-renal AKI?
- Intrarenal: crystals and proteins
- Extrarenal: pelvis, ureter, bladder, urethra, prostate