Acute Renal Failure Flashcards
ARF = AKI
Absolute increase in serum creatinine of 0.3 mg/dL
or
50% increase in serum Creatinine
or
Reduction in urine output consisting of oliguria of less than 0.5 mL/kg/hr for longer than 6 hours
Acute vs Chronic
Creatinine before
Kidney size
Urine sediment
Acute
No change in creatinine
Large or normal kidney
Casts in urine
Chronic
Steady increase in creatinine
Small, scarred kidneys
Bland sediment in urine
Anemia, hyperparathyroidism, A/V fistula, hyperphosphatemia
Most likely cause of ARF
Pre-renal
Prerenal
Normal or hyaline casts
High BUN/creatinine ratio
Low FE
Intra-renal
Tubular cell injury - Muddybrown, granular, epithelial - High FE Interstitial nephritis - Pyruria, hematuria, mild proteinuria, granular and epithelial casts, eosinophils -High FE Glomerular - Red cells, dysmorphic red cells and red cell casts -Low FE Vascular - Normal or hematuria, mild proteinuria -Low FE
Low BUN/creatinine ratio
Post-renal
Normal or hematuria, granular, pyruria
Renal US
Signs of hydronephrosis Kidneys size PCKD Stones Tumors
Pre-renal treatment/confirmation
Increase volume - symptoms should resolve
Albumin with stress
Decreases
Damage to kidneys with pre-renal azotemia
None
Cause of pre-renal
Hypovolemia
- Shock, dehydration, blood loss, V/D, sweating
Effective intravascular volume
- CHF, cirrhosis, hepatorenal syndrome, peritonitis
Systemic dilation and renal vasocontriction
- Sepsis, hepatorenal syndrome
Large vessel vascular disease
Medications that make pre-renal worse
Cyclosporine Tacrolimus ACEIs, ARBs, NSAIDs Radiocontrast agents
ATN in UA
Sodium greater than 20
Muddy brown and granular casts
