I just listened to the podcast of and reviewed the show notes of the IBCC chapter & cast: Acute Kidney Injury
January 2, 2019 by Dr. Josh Farkas from his Internet Book Of Critical Care
And here are some excerpts from the chapter;
more detailed understanding of types & prognosis
- Prognosis depends on changes in urine output and creatinine (figure above).3 Some specific types bear mention:
- (1) Isolated oliguria (low urine output with stable creatinine).
- These patients rarely required dialysis, unless oliguria is profound (Stage 3).
- This may often represent “pre-renal” renal failure – the kidney is compensating for hypoperfusion by reducing urine output, but is continuing to function adequately.
- Oliguria should be taken seriously and evaluated adequately. However, <12 hours of oliguria isn’t necessarily a disaster – especially if the creatinine remains stable.
- (2) Non-oliguric renal failure (elevated creatinine with normal urine output)
- The vast majority of these patients (99.7% overall) won’t require dialysis.
causes of AKI
- Pre-renal: Disorders of perfusion
- Shock of any etiology
- Hepatorenal syndrome
- Abdominal compartment syndrome
- Hypertensive emergency
- Thrombotic thrombocytopenic purpura & hemolytic uremic syndrome
- Intrinsic renal failure
- Nephrotoxic medications (listed below)
- Cellular lysis (rhabdomyolysis, hemolysis, tumor lysis syndrome)
- Acute glomerulonephritis
- Acute tubulointerstitial nephritis (ATIN)
- Acute tubular necrosis (ATN)
- Post-renal: Urologic obstruction
- Prostate obstruction
- Occluded or malpositioned Foley catheter
common nephrotoxins [See Chapter Text]
tests to evaluate the cause of AKI
AKI panel: tests to order
- Electrolytes (including Ca/Phos/Mg)
- Creatinine Kinase [See my Rhabdomyolysis Post]
- Interpretation shown above.
- If urinalysis suggests glomerulonephritis or acute interstitial nephritis, consult nephrology to review the urine microscopy and consider renal biopsy.
- Additional labs if indicated
- Relevant drug levels (e.g. vancomycin, aminoglycoside, cyclosporine, tacrolimus)
- Tumor lysis labs if malignancy (lytes, calcium, phosphate, uric acid)
- Renal & bladder ultrasound
- Main role is exclusion of hydronephrosis, but may provide additional information (e.g. scarred or polycystic kidneys).
- Immediate bedside ultrasonography may expedite diagnosis (don’t forget to look at the bladder).