Difference between revisions of "Acute kidney injury"

(Dialysis)
Line 19: Line 19:
 
**Especiallyif GFR <60, hypovolemic  
 
**Especiallyif GFR <60, hypovolemic  
 
*Atherosclerosis
 
*Atherosclerosis
*Chronic hypertension
+
*Chronic [[hypertension]]
 
*Chronic kidney disease
 
*Chronic kidney disease
*NSAIDs
+
*[[NSAIDs]]
*ACEI/ARB
+
*[[ACEI]]/[[ARB]]
 
*[[Sepsis]]
 
*[[Sepsis]]
 
*[[Hypercalcemia]]
 
*[[Hypercalcemia]]
*Hepatorenal syndrome
+
*[[Hepatorenal syndrome]]
  
 
==Clinical Features==
 
==Clinical Features==
 
*Acute renal failure itself has few symptoms until severe uremia develops:
 
*Acute renal failure itself has few symptoms until severe uremia develops:
**[[Nausea/vomiting]], drowsiness, fatigue, confusion, coma
+
**[[Nausea/vomiting]], drowsiness, fatigue, confusion, [[coma]], [[pericarditis]]
 
*Patients more likely to present with symptoms related to underlying cause:
 
*Patients more likely to present with symptoms related to underlying cause:
 
**Prerenal
 
**Prerenal
***Thirst, orthostatic light-headedness, decreasing urine output
+
***Thirst, orthostatic lightheadedness, decreasing urine output
 
**Intrinsic
 
**Intrinsic
 
***[[Flank pain]], [[hematuria]]
 
***[[Flank pain]], [[hematuria]]
Line 38: Line 38:
 
****Papillary necrosis
 
****Papillary necrosis
 
****Crystal-induced nephropathy
 
****Crystal-induced nephropathy
***Myalgias, [[seizures]], recreational intoxication
+
***[[Myalgia]]s, [[seizures]], recreational intoxication
 
****Pigment-induced ARF ([[rhabdomyolysis]])
 
****Pigment-induced ARF ([[rhabdomyolysis]])
 
***Darkening urine and edema (esp with preceding pharyngitis or cutaneous infection)
 
***Darkening urine and edema (esp with preceding pharyngitis or cutaneous infection)
Line 45: Line 45:
 
****Acute interstitial nephritis
 
****Acute interstitial nephritis
 
***[[Cough]], [[dyspnea]], [[hemoptysis]]
 
***[[Cough]], [[dyspnea]], [[hemoptysis]]
****Goodpasture, granulomatosis with polyangiitis (Wegener's)
+
****[[Goodpasture syndrome]], [[granulomatosis with polyangiitis]] (Wegener's)
 
**Postrenal
 
**Postrenal
***Alternating oliguria and polyuria is pathognomonic of obstruction
+
***Alternating oliguria and [[polyuria]] is pathognomonic of obstruction
 
***Anuria
 
***Anuria
  
Line 53: Line 53:
 
[[File:Differential Diagnosis of Acute Kidney Injury.png|thumb]]
 
[[File:Differential Diagnosis of Acute Kidney Injury.png|thumb]]
 
===Prerenal===
 
===Prerenal===
*Hypovolemia
+
*[[Hypovolemia]]
**GI: decreased intake, vomiting and diarrhea
+
**GI: decreased intake, [[vomiting]] and [[diarrhea]]
**Hemorrhage
+
**[[Hemorrhage]]
**Pharmacologic: diuretics
+
**Pharmacologic: [[diuretics]]
 
**Third spacing
 
**Third spacing
 
***[[Pancreatitis]]
 
***[[Pancreatitis]]
**Skin losses: fever, burns
+
**Skin losses: [[hyperthermia]], [[burns]]
 
**Miscellaneous
 
**Miscellaneous
 
***Hypoaldosteronism
 
***Hypoaldosteronism
 
***Salt-losing nephropathy
 
***Salt-losing nephropathy
***Postobstructive diuresis
+
***[[Postobstructive diuresis]]
 
*[[Hypotension]]
 
*[[Hypotension]]
 
**[[Sepsis]]
 
**[[Sepsis]]
Line 73: Line 73:
 
***[[Beta-blockers]]
 
***[[Beta-blockers]]
 
***[[Calcium-channel blockers]]
 
***[[Calcium-channel blockers]]
***Antihypertensive medications
+
***[[Antihypertensive medications]]
 
**[[High output heart failure]]
 
**[[High output heart failure]]
 
***[[Thyrotoxicosis]]
 
***[[Thyrotoxicosis]]
Line 101: Line 101:
 
**[[Aminoglycosides]], [[Contrast-Induced Nephropathy|radiocontrast]], [[amphotericin B]], heme pigments ([[rhabdomyolysis]], hemolysis)
 
**[[Aminoglycosides]], [[Contrast-Induced Nephropathy|radiocontrast]], [[amphotericin B]], heme pigments ([[rhabdomyolysis]], hemolysis)
 
**Obstruction
 
**Obstruction
***Uric acid, calcium oxalate from [[Ethylene Glycol Toxicity]], [[Multiple myeloma]] (immunoglobin light chains), amyloid
+
***Uric acid, calcium oxalate from [[Ethylene Glycol Toxicity]], [[Multiple myeloma]] (immunoglobin light chains), [[amyloidosis]]
***Pharmacologic: sulfonamide, triamterene, [[acyclovir]], indinavir
+
***Pharmacologic: [[sulfonamides]], triamterene, [[acyclovir]], indinavir
 
*Interstitial diseases
 
*Interstitial diseases
 
**Acute interstitial nephritis: typically a drug reaction ([[NSAIDs]], [[Penicillins]] and antibiotics, [[Diuretics]], [[phenytoin]])
 
**Acute interstitial nephritis: typically a drug reaction ([[NSAIDs]], [[Penicillins]] and antibiotics, [[Diuretics]], [[phenytoin]])
 
**Infection: bilateral pyelonephritis, [[Legionella]], [[Hantavirus]]
 
**Infection: bilateral pyelonephritis, [[Legionella]], [[Hantavirus]]
**Infiltrative disease: sarcoidosis, lymphoma
+
**Infiltrative disease: [[sarcoidosis]], [[lymphoma]]
 
**Autoimmune diseases: [[SLE]]
 
**Autoimmune diseases: [[SLE]]
 
*Glomerular diseases
 
*Glomerular diseases
 
**Rapidly progressive glomerulonephritis
 
**Rapidly progressive glomerulonephritis
***Goodpasture, [[granulomatosis with polyangiitis]] (Wegener's) [[HSP]], [[SLE]], membranoproliferative GN
+
***[[Goodpasture syndrome]], [[granulomatosis with polyangiitis]] (Wegener's) [[HSP]], [[SLE]], membranoproliferative GN
 
**Postinfectious [[glomerulonephritis]]
 
**Postinfectious [[glomerulonephritis]]
 
*Small-vessel diseases
 
*Small-vessel diseases
 
**Microvascular thrombosis
 
**Microvascular thrombosis
***[[Preeclampsia]], [[HUS]], [[DIC]], [[Thrombotic Thrombocytopenic Purpura (TTP)|TTP]], vasculitis (PAN, SCD, atheroembolism)
+
***[[Preeclampsia]], [[HUS]], [[DIC]], [[Thrombotic Thrombocytopenic Purpura (TTP)|TTP]], [[vasculitis]] (PAN, SCD, atheroembolism)
 
**[[Malignant hypertension]]
 
**[[Malignant hypertension]]
 
**[[Scleroderma]]
 
**[[Scleroderma]]
Line 142: Line 142:
 
***[[Phimosis]] or urethral stricture (male preponderance)
 
***[[Phimosis]] or urethral stricture (male preponderance)
 
***Neurogenic bladder
 
***Neurogenic bladder
****[[Diabetes mellitus]], spinal cord disease, multiple sclerosis, Parkinson's
+
****[[Diabetes mellitus]], spinal cord disease, [[multiple sclerosis]], [[Parkinson's disease]]
****Pharmacologic: anticholinergics, a-adrenergic antagonists, opioids
+
****Pharmacologic: [[anticholinergics]], [[alpha antagonist|a-adrenergic antagonists]], [[opioids]]
 
*Adults
 
*Adults
 
**Urethra and bladder outlet
 
**Urethra and bladder outlet
Line 150: Line 150:
 
***Obstructed catheters
 
***Obstructed catheters
 
**Ureter
 
**Ureter
***Calculi, uric acid crystals
+
***[[Ureteral calculi]], uric acid crystals
 
***Papillary necrosis
 
***Papillary necrosis
****SCD, DM, pyelonephritis
+
****[[Sickle cell disease]], [[DM]], [[pyelonephritis]]
 
***Tumor: Ureter, uterus, prostate, bladder, colon, rectum; retroperitoneal lymphoma
 
***Tumor: Ureter, uterus, prostate, bladder, colon, rectum; retroperitoneal lymphoma
 
***Retroperitoneal fibrosis: idiopathic, [[tuberculosis]], [[sarcoidosis]], [[propranolol]]
 
***Retroperitoneal fibrosis: idiopathic, [[tuberculosis]], [[sarcoidosis]], [[propranolol]]
Line 159: Line 159:
 
****[[Abdominal aortic aneurysm|Aortic aneurysm]]
 
****[[Abdominal aortic aneurysm|Aortic aneurysm]]
 
****Pregnant uterus
 
****Pregnant uterus
****IBD
+
****[[IBD]]
****Trauma
+
****[[Renal trauma|Renal]] or [[ureter trauma]]
  
 
==Evaluation==
 
==Evaluation==
Line 199: Line 199:
 
===Imaging===
 
===Imaging===
 
*[[CXR]]
 
*[[CXR]]
*Evidence of volume overload, pneumonia
+
**Evidence of volume overload, pneumonia
*US
+
*US: [[renal ultrasound|renal]]/[[bladder ultrasound|bladder]]
 
**Test of choice in setting of acute renal failure
 
**Test of choice in setting of acute renal failure
 
**Bladder size (post-void)
 
**Bladder size (post-void)
Line 208: Line 208:
 
**Useful to determine cause of post renal failure (identification of abdominal masses etc.)
 
**Useful to determine cause of post renal failure (identification of abdominal masses etc.)
 
**Should generally not be used with IV contrast due to potential risk for [[Contrast-Induced Nephropathy|CIN]]
 
**Should generally not be used with IV contrast due to potential risk for [[Contrast-Induced Nephropathy|CIN]]
**Indicated if hydronephrois found on [[ultrasound]] in order to define the location of obstruction
+
**Indicated if hydronephrosis found on [[ultrasound]] in order to define the location of obstruction
  
 
==Management==
 
==Management==
 
''Treat underlying cause''
 
''Treat underlying cause''
*Prerenal: IVF
+
*Prerenal: [[IVF]] (or [[pRBCs]] if bleeding)
 
*Intrinsic: Depends on cause
 
*Intrinsic: Depends on cause
 
*Obstruction:
 
*Obstruction:

Revision as of 15:57, 18 August 2019

Background

  • Majority of cases of community-acquired ARF is secondary to volume depletion although consideration of pre-renal, post renal, and renal causes are important.

RIFLE Classification

  • Risk - Serum creatinine increased 1.5x baseline
  • Injury - Serum creatinine increased 2.0x baseline
  • Failure - Serum creatinine increased 3.0x baseline OR creatinine >4 and acute increase >0.5
  • Loss - Complete loss of kidney function for >4wk
  • ESRD - Need for renal replacement therapy for >3mo

Chronic Kidney Disease Stages

  • Useful if patient's baseline creatinine is unknown
    • Stage 1: Kidney damage (e.g. proteinuria) and normal GFR; GFR >90
    • Stage 2: Kidney damage (e.g. proteinuria) and mild decrease in GFR; GFR 60-89
    • Stage 3: Moderate decrease in GFR; GFR >30-59
    • Stage 4: Severe decrease in GFR; GFR 15-29
    • Stage 5: Kidney failure (dialysis or kidney transplant needed); GFR <15

Risk Factors

Clinical Features

Etiologies

Differential Diagnosis of Acute Kidney Injury.png

Prerenal

Intrinsic

Postrenal

Evaluation

  • Prerenal
    • BUN/creatinine ratio > 20
    • FeNa <1% ((urine sodium/plasma sodium) / (urine creatinine / serum creatinine))
      • < 2% for neonates
    • Urine osm >500
    • Urine sodium < 20 mEq/L
    • Specific gravity > 1.020
    • Fractional excretion of urea < 35%
    • Microscopic analysis
      • Hyaline casts
  • Instrinsic
    • FeNa >1%
      • > 2.5% for neonates
    • Urine Osm <350
    • Urine sodium > 40 mEq/L
    • Specific gravity < 1.020
    • Fractional excretion of urea > 50%
    • Microscopic analysis
      • Acute glomerulonephritis: RBCs, casts
      • Acute tubular necrosis: protein, tubular epithelial cells
  • Postrenal
    • FeNa >1%
    • Urine Osm <350

Work-up

  • Urine
  • Prostate exam
  • Urinalysis, urine sodium, urine creatinine, urine urea
  • ECG (hyperkalemia)
  • Chronic renal failure features
    • Anemia, thrombocytopenia
    • Iron studies with low Fe, low TIBC, low iron saturation, normal ferritin
    • Secondary rise in PTH, high phos, low calcium

Imaging

  • CXR
    • Evidence of volume overload, pneumonia
  • US: renal/bladder
    • Test of choice in setting of acute renal failure
    • Bladder size (post-void)
    • Hydronephrosis
    • IVC collapsibility (prerenal)
  • CT
    • Useful to determine cause of post renal failure (identification of abdominal masses etc.)
    • Should generally not be used with IV contrast due to potential risk for CIN
    • Indicated if hydronephrosis found on ultrasound in order to define the location of obstruction

Management

Treat underlying cause

  • Prerenal: IVF (or pRBCs if bleeding)
  • Intrinsic: Depends on cause
  • Obstruction:
    • Note: Postobstructive diuresis can result in significant volume loss and death
      • Typically occurs when obstruction has been prolonged / has resulted in renal failure
      • Admit patients with persistent diuresis of >250 mL/h for >2hr
    • Foley Catheter, consider Coude Catheter
    • Suprapubic (if Coude fails)

Dialysis

  • Indicated for:
    • A: Acidosis (severe)
    • E: Electrolyte abnormality (e.g. uncontrolled hyperkalemia)
    • I: Ingestions (lithium, ASA, methanol, ethylene glycol, theophylline)
    • O: Overload (volume) with persistent hypoxia
    • U: Uremic pericarditis/encephalopathy/bleeding dyscrasia
    • Also:
      • Na <115 or >165 mEq/L
      • creatinine > 10
      • BUN >100
  • See Dialysis catheter placement
  • See Austere peritoneal dialysis

Phlebotomy to Treat Pulmonary Edema

  • Possible last ditch effort to tide patient over to formal dialysis if hours away
  • If traditional pulmonary edema treatments are not working for SCAPE patient, one may attempt to remove 200-300 cc of blood as a bridge to dialysis[1]
  • If Hb too low, may consider temporary venous tourniquets on each leg proximally q30 min to reduce preload volume to the heart, alternating legs

Disposition

  • Admit

See Also

External Links

References

  1. Eiser AR et al. Phlebotomy for pulmonary edema in dialysis patients. Clin Nephrol. 1997 Jan;47(1):47-9.