Prerenal Acute Kidney Injury Pathophysiology and Presentation
- Decreased Renal Perfusion
- Decreased GFR
- Increased Sodium and Water Reabsorption
- Edema
- Dyspnea
- Hypotension with Tachycardia
- Altered Mental Status
- Oliguria
- NSAIDs
- Renal Artery Stenosis
- ACE Inhibitors
Prerenal Acute Kidney Injury Diagnosis and Management
- BUN:Creatinine Ratio > 20:1
- Fractional Excretion of Sodium (FENa) < 1%
- Urine Osmolality > 500 mOsm/kg
- Hyaline Casts
- Fluid Replacement
- Monitor Renal Function
- Diuretics
Acute Tubular Necrosis
- Ischemic Injury
- Nephrotoxic Injury
- Granular Muddy Brown Casts
- Intrinsic Kidney Injury
- Oliguric Phase
- Metabolic Acidosis
- Hyperkalemia
- Increase in BUN and Creatinine
- Polyuria Phase
- Decrease in BUN and Creatinine
- Hypokalemia
- Supportive Care
Casts in Urine (Differential Diagnosis)
- RBC Casts
- Glomerular Disease
- WBC Casts
- Acute Interstitial Nephritis
- Acute Pyelonephritis
- Fatty Casts
- Maltese Cross Sign
- Nephrotic Syndrome
- Granular Muddy Brown Casts
- Acute Tubular Necrosis (ATN)
- Waxy Casts
- End Stage Renal Disease (ESRD) or Chronic Kidney Disease (CKD)
- Hyaline Casts
- Non-Specific
Sickle Cell Anemia (Signs and Complications)
- Crew-cut on Skull X-ray
- Auto-splenectomy
- Painful Crisis
- Aplastic Crisis
- Splenic-sequestration Crisis
- Hyper-hemolytic Syndrome
- Renal Papillary Necrosis
- Salmonella osteomyelitis
- Pulmonary Hypertension
- Hyposthenuria
Postrenal Acute Kidney Injury Pathophysiology and Presentation
- Bilateral Outflow Obstruction
- Decreased GFR
- Benign Prostatic Hyperplasia (BPH)
- Nephrolithiasis
- Neoplasm
- Neurogenic Bladder
- Bladder Distension
- Lower Abdominal Pain
- Edema
- Oliguria
Post Renal Acute Kidney Injury (AKI) Diagnosis and Management
- Physical Examination
- BUN:Creatinine ratio of 20:1 in the Initial Stages
- BUN:Creatinine ratio of 10:1 in the late stages
- Urine Osmolality <350 mOsm/kg
- Variable Fractional Excretion of Sodium (FENa)
- Ultrasound
- CT Scan
- Treat Underlying Cause
Intrinsic Causes of Acute Kidney Injury
- Acute Tubular Necrosis
- Acute Interstitial Nephritis
- Vasculitis
- Malignant Hypertension
- Acute Glomerulonephritis
- Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP-HUS)
- Fractional Excretion of Sodium (FeNa) > 2%
- Urine Osmolality < 350 mOsm/kg
- Urine Na+ >40 mEg/L
- Serum BUN/Cr < 15
- Treat Underlying Disorder