Acute Kidney Injury (AKI)

Acute Kidney Injury (AKI)

• Defined as partial or complete impairment of kidney function that results in the inability to excrete metabolic waste products and water
• Affects all body systems, requiring challenging treatments and dietary changes that impact lifestyle, occupation, family relationships, and self-image

Comparison of AKI and Chronic Kidney Disease (CKD)

• Onset:
  • AKI: Sudden
  • CKD: Gradual, over years
• Causes:
  • AKI: Acute tubular necrosis, ischemia, nephrotoxins, sepsis
  • CKD: Diabetic nephropathy, hypertension, glomerulonephritis
• Diagnostic criteria:
  • AKI: Acute reduction in urine output and/or elevation in serum creatinine
  • CKD: GFR < 60 mL/min/1.73m2 for > 3 months and/or kidney damage > 3 months
• Reversibility:
  • AKI: Potentially reversible
  • CKD: Progressive and irreversible
• Cause of death:
  • AKI: Infection
  • CKD: Cardiovascular disease

Acute Kidney Injury (AKI)

• Ranges from slight deterioration to severe impairment
• Rapid loss of kidney function characterized by:
  • Rise in serum creatinine and/or reduction in urine output
  • Elevated BUN and K+
  • Azotemia—accumulation of nitrogenous waste products
• High mortality rate; often associated with other life-threatening conditions

Causes of Acute Kidney Injury

• Prerenal:
  • Factors reducing systemic circulation, causing decreased renal blood flow and oliguria
  • Examples: Severe dehydration, heart failure, decreased CO
• Intrarenal:
  • Direct damage to kidney tissue
  • Examples: Prolonged ischemia, nephrotoxins, hemoglobinuria, myoglobinuria
• Postrenal:
  • Mechanical obstruction of outflow, causing reflux into renal pelvis and impaired kidney function
  • Examples: Benign prostatic hyperplasia, prostate cancer, calculi, trauma, extrarenal tumors

Clinical Manifestations of AKI

• Oliguric phase:
  • Urinary changes: Oliguria, casts, RBCs, WBCs, protein
  • Fluid volume: Decreased urine output, fluid retention, edema, hypertension
  • Metabolic acidosis: Impaired kidney function, decreased bicarbonate production
  • Sodium balance: Increased excretion, hyponatremia
  • Potassium excess: Impaired excretion, hyperkalemia
  • Hematologic disorders: Leukocytosis, infection
  • Waste product accumulation: Increased BUN and serum creatinine levels
  • Neurologic disorders: Fatigue, difficulty concentrating, seizures, stupor, coma
• Diuretic phase:
  • Increased urine output, osmotic diuresis
• Recovery phase:
  • Increased GFR, decreased BUN and creatinine levels

Diagnostic Studies for AKI

• Thorough history
• Serum creatinine, BUN, electrolytes
• Urinalysis
• Renal ultrasound
• Renal scan
• CT scan
• Renal biopsy

Interprofessional Care for AKI

• Eliminate cause
• Manage signs and symptoms
• Prevent complications
• Ensure adequate intravascular volume and cardiac output
• Closely monitor fluid intake during oliguric phase
• Hyperkalemia therapies
• Indications for renal replacement therapy (RRT)
• Renal replacement therapy (RRT) options: Peritoneal dialysis, intermittent hemodialysis, continuous renal replacement therapy
• Nutrition therapy: Maintain adequate caloric intake, restrict sodium, potassium, and phosphate

Nursing Management for AKI

• Nursing assessment: Measure vital signs, daily weights, strict intake and output, examine urine
• Nursing diagnoses: Electrolyte imbalance, fluid imbalance, risk for infection, anxiety
• Nursing planning: Patient will completely recover without loss of kidney function, maintain normal fluid and electrolyte balance, have decreased anxiety, adhere to follow-up care
• Health promotion: Prevention and early recognition, identify and monitor high-risk populations, control exposure to nephrotoxic drugs and industrial chemicals
• Nursing implementations: Accurate intake and output, daily weights, assess for hypervolemia or hypovolemia, assess for potassium and sodium disturbances, meticulous aseptic technique, careful use of nephrotoxic drugs, skin care measures/mouth care
• Nursing evaluation: Patient will regain and maintain normal fluid and electrolyte balance, adhere to treatment regimen, have no complications, and have complete recovery