Acute Kidney Injury (AKI) - Etiology, Pathophysiology, and Treatment - PDF

Acute Kidney Injury Copyright © 2017, Elsevier Inc. All Rights Reserved. Causes of Acute Kidney Injury Prerenal, intrarenal, and post renal causes of acute kidney injury (AKI). Copyright © 2017, Elsevier Inc. All Rights Reserved.  Etiology and Pathophysiology  Prerena...

Acute Kidney Injury Copyright © 2017, Elsevier Inc. All Rights Reserved. Causes of Acute Kidney Injury Prerenal, intrarenal, and post renal causes of acute kidney injury (AKI). Copyright © 2017, Elsevier Inc. All Rights Reserved.  Etiology and Pathophysiology  Prerenal  Causes are factors that reduce systemic circulation, causing reduction in renal blood flow  Severe dehydration, heart failure, ↓ CO  Decreases glomerular filtration rate  Causes oliguria  Intrarenal  Causes include conditions that cause direct damage to kidney tissue  Prolonged ischemia, nephrotoxins  Hemoglobin released from hemolyzed RBCs  Myoglobin released from necrotic muscle cells Copyright © 2017, Elsevier Inc. All Rights Reserved.  Etiology and Pathophysiology  Intra renal  Acute tubular necrosis (ATN)  Results from ischemia, nephron toxins, or sepsis  Severe ischemia causes disruption in basement membrane  Nephro toxic agents cause necrosis of tubular epithelial cells  Potentially reversible  Postrenal  Causes include mechanical obstruction of outflow  Benign prostatic hyperplasia  Prostate cancer  Calculi  Trauma  Extrarenal tumors  Bilateral ureteral obstruction Copyright © 2017, Elsevier Inc. All Rights Reserved. Etiology- AKI Copyright © 2017, Elsevier Inc. All Rights Reserved. Classificatio n  RIFLE classification  Risk (R)  Injury (I)  Failure (F)  Loss (L)  End-stage renal disease (E) Copyright © 2017, Elsevier Inc. All Rights Reserved.  Clinical Manifestations  Oliguric phase  Urinary changes- oliguria  Urinary output less than 400 mL/day  Occurs within 1 to 7 days after injury  Lasts 10 to 14 days  Urinalysis may show casts, RBCs, WBCs  Fluid volume  Hypovolemia may exacerbate AKI  Decreased urine output -fluid retention  Neck veins distended  Bounding pulse  Edema  Hypertension  Fluid overload can lead to heart failure, pulmonary edema, and pericardial and pleural effusions Copyright © 2017, Elsevier Inc. All Rights Reserved.  Clinical Manifestations  Metabolic acidosis  Impaired kidney cannot excrete hydrogen ions  Serum bicarbonate production is decreased  Severe acidosis develops  Kussmaul respirations  Sodium balance  Increased excretion of sodium  Hyponatremia can lead to cerebral edema  Potassium excess  Impaired ability of kidneys to excrete potassium  Increased risk with massive tissue trauma  Usually asymptomatic  ECG changes Copyright © 2017, Elsevier Inc. All Rights Reserved.  Clinical Manifestations  Oliguric phase  Hematologic disorders  Leukocytosis  Waste product accumulation  Elevated BUN and serum creatinine levels  Neurologic disorders  Fatigue and difficulty concentrating  Seizures, stupor, coma Copyright © 2017, Elsevier Inc. All Rights Reserved. Clinical Manifestations  Diuretic phase  Daily urine output is 1 to 3 L  May reach 5 L or more  Monitor for hyponatremia, hypokalemia, and dehydration  Recovery phase  May take up to 12 months for kidney function to stabilize Copyright © 2017, Elsevier Inc. All Rights Reserved. Diagnostic studies  Thorough history  Serum creatinine  Urinalysis  Kidney ultrasonography  Renal scan  CT scan  Renal biopsy Contraindicated  MRI with gadolinium contrast medium  Magnetic resonance angiography (MRA) with gadolinium contrast medium  Nephrogenic systemic fibrosis  Contrast-induced nephropathy (CIN) Copyright © 2017, Elsevier Inc. All Rights Reserved.  Interprofessional Care  Ensure adequate intravascular volume and cardiac output  Force fluids  Loop diuretics (e.g., furosemide [Lasix])  Osmotic diuretics (e.g., mannitol)  Closely monitor fluid intake during oliguric phase  Hyperkalemia  Insulin and sodium bicarbonate  Calcium carbonate  Sodium polystyrene sulfonate (Kayexalate) Copyright © 2017, Elsevier Inc. All Rights Reserved.  Interprofessiona l Care  Indications for renal replacement therapy (RRT)  Volume overload  Elevated serum potassium level  Metabolic acidosis  BUN level > 120 mg/dL (43 mmol/L)  Significant change in mental status  Pericarditis, pericardial effusion, or cardiac tamponade  Renal replacement therapy (RRT)  Peritoneal dialysis (PD)  Not frequently used  Continuous renal replacement therapy (CRRT)  Cannulation of artery and vein Copyright © 2017, Elsevier Inc. All Rights Reserved.  Interprofessional Care Nutritional therapy  Maintain adequate caloric intake  Primarily carbohydrates and fat  Limited protein  Restrict sodium  Increase dietary fat  Enteral nutrition Copyright © 2017, Elsevier Inc. All Rights Reserved. Nursing Management  Nursing Assessment  Measure vital signs  Measure fluid intake and output  Examine urine  Assess general appearance  Observe dialysis access site  Mental status/level of consciousness  Oral mucosa  Lung sounds  Heart rhythm  Laboratory values  Diagnostic test results Copyright © 2017, Elsevier Inc. All Rights Reserved.  Nursing Management  Measure daily weight  Monitor electrolyte balance  Replace significant fluid losses  Provide aggressive diuretic therapy for fluid overload  Use nephrotoxic drugs sparingly  Assess for signs of hypervolemia or hypovolemia  Assess for potassium and sodium disturbances  Meticulous aseptic technique  Skin care measures/mouth care Copyright © 2017, Elsevier Inc. All Rights Reserved.