Acute Kidney Injury – Definition & Classification HW
Compare the pathophysiology of major etiologies of acute renal failure including decreased renal perfusion (pre-renal), intrinsic renal disease, and acute renal obstruction (post renal). Calculate fractional excretion of sodium and apply it to distinguish between pre-renal and intrinsic renal disease. Develop appropriate initial management plan for acute renal failure including volume management, dietary recommendations, drug dosage alterations, electrolyte monitoring, and indications for dialysis. Identify risk factors for contrast-induced nephropathy and recommend steps to prevent this complication. Interpret a urinalysis, including microscopic examination for casts, red blood cells, white blood cells, and crystals. Calculate the anion gap and generate a differential diagnosis for metabolic acidosis.
Knowledge
Acute Kidney Injury – Definition & Classification
Definition
Acute kidney injury (AKI) is defined by an abrupt (within 48 hours) decrease in glomerular filtration function with a concomitant elevation in serum creatinine. In this setting, the kidneys are unable to maintain fluid, electrolyte, and acid-base homeostasis. Classification
Development of consensus definitions for acute kidney injury over the past several years have improved physicians’ ability to describe acute kidney injury with consistent terminology. This is of benefit for both research and for clinical care prognostication as it has been demonstrated that categories of worsening acute kidney injury are predictive of morbidity including future chronic kidney disease and mortality during the acute kidney injury episode. The first consensus definition was called the RIFLE criteria. Subsequent criteria were developed by the Acute Kidney Injury Network (AKIN). These criteria have been merged and simplified by the Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Acute Kidney Injury. In the KDIGO guidelines acute kidney injury is defined as: 1. An increase in serum creatinine ≥ 0.3 mg/dl within 48 hours – or – 2. Increase in serum creatinine to ≥ 1.5 times baseline, which is known or presumed to have to have occurred within the prior seven days – or – 3. Urine volume < 0.5 ml/kg/hr for six hours In the KDIGO guidelines, acute kidney injury is categorized in to three progressively worsening stages:
Stage Serum creatinine Urine output
———–
HW Definition & Classification of Acute Kidney Injury
HW Definition & Classification of Acute Kidney Injury
Examine the pathophysiology of key causes of acute renal failure, such as decreased renal perfusion (pre-renal), intrinsic renal disease, and acute renal obstruction (post renal). Calculate sodium fractional excretion and use it to differentiate between pre-renal and intrinsic renal illness. Create an effective initial management strategy for acute renal failure, including volume control, nutritional recommendations, medicine dosage changes, electrolyte monitoring, and dialysis indications. Determine the risk factors for contrast-induced nephropathy and make recommendations to avoid this condition. Interpret urinalysis, which includes microscopic inspection for casts, red blood cells, white blood cells, and crystals. Calculate the anion gap and generate a differential diagnosis for metabolic acidosis.
Knowledge
Acute Kidney Injury – Definition & Classification
Definition
Acute kidney
