Acute Kidney Injury in Lower-Extremity Joint Arthroplasty

» Acute kidney injury, defined as an increase in serum creatinine of 0.3 mg/dL or >50% of baseline or sustained oliguria with urine output of <0.5 mL/kg/hr for >6 hours, affects 2% to 15% of patients undergoing lower-extremity joint arthroplasty. Patients who develop acute kidney injury have an increased length of hospitalization and a greater cost of care, are less likely to be discharged home postoperatively, and have increased short-term and long-term mortality. » Risk factors for acute kidney injury after lower-extremity joint arthroplasty include older age, male sex, obesity, diabetes, hypertension, congestive heart failure, and especially underlying chronic kidney disease. » Consensus guidelines have not been updated to reflect recent research into the perioperative effects on angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs); most patients taking these medications chronically without systolic heart failure should omit the dose prior to the surgical procedure to reduce the risk of perioperative hypotension and acute kidney injury. » In patients at an increased risk for acute kidney injury, efforts should be made when clinically appropriate to minimize exposure to potential nephrotoxins including nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 (COX-2) inhibitors, intravenous computed tomography (CT) contrast, and antibiotics with higher rates of nephrotoxicity such as vancomycin and aminoglycosides. » The initial evaluation for patients developing acute kidney injury after lower-extremity joint arthroplasty should include ruling out urinary obstruction, clinical volume status assessment, determining whether intraoperative or postoperative hypotension has occurred, urinalysis, and urine electrolyte studies.