Kidney injury after hip replacement linked to increased complications
Among patients undergoing total hip arthroplasty, acute kidney injury occurs in 1.5% of hospitalizations, and is associated with increased implant infection, health care use and death following surgery, according to findings published in Arthritis Research & Therapy.
“Acute kidney injury (AKI) is an uncommon, but a clinically important post-surgical complication,” Jasvinder A. Singh, MD, MPH, of the Birmingham Veterans Affairs Medical Center, in Alabama, and John D. Cleveland, MD, of the University of Alabama at Birmingham, wrote. “AKI is a risk factor for the development of chronic kidney disease (CKD) and higher mortality. Post-surgical AKI leads to higher adjusted health care costs (1.6-times) and longer hospital stays. Thus, post-operative AKI leads to a major health care burden.”
“Total hip arthroplasty (THA) is the second most commonly performed arthroplasty in the U.S. with a growing demand due to associated pain relief and improvement in function,” they added.
To determine whether acute kidney injury is linked with more complications and health care use among patients undergoing total hip replacement, Singh and Cleveland conducted a retrospective cohort study using data from the U.S. National Inpatient Sample. According to the researchers, this database is a 20% stratified sample of all discharges from U.S. community hospitals, provided by the Agency for Healthcare Research and Quality Healthcare Cost and Utilization Project.
For their study, Singh and Cleveland included all hospitalizations for primary total hip arthroplasty in the United States from 1998 to 2014, identified by an ICD-9-CM code of 81.51. The researchers performed a multivariable-adjusted logistic regression to evaluate the association of acute kidney injury with complications — including infection, transfusion, revision, and mortality — following surgery. In addition, they determined the link between post-surgery acute kidney injury and health care use, based on total hospital charges, discharge to a rehabilitation facility and length of hospital stay.
According to Singh and Cleveland, among the 4.1 million primary total hip replacements included in the study, 61,077 — or 1.5% — ultimately developed acute kidney injury during hospitalization.
After adjusting for age, gender, race, income, underlying diagnosis, medical comorbidity and the insurance payer, acute kidney injury in primary total hip replacement was associated with significantly higher implant infection (OR = 2.34; 95% CI, 1.87, 2.93), transfusion (OR = 2.46; 95% CI, 2.37, 2.56), revision (OR = 2.54; 95% CI, 2.16, 2.98) and death (OR = 8.52; 95% CI, 7.47, 9.73). Kidney injury was also associated with significantly higher total hospital charges above the median (OR = 2.29; 95% CI, 1.99, 2.65), discharge to a rehabilitation facility (OR = 2.11; 95% CI, 2.02, 2.20), and hospital stay of more than3days (OR = 4.34; 95% CI, 4.16, 4.53).
“AKI in patients who underwent primary THA was independently associated with each of the four post-operative in-hospital complications in adjusted analyses, including mortality,” Singh and Cleveland wrote. “AKI was also associated with higher health care utilization post-THA in adjusted analyses.”
“Quality initiatives that further improve the care pathways for patients undergoing primary THA may reduce the risk of AKI, and associated complications and excess health care utilization,” they added. “Research studies need to explore the mechanisms of AKI in patients undergoing primary THA and examine interventions that target modifiable risk factors for AKI.” – by Jason Laday
Disclosure: Singh reports consultant fees from Clearview Health Care Partners, Clinical Care Options, Crealta/Horizon, Fidia, Medscape, Medisys, Putnam Associates, Spherix, UBM LLC, WebMD, as well as stock options in Amarin Pharmaceuticals and Viking Therapeutics. Cleveland reports no relevant financial disclosures.