Authors: Bell S et al. BMJ 2015 Nov 11.
Predictors of postoperative AKI include older age, male sex, and use of ACE inhibitors and ARBs.
Acute kidney injury (AKI) after surgery is associated with excess risk for death. In this study, researchers developed and validated a model for predicting AKI following orthopedic surgery. Analysis involved 10,600 adults (mean age, 71) who underwent orthopedic surgery in Scotland from 2005 through 2011; 6200 patients were in the development group, and 4400 were in the validation group. Mean baseline estimated glomerular filtration rate (eGFR) in both groups was 71 mL/minute/1.73 m2.
Postoperative AKI occurred in 11% of patients in the development group and in 7% of the validation group. Seven predictors of AKI were identified: older age, male sex, diabetes, lower eGFR, use of angiotensin-converting–enzyme (ACE) inhibitors or angiotensin-receptor blockers (ARBs), larger number of prescribed drugs, and higher American Society of Anesthesiologists grade. Both short-term and long-term survival were lower in patients with AKI than in those without AKI.
This study affirms what experienced clinicians know: Older age, diabetes, baseline renal insufficiency, and comorbidity are associated with greater risk for AKI after orthopedic surgery, and AKI, in turn, is associated with higher mortality. In addition, perioperative use of ACE inhibitors and ARBs was associated with excess risk for AKI, but whether these drugs should routinely be withheld perioperatively is controversial.