Dexmedetomidine May Reduce the Incidence of Acute Kidney Injury in Elderly Patients Undergoing Orthopedic Surgery: A Randomized, Double-Blind Clinical Trial.

BACKGROUND

Acute kidney injury (AKI) is a common complication in elderly patients undergoing orthopedic surgery, yet the renoprotective role of dexmedetomidine in this patient population remains unclear. This study aimed to evaluate the effect of dexmedetomidine on the incidence of AKI in elderly patients undergoing lower extremity orthopedic procedures.

METHODS

In this randomized, double-blind, placebo-controlled trial, 300 patients aged ≥ 65 scheduled for lower extremity orthopedic surgery were randomized to receive either dexmedetomidine (0.4 μg/kg infused for 10 minutes before induction, followed by 0.4 μg/kg/h until 30 minutes before skin closure) or normal saline (control). The primary outcome was the incidence of AKI within 48 hours postoperatively, based on AKI Network criteria. Secondary outcomes included serum cystatin C and estimated glomerular filtration rate on postoperative day (POD) 1, 2, and 3, in-hospital complications (postoperative nausea and vomiting, delirium, pneumonia, stroke), intensive care unit admission, length of hospital stay, and in-hospital mortality.

RESULTS

Of 295 patients who completed the study (62.7% female; mean age, 74 years), AKI occurred in 4.7% (7/149) of the dexmedetomidine group compared with 11.6% (17/146) of the control group (odds ratio = 0.37; 95% CI, 0.15 to 0.93; P = 0.035). This difference remained significantly after adjustment for baseline covariates (adjusted odds ratio = 0.36; 95% CI, 0.14 to 0.90; P = 0.030). All AKI cases were AKIN stage 1. Serum cystatin C on POD 1 were lower in the dexmedetomidine group (mean [SD], 1.06 [0.30] vs 1.17 [0.32] mg/L; P = 0.003). No significant between-group differences were observed in other secondary outcomes.

CONCLUSION

Dexmedetomidine administration was associated with a reduced incidence of AKI in elderly patients undergoing lower extremity orthopedic surgery. The renoprotective effects of dexmedetomidine in this patient population warrant validation in multicenter trials.

CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2400088225).