Short- and long-term outcomes after postsurgical acute kidney injury requiring dialysis

OBJECTIVE: Prompt assessment of perioperative complications is critical for the comprehensive care of surgical patients. Acute kidney injury requiring dialysis (AKI-D) is associated with high mortality, yet little is known about how long-term outcomes of patients have evolved. The association of AKI-D with postsurgical outcomes has not been well studied. METHODS: We investigated patients from the National Health Insurance Research Database and validated by the multicenter Clinical Trial Consortium for Renal Diseases cohort. All patients with AKI-D 18 years or older undergoing four major surgeries (cardiothoracic, esophagus, intestine, and liver) were retrospectively investigated (N=106,573). Patient demographics, surgery type, comorbidities before admission, and postsurgical outcomes, including the in-hospital, 30-day, and long-term mortality together with dialysis dependence were collected. RESULTS: AKI-D is the top risk factor for 30-day and long-term mortality after major surgery. Of 1,664 individuals with AKI-D and 6,656 matched controls, AKI-D during the hospital stay was associated with in-hospital (adjusted hazard ratio [aHR]=3.04, 95% CI 2.79–3.31), 30-day (aHR=3.65, 95% CI 3.37–3.94), and long-term (aHR=3.22, 95% CI 3.01–3.44) mortality. Patients undergoing cardiothoracic surgery (CTS) showed less in-hospital (aHR=0.85, 95% CI 0.75–0.97), 30-day (aHR=0.79, 95% CI 0.70–0.89), and long-term (aHR=0.80, 95% CI 0.72–0.90) mortality compared with non-CTS patients with AKI-D. CTS patients had a high risk of 30-day dialysis dependence (subhazard ratio [sHR]=1.67, 95% CI 1.18–2.38), but the risk of long-term dialysis dependence was similar (sHR=1.38, 95% CI 0.96–2.00) after AKI-D by taking mortality as a competing risk. Non-CTS patients had more comorbidities of sepsis, azotemia, hypoalbuminemia, and metabolic acidosis compared with CTS patients. CONCLUSION: AKI exhibits paramount effects on postsurgical outcomes that extend well beyond discharge from the hospital. The goal of the perioperative assessment should include the reassurance of enhancing renal function recovery among different surgeries, and optimized follow-up is warranted in attenuating the complications after postsurgical AKI has occurred.