Acute kidney injury in critically ill patients after oncological surgery: Risk factors and 1-year mortality

Abstract

Aim: We aimed to identify risk factors associated with acute kidney injury (AKI) and to analyse 1-year mortality after oncological surgery.

Methods: We retrospectively included 434 adult patients admitted to the intensive care unit (ICU) after oncological surgery, and classified AKI according to the Kidney Disease: Improving Global Outcomes criteria. We performed logistic regression and Cox regression analyses to evaluate AKI and mortality risk factors.

Results: Sixty-one percent of patients (n = 264) developed AKI. Previous abdominal radiotherapy and abdominal surgical packing were independently associated with stage 2 and 3 AKI, with adjusted odds ratio (OR) of 2.6 (95% confidence interval [CI] 1.3-5.5, p = .010) and OR of 2.6 (95% CI 1.2-5.5, p = .014), respectively. Other independent risk factors were: glomerular filtration rate (eGFR) <60 ml/min/1.73m² (OR 3.6, 95% CI 1.2-11.4, p = .028), abdominal surgery 2.6 (1.4-4.9, p = .003), intraoperative diuresis <1 ml/k/h (OR 2.4, 95% CI 1.4-4.0, p = .001), sepsis (OR 2.5, 95% CI 1.3-4.6, p = .002) and mechanical ventilation at ICU admission (OR 7.7, 95% CI 3.2-18.6, p < .001). Stage 2 and stage 3 AKI were independently associated with 1-year mortality, with adjusted hazard ratios (HR) of 2.6 (95% CI 1.3-5.0, p = .005) and HR of 5.0 (95% CI 2.6-9.6, p < .001), respectively. Additionally, patients who had postsurgical AKI, had a lower eGFR at 1-year follow-up. These findings may be limited by the retrospective single centre design of our study.

Conclusion: In addition to the conventional risk factors, our results suggest that abdominal radiotherapy and abdominal surgical packing could be independent risk factors for AKI after oncological surgery.

Keywords: acute kidney injury; cancer; critical illness; mortality; surgery.