Community-acquired versus hospital-acquired acute kidney injury in patients with acute exacerbation of COPD requiring hospitalization in China

Chang-chun Cao,1,* Da-wei Chen,2,* Jing Li,2 Meng-qing Ma,2 Yu-bao Chen,3 Yi-zhi Cao,4 Xi Hua,2 Wei Shao,1 Xin Wan2 1Department of Nephrology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; 2Department of Nephrology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; 3Department of Respiratory Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; 4The First Clinical Medical College, Nanjing Medical University, Nanjing, Jiangsu, China *These authors contributed equally to this work Purpose: Previous studies have described the incidence, risk factors, and outcomes for patients with acute exacerbations of COPD (AECOPD) developing acute kidney injury (AKI). However, little is known about the differences between community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI) in patients with AECOPD. Thus, in this study, we compared prevalence, risk factors, and outcomes for these patients with CA-AKI and HA-AKI. Patients and methods: This study was conducted from January 2014 to January 2017, and data from adult inpatients with AECOPD were analyzed retrospectively. A total of 1,768 patients were included, 280 patients were identified with CA-AKI and 97 patients were with HA-AKI. Results: Prevalence of CA-AKI was 15.8% and that of HA-AKI was 5.5%, giving an overall AKI prevalence of 21.3%. Patients with CA-AKI had a higher prevalence of chronic kidney disease (CKD) and lower prevalence of chronic cor pulmonale than patients with HA-AKI. Risk factors for developing HA-AKI and CA-AKI were similar, such as being elderly, requirement for mechanical ventilation, and a history of coronary artery disease and CKD. Patients with HA-AKI were more likely to have stage 3 AKI and worse short-term outcomes. In comparison with patients with CA-AKI, those with HA-AKI were more likely to require non-invasive mechanical ventilation (31.3% versus 16.8%; P = 0.003) and had a longer duration of mechanical ventilation (11 days versus 8 days; P = 0.020), longer hospitalization (14 days versus 12 days; P = 0.038), and higher inpatient mortality (32.0% versus 13.2%; P < 0.001). Patients with HA-AKI had worse (multivariate-adjusted) inpatient survival than those with CA-AKI (hazard ratio, 1.7 [95% confidence interval, 1.03–2.81; P = 0.038] for the HA-AKI group). Conclusion: AKI was common in patients with AECOPD requiring hospitalization. CA-AKI was more common than HA-AKI but otherwise demonstrated similar demographics and risk factors. Nevertheless, patients with HA-AKI had worse short-term outcomes. Keywords: acute exacerbation of COPD, community-acquired acute kidney injury, hospital-acquired acute kidney injury, short-term outcome