Analysis of risk factors and clinical characteristics of elderly patients with persistent acute kidney injury

Abstract

Objective To investigate the incidence of transient acute kidney injury (AKI) and persistent AKI, the clinical characteristics of AKI patients, and the risk factors associated with persistent AKI in the elderly. Methods A retrospective analysis of 744 cases of ≥75-year-old inpatients who attended the National Geriatrics Clinical Research Center of the Chinese PLA General Hospital from January 2007 to December 2018. According to the recovery of serum creatinine (Scr) at 48 hours after AKI, the patients were divided into transient AKI group and persistent AKI group. SPSS 17.0 software was used for statistical analysis. Multivariate logistic regression method was used to analyze the risk factors related to persistent AKI in the elderly. Results Among the 744 cases of elderly patients with AKI, 701 cases were male (94.2%) with a median of 88 years (84-91). 8.3% of the patients suffered from transient AKI (62/744) and 91.7% of the patients persistent AKI (682/744). Compared with the transient group, the persistent AKI group showed a higher proportion of patients with a hypertension history (72.4% vs 83.9%, P=0.041), a higher 90-day mortality rate (37.4% vs 8.1%, P<0.001). a higher proportion of patients with AKI stage 3 (33.1% vs 8.1%, P<0.001), and higher levels of Scr (130.0 vs 116.1 μmol/L, P<0.001), peak Scr (147.6 vs 117.9 μmol/L, P<0.001), BUN (13.1 vs 9.3 mmol/L, P<0.001), serum uric acid (368.1 vs 338.3 μmol/L, P=0.006), and serum sodium (141 vs 138 mmol/L, P<0.001) on diagnosis of AKI. Compared with the transient group, the persistent AKI group also had more patients with mechanical ventilation (42.5% vs 12.9%, P<0.001), hypoalbuminemia (34.1±5.6 and 36.1±5.3 g/L, P=0.006), and anemia (111±22 vs 119±20 g/L, P=0.009). Multivariate logistic regression analysis showed that the peak Scr (OR=1.011, 95%CI: 1.004-1.019, P=0.002), increased serum sodium (OR=1.055, 95%CI: 1.015-1.097, P=0.007), and mechanical ventilation (OR=2.912, 95%CI: 1.334-6.357, P=0.007) were independent risk factors for the development of persistent AKI in the elderly patients. Conclusion The incidence of persistent AKI in the elderly patients was as high as 92%, and early diagnosis and treatment of risk factors could reduce persistent kidney damage. Key words: Acute kidney injury; Transient AKI; Persistent AKI; Elderly; Risk factor