Li Q, et al. – The goal of this paper was to investigate the incidence, clinical features and prognostic effect of transient and persistent acute kidney injury (AKI) in very elderly patients. AKI was determined as being common in very elderly patients, with transient renal injury representing close to 42% of all cases of geriatric AKI. More frequent serum creatinine (SCr) measurements could facilitate an early diagnosis of transient geriatric AKI. Persistent geriatric AKI exhibited an independent correlation with a considerably higher risk of 90–day mortality.

Methods

• The recruitment constituted very elderly patients (≥75 years) from the geriatric department of the Chinese PLA General Hospital between 2007 and 2015.
• AKI was defined according to the 2012 Kidney Disease: Improving Global Outcomes criteria.
• Candidates were divided into transient or persistent AKI groups, on the basis of their renal function at 3 days post-AKI.
• Renal function recovery was defined as a return to the baseline serum creatinine (SCr) levels.

Results

• 668 geriatric patients (39.0%) experienced AKI, and 652 satisfied the inclusion criteria.
• Among 652 patients, 270 (41.4%) had transient AKI, and 382 (58.6%) had persistent AKI.
• The 90-day mortality was found to be 5.9% in patients with transient AKI and 53.1% in patients with persistent AKI.
• Multivariate analysis disclosed that low hemoglobin levels (odds ratio [OR] =0.989; 95% CI: 0.980-0.999; P=0.025), low mean aortic pressure (OR =0.985; 95% CI: 0.971-1.000; P=0.043), peak SCr (OR =1.020; 95% CI: 1.015-1.026; P<0.001) levels, high uric acid (OR =1.002; 95% CI: 1.000-1.003; P=0.040) levels, high blood urea nitrogen (OR =1.028; 95% CI: 1.000-1.056; P=0.047) levels, and mechanical ventilation requirements (OR =1.610; 95% CI: 1.012-2.562; P=0.044) exhibited a correlation with persistent AKI.
• Persistent AKI (hazard ratio [HR] =5.741; 95% CI: 3.356-9.822; P<0.001) and more severe AKI stages (stage 2: HR =3.363; 95% CI: 1.973-5.732; P<0.001 and stage 3: HR =4.741; 95% CI: 2.807-8.008; P<0.001) displayed a link with 90-day mortality.