The impact of transient and persistent acute kidney injury on short-term outcomes in very elderly patients

Abstract

ObjectivesAcute kidney injury (AKI) is a common complication in elderly patients and is associated with poor outcomes. However, the effect of transient and persistent geriatric AKI on short-term mortality is unclear. We aimed to study the incidence, clinical characteristics, and prognostic impact of transient and persistent AKI in such patients.MethodsWe retrospectively enrolled 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. AKI patients were divided into transient or persistent AKI groups based on their renal function at 3 days post-AKI. Renal function recovery was defined as a return to the baseline serum creatinine (SCr) levels.ResultsIn total, 668 geriatric patients (39.0%) experienced AKI, and 652 satisfied the inclusion criteria. Of these 652 patients, 270 (41.4%) had transient AKI, and 382 (58.6%) had persistent AKI. The 90-day mortality was 5.9% in patients with transient AKI and 53.1% in patients with persistent AKI. Multivariate analysis revealed 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) were associated 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) were associated with 90-day mortality.ConclusionAKI is common in very elderly patients, with transient renal injury representing close to 42% of all cases of geriatric AKI. More frequent SCr measurements may be helpful for the early diagnosis of transient geriatric AKI. Persistent geriatric AKI is independently associated with a significantly higher risk of 90-day mortality.

AKI in the very elderly patients without preexisting chronic kidney disease: a comparison of 48-hour window and 7-day window for diagnosing AKI using the KDIGO criteria

“… 20 Therefore, some patients with AKI could be misclassified as not having AKI. 22 One explanation might be the definition of AKI, which is neither uniformly known nor accepted in the non-nephrologic community. Although the KDIGO criteria provide a 48-hour or 7-day window for diagnosis, these criteria are not commonly used in real clinical settings.…”

“…9 Other possible reasons in the very elderly include MV-related complications, poor nutritional status, and more patients in KDIGO stage 3. 22 1) MV is a common and important intervention in the elderly. MV affects systemic and renal blood flow and can cause hypotension and fluid reactive shock, affecting renal perfusion by decreasing GFR and reducing cardiac output and stimulating hormonal and sympathetic pathways, causing or promoting the development of AKI.…”

The need for disruptive innovation in acute kidney injury

“…Transient AKI can be categorized as a fluid-responsive AKI as correction of renal perfusion by fluid resuscitation will rapidly improve renal function in transient AKI patients. In several different clinical conditions, the prognosis of transient AKI was reportedly better than persistent AKI [21][22][23][24][25]. Persistent AKI is generally diagnosed with more severe AKI stage, i.e., higher serum creatinine and lower urine output (oliguria or anuria) compared with transient AKI.…”

Duration of acute kidney injury, 90-day mortality, and chronic kidney disease progression in very elderly patients

“…[11] We have previously shown that patients with P-AKI (elevated Scr level over 3 days) are more likely to experience more severe AKI and have a higher 90day mortality than patients with T-AKI (in whom Scr returned to baseline levels within 3 days). [8] In this study, however, the diagnoses of T-AKI and P-AKI were not made based on the 2017 Acute Disease Quality Initiative (ADQI) criteria, and RF recovery was not assessed 90 days post-AKI. [12] The aim of the current study was to evaluate the prognostic impact of AKI duration on 90-day mortality and progression of new-onset CKD in very elderly patients after AKI development.…”

“…[2,4] In fact, AKI duration recently has been viewed as another independent risk factor for a poorer outcome: longer duration of AKI (also called persistent AKI or P-AKI), typically defined as more than 48-72 h after onset, has been associated with a higher risk for CKD and death compared to short-duration AKI (also called transient AKI or T-AKI). [5][6][7][8][9] However, a recent intensive care unit patient-based retrospective study showed that although P-AKI is associated with poorer hospital survival, this association was attenuated after accounting for AKI severity. [10] Limited information is available on the association between the duration of the increase in Scr and clinical outcomes in very elderly patients.…”