Qinglin Li, Meng Zhao, Jing Du, Xiaodan Wang

A delayed nephrology consultation (NC) may be associated with a poor prognosis in acute kidney injury (AKI) patients. The aims of this study were to compare the clinical and laboratory characteristics of elderly AKI patients evaluated and not evaluated by nephrologists and to generate a hypothesis regarding the relationship between the timing of the NC and 90-day outcomes. From 2007 to 2015, this study explored associations among the presence and timing of NC with the non-intensive care unit stay and 90-day mortality in elderly AKI patients at the Geriatric Department of the Chinese People's Liberation Army General Hospital. Early NC and delayed NC were defined as NCs performed before and 2 days after the day of AKI diagnosis, respectively. Multivariable logistic regression was used to adjust for confounding and selection bias. In total, 623 patients were included for the final analysis, of whom 162 (26%) were evaluated by nephrologists. The 90-day mortality rate was 33.2%, and dialysis was required in 1.4% of patients (9/623). Multivariable analysis showed that a higher prevalence of preexisting chronic obstructive pulmonary disease, AKI diagnosis time, peak serum creatinine level, blood urea nitrogen level, AKI stage, and mortality was associated with the NC. The NC was delayed (>48 h) in 59 patients (36.4%) (median time to consultation, 4 days). The median AKI diagnosis time, presence of oliguria, uric acid level, and a more severe AKI stage were associated with delayed consultation. Moreover, delayed consultation presented a similar 90-day mortality rate to that of an early NC (50.8% vs 44.7%, respectively, P=0.448). In very elderly AKI patients, those evaluated by nephrologists have more severe AKI and a higher mortality rate than those not evaluated by nephrologists. An earlier NC may not be associated with improved 90-day survival.