Incidence of acute kidney injury in hospitalized children

Objective To investigate the prevalence, missed diagnosis rate and causes of acute kidney injury (AKI) in hospitalized children, and its impact on hospitalization cost, length of stay and outcome. Methods The data of children admitted in Children's Hospital Affiliated to Capital Institute of Pediatrics from December 1st to 31st 2014 were collected, and those whose serum creatinine (Scr) were measured at least two times were selected. Patients were diagnosed as AKI according to the diagnostic criteria of 2012 Kidney Disease: Improving Global Outcomes, then divided into AKI group and non-AKI group, the former of which was further divided into AKI1 group (Scr peak value in normal range) and AKI2 group (Scr peak value above normal range). The causes and impact of AKI on hospitalization cost, length of stay and outcome in different groups were compared and analyzed. Results (1) Among 921 patients with at least two Scr results, 170 patients met with the diagnostic criteria of AKI, including 100 males and 70 females. There were 112(65.9%) in AKI stage 1, 43(25.3%) in stage 2, and 15(8.8%) in stage 3. The overall prevalence of AKI was 18.5%. With only 7 cases getting diagnosed, the diagnostic rate was 4.1%, while 95.9% of patients missed diagnosis. (2) Among AKI patients, 67 cases had pre-renal causes, 103 cases had intra-renal causes and mixed factors. 100(58.8%) cases got complete recovery, 34(20.0%) cases recovered partially and 36(21.2%) cases did not improve, including 4 cases of death. (3) The prevalence of AKI among those below 1-year old was higher than children elder than 1-year (23.0% vs 15.5%, P=0.004). The prevalence of AKI in surgical ward was higher than medical ward (30.7% vs 15.8%, P 0.05). The hospitalization time in AKI2 group was shorter than that in AKI1 group (P=0.038). Conclusions Among hospitalized children the missed diagnosis rate of AKI is high. Pre-renal factor is the main cause of AKI. Children younger than 1-year old are more susceptible to AKI. AKI children have lower age and higher hospitalization time, hospitalization costs and mortality than non-AKI children. The effect of Scr fluctuation within normal levels needs to be further studied. Key words: Child, hospitalized; Diagnosis; Acute kidney injury