Clinical Features and Risk Factors Associated with Mortality in Critically ill Children Requiring Continuous Renal Replacement Therapy

Background: The aims of this study were to describe the epidemiology and demographic characteristics of critically ill children requiring continuous renal replacement therapy (CRRT) at our pediatric intensive care unit (PICU) and to explore risk factors associated with mortality. Methods: A retrospective cohort of 121 critically ill children who received CRRT from May 2015 to May 2020 in the PICU of a tertiary healthcare institution was evalauted. The demographic information, admission diagnosis, indication for CRRT, clinical variables at the initiation of CRRT, time related variables and the laboratory results at initiation of CRRT were compared between survivors and non-survivors.Results: The most common diagnoses were renal disease (30.6%), hemato-oncological disease (12.4%), and sepsis (11.6%). The overall mortality was 29.8%. When compared according to diagnosis at admission, we found that patients with hemato-oncologic disease (73.3%) and those with pneumonia/respiratory failure (72.7%) had the highest mortality, while patients with renal disease had the lowest mortality (5.4%). The most common CRRT indications were: electrolyte or acid base imbalance (38.8%), acute kidney injury (29.8%) and fluid overload (14.9%). There was no relationship between mortality and indication for CRRT. The time interval between PICU admission and CRRT initiation was also unassociated with mortality (p=0.146). In patients diagnosed with sepsis, time until the initiation of CRRT was significantly shorter in survivors compared to non-survivors (p=0.004). Based on multivariate logistic regression, presence of comorbidity (odds ratio: 5.71; %95 CI: 1.16-27.97), being diagnosed with pneumonia/respiratory failure at admission (odds ratio: 16.16; %95 CI: 1.56-167.01), and high lactate level at the initiation of CRRT (odds ratio: 1.43; %95 CI: 1.17-1.79) were independently associated with mortality.Conclusions: In the context of the population studied mortality rate was lower than previously reported. In critically ill children requiring CRRT, mortality seems to be related to underlying disease, presence of comorbidity, and high lactate levels at CRRT initiation. We also found that early initiation of CRRT in sepsis can reduce mortality.