(812) Thrombotic Microangiopathy Syndromes in Children: An Analysis of the Kids' Inpatient Database

Introduction: Thrombotic microangiopathy (TMA) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and end-organ involvement. This study aims to describe the epidemiology and outcomes associated with TMA in hospitalized children in the U.S.

Methods: We conducted a retrospective analysis of the Kids’ Inpatient Database (KID) for the years 2016 and 2019. The study included children aged 20 years or younger who had a discharge diagnosis of hemolytic uremic syndrome and/or TMA. We stratified TMA into 5 groups: Shiga-toxin E. coli (STEC), Transplant, Malignancy, Rheumatologic, and Other. We used ICD-10 CM and PRS codes, as well as CCSR, to identify relevant conditions and procedures. The chi-square test and binary logistic regression were used for inferential statistics. Descriptive data are presented as frequency or median with IQR, and categorical data as odds ratios with 95% CI.

Results: Out of 12,168,823 discharges, there were 3,152 TMA discharges (2.59 per 10,000). Females accounted for 55.4% and white children for 55.6% of the TMA discharges. The median age was 6 years (IQR 2-14). The median length of stay was 9 days (IQR 4-20). The mortality rate was 4.8%. By stratification, Other, STEC, Transplant, Malignancy, and Rheumatologic accounted for 57.2%, 19.3%, 14.4%, 4.2% and 3.6% of TMA discharges, respectively. Binary logistic regression analysis revealed that Malignancy (OR 5.31; 2.01-14.03) and Transplant (OR 15.87; 5.72-44.03) groups were associated with increased risk of mortality. Mechanical ventilation (OR 19.85; 11.96-32.96) and vasopressor infusion (OR 6.61; 3.01-14.52) use were associated with increased risk of mortality as well. Dialysis (HD or PD) or plasmapheresis use, as well as demographic characteristics (gender, age, race/ethnicity, patient location, median household income), were not associated with an increased risk of mortality.

Conclusions: TMA in hospitalized children in the U.S. is relatively rare with a low prevalence but has a mortality rate of 4.8%. Malignancy, Transplant, mechanical ventilation, and vasopressor support are associated with increased mortality. The need for dialysis is not associated with increased mortality.