(797) Impact of IVIG Initiation on Morbidity in Multisystem Inflammatory Syndrome in Children

Introduction: Multisystem inflammatory syndrome in children (MIS-C) is an unprecedented hyper-inflammatory immune response syndrome associated with SARS-CoV-2. Gold standard of treatment for MIS-C includes both intravenous immunoglobulin and glucocorticoids. Our primary objective evaluated if time to treatment with IVIG impacted hospital length of stay (LOS). We hypothesize that earlier administration of IVIG correlates with a reduction in patient morbidity, specifically hospital LOS.

Methods: Retrospective chart review of MIS-C patients 0-21 years of age admitted to a single-center from 03/2020-02/2022 were included. Overall, 158 patients met initial inclusion criteria; 58 patients were excluded. Our primary objective analyzed the effect of time to IVIG initiation on hospital LOS. Secondary outcomes analyzed treatment timing on hospital mortality, vasoactive infusion score, oxygen therapy, and ICU LOS.

Results: The mean age of patients was 9.8+/-4.9 years, with 57 males and 43 females. Median hospital LOS was 6.0 [5.0,7.0] days, and ICU LOS 1.0 [0.0,3.0]. There was one mortality in our cohort. We found no statistically significant correlation between time to IVIG and hospital LOS(R=-0.01,P=0.9) nor between time to methylprednisolone and hospital LOS(R=-0.03,P=0.8). Average time post-admission to treatment with IVIG was 17.3+/-16.7hrs and 18.9+/-24.3hrs for methylprednisolone. Average hospital LOS was 6.3days and ICU LOS 2.1days. Also, 26(46.4%) had an abnormal chest X-ray. On echocardiogram, 37 had systolic dysfunction, 6 with diastolic dysfunction, 14 with coronary involvement, and average ejection fraction of 57.7+/-9.8. Additionally, 74 patients received antibiotics, 98 got aspirin, and 15 had anakinra.

Conclusions: Among children treated with IVIG and methylprednisolone for MIS-C, time to initiation of IVIG therapy did not affect hospital or ICU LOS. Likewise, neither hospital nor ICU length of stay were impacted by earlier treatment with methylprednisolone. In a sub-analysis, there was no positive correlation found between time to IVIG administration, hospital vasoactive infusion score, or oxygen requirement. These results suggest no benefit of early IVIG administration on patient morbidity, specifically hospital LOS. Future studies are recommended to assess similar impacts in critically ill children.