Severe SARS-CoV-2 Infection in a Pediatric Patient Requiring Extracorporeal Membrane Oxygenation

Successful extracorporeal membrane oxygenation therapy in a child with coronavirus 2019 disease-associated ARDS and chemotherapy for Ewing's sarcoma

Most children and adolescents with SARS-CoV-2 infection show no or mild symptoms, but those with medical histories can be susceptible to more severe forms of disease. There are few reported cases of extracorporeal membrane oxygenation (ECMO) in pediatric patients with coronavirus disease 2019 (COVID-19). We present a previously healthy 13-year-old male diagnosed with metastatic Ewing's sarcoma at the same time as catastrophic acute respiratory distress syndrome due to COVID-19, who was successfully supported by venovenous-ECMO while he received the corresponding chemotherapy protocol.ECMO can be used as salvage therapy in oncology pediatric patients with respiratory failure secondary to COVID-19. In addition, successful chemotherapy can be administered while patients are supported on ECMO.

Efficacy of extracorporeal membrane oxygenation in pediatric COVID-19 and MIS-C cases: A single-center experience

Background

This study aimed to evaluate the need and the indication of extracorporeal membrane oxygenation (ECMO) in patients diagnosed with coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) followed up in the pediatric intensive care unit by the demographic, clinical, and laboratory data and treatment response.

Methods

A total of 79 patients (43 males, 36 females; median age: 138 months; range, 6 to 210 months) with COVID-19 and MIS-C followed up between September 2020 - September 2021 were included in this retrospective study. Demographic and clinical data were retrospectively collected from patient files, and clinical data, laboratory findings, chest X-rays, and echocardiography results of six patients (1 male and 5 female, median age: 159 months, range, 13 to 210 months) who needed ECMO due to poor response to medical treatment were recorded before and after the ECMO therapy.

Results

Extracorporeal membrane oxygenation therapy was performed on one patient with a positive COVID-19 polymerase chain reaction test and five patients with MIS-C in our unit. Five patients were supported with venoarterial (v-a) ECMO, and one patient was supported with venovenous ECMO. Median hospitalization time was 29 (range, 24 to 50) days, median Pediatric Risk of Mortality score was 19.5 (range, 11 to 36), and median length of mechanical ventilation was 23.5 (range, 10 to 45) days. The median vasoactive inotropic score was 55.5 (range, 18 to 110) before ECMO, while the median vasoactive inotropic score was 11 (range, 0 to 34) after ECMO. Four patients were successfully weaned off ECMO, and one of these patients was lost due to brain death 15 days after the weaning. One patient infected with the delta variant of COVID-19, which remained positive during the clinical course, and one patient diagnosed with MIS-C was lost despite the v-a ECMO support. Three of the patients were discharged. Thrombosis developed in the superficial femoral artery of one patient on the cannulated side during v-a ECMO. No death due to complications of ECMO was recorded.

Conclusion

In our study, although the majority of our patients followed up with the diagnosis of COVID-19 and MIS-C showed a mild or moderate clinical course, it was observed that a severe clinical course could develop in a small number of patients and that ECMO treatment may be needed in these patients. In agreement with the ECMO studies with different indications in the literature, we conclude that ECMO therapy may markedly contribute to the prognosis in COVID-19 and MIS-C patients when the initiation and termination timing of therapy is correct.

Model-Informed Repurposing of Medicines for SARS-CoV-2: Extrapolation of Antiviral Activity and Dose Rationale for Paediatric Patients

Repurposing of remdesivir and other drugs with potential antiviral activity has been the basis of numerous clinical trials aimed at SARS-CoV-2 infection in adults. However, expeditiously designed trials without careful consideration of dose rationale have often resulted in treatment failure and toxicity in the target patient population, which includes not only adults but also children. Here we show how paediatric regimens can be identified using pharmacokinetic-pharmacodynamic (PKPD) principles to establish the target exposure and evaluate the implications of dose selection for early and late intervention. Using in vitro data describing the antiviral activity and published pharmacokinetic data for the agents of interest, we apply a model-based approach to assess the exposure range required for adequate viral clearance and eradication. Pharmacokinetic parameter estimates were subsequently used with clinical trial simulations to characterise the probability target attainment (PTA) associated with enhanced antiviral activity in the lungs. Our analysis shows that neither remdesivir, nor anti-malarial drugs can achieve the desirable target exposure range based on a mg/kg dosing regimen, due to a limited safety margin and high concentrations needed to ensure the required PTA. To date, there has been limited focus on suitable interventions for children affected by COVID-19. Most clinical trials have defined doses selection criteria empirically, without thorough evaluation of the PTA. The current results illustrate how model-based approaches can be used for the integration of clinical and nonclinical data, providing a robust framework for assessing the probability of pharmacological success and consequently the dose rationale for antiviral drugs for the treatment of SARS-CoV-2 infection in children.