Diagnostic value of pleural ultrasound to refine endotracheal tube placement in pediatric intensive care unit.

AIM: To assess the diagnostic performance of a simplified lung point-of-care ultrasound (POCUS) to confirm the correct positioning of an endotracheal tube (ETT) in a pediatric intensive care unit (PICU) used to chest radiography (CXR), and to compare the time to obtain the ETT position between POCUS and CXR. METHODS: We conducted a single-center prospective study in critically ill children requiring urgent endotracheal intubation. Esophageal tube malposition was first avoided using auscultation and end-tidal CO2. The ETT position was assessed with CXR and lung POCUS using the lung sliding sign on a pleural window. All of the investigators had to read guidelines and received 1-h training on the technical aspects of lung sliding. The primary objective was the accuracy of POCUS in confirming correct nonselective endotracheal intubation as compared with CXR. RESULTS: A total of 71 patients were included from December 2016 to November 2018. CXR identified proper nonselective ETT placement in 43 of 71 (61%) patients, while the rate for selective intubation was 39%. The sensitivity and specificity of POCUS as compared with CXR were 77% and 68%, respectively. Median time to POCUS was significantly shorter than CXR (2 min to perform POCUS, 10 min to obtain radiographs, p<10-4). CONCLUSION: Pleural ultrasound, although faster than CXR, appears to be inadequate for identifying selective ETT after urgent intubation in a PICU less accustomed to this kind of ultrasound. In this heterogeneous and fragile population, timely POCUS may remain useful at the bedside as compared with auscultation, aiming at guiding optimal ETT placement and reducing respiratory complications, provided by trained physicians.

Polyclonal expansion of TCR Vbeta 21.3+ CD4+ and CD8+ T cells is a hallmark of Multisystem Inflammatory Syndrome in Children.

Multiple Inflammatory Syndrome in Children (MIS-C) is a delayed and severe complication of SARS-CoV-2 infection that strikes previously healthy children. As MIS-C combines clinical features of Kawasaki disease and Toxic Shock Syndrome (TSS), we aimed to compare the immunological profile of pediatric patients with these different conditions. We analyzed blood cytokine expression, and the T cell repertoire and phenotype in 36 MIS-C cases, which were compared to 16 KD, 58 TSS, and 42 COVID-19 cases. We observed an increase of serum inflammatory cytokines (IL-6, IL-10, IL-18, TNF-α, IFNγ, CD25s, MCP1, IL-1RA) in MIS-C, TSS and KD, contrasting with low expression of HLA-DR in monocytes. We detected a specific expansion of activated T cells expressing the Vß21.3 T cell receptor ß chain variable region in both CD4 and CD8 subsets in 75% of MIS-C patients and not in any patient with TSS, KD, or acute COVID-19; this correlated with the cytokine storm detected. The T cell repertoire returned to baseline within weeks after MIS-C resolution. Vß21.3+ T cells from MIS-C patients expressed high levels of HLA-DR, CD38 and CX3CR1 but had weak responses to SARS-CoV-2 peptides in vitro. Consistently, the T cell expansion was not associated with specific classical HLA alleles. Thus, our data suggested that MIS-C is characterized by a polyclonal Vß21.3 T cell expansion not directed against SARS-CoV-2 antigenic peptides, which is not seen in KD, TSS and acute COVID-19.