Cross-reactive immunity against the SARS-CoV-2 Omicron variant is low in pediatric patients with prior COVID-19 or MIS-C.

Neutralization capacity of antibodies against Omicron after a prior SARS-CoV-2 infection in children and adolescents is not well studied. Therefore, we evaluated virus-neutralizing capacity against SARS-CoV-2 Alpha, Beta, Gamma, Delta and Omicron variants by age-stratified analyses (<5, 5-11, 12-21 years) in 177 pediatric patients hospitalized with severe acute COVID-19, acute MIS-C, and in convalescent samples of outpatients with mild COVID-19 during 2020 and early 2021. Across all patients, less than 10% show neutralizing antibody titers against Omicron. Children <5 years of age hospitalized with severe acute COVID-19 have lower neutralizing antibodies to SARS-CoV-2 variants compared with patients >5 years of age. As expected, convalescent pediatric COVID-19 and MIS-C cohorts demonstrate higher neutralization titers than hospitalized acute COVID-19 patients. Overall, children and adolescents show some loss of cross-neutralization against all variants, with the most pronounced loss against Omicron. In contrast to SARS-CoV-2 infection, children vaccinated twice demonstrated higher titers against Alpha, Beta, Gamma, Delta and Omicron. These findings can influence transmission, re-infection and the clinical disease outcome from emerging SARS-CoV-2 variants and supports the need for vaccination in children.

The Use and Duration of Preintubation Respiratory Support Is Associated With Increased Mortality in Immunocompromised Children With Acute Respiratory Failure.

OBJECTIVES: To determine the association between preintubation respiratory support and outcomes in patients with acute respiratory failure and to determine the impact of immunocompromised (IC) diagnoses on outcomes after adjustment for illness severity. DESIGN: Retrospective multicenter cohort study. SETTING: Eighty-two centers in the Virtual Pediatric Systems database. PATIENTS: Children 1 month to 17 years old intubated in the PICU who received invasive mechanical ventilation (IMV) for greater than or equal to 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: High-flow nasal cannula (HFNC) or noninvasive positive-pressure ventilation (NIPPV) or both were used prior to intubation in 1,825 (34%) of 5,348 PICU intubations across 82 centers. When stratified by IC status, 50% of patients had no IC diagnosis, whereas 41% were IC without prior hematopoietic cell transplant (HCT) and 9% had prior HCT. Compared with patients intubated without prior support, preintubation exposure to HFNC (adjusted odds ratio [aOR], 1.33; 95% CI, 1.10-1.62) or NIPPV (aOR, 1.44; 95% CI, 1.20-1.74) was associated with increased odds of PICU mortality. Within subgroups of IC status, preintubation respiratory support was associated with increased odds of PICU mortality in IC patients (HFNC: aOR, 1.50; 95% CI, 1.11-2.03; NIPPV: aOR, 1.76; 95% CI, 1.31-2.35) and HCT patients (HFNC: aOR, 1.75; 95% CI, 1.07-2.86; NIPPV: aOR, 1.85; 95% CI, 1.12-3.02) compared with IC/HCT patients intubated without prior respiratory support. Preintubation exposure to HFNC/NIPPV was not associated with mortality in patients without an IC diagnosis. Duration of HFNC/NIPPV greater than 6 hours was associated with increased mortality in IC HCT patients (HFNC: aOR, 2.41; 95% CI, 1.05-5.55; NIPPV: aOR, 2.53; 95% CI, 1.04-6.15) and patients compared HCT patients with less than 6-hour HFNC/NIPPV exposure. After adjustment for patient and center characteristics, both preintubation HFNC/NIPPV use (median, 15%; range, 0-63%) and PICU mortality varied by center. CONCLUSIONS: In IC pediatric patients, preintubation exposure to HFNC and/or NIPPV is associated with increased odds of PICU mortality, independent of illness severity. Longer duration of exposure to HFNC/NIPPV prior to IMV is associated with increased mortality in HCT patients.

Prognostic relevance and inter-observer reliability of chest-imaging in pediatric ARDS: a pediatric acute respiratory distress incidence and epidemiology (PARDIE) study.

PURPOSE: Definitions of acute respiratory distress syndrome (ARDS) include radiographic criteria, but there are concerns about reliability and prognostic relevance. This study aimed to evaluate the independent relationship between chest imaging and mortality and examine the inter-rater variability of interpretations of chest radiographs (CXR) in pediatric ARDS (PARDS). METHODS: Prospective, international observational study in children meeting Pediatric Acute Lung Injury Consensus Conference (PALICC) criteria for PARDS, which requires new infiltrate(s) consistent with pulmonary parenchymal disease, without mandating bilateral infiltrates. Mortality analysis focused on the entire cohort, whereas inter-observer variability used a subset of patients with blinded, simultaneous interpretation of CXRs by intensivists and radiologists. RESULTS: Bilateral infiltrates and four quadrants of alveolar consolidation were associated with mortality on a univariable basis, using CXRs from 708 patients with PARDS. For patients on either invasive (IMV) or non-invasive ventilation (NIV) with PaO2/FiO2 (PF) ratios (or SpO2/FiO2 (SF) ratio equivalent) > 100, neither bilateral infiltrates (OR 1.3 (95% CI 0.68, 2.5), p = 0.43), nor 4 quadrants of alveolar consolidation (OR 1.6 (0.85, 3), p = 0.14) were associated with mortality. For patients with PF ≤ 100, bilateral infiltrates (OR 3.6 (1.4, 9.4), p = 0.01) and four quadrants of consolidation (OR 2.0 (1.14, 3.5), p = 0.02) were associated with higher mortality. A subset of 702 CXRs from 233 patients had simultaneous interpretations. Interobserver agreement for bilateral infiltrates and quadrants was "slight" (kappa 0.31 and 0.33). Subgroup analysis showed agreement did not differ when stratified by PARDS severity but was slightly higher for children with chronic respiratory support (kappa 0.62), NIV at PARDS diagnosis (kappa 0.53), age > 10 years (kappa 0.43) and fluid balance > 40 ml/kg (kappa 0.48). CONCLUSION: Bilateral infiltrates and quadrants of alveolar consolidation are associated with mortality only for those with PF ratio ≤ 100, although there is high- inter-rater variability in these chest-x ray parameters.

Multiple Organ Dysfunction in Children Mechanically Ventilated for Acute Respiratory Failure.

OBJECTIVES: The impact of extrapulmonary organ dysfunction, independent from sepsis and lung injury severity, on outcomes in pediatric acute respiratory failure is unclear. We sought to determine the frequency, timing, and risk factors for extrapulmonary organ dysfunction and the independent association of multiple organ dysfunction syndrome with outcomes in pediatric acute respiratory failure. DESIGN: Secondary observational analysis of the Randomized Evaluation of Sedation Titration for Respiratory Failure cluster-randomized prospective clinical trial conducted between 2009 and 2013. SETTING: Thirty-one academic PICUs in the United States. PATIENTS: Two thousand four hundred forty-nine children mechanically ventilated for acute respiratory failure enrolled in Randomized Evaluation of Sedation Titration for Respiratory Failure. MEASUREMENTS AND MAIN RESULTS: Organ dysfunction was defined using criteria published for pediatric sepsis. Multiple organ dysfunction syndrome was defined as respiratory dysfunction one or more extrapulmonary organ dysfunctions. We used multivariable logistic regression to identify risk factors for multiple organ dysfunction syndrome, and logistic or proportional hazards regression to compare clinical outcomes. All analyses accounted for PICU as a cluster variable. Overall, 73% exhibited extrapulmonary organ dysfunction, including 1,547 (63%) with concurrent multiple organ dysfunction syndrome defined by onset on day 0/1 and 244 (10%) with new multiple organ dysfunction syndrome with onset on day 2 or later. Most patients (93%) with indirect lung injury from sepsis presented with concurrent multiple organ dysfunction syndrome, whereas patients with direct lung injury had both concurrent (56%) and new (12%) multiple organ dysfunction syndrome. Risk factors for concurrent multiple organ dysfunction syndrome included older age, illness severity, sepsis, cancer, and moderate/severe lung injury. Risk factors for new multiple organ dysfunction syndrome were moderate/severe lung injury and neuromuscular blockade. Both concurrent and new multiple organ dysfunction syndrome were associated with 90-day in-hospital mortality (concurrent: adjusted odds ratio, 6.54; 95% CI, 3.00-14.25 and new: adjusted odds ratio, 3.21; 95% CI, 1.48-6.93) after adjusting for sepsis, moderate/severe lung injury, and other baseline characteristics. CONCLUSIONS: Extrapulmonary organ dysfunction was common, generally occurred concurrent with respiratory dysfunction (especially in sepsis), and was a major risk factor for mortality in pediatric acute respiratory failure.

A Simple and Robust Bedside Model for Mortality Risk in Pediatric Patients With Acute Respiratory Distress Syndrome.

OBJECTIVES: Despite declining mortality, acute respiratory distress syndrome is still involved in up to one third of pediatric intensive care deaths. The recently convened Pediatric Acute Lung Injury Consensus Conference has outlined research priorities for the field, which include the need for accurate bedside risk stratification of patients. We aimed to develop a simple yet robust model of mortality risk among pediatric patients with acute respiratory distress syndrome to facilitate the targeted application of high-risk investigational therapies and stratification for enrollment in clinical trials. DESIGN: Prospective, multicenter cohort. SETTING: Five academic PICUs. PATIENTS: Three hundred eight children greater than 1 month and less than or equal to 18 years old, admitted to the ICU, with bilateral infiltrates on chest radiograph and PaO2/FIO2 ratio less than 300 in the clinical absence of left atrial hypertension. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Twenty clinical variables were recorded in the following six categories: demographics, medical history, oxygenation, ventilation, radiographic imaging, and multiple organ dysfunction. Data were measured 0-24 and 48-72 hours after acute respiratory distress syndrome onset (day 1 and 3) and examined for associations with hospital mortality. Among 308 enrolled patients, mortality was 17%. Children with a history of cancer and/or hematopoietic stem cell transplant had higher mortality (47% vs 11%; p < 0.001). Oxygenation index, the PaO2/FIO2 ratio, extrapulmonary organ dysfunction, Pediatric Risk of Mortality-3, and positive cumulative fluid balance were each associated with mortality. Using two statistical approaches, we found that a parsimonious model of mortality risk using only oxygenation index and cancer/hematopoietic stem cell transplant history performed as well as other more complex models that required additional variables. CONCLUSIONS: In the PICU, oxygenation index and cancer/hematopoietic stem cell transplant history can be used on acute respiratory distress syndrome day 1 or day 3 to predict hospital mortality without the need for more complex models. These findings may simplify risk assessment for clinical trials, counseling families, and high-risk interventions such as extracorporeal life support.

Elevated soluble thrombomodulin is associated with organ failure and mortality in children with acute respiratory distress syndrome (ARDS): a prospective observational cohort study.

INTRODUCTION: The significance of endothelial injury in children with the acute respiratory distress syndrome (ARDS) has not been well studied. Plasma levels of soluble thrombomodulin (sTM), an endothelial surface protein involved in coagulation, have been associated with endothelial injury. We hypothesized that elevated plasma sTM would correlate with mortality and organ failure in children with ARDS. METHODS: We conducted a multicenter prospective observational study of pediatric patients with ARDS between 2008 and 2014. sTM was measured in plasma collected less than 24 hours from ARDS diagnosis. Outcomes were intensive care unit mortality and organ dysfunction by pediatric logistic organ dysfunction scores. Logistic regression was used to adjust for clinically relevant covariates. RESULTS: Plasma sTM was higher in patients with indirect lung injury compared to direct lung injury (100 ng/mL vs. 86 ng/mL, p = 0.02). Increased sTM levels were correlated with more organ dysfunction in the entire study population (Spearman's rho = 0.37, p < 0.01). Overall mortality was 16%. sTM levels were associated with increased mortality in patients with indirect lung injury (OR 2.7 per log(sTM), p = 0.02). These relationships were independent of age, oxygenation defect, or presence of acute kidney injury. CONCLUSION: Elevated plasma sTM levels are associated with organ dysfunction in children with ARDS and with higher mortality in children with indirect lung injury. These findings highlight the importance of endothelial injury in children with ARDS and may guide the development of future therapies targeted toward endothelial stabilization, repair, or functional replacement in this population.

Biomarkers and genetics of brain injury risk in diabetic ketoacidosis: A pilot study.

Diabetic ketoacidosis (DKA) is the primary cause of death for children with diabetes, especially when complicated by cerebral edema. Central nervous system (CNS) involvement is common, however the mechanism of, and predictors of CNS dysfunction/injury are largely unknown. In this observational pilot study, blood was collected from pediatric DKA patients at three time points (consent, 12 hr and 24 hr after beginning treatment), to test genetic markers, ribonucleic acid expression and plasma biomarkers reflecting inflammation (tumor necrosis factor-alpha [TNF-α], interleukin-6 [IL-6]) and cerebral dysfunction and/or possible injury (S100ß, glial fibrillary acidic protein [GFAP]). Thirty patients were enrolled in the study. The average age was 11.3 yr, 73% were new onset diabetes and 53% were female. Forty percent exhibited abnormal mentation (Glasgow Coma Scale <15), consistent with CNS dysfunction. IL-6 and TNF-α were elevated in plasma, suggesting systemic inflammation. GFAP was measurable in 45% of patients and correlated positively with GCS. Only two patients had detectable levels of S100ß. In conclusion, children with DKA often present with evidence of acute neurologic dysfunction or injury. We have demonstrated the feasibility of exploring genetic and biochemical markers of potential importance in the pathophysiology of CNS dysfunction and/or possible injury in DKA. We have identified IL-6, TNF-α and GFAP as potentially important markers for further exploration. A larger, follow-up study will help to better understand the extent and type of CNS injury in DKA as well as the mechanism underlying this dysfunction/injury.

Red blood cell transfusion in pediatric patients with severe chronic anemia: how slow is necessary?

Historic practice recommends slow transfusion for children with chronic anemia and hemoglobin less than 5.0 g/dl due to the theoretical risk of transfusion-associated circulatory overload (TACO). In our pediatric intensive care unit (PICU), we have been utilizing a more liberal transfusion practice in patients without underlying cardiopulmonary disease, and a faster transfusion rate appears safe in this population. Rate of transfusion must be based on multiple factors including convenience, timeliness of procedures and transport to an appropriate care facility, risk of alloimmunization and wastage of blood, stress for the family, and need for PICU monitoring.

Using acupuncture for acute pain in hospitalized children.

OBJECTIVE: Clinical study to determine the acceptability and feasibility of acupuncture for acute postoperative pain control in hospitalized children. DESIGN: Nonrandomized clinical trial. SETTING: A single, tertiary referral pediatric intensive care unit. PATIENTS: A total of 20 patients aged 7 months to 18 years. Eleven of the patients had posterior spinal fusion surgery and the remaining nine patients had other surgical diagnoses. INTERVENTIONS: Two 10- to 15-minute sessions of acupuncture 24-48 hours apart. OUTCOME MEASURES AND RESULTS: The treatment was highly accepted (27 patients were approached and 4 patients refused; of the 23 patients enrolled, 20 patients completed the study). Acupuncture was well tolerated by patients without adverse events related to treatment. In follow-up interviews, 70% of both parents and patients believed acupuncture helped the child's pain. Eighty-five percent of the parents said they would pay out of pocket for acupuncture if not covered by insurance. The pain scores, vital signs, and narcotic usage were recorded before and several times after acupuncture. In posterior spinal fusion patients, the mean pain scores (0-10) immediately before and 4 and 24 hours after acupuncture were: 3.7, 1.7, and 3.1, respectively, after the first acupuncture session and 3.7, 2.2, and 3.1, respectively, after the second session. In the other surgical cohort, the mean pain scores immediately before and 4 and 24 hours after the first session of acupuncture were 2.5, 0.3, and 1.6, respectively. CONCLUSIONS: Our results support that acupuncture is highly accepted and feasible in critically ill, postoperative pediatric patients with acute pain. Our findings suggest that acupuncture may be a potentially useful adjunctive tool for acute pediatric postoperative pain management. A randomized, controlled clinical trial is warranted to confirm these findings.

Zinc homeostasis in pediatric critical illness.

OBJECTIVE: We explored the hypothesis that marked decline in plasma zinc concentrations among critically ill children is related to shifts in metallothionein expression and inflammation. DESIGN: Prospective pilot study. SETTING: Intensive care unit of tertiary care children's hospital. PATIENTS: All children (<18 yrs) with unadjusted Pediatric Risk of Mortality III score >5 or at least one organ failure admitted to the pediatric intensive care unit from March through August 2006 were eligible for enrollment. INTERVENTIONS: After consent, blood samples were collected on days 1 and 3 of illness and analyzed for serum chemistries, plasma zinc and copper levels, metallothionein isoform expression, and cytokine levels. MEASUREMENTS AND MAIN RESULTS: Twenty patients were enrolled, with median age of 2.9 yrs (interquartile range, 0.7-10.1). Male to female ratio was 1.2:1. All patients had low zinc levels (mean, 0.43; range, 0.26-0.66 mug/dL) on day 1 of pediatric intensive care unit admission, and remained low (mean, 0.51; range, 0.26-0.81 mug/dL) on day 3, even when corrected for hypoalbuminemia. In comparison, serum copper levels were normal. On day 1, there was a positive correlation between zinc levels and expression of MT-1A (p < 0.01), MT-1G (p = 0.02), and MT-1H (p = 0.03). Plasma zinc levels correlated inversely with C-reactive protein levels (r = -.75, p = 0.01) and interleukin-6 levels (r = -.53, p = 0.04) on day 3. On day 3, patients with two or more organ failures had significantly lower plasma zinc concentrations compared with patients with