[Paraneoplastic pemphigus with underlying Castleman's disease in a 16-year-old girl]. / Morbus Castleman-assoziierter paraneoplastischer Pemphigus bei einer 16-jährigen Patientin.

Paraneoplastic pemphigus is a rare, life-threatening autoimmune disease that is clinically characterized by mostly extensive and refractory mucosal erosions and polymorphous skin lesions. We report here on a 16-year-old girl with isolated oral erosions, in whom mucosal pemphigoid was initially suspected and after treatment with prednisolone and dapsone marked improvement was achieved. However, a few months later the patient developed massive respiratory insufficiency as a result of bronchiolitis obliterans, so that a lung transplant was planned. As part of the preparatory diagnostic workup, unicentric, abdominally localized Castleman's disease was diagnosed, which ultimately led to the diagnosis of paraneoplastic pemphigus as evidenced by envoplakin autoantibodies. Tumor resection and subsequent lung transplantation achieved good results with sustained mucocutaneous remission.

A placebo-controlled, crossover trial to investigate the efficacy of tiotropium bromide or placebo added to usual care in stable symptomatic post-hematopoietic stem cell transplantation (HSCT) bronchiolitis obliterans syndrome (BOS).

BACKGROUND: Despite the fundamental progress in hematopoietic stem cell transplant, this treatment is also associated with complications. Graft-versus-host disease is a possible complication of HSCT. Bronchiolitis obliterans syndrome (BOS) is the pulmonary form of this syndrome. Due to the high morbidity and mortality rate of BOS, various studies have been conducted in the field of drug therapy for this syndrome, although no standard treatment has yet been proposed. According to the hypotheses about the similarities between BOS and chronic obstructive pulmonary disease, the idea of using tiotropium bromide as a bronchodilator has been proposed. METHOD/DESIGN: A randomized, double-blind, placebo-controlled, and crossover clinical trial is being conducted to evaluate the efficacy of tiotropium in patients with BOS. A total of 20 patients with BOS were randomly assigned (1:1) to receive a once-daily inhaled capsule of either tiotropium bromide (KP-Tiova Rotacaps 18 mcg, Cipla, India) or placebo for 1 month. Patients will receive tiotropium bromide or placebo Revolizer added to usual standard care. Measurements will include spirometry and a 6-min walking test. ETHICS/DISSEMINATION: This study was approved by the Research Ethics Committees of Imam Khomeini Hospital Complex, Tehran University of Medical Science. Recruitment started in September 2022, with 20 patients randomized. The treatment follow-up of participants with tiotropium is currently ongoing and is due to finish in April 2024. The authors will disseminate the findings in peer-reviewed publications, conferences, and seminar presentations. TRIAL REGISTRATION: Iranian Registry of Clinical Trial (IRCT) IRCT20200415047080N3. Registered on 2022-07-12, 1401/04/21.

Longitudinal changes in lung function following post-9/11 military deployment in symptomatic veterans.

RATIONALE: Exposure to burn pit smoke, desert and combat dust, and diesel exhaust during military deployment to Southwest Asia and Afghanistan (SWA) can cause deployment-related respiratory diseases (DRRDs) and may confer risk for worsening lung function after return. METHODS: Study subjects were SWA-deployed veterans who underwent occupational lung disease evaluation (n=219). We assessed differences in lung function by deployment exposures and DRRD diagnoses. We used linear mixed models to assess changes in lung function over time. RESULTS: Most symptomatic veterans reported high intensity deployment exposure to diesel exhaust and burn pit particulates but had normal post-deployment spirometry. The most common DRRDs were deployment-related distal lung disease involving small airways (DDLD, 41%), deployment-related asthma (DRA, 13%), or both DRA/DDLD (24%). Those with both DDLD/DRA had the lowest estimated mean spirometry measurements five years following first deployment. Among those with DDLD alone, spirometry measurements declined annually, adjusting for age, sex, height, weight, family history of lung disease, and smoking. In this group, the forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) ratio declined 0.2% per year. Those with more intense inhalational exposure had more abnormal lung function. We found significantly lower estimated FVC and total lung capacity five years following deployment among active duty participants (n=173) compared to those in the reserves (n=26). CONCLUSIONS: More intense inhalational exposures were linked with lower post-deployment lung function. Those with distal lung disease (DDLD) experienced significant longitudinal decline in FEV1/FVC ratio, but other DRRD diagnosis groups did not.

Infant Bronchiolitis Endotypes and the Risk of Developing Childhood Asthma: Lessons From Cohort Studies.

Severe bronchiolitis (i.e., bronchiolitis requiring hospitalization) during infancy is a heterogeneous condition associated with a high risk of developing childhood asthma. Yet, the exact mechanisms underlying the bronchiolitis-asthma link remain uncertain. Birth cohort studies have reported this association at the population level, including only small groups of patients with a history of bronchiolitis, and have attempted to identify the underlying biological mechanisms. Although this evidence has provided valuable insights, there are still unanswered questions regarding severe bronchiolitis-asthma pathogenesis. Recently, a few bronchiolitis cohort studies have attempted to answer these questions by applying unbiased analytical approaches to biological data. These cohort studies have identified novel bronchiolitis subtypes (i.e., endotypes) at high risk for asthma development, representing essential and enlightening evidence. For example, one distinct severe respiratory syncytial virus (RSV) bronchiolitis endotype is characterized by the presence of Moraxella catarrhalis and Streptococcus pneumoniae, higher levels of type I/II IFN expression, and changes in carbohydrate metabolism in nasal airway samples, and is associated with a high risk for childhood asthma development. Although these findings hold significance for the design of future studies that focus on childhood asthma prevention, they require validation. However, this scoping review puts the above findings into clinical context and emphasizes the significance of future research in this area aiming to offer new bronchiolitis treatments and contribute to asthma prevention.

Association of Fluid Overload with Escalation of Respiratory Support and Endotracheal Intubation in Acute Bronchiolitis Patients.

Fluid overload has been associated with increased oxygen requirement, prolonged duration of mechanical ventilation, and longer length of hospital stay in children hospitalized with pulmonary diseases. Critically ill infants with bronchiolitis admitted to the pediatric intensive care unit (PICU) also tend to develop fluid overload and there is limited information of its role on noninvasive respiratory support. Thus, our primary objective was to study the association of fluid overload in patients with bronchiolitis admitted to the PICU with respiratory support escalation (RSE) and need for endotracheal intubation (ETI). Infants ≤24 months of age with bronchiolitis and admitted to the PICU between 9/2009 and 6/2015 were retrospectively studied. Demographic variables, clinical characteristics including type of respiratory support and need for ETI were evaluated. Fluid overload as assessed by net fluid intake and output (net fluid balance), cumulative fluid balance (CFB) (mL/kg), and percentage fluid overload (FO%), was compared between patients requiring and not requiring RSE and among patients requiring ETI and not requiring ETI at 0 (PICU admission), 12, 24, 36, 48, 72, 96, and 120 hours. One-hundred sixty four of 283 patients with bronchiolitis admitted to the PICU qualified for our study. Thirty-four of 164 (21%) patients required escalation of respiratory support within 5 days of PICU admission and of these 34 patients, 11 patients required ETI. Univariate analysis by Kruskal-Wallis test of fluid overload as assessed by net fluid balance, CFB, and FO% between 34 patients requiring and 130 patients not requiring RSE and among 11 patients requiring ETI and 153 patients not requiring ETI, at 0, 12, 24, 36, 48, 72, 96 and 120 hours did not reveal any significant difference ( p >0.05) at any time interval. Multivariable logistic regression analysis revealed higher PRISM score (odds ratio [OR]: 4.95, 95% confidence interval [95% CI]: 1.79-13.66; p = 0.002), longer hours on high flow nasal cannula (OR: 4.86, 95% CI: 1.68-14.03; p = 0.003) and longer hours on noninvasive ventilation (OR: 11.16, 95% CI: 3.36-36.98; p < 0.001) were associated with RSE. Fluid overload as assessed by net fluid balance, CFB, and FO% was not associated with RSE or need for ETI in critically ill bronchiolitis patients admitted to the PICU. Further prospective studies involving larger number of patients with bronchiolitis are needed to corroborate our findings.

Total face mask with neurally adjusted ventilatory assist as a rescue therapy in infants with severe bronchiolitis.

Severe bronchiolitis patients are often supported with non-invasive ventilation (NIV). In case of NIV failure, we recently started to use non-invasive neurally adjusted ventilatory assist ventilation (NIV-NAVA) with a total face mask interface (TFM) and report now our experience with this modality of respiratory support. Retrospective study was made from October 2022 to May 2023 at the Geneva University Hospital Paediatric Intensive Care Unit. Inclusion criteria were children, aged from 0 to 6 months, with severe bronchiolitis with initial NIV failure and switch to NIV-NAVA-TFM. From 49 children with respiratory syncytial virus (RSV)-induced bronchiolitis requiring any form of respiratory support, 10 (median age 61 days (IQR 44-73) failing CPAP or NIV underwent rescue treatment with NIV-NAVA using a TFM. Patients were switched to TFM-NIV-NAVA 8 h (IQR 3-22) after admission for 24.5 h (IQR 13-60). After initiation of TFM-NIV-NAVA, oxygenation improved significantly as early as 1 h after initiation, whereas transcutaneous CO2 values remained stable. None of the patients needed to be intubated and there was no episode of TFM discontinuation due to interface discomfort or other unwanted side effects. Sedation was used in all patients with high proportion of intravenous dexmedetomidine. Median ventilatory assistance duration was 2.5 days (IQR 2-4) and median PICU stay was 4.5 (IQR 3-6).   Conclusion: In infants with severe RSV-induced bronchiolitis, respiratory support with TFM-NIV-NAVA seems to be feasible as a rescue therapy and might be considered in selected patients. What is Known: • Bronchiolitic patients with NIV support failure may require invasive mechanical ventilation. • Interface related complications, especially facial sores, can be a cause of NIV failure. What is New: • Total face mask with non-invasive neurally adjusted ventilatory assist (TFM-NIV-NAVA) seems feasible as a rescue therapy in deteriorating patients with CPAP or NIV failure. • TFM-NIV-NAVA can improve oxygenation rapidly in patients with aggravating hypoxemia and seems to be well tolerated.

Infant Bronchiolitis Endotypes and the Risk of Developing Childhood Asthma: Lessons From Cohort Studies

Severe bronchiolitis (i.e., bronchiolitis requiring hospitalization) during infancy is a heterogeneous condition associated with a high risk of developing childhood asthma. Yet, the exact mechanisms underlying the bronchiolitis-asthma link remain uncertain. Birth cohort studies have reported this association at the population level, including only small groups of patients with a history of bronchiolitis, and have attempted to identify the underlying biological mechanisms. Although this evidence has provided valuable insights, there are still unanswered questions regarding severe bronchiolitis-asthma pathogenesis. Recently, a few bronchiolitis cohort studies have attempted to answer these questions by applying unbiased analytical approaches to biological data. These cohort studies have identified novel bronchiolitis subtypes (i.e., endotypes) at high risk for asthma development, representing essential and enlightening evidence. For example, one distinct severe respiratory syncytial virus (RSV) bronchiolitis endotype is characterized by the presence of Moraxella catarrhalis and Streptococcus pneumoniae, higher levels of type I/II IFN expression, and changes in carbohydrate metabolism in nasal airway samples, and is associated with a high risk for childhood asthma development. Although these findings hold significance for the design of future studies that focus on childhood asthma prevention, they require validation. However, this scoping review puts the above findings into clinical context and emphasizes the significance of future research in this area aiming to offer new bronchiolitis treatments and contribute to asthma prevention. (AU)

Respiratory Syncytial Virus Infection and Apnea Risk As Criteria for Hospitalization in Full Term Healthy Infants.

Introduction Apnea is recognized as a serious and potentially life-threatening complication associated with Respiratory Syncope Virus (RSV). The literature reports a wide range of apnea rates for infants with comorbid factors. Prematurity and young chronological age have been historically associated with the risk of apnea in hospitalized infants. Few studies have specifically examined the risk of apnea in healthy infants presenting to the emergency department. Methods This is a retrospective review of infants diagnosed with RSV using a PCR assay. Patients were divided into "mild" and "severe" cohorts based on symptoms at presentation. This study occurred in the NYU Langone Long Island (NYULI) pediatric emergency department (ED), a midsize academic hospital in the Northeast United States. The study included infants <6 months of age, born full term without comorbid conditions such as chronic lung or cardiac conditions, seen in NYULI ED over three consecutive RSV seasons (2017-2020). The primary outcome was the risk of apneic events. Secondary outcomes included hospital admission, ICU admission, length of stay, and supplemental oxygen support. Results The risk of apnea was <2%, regardless of disease severity. There were no significant differences in demographics between mild and severe disease. Cohorts differed significantly in the number of hospitalizations (41 milds vs. 132 severe), ICU admissions (2 milds vs. 27 severe), need for oxygen support (17 milds vs. 92 severe), hospital readmissions (2 milds vs. 42 severe), and length of stay (2 days milds vs. 3 days severe). Conclusions Apnea does not pose a significant risk for healthy full-term infants with RSV disease of any severity. The decision to admit this population to the hospital should be based on clinical presentation and not solely on the perceived risk of apnea.

Respiratory syncytial virus-associated hospitalizations among children: an Italian retrospective observational study.

BACKGROUND: Respiratory syncytial virus (RSV), a single-stranded RNA virus, is a leading cause of hospitalization in infants, especially ≤ 2 months of life. In the light new immunization strategies adoption, we described epidemiological and clinical characteristics of RSV-associated hospitalizations in pediatric and neonatal intensive care units of the Policlinico Foggia Hospital, Apulia Region, Italy. METHODS: Hospitalized children with a laboratory-confirmed RSV infection from 2011 to 2023 were retrospectively evaluated. Clinical information was collected from Hospital Discharge Registry in the period 2011-2020. The proportion of the hospitalization for acute respiratory infections (ARIs) associated to RSV was calculated and the hospitalization cost was analyzed by using the diagnosis-related group reimbursement rate. The anticipated impact of immunization either with monoclonal antibodies or maternal immunization on the number of hospitalizations was estimated. All analyses and quality assessment were performed using STATA/SE15.0. RESULTS: A total of 1,005 RSV-cases were included in the study, of which 86.3% occurred between December-March. In the period 2011-2020, 832 RSV-cases were matched with the corresponding hospital admissions; 75.2% were aged < 1 year (49.6% 0-2 months). Bronchiolitis was the most frequent admission diagnosis occurring in 63.3% of patients; 25% of children were affected by a very severe RSV-disease. Younger age ≤ 2 months (OR:14.8, 95%CI:8.30-26.31, p = 0.000), higher length-of-hospital-stay (OR:1.01, 95%CI:1.0-1.02, p = 0.030) and history of prematurity (OR:4.4, 95%CI:1.57-12.11, p = 0.005) were associated with a higher disease severity. RSV caused 48.9% of ARIs among children < 1 year. The mean cost of an RSV-associated hospitalization was 3,036 euros/year, with the higher cost in the 0-2 months age group (4,225 euros/year). Immunization programs with nirsevimab could prevent 51.4 RSV hospitalizations/year and 18.1 very severe RSV disease/year in infants < 1 year of age. RSV vaccine could prevent 46.1 of hospitalizations/year caused by RSV within 180 days after birth. CONCLUSIONS: Our study contributes to outlining the baseline profile of RSV-associated hospitalizations among Italian children by providing epidemiological/clinical/economic estimates. While awaiting new recommendations on immunization, healthcare-workers should persist in implementing public health measures and appropriate case management to control RSV seasonal epidemics. Strengthened laboratory RSV surveillance is needed to inform the implementation of the new immunization strategies.

A comparative analysis of non-pharmaceutical interventions for preventing the respiratory syncytial virus in 30 European countries.

AIM: Respiratory syncytial virus (RSV) is a leading cause of childhood respiratory infections. Non-pharmaceutical interventions (NPIs) can help to reduce RSV transmission and our aim was to provide an overview of recommended NPIs across Europe during the 2022-2023 epidemic season. METHODS: The webpages of national European public health agencies and ministries were reviewed and the information they provided on RSV prevention was compared with the December 2022 guidelines from the European Centre for Disease Prevention and Control. RESULTS: We examined 30 countries, leading to 21 issued recommendations for RSV prevention through institutional channels, including six that were specific for the 2022-2023 season. The top five recommendations were: hand and respiratory hygiene (95%), avoiding crowded spaces (67%), staying at home when ill (62%), cleaning household items (57%) and limiting contact with sick people (57%). They also included: face masks (33%), ventilating indoor spaces (29%), properly disposing of contaminated material (13%) and keeping siblings home from preschool if there was a newborn infant in the family (10%). CONCLUSION: There was significant heterogeneity in the NPIs recommended by different countries during RSV epidemics. Ongoing evaluation is essential to optimise the effectiveness of NPIs and adapt to changing RSV patterns.

Determinants of radiological patterns and severity in immunocompromised adults with Metapneumovirus infection.

BACKGROUND: Human Metapneumovirus (HMPV) belongs to the Pneumoviridae family and is responsible for respiratory infections. Mild infections are well-recognized in children, while its precise impact in various categories of immunocompromised adults has not been well addressed. RESEARCH QUESTION: We retrospectively studied HMPV infections in immunocompromised adults followed in two large French university medical centers. STUDY DESIGN AND METHODS: We identified immunocompromised adults with positive HMPV Polymerase Chain Reaction (PCR) for 36 months and reviewed their medical charts. For lung transplant recipients (LTR), FEV1 was collected at baseline, during and after infection. Imaging was centralized and chest involvement was categorized by dominant CT patterns. We compared severe patients (requiring oxygen or ventilation) and non hypoxemic patients. RESULTS: Seventy-two patients were included, 27 were LTR, 25 had a hematological malignancy or were hematopoietic stem cell recipients, 20 had another immunocompromised status. Twenty patients (28%) presented a hypoxemic infection, requiring hospitalization and intensive care units transfers in 50/72 (69.4%) and 9/72 (12.5%) respectively, with only one death. Hypoxemia was less pronounced in LTRs (p = 0.014). Finally, age and dyspnea remained independent factors associated with hypoxemia (p < 0.005). The most frequent radiological patterns were bronchopneumonia (34.2%) and bronchiolitis (39.5% and 64.3% in the overall population and in LTRs respectively, p = 0.045). FEV1 improved in LTRs at one month and 85% had recovered their baseline FEV1 within 6 months. INTERPRETATIONS: In immunocompromised adults, HMPV infections required frequent hospitalizations and ICU transfers, while mortality is low. In LTRs, bronchiolitis pattern was predominant with short and long-term favorable outcome.

Experience of an Italian Pediatric Third Level Emergency Department during the 2022-2023 Bronchiolitis Epidemic: A Focus on Discharged Patients and Revisits.

The aim of this study was to describe the 2022-2023 bronchiolitis epidemic season (the second after COVID-19 pandemic and the first without social restriction), focusing on patients discharged home from a pediatric emergency department (PED) and on those revisited within 72 h. We performed a retrospective observational study in an Italian tertiary care children's hospital, reviewing PED accesses from 1 October 2022 to 31 March 2023. The number of hospitalizations for bronchiolitis was extracted from hospital discharge forms. A total of 512 patients diagnosed with bronchiolitis were admitted to PED (2.8% of total admissions). Accesses increased sharply from November to January, with a peak in December, in both admissions and hospitalizations. More than half of the patients (55.5%) were safely discharged home, while 38 (13.4%) came back to PED for a revisit. Overall PED accesses and hospitalizations for bronchiolitis increased since the previous epidemic season, and particularly compared to the pandemic and pre-pandemic eras. Empowering the collaboration between all healthcare provisioners is fundamental to suitable management of patients. Monitoring the epidemiology and seasonality of bronchiolitis is a starting point for an effective internal organization of pediatric departments and to further evaluate its socio-economic burden.

Parent and staff experiences of a feasibility trial evaluating neurally adjusted ventilatory assist in infants with acute viral bronchiolitis: A qualitative study.

BACKGROUND: There is limited literature regarding family and staff experiences of participating in clinical trials. A qualitative study was embedded in the NAVABronch feasibility trial evaluating the effectiveness of a novel mode of ventilation, neurally adjusted ventilatory assist (NAVA), in infants with acute viral bronchiolitis. AIMS AND OBJECTIVES: The aim of this qualitative study was to explore the experiences of parents and health care practitioners (HCPs) involved in the NAVABronch Trial. STUDY DESIGN: Semi-structured interviews were conducted with two parents and two focus groups were held with six HCPs. FINDINGS: Four themes were identified from the focus groups: (1) Creating staff engagement, (2) Education to deliver NAVA, (3) Normalizing NAVA in clinical practice (4) Creating meaningful study outcomes and (5) support of parents during the trial, this theme was generated from the parent interviews. The findings indicated the need for education regarding NAVA for HCPs which would lead to increased confidence, better guidance around the use of NAVA and the need for NAVA to be normalized and embedded into the unit culture. Parents identified the need for further support around preparation for what may happen as a result of the interventions, particularly the weaning of sedation. CONCLUSION: Our study indicates that staff and parents had no concerns regarding the trial methods and procedures. RELEVANCE TO CLINICAL PRACTICE: Conducting clinical trials in Paediatric Intensive Care Units (PICUs) is challenging and complex. There is limited literature regarding family and staff experiences of participating in clinical trials. Understanding their experiences is crucial in ensuring trial success.

Air pollution and bronchiolitis: a case-control study in Antwerp, Belgium.

This case-control study aimed to investigate the association between short-term (1 to 5 days) and medium-term (31 days) exposure to air pollutants (PM2.5, PM10, BC, NO2) at home/daycare and the risk of 'severe bronchiolitis' (defined as 'requiring hospitalization for bronchiolitis') in children under 2 years in Antwerp, Belgium. We included 118 cases and 79 controls admitted to three general hospitals from October 2020 to June 2021. Exposure levels were predicted using an interpolation model based on fixed measuring stations. We used unconditional logistic regression analysis to assess associations, with adjustment for potential confounders. There were hardly any significant differences in the day-to-day air pollution values between cases and controls. Medium-term (31 days) exposure to PM2.5, PM10, and NO2 was however significantly higher in cases than controls in univariate analysis. Logistic regression revealed an association between severe bronchiolitis and interquartile range (IQR) increases of PM2.5 and PM10 at home and in daycare, as well as IQR increases of NO2 in daycare. Controls were however overrepresented in low pollution periods. Time-adjustment reduced the odds ratios significantly at home for PM2.5 and PM10 (aOR 1.54, 95%CI 0.51-4.65; and 2.69, 95%CI 0.94-7.69 respectively), and in daycare for. PM2.5 (aOR 2.43, 95%CI 0.58-10.1). However, the association between severe bronchiolitis and medium-term air pollution was retained in daycare for IQR increases of PM10 (aOR 5.13, 95%CI 1.24-21.28) and NO2 (aOR 3.88, 95%CI 1.56-9.61) in the time-adjusted model.  Conclusion: This study suggests a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. Larger studies are warranted to confirm these findings. What is Known: • Bronchiolitis is a leading cause of hospitalization in infants globally and causes a yearly seasonal wave of admissions in paediatric departments worldwide. • Existing studies, mainly from the USA, show heterogeneous outcomes regarding the association between air pollution and bronchiolitis. What is New: • There is a possible link between severe bronchiolitis and medium-term (31 days) air pollution exposure (PM10 and NO2), particularly in daycare. • Larger studies are needed to validate these trends.

Advances in pediatric emergency from 2023.

Most children receive emergency care by general emergency physicians and not in designated children's hospitals. There are unique considerations in the care of children that differ from the care of adults. Many management principles can be extrapolated from adult studies, but the unique pathophysiology of pediatric disease requires specialized attention and management updates. This article highlights ten impactful articles from the year 2023 whose findings can improve the care of children in the Emergency Department (ED). These studies address pediatric resuscitation, traumatic arrest, septic shock, airway management, nailbed injuries, bronchiolitis, infant fever, cervical spine injuries, and cancer risk from radiation (Table 1). The findings in these articles have the potential to impact the evaluation and management of children (Table 2).

Oral enteral nutrition in the emergency department for children with bronchiolitis hospitalized on high flow nasal cannula.

OBJECTIVES: We assessed whether initiation of oral enteral nutrition in the emergency department (ED) for patients with bronchiolitis hospitalized on humidified high flow nasal cannula (HHFNC) was associated with a shorter hospital length of stay (LOS) without an increase in return ED visits or hospital readmissions. PATIENTS AND METHODS: This retrospective cohort study included children ≤24 months of age with bronchiolitis hospitalized to the general pediatric floor on HHFNC in two time periods: October 1, 2018 - April 30, 2019, and following implementation of a revised institutional bronchiolitis pathway that encouraged enteral nutrition initiation in the ED, October 1, 2021 - April 30, 2022. The primary outcome of interest was hospital LOS where the exposure was enteral feeding in the ED. RESULTS: We included 391 'fed', 114 'not fed' and 304 'unknown' patients. HHFNC treatment time (25 h for 'fed' vs. 43 h for 'not fed' vs. 35 h for'unknown', p = 0.0001) and hospital LOS (39 h for 'fed' vs. 56 h for 'not fed' vs. 48 h for 'unknown', p = 0.0001) was shorter in the 'fed' group. There were no significant differences in return ED visits or hospital readmissions. Using our median LOS (45.1 h, inter-quartile range 30.2, 64.4 h) while controlling for age, sex, initial HHFNC flow rate, the respiratory oxygenation (ROX) index, viral etiology, and time period, an adjusted logistic regression analysis demonstrated that patients fed in the ED were 1.8 times more likely to have a hospital LOS of <45 h (aOR 1.88, 95% CI 1.11-3.18, p = 0.019). CONCLUSIONS: Initiation of oral enteral nutrition in the ED for patients with bronchiolitis on HHFNC is associated with a shorter hospital LOS without an increase in return ED visits or hospital readmissions. Future prospective studies are needed to develop feeding recommendations for children with bronchiolitis receiving HHFNC support.

Association of vitamin D with disease severity in infants with bronchiolitis.

Vitamin D's role in immune system regulation and its contribution to host defenses against respiratory infections may have implications for bronchiolitis pathophysiology. This cross-sectional study aimed to determine the association between the clinical severity of bronchiolitis and serum vitamin D levels in infants. Infants aged 1 month to 12 months, diagnosed with bronchiolitis, and healthy controls attending routine immunization were enrolled. Baseline characteristics were recorded, including clinical details, bronchiolitis severity, and course during hospital stay. Bronchiolitis severity score (BSS) was used to score the severity. A 1-2 ml serum sample was obtained for vitamin D levels estimation. The median age of cases (n = 64; 65.6% male) was 5 [3, 8] months, and that of the control group (n = 30) was 3 [2, 9] months. No statistically significant differences were observed between the two groups in age, gender, weight, mode of delivery, family history of atopy/asthma, feeding pattern, smoke exposure, and daily vitamin D supplementation. The median vitamin D levels were not significantly different between the groups (p = 0.68). Among infants with bronchiolitis, 62.5% had vitamin D insufficiency (≤ 20 ng/ml). A significantly higher median BSS indicates that infants with vitamin D insufficiency exhibited more severe disease (p = 0.019). Although a negative correlation between BSS and vitamin D levels was noted, it did not reach statistical significance [rs = (-)0.17; p = 0.16]. CONCLUSION:  Infants with Vitamin D insufficiency experienced more severe bronchiolitis with elevated BSS scores. It highlights the potential role of vitamin D deficiency in severe bronchiolitis. WHAT IS KNOWN: • Vitamin D level is low in infants with bronchiolitis. WHAT IS NEW: • Infant with low vitamin D level experienced more severe bronchiolitis.

Mechanical Ventilation during Bronchiolitis: The Macklin Effect.

This is a case of barotrauma imaging (Macklin effect) after invasive mechanical ventilation in a 14-week-old newborn with complicated bronchiolitis. Teaching point: Imaging could help us improve defining the anatomical boundaries of the Macklin effect, an incompletely known anatomo-physiological entity.

Does weight influence the course of RSV bronchiolitis in hospitalized infants?

Acute bronchiolitis is among the most common causes of hospitalizations in infants worldwide. Associations between weight and severity of respiratory syncytial virus (RSV) bronchiolitis remain unclear. The aim of this study was to evaluate this association. A single-center, retrospective cohort study of infants aged under 24 months, who were hospitalized between 2018 and 2022 for RSV bronchiolitis. Data from computerized medical records were extracted using the MDclone platform. Participants were divided into three groups according to weight percentiles: underweight (below 5th percentile), normal-weight, and overweight (above 85th percentile). A total of 1936 infants (mean age 6.3 months, 55% males) were included, comprising 274 infants who were underweight, 1470 with normal weight, and 192 with overweight. Underweight infants had a higher rate of admission to the pediatric intensive care unit (PICU) (9.1% vs. 3.5%, P < 0.005) and prolonged length of stay (LOS) in the hospital (3.13 vs. 2.79 days P < 0.001) compared to those with normal weight. Hyponatremia was also more common in the underweight group (23% vs. 15%, P < 0.001). A multivariable model accounting for prematurity and birthweight predicted a relative risk of 2.01 (95% CI 1.13-3.48, P = 0.015) for PICU admission and 1.42 (95% CI 1.17-1.7, P < 0.001) for a prolonged LOS. Being overweight was not associated with a more severe disease.  Conclusion: Underweight infants, hospitalized for RSV bronchiolitis, had a more severe disease course with a higher complication rate, including PICU admission and prolonged LOS. Thus, careful attention and supervision should be given to this subgroup of infants. What is Known: • Established risk factors for severe bronchiolitis include prematurity, BPD, CHD, and compromised immunity. • Abnormal weight status has been associated with an increased risk for morbidity and mortality from infectious diseases, proposedly due to the effects on endocrine and immunologic systems. What is New: • Underweight infants hospitalized with RSV bronchiolitis face an independent risk of PICU admission and prolonged hospital stay. • Conversely, overweight infants did not display associations with severity measures in our study.