Noninvasive Positive Pressure Ventilation Use and In-Hospital Cardiac Arrest in Bronchiolitis.

IMPORTANCE: A recent study showed an association between high hospital-level noninvasive positive pressure ventilation (NIPPV) use and in-hospital cardiac arrest (IHCA) in children with bronchiolitis. OBJECTIVES: We aimed to determine if patient-level exposure to NIPPV in children with bronchiolitis was associated with IHCA. DESIGN, SETTING AND PARTICIPANTS: Retrospective cohort study at a single-center quaternary PICU in North America including children with International Classification of Diseases primary or secondary diagnoses of bronchiolitis in the Virtual Pediatric Systems database. MAIN OUTCOMES AND MEASURES: The primary exposure was NIPPV and the primary outcome was IHCA. MEASUREMENTS AND MAIN RESULTS: Of 4698 eligible ICU admissions with bronchiolitis diagnoses, IHCA occurred in 1.2% (57/4698). At IHCA onset, invasive mechanical ventilation (IMV) was the most frequent level of respiratory support (65%, 37/57), with 12% (7/57) receiving NIPPV. Patients with IHCA had higher Pediatric Risk of Mortality-III scores (3 [0-8] vs. 0 [0-2]; p < 0.001), more frequently had a complex chronic condition (94.7% vs. 46.2%; p < 0.001), and had higher mortality (21.1% vs. 1.0%; p < 0.001) compared with patients without IHCA. Return of spontaneous circulation (ROSC) was achieved in 93% (53/57) of IHCAs; 79% (45/57) survived to hospital discharge. All seven children without chronic medical conditions and with active bronchiolitis symptoms at the time of IHCA achieved ROSC, and 86% (6/7) survived to discharge. In multivariable analysis restricted to patients receiving NIPPV or IMV, NIPPV exposure was associated with lower odds of IHCA (adjusted odds ratio [aOR], 0.07; 95% CI, 0.03-0.18) compared with IMV. In secondary analysis evaluating categorical respiratory support in all patients, compared with IMV, NIPPV was associated with lower odds of IHCA (aOR, 0.35; 95% CI, 0.14-0.87), whereas no difference was found for minimal respiratory support (none/nasal cannula/humidified high-flow nasal cannula [aOR, 0.56; 95% CI, 0.23-1.36]). CONCLUSIONS AND RELEVANCE: Cardiac arrest in children with bronchiolitis is uncommon, occurring in 1.2% of bronchiolitis ICU admissions. NIPPV use in children with bronchiolitis was associated with lower odds of IHCA.

Geographic Progression of Infant Respiratory Syncytial Virus Associated Bronchiolitis Across the United States Before and Since the Onset of COVID-19: Results From Four Health Systems, 2015-2023.

BACKGROUND: Respiratory syncytial virus (RSV) is a substantial cause of infant morbidity and mortality due to seasonal peaks of bronchiolitis across the United States. Clinical and viral surveillance plays a pivotal role in helping hospital systems prepare for expected surges in RSV bronchiolitis. Existing surveillance efforts have shown a geographic pattern of RSV positivity across the United States, with cases typically starting in the southeast and spreading north and west. Public health measures implemented due to the COVID-19 pandemic disrupted viral transmission across the nation and altered the expected seasonality of RSV. The impact of these changes on the geographic progression of infant RSV bronchiolitis across the United States has not been described. METHODS: Here, we used clinical and viral surveillance data from four health care systems located in different regions of the United States to describe the geographic progression of infant RSV bronchiolitis across the country from 2015 to 2023. RESULTS: Prior to widespread circulation of SARS-CoV-2, infant RSV bronchiolitis followed an established geographic pattern associated with seasonal epidemics originating in Florida and spreading north (North Carolina and New York) and later westward (Nevada). Although public health and social measures implemented during the COVID-19 pandemic disrupted the seasonality of RSV disease, infant RSV bronchiolitis epidemics progressed across the nation in a pattern identical to the prepandemic era. CONCLUSIONS: Our findings highlight the importance of ongoing clinical and viral surveillance to optimally track the onset of RSV epidemics and allow health care systems to prepare for expected RSV bronchiolitis surges.

Respiratory Support Practices for Bronchiolitis in the Pediatric Intensive Care Unit.

Importance: Admissions to the pediatric intensive care unit (PICU) due to bronchiolitis are increasing. Whether this increase is associated with changes in noninvasive respiratory support practices is unknown. Objective: To assess whether the number of PICU admissions for bronchiolitis between 2013 and 2022 was associated with changes in the use of high-flow nasal cannula (HFNC), noninvasive ventilation (NIV), and invasive mechanical ventilation (IMV) and to identify factors associated with HFNC and NIV success and failure. Design, Setting, and Participants: This cross-sectional study examined encounter data from the Virtual Pediatric Systems database on annual PICU admissions for bronchiolitis and ventilation practices among patients aged younger than 2 years admitted to 27 PICUs between January 1, 2013, and December 31, 2022. Use of HFNC and NIV was defined as successful if patients were weaned to less invasive support (room air or low-flow nasal cannula for HFNC; room air, low-flow nasal cannula, or HFNC for NIV). Main Outcomes and Measures: The main outcome was the number of PICU admissions for bronchiolitis requiring the use of HFNC, NIV, or IMV. Linear regression was used to analyze the association between admission year and absolute numbers of encounters stratified by the maximum level of respiratory support required. Multivariable logistic regression was used to analyze factors associated with HFNC and NIV success and failure (defined as not meeting the criteria for success). Results: Included in the analysis were 33 816 encounters for patients with bronchiolitis (20 186 males [59.7%]; 1910 patients [5.6%] aged ≤28 days and 31 906 patients [94.4%] aged 29 days to <2 years) treated at 27 PICUs from 2013 to 2022. A total of 7615 of 15 518 patients (49.1%) had respiratory syncytial virus infection and 1522 of 33 816 (4.5%) had preexisting cardiac disease. Admissions to the PICU increased by 350 (95% CI, 170-531) encounters annually. When data were grouped by the maximum level of respiratory support required, HFNC use increased by 242 (95% CI, 139-345) encounters per year and NIV use increased by 126 (95% CI, 64-189) encounters per year. The use of IMV did not significantly change (10 [95% CI, -11 to 31] encounters per year). In all, 22 381 patients (81.8%) were successfully weaned from HFNC to low-flow oxygen therapy or room air, 431 (1.6%) were restarted on HFNC, 3057 (11.2%) were escalated to NIV, and 1476 (5.4%) were escalated to IMV or extracorporeal membrane oxygenation (ECMO). Successful use of HFNC increased from 820 of 1027 encounters (79.8%) in 2013 to 3693 of 4399 encounters (84.0%) in 2022 (P = .002). In all, 8476 patients (81.5%) were successfully weaned from NIV, 787 (7.6%) were restarted on NIV, and 1135 (10.9%) were escalated to IMV or ECMO. Success with NIV increased from 224 of 306 encounters (73.2%) in 2013 to 1335 of 1589 encounters (84.0%) in 2022 (P < .001). In multivariable logistic regression, lower weight, higher Pediatric Risk of Mortality III score, cardiac disease, and PICU admission from outside the emergency department were associated with greater odds of HFNC and NIV failure. Conclusions and Relevance: Findings of this cross-sectional study of patients aged younger than 2 years admitted for bronchiolitis suggest there was a 3-fold increase in PICU admissions between 2013 and 2022 associated with a 4.8-fold increase in HFNC use and a 5.8-fold increase in NIV use. Further research is needed to standardize approaches to HFNC and NIV support in bronchiolitis to reduce resource strain.

Correlation analysis between serum total IgE and FeNO and idiosyncratic reaction in bronchiolitis.

OBJECTIVE: This article focused on the correlation between the changes of serum total Immunoglobulin E (IgE) and Fractional exhaled Nitric Oxide (FeNO) and idiosyncratic reactions in children with bronchiolitis. METHODS: One hundred children with bronchiolitis and fifty healthy children were enrolled. Serum total IgE and FeNO were assessed, and the diagnostic value for bronchiolitis and the correlation with the severity of bronchiolitis were analyzed. Bronchiolitis children were divided into idiosyncratic + bronchiolitis and non-idiosyncratic + bronchiolitis groups, the relationship between serum total IgE and FeNO and idiosyncratic reaction was determined, and the diagnostic value of serum total IgE and FeNO for idiosyncratic bronchiolitis was examined. RESULTS: FeNO in bronchiolitis children was lower than that in healthy children but there was no significant difference in serum total IgE levels between the two populations. Serum total IgE increased while FeNO decreased with the aggravation of bronchiolitis in bronchiolitis children. The serum total IgE was positively correlated while FeNO was negatively correlated with the severity of bronchiolitis. Serum total IgE was higher in children with idiosyncratic bronchiolitis, but serum total IgE and FeNO were not the risk factors for idiosyncratic bronchiolitis; Area Under the Curve (AUC) of serum total IgE and FeNO for the diagnosis of idiosyncratic bronchiolitis was less than 0.7. CONCLUSION: Serum total IgE and FeNO in children with bronchiolitis are related to disease severity and idiosyncratic reaction. FeNO has a diagnostic value for bronchiolitis, but not for idiosyncratic bronchiolitis.

Antibiotic Use in Korean Children Diagnosed With Acute Bronchiolitis: Analysis of the National Health Insurance Reimbursement Data.

BACKGROUND: Acute bronchiolitis, the most common lower respiratory tract infection in infants, is mostly caused by respiratory viruses. However, antibiotics are prescribed to about 25% of children with acute bronchiolitis. This inappropriate use of antibiotics for viral infections induces antibiotic resistance. This study aimed to determine the antibiotic prescription rate and the factors associated with antibiotic use in children with acute bronchiolitis in Korea, where antibiotic use and resistance rates are high. METHODS: Healthcare data of children aged < 24 months who were diagnosed with acute bronchiolitis between 2016 and 2019 were acquired from the National Health Insurance system reimbursement claims data. Antibiotic prescription rates and associated factors were evaluated. RESULTS: A total of 3,638,424 visits were analyzed. The antibiotic prescription rate was 51.8%, which decreased over time (P < 0.001). In the multivariate analysis, toddlers (vs. infants), non-capital areas (vs. capital areas), primary clinics and non-tertiary hospitals (vs. tertiary hospitals), inpatients (vs. outpatients), and non-pediatricians (vs. pediatricians) showed a significant association with antibiotic prescription (P < 0.001). Fourteen cities and provinces in the non-capital area exhibited a wide range of antibiotic prescription rates ranging from 41.2% to 65.4%, and five (35.7%) of them showed lower antibiotic prescription rates than that of the capital area. CONCLUSION: In Korea, the high antibiotic prescription rates for acute bronchiolitis varied by patient age, region, medical facility type, clinical setting, and physician specialty. These factors should be considered when establishing strategies to promote appropriate antibiotic use.

Trends in RSV testing patterns among infants presenting with bronchiolitis: Results from four United States health systems, 2015-2023.

BACKGROUND: Bronchiolitis due to respiratory syncytial virus (RSV) is the leading cause of hospitalization among American infants. The overall burden of RSV among infants has been historically under-estimated due to variable testing practices, particularly in the outpatient setting. Universal masking and social distancing implemented during the coronavirus disease 2019 (COVID-19) pandemic altered RSV seasonality, however potential consequences on RSV testing practices across different healthcare settings and sociodemographic groups have not been described. Variable testing practices could also affect accurate assessment of the effects of two recently approved RSV preventative agents targeting infants. METHODS: Utilizing real-time clinical and viral surveillance, we examined RSV testing practices among infants with bronchiolitis within four United States healthcare systems across different healthcare settings and sociodemographic groups pre- and post-COVID-19. RESULTS: RSV testing among infants with bronchiolitis increased since 2015 within each healthcare system across all healthcare settings and sociodemographic groups, with a more dramatic increase since the COVID-19 pandemic. Outpatient testing remained disproportionately low compared to hospital-based testing, although there were no major differences in testing frequency among sociodemographic groups in either setting. CONCLUSIONS: Although RSV testing increased among infants with bronchiolitis, relatively low outpatient testing rates remain a key barrier to accurate RSV surveillance.

Sociodemographic Factors and Trends in Bronchiolitis-Related Emergency Department Visit and Hospitalization Rates.

Importance: Bronchiolitis is the most common and most cumulatively expensive condition in pediatric hospital care. Few population-based studies have examined health inequalities in bronchiolitis outcomes over time. Objective: To examine trends in bronchiolitis-related emergency department (ED) visit and hospitalization rates by sociodemographic factors in a universally funded health care system. Design, Setting, and Participants: This repeated cross-sectional cohort study was performed from April 1, 2004, to March 31, 2022, using population-based health administrative data from children younger than 2 years in Ontario, Canada. Main Outcome and Measures: Bronchiolitis ED visit and hospitalization rates per 1000 person-years reported for the equity stratifiers of sex, residence location (rural vs urban), and material resources quintile. Trends in annual rates by equity stratifiers were analyzed using joinpoint regression and estimating the average annual percentage change (AAPC) with 95% CI and the absolute difference in AAPC with 95% CI from April 1, 2004, to March 31, 2020. Results: Of 2 921 573 children included in the study, 1 422 088 (48.7%) were female and 2 619 139 (89.6%) lived in an urban location. Emergency department visit and hospitalization rates were highest for boys, those with rural residence, and those with least material resources. There were no significant between-group absolute differences in the AAPC in ED visits per 1000 person-years by sex (female vs male; 0.22; 95% CI, -0.92 to 1.35; P = .71), residence (rural vs urban; -0.31; 95% CI -1.70 to 1.09; P = .67), or material resources (quintile 5 vs 1; -1.17; 95% CI, -2.57 to 0.22; P = .10). Similarly, there were no significant between-group absolute differences in the AAPC in hospitalizations per 1000 person-years by sex (female vs male; 0.53; 95% CI, -1.11 to 2.17; P = .53), residence (rural vs urban; -0.62; 95% CI, -2.63 to 1.40; P = .55), or material resources (quintile 5 vs 1; -0.93; 95% CI -3.80 to 1.93; P = .52). Conclusions and Relevance: In this population-based cohort study of children in a universally funded health care system, inequalities in bronchiolitis ED visit and hospitalization rates did not improve over time.

Multicenter Quality Collaborative to Reduce Overuse of High-Flow Nasal Cannula in Bronchiolitis.

BACKGROUND AND OBJECTIVES: High-flow nasal cannula (HFNC) for bronchiolitis increased over the past decade without clear benefit. This quality improvement collaborative aimed to reduce HFNC initiation and treatment duration by 30% from baseline. METHODS: Participating hospitals either reduced HFNC initiation (Pause) or treatment duration (Holiday) in patients aged <24 months admitted for bronchiolitis. Participants received either Pause or Holiday toolkits, including: intervention protocol, training/educational materials, electronic medical record queries for data acquisition, small-group coaching, webinars, and real-time access to run charts. Pause arm primary outcome was proportion of patients initiated on HFNC. Holiday arm primary outcome was geometric mean HFNC treatment duration. Length of stay (LOS) was balancing measure for both. Each arm served as contemporaneous controls for the other. Outcomes analyzed using interrupted time series (ITS) and linear mixed-effects regression. RESULTS: Seventy-one hospitals participated, 30 in the Pause (5746 patients) and 41 in the Holiday (7903 patients). Pause arm unadjusted HFNC initiation decreased 32% without LOS change. ITS showed immediate 16% decrease in initiation (95% confidence interval [CI] -27% to -5%). Compared with contemporaneous controls, Pause hospitals reduced HFNC initiation by 23% (95% CI -35% to -10%). Holiday arm unadjusted HFNC duration decreased 28% without LOS change. ITS showed immediate 11.8 hour decrease in duration (95% CI -18.3 hours to -5.2 hours). Compared with contemporaneous controls, Holiday hospitals reduced duration by 11 hours (95% CI -20.7 hours to -1.3 hours). CONCLUSIONS: This quality improvement collaborative reduced HFNC initiation and duration without LOS increase. Contemporaneous control analysis supports intervention effects rather than secular trends toward less use.

Reducing unwarranted chest x-rays in bronchiolitis: Importance of a robust analysis.

AIM: Bronchiolitis is the commonest reason for hospitalisation amongst infants and is often a target for low-value care (LVC) reduction. We aimed to assess the impact of a multifaceted intervention (clinician education, parent engagement, audit-feedback) on rates of chest x-rays (CXR) in bronchiolitis. METHODS: Longitudinal study of CXRs ordered in infants (1-12 months) diagnosed with bronchiolitis in the Emergency Department (ED) of an Australian paediatric hospital between May 2016 and February 2023. We used logistic regression to measure the impact of the intervention on unwarranted CXR orders, controlling for other potential impacting variables such as time, patient characteristics (age/sex), clinical variables (fever, hypoxia, tachypnoea), seasonal factors (month, day of the week, business hours) and time passed since intervention. RESULTS: Ten thousand one hundred and nine infants were diagnosed with bronchiolitis in the ED over the study period, with 939 (9.3%) receiving a CXR, of which 69% (n = 651) were considered unwarranted. Rates of unwarranted CXRs reduced from 7.9% to 5.4% post-intervention (P < 0.0001). Logistic regression showed the intervention had no significant effect (OR 0.89, 95% CI 0.65-1.23) once other variables and underlying time-based trends were accounted for. CONCLUSIONS: Although pre-post rates appeared significantly improved, a robust analysis demonstrated that our multi-faceted intervention was not effective in reducing CXRs in bronchiolitis. The decision to order CXR was associated with clinical features that overlap with pneumonia suggesting ongoing misconceptions regarding the role of CXR for this indication. Our study highlights the value of large electronic medical record datasets and robust methodology to avoid falsely attributing underlying trends to the LVC intervention.

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 Hospital-Based Burden of Disease in Children Younger Than 5 Years, 2015-2022.

Importance: Respiratory syncytial virus (RSV) resurgences have been noted following the COVID-19 pandemic in many countries. Recent findings suggest that the 2021 and 2022 RSV seasons were more severe than in past seasons, and age distribution may have shifted toward older children in the younger than 5 years age group. Objectives: To estimate age-specific changes in RSV hospital-based burden of disease before and after the COVID-19 pandemic and to compare incidence by Medicaid use. Design, Setting, and Participants: This retrospective cohort study included children younger than 5 years diagnosed with RSV and bronchiolitis at 50 US children's hospitals in 10 US geographic regions. The included participants had an encounter in intensive care, inpatient, emergency, or observational units, between June 1, 2015, and March 31, 2023. Exposures: Diagnosis of RSV, bronchiolitis, or both at encounter. Main Outcome and Measures: Incidence rate ratio of hospital use within each care unit before vs after the COVID-19 pandemic. It was hypothesized a priori that incidence of hospital use would increase overall in 2021 and 2022 compared with 2015 to 2019 and that the increase would be greater among children 12 months and older. Results: Of 924 061 study participants (median [IQR] age, 8 (5-16) months; 535 619 [58.0%] male), 348 077 (37.7%) were diagnosed with RSV. Of these, 187 850 (54.0%) were hospitalized. Incidence rate ratios of hospitalization increased for all ages in 2021 and 2022 compared with 2015 to 2019. Children aged 24 to 59 months were 4.86 (95% CI, 4.75-4.98) times as likely to be hospitalized in 2022 compared with 2015 to 2019, whereas infants aged 0 to 5 months were 1.77 (95% CI, 1.74-1.80) times as likely. Medicaid patients were more likely to be hospitalized than non-Medicaid patients regardless of year. Conclusions and Relevance: Hospitalizations for RSV and bronchiolitis demonstrated atypical seasonality in 2021 and 2022, with an overall increase in RSV encounters. Postpandemic RSV hospitalization increased for all ages, but especially among older children, whereas bronchiolitis hospitalization was decreased or unchanged compared with earlier seasons. These findings suggest some of the observed increase in RSV hospital use may be due to increased testing.

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.

Addressing global health disparities in the management of RSV infection in infants and children: Strategies for preventing bronchiolitis and post-bronchiolitis recurrent wheezing.

Background: The topic of equitable access to health care and its impact on exacerbating worldwide inequities in child health not only strikes at the heart of our health-care delivery systems but also deeply resonates with our collective social consciences. Nowhere is this better seen on a global scale than in the burden of illness caused by respiratory syncytial virus (RSV) infection, which extracts the most severe morbidity and mortality in infants and children in low- and middle-income countries (LMIC). This report addresses global health disparities that exist in the management of RSV infection in infants and children, and offers strategies for preventing bronchiolitis and postbronchiolitis recurrent wheezing in LMICs. Methods: A systematic literature review was conducted across the PubMed data bases of RSV infection and the socioeconomic impact of bronchiolitis and postbronchiolitis recurrent wheezing in LMICs. Results: The results of the present study address the many issues that deal with the question if prevention of RSV bronchiolitis can mitigate recurrent wheezing episodes and links RSV risks, downstream effects, prevention, malnutrition, and socioeconomic restraints of developing countries with a call for possible global action. Conclusion: The present study stresses the importance of considering the linkage between malnutrition and disease susceptibility because of the known relationships between undernutrition and greater vulnerability to infectious diseases, including RSV infection. These complex interactions between infectious disease and undernutrition also raise issues on the longer-term sequelae of postbronchiolitis recurrent wheezing. This prompts a discussion on whether industrialized countries should prioritize the provision of newly developed monoclonal antibodies and RSV vaccines to LMICs or whether vital nutritional needs should be a first focus. The resolution of these issues will require research and greater international discourse.

Transition to Weight-Based High-Flow Nasal Cannula Use Outside of the ICU for Bronchiolitis.

Importance: Most children's hospitals have adopted weight-based high-flow nasal cannula (HFNC) bronchiolitis protocols for use outside of the intensive care unit (ICU) setting. Whether these protocols are achieving their goal of reducing bronchiolitis-related ICU admissions remains unknown. Objective: To measure the association between hospital transition to weight-based non-ICU HFNC use and subsequent ICU admission. Design, Setting, and Participants: This multicenter retrospective cohort study was conducted with a controlled interrupted time series approach and involved 18 children's hospitals that contribute data to the Pediatric Health Information Systems database. The cohort included patients aged 0 to 24 months who were hospitalized with a diagnosis of bronchiolitis between January 1, 2010, and December 31, 2021. Data were analyzed from July 2023 to January 2024. Exposure: Hospital-level transition from ICU-only to weight-based non-ICU protocol for HFNC use. Data for the ICU-only group were obtained from a previously published survey. Main Outcomes and Measures: Proportion of patients with bronchiolitis admitted to the ICU. Results: A total of 86 046 patients with bronchiolitis received care from 10 hospitals in the ICU-only group (n = 47 336; 27 850 males [58.8%]; mean [SD] age, 7.6 [6.2] years) and 8 hospitals in the weight-based protocol group (n = 38 710; 22 845 males [59.0%]; mean [SD] age, 7.7 [6.3] years). Mean age and sex were similar for patients between the 2 groups. Hospitals in the ICU-only group vs the weight-based protocol group had higher proportions of Black (26.2% vs 19.8%) and non-Hispanic (81.6% vs 63.8%) patients and patients with governmental insurance (68.1% vs 65.9%). Hospital transition to a weight-based HFNC protocol was associated with a 6.1% (95% CI, 8.7%-3.4%) decrease per year in ICU admission and a 1.5% (95% CI, 2.8%-0.1%) reduction per year in noninvasive positive pressure ventilation use compared with the ICU-only group. No differences in mean length of stay or the proportion of patients who received invasive mechanical ventilation were found between groups. Conclusions and Relevance: Results of this cohort study of hospitalized patients with bronchiolitis suggest that transition from ICU-only to weight-based non-ICU HFNC protocols is associated with reduced ICU admission rates.

Management and outcomes of bronchiolitis in Italy and Latin America: a multi-center, prospective, observational study.

We aimed to describe differences in the epidemiology, management, and outcomes existing between centers located in countries which differ by geographical location and economic status during to post-pandemic bronchiolitis seasons.  This was a prospective observational cohort study performed in two academic centers in Latin America (LA) and three in Italy. All consecutive children with a clinical diagnosis of bronchiolitis were included, following the same data collection form.  Nine hundred forty-three patients have been enrolled: 275 from the two Latin American Centers (San Jose, 215; Buenos Aires, 60), and 668 from Italy (Rome, 178; Milano, 163; Bologna, 251; Catania, 76). Children in LA had more frequently comorbidities, and only rarely received palivizumab. A higher number of patients in LA had been hospitalized in a ward (64% versus 23.9%, p < 0.001) or in a PICU (16% versus 6.2%, p < 0.001), and children in LA required overall more often respiratory support, from low flow oxygen to invasive mechanical ventilation, except for CPAP which was more used in Italy. There was no significant difference in prescription rates for antibiotics, but a significantly higher number of patients treated with systemic steroids in Italy. CONCLUSIONS: We found significant differences in the care for children with bronchiolitis in Italy and LA. Reasons behind such differences are unclear and would require further investigations to optimize and homogenize practice all over the world. WHAT IS KNOWN: • Bronchiolitis is among the commest cause of morbidity and mortality in infants all over the world. WHAT IS NEW: • There are significant differences on how clinicians care for bronchiolitis in different centers and continents. Differences in care can be principally due to different local practices than differences in patients severity/presentations. • Understanding these differences should be a priority to optime and standardize bronchiolitis care globally.

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.

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.

High-flow nasal cannula therapy for infants with bronchiolitis.

BACKGROUND: Bronchiolitis is a common lower respiratory tract illness, usually of viral aetiology, affecting infants younger than 24 months of age and is the most common cause of hospitalisation of infants. It causes airway inflammation, mucus production and mucous plugging, resulting in airway obstruction. Effective pharmacotherapy is lacking and bronchiolitis is a major cause of morbidity and mortality. Conventional treatment consists of supportive therapy in the form of fluids, supplemental oxygen, and respiratory support. Traditionally, oxygen delivery is as a dry gas at 100% concentration via low-flow nasal prongs. However, the use of heated, humidified, high-flow nasal cannula (HFNC) therapy enables delivery of higher inspired gas flows of an air/oxygen blend, at 2 to 3 L/kg per minute up to 60 L/min in children. It can provide some level of continuous positive airway pressure (CPAP) to improve ventilation in a minimally invasive manner. This may reduce the need for invasive respiratory support, thus potentially lowering costs, with clinical advantages and fewer adverse effects. OBJECTIVES: To assess the effects of HFNC therapy compared with conventional respiratory support in the treatment of infants with bronchiolitis. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, and Web of Science (from June 2013 to December 2022). In addition, we consulted ongoing trial registers and experts in the field to identify ongoing studies, checked reference lists of relevant articles, and searched for conference abstracts. Date restrictions were imposed such that we only searched for studies published after the original version of this review. SELECTION CRITERIA: We included randomised controlled trials (RCTs) or quasi-RCTs that assessed the effects of HFNC (delivering oxygen or oxygen/room air blend at flow rates greater than 4 L/minute) compared to conventional treatment in infants (< 24 months) with a clinical diagnosis of bronchiolitis. DATA COLLECTION AND ANALYSIS: Two review authors independently used a standard template to assess trials for inclusion and extract data on study characteristics, risk of bias elements, and outcomes. We contacted trial authors to request missing data. Outcome measures included the need for invasive respiratory support and time until discharge, clinical severity measures, oxygen saturation, duration of oxygen therapy, and adverse events. MAIN RESULTS: In this update we included 15 new RCTs (2794 participants), bringing the total number of RCTs to 16 (2813 participants). Of the 16 studies, 11 compared high-flow to low-flow, and five compared high-flow to CPAP. These studies included infants less than 24 months of age as stated in our selection criteria. There were no significant differences in sex. We found that when comparing high-flow to low-flow oxygen therapy for infants with bronchiolitis there may be a reduction in the total length of hospital stay (mean difference (MD) -0.65 days, 95% confidence interval (CI) -1.23 to -0.06; P < 0.00001, I2 = 89%; 7 studies, 1951 participants; low-certainty evidence). There may also be a reduction in the duration of oxygen therapy (MD -0.59 days, 95% CI -1 to -0.18; P < 0.00001, I2 = 86%; 7 studies, 2132 participants; low-certainty evidence). We also found that there was probably an improvement in respiratory rate at one and 24 hours, and heart rate at one, four to six, and 24 hours in those receiving high-flow oxygen therapy when compared to pre-intervention baselines. There was also probably a reduced risk of treatment escalation in those receiving high-flow when compared to low-flow oxygen therapy (risk ratio (RR) 0.55, 95% CI 0.39 to 0.79; P = 0.001, I2 = 43%; 8 studies, 2215 participants; moderate-certainty evidence). We found no difference in the incidence of adverse events (RR 1.2, 95% CI 0.38 to 3.74; P = 0.76, I2 = 26%; 4 studies, 1789 participants; low-certainty evidence) between the two groups. The lack of comparable outcomes in studies comparing high-flow and CPAP, as well as the small numbers of participants, limited our ability to perform meta-analysis on this group. AUTHORS' CONCLUSIONS: High-flow nasal cannula therapy may have some benefits over low-flow oxygen for infants with bronchiolitis in terms of a greater improvement in respiratory and heart rates, as well as a modest reduction in the length of hospital stay and duration of oxygen therapy, with a reduced incidence of treatment escalation. There does not appear to be a difference in the number of adverse events. Further studies comparing high-flow nasal cannula therapy and CPAP are required to demonstrate the efficacy of one modality over the other. A standardised clinical definition of bronchiolitis, as well as the use of a validated clinical severity score, would allow for greater and more accurate comparison between studies.