ROX (Respiratory rate-OXygenation) index to predict early response to high-flow nasal cannula therapy in infants with viral bronchiolitis.

INTRODUCTION: High-flow nasal cannula (HFNC) is commonly used as first step respiratory support in infants with moderate-to-severe acute viral bronchiolitis (AVB). This device, however, fails to effectively manage respiratory distress in about a third of patients, and data are limited on determinants of patient response. The respiratory rate-oxygenation (ROX) index is a relevant tool to predict the risk for HFNC failure in adult patients with lower respiratory tract infections. The primary objective of this study was to assess the relationship between ROX indexes collected before and 1 h after HFNC initiation, and HFNC failure occurring in the following 48 h in infants with AVB. METHOD: This is an ancillary study to the multicenter randomized controlled trial TRAMONTANE 2, that included 286 infants of less than 6 months with moderate-to-severe AVB. Collection of physiological variables at baseline (H0), and 1 h after HFNC (H1), included heart rate (HR), respiratory rate (RR), fraction of inspired oxygen (FiO2), respiratory distress score (modified Wood's Clinical Asthma Score [mWCAS]), and pain and discomfort scale (EDIN). ROX and ROX-HR were calculated as SpO 2 FiO 2 RR $\frac{\left(\frac{{\mathrm{SpO}}_{2}}{{\mathrm{FiO}}_{2}}\right)}{\mathrm{RR}}$ and 100 × ROX HR $100\times \frac{\mathrm{ROX}}{\mathrm{HR}}$ , respectively. Predefined HFNC failure criteria included increase in respiratory distress score or RR, increase in discomfort, and severe apnea episodes. The accuracies of ROX, ROX-HR indexes and clinical variable to predict HFNC failure were assessed using receiver operating curve analysis. We analyzed predictive factors of HFNC failure using multivariate logistic regressions. RESULT: HFNC failure occurred in 111 of 286 (39%) infants, and for 56 (50% of the failure) of them within the first 6 h. The area under the curve of ROX indexes at H0 and H1 were, respectively, 0.56 (95% confidence interval [CI] 0.48-0.63, p = 0.14), 0.56 (95% CI 0.49-0.64, p = 0.09). ROX-HR performances were better but remained poorly discriminant. HFNC failure was associated with higher mWCAS score at H1 (p < 0.01) and lower decrease in EDIN scale during the first hour of HFNC delivery (p = 0.02). In the multivariate analyses, age and mWCAS score were were found to be independent factors associated with HFNC failure at H0. At H1, weight and mWCAS were associated factors. CONCLUSION: In this study, neither ROX index, nor physiological variables usually collected in infants with AVB had early discriminatory capacity to predict HFNC failure.

Measurement of the interbronchial angle in acute viral bronchiolitis.

BACKGROUND: Acute viral bronchiolitis (AVB) is the most common lower airway infection in children under 2 years. Attempts to determine disease severity based on clinical and radiological manifestations are a major challenge. Measurements of the anatomy of the trachea and main bronchi are not only limited to pure anthropometry, but are also useful for better care of critically ill patients. The purpose of the study is to verify the association between measurements of the interbronchial angle (ITB) and the severity of respiratory disease. METHODS: A cross-sectional study, which included all patients admitted to the Santo Antônio Children's Hospital, over a period of 1 year, with diagnosis of AVB by respiratory syncytial virus (RSV) was designed. ITB angle was measured and clinical characteristics were analyzed. Quantitative variables were compared and correlation analysis was performed using Pearson's correlation coefficient. A receiving operator characteristic (ROC) curve was performed. P-value <0.05 was statistically significant. RESULTS: A total of 425 patients with AVB due to RSV were included. Most of these patients were male and the median age was 130 days, 91.11% of them required oxygen therapy through a nasal catheter, 3.3% used noninvasive ventilation and 4% used mechanical ventilation. Those who required MV or NIV and intensive care unit support were considered severe. The mean ITB was lower for these patients than for those of lesser severity (p < 0.05). CONCLUSION: The present study demonstrates that there is an association between ITB and AVB severity. The smaller the ITB, the greater the disease severity.

Head-to-Head Comparison Between Respiratory Syncytial Virus and Human Metapneumovirus Bronchiolitis in the Setting of Increased Viral Testing.

We compared the epidemiology, severity and management of hospitalized respiratory syncytial virus (n = 305) and human metapneumovirus (n = 39) bronchiolitis in a setting with high respiratory virus testing (95% of admissions tested). Respiratory syncytial virus-positive infants were younger and tended to require more hydration support and longer hospital stays compared to human metapneumovirus-positive infants. Respiratory support requirements were similar between groups despite significant age differences.

Evidentia praxis: nirsevimab y prevención de bronquiolitis en lactantes nacidos a término / Evidentia praxis: Nirsevimab and bronchiolitis prevention in term-born infants

Analizamos la evidencia publicada sobre la eficacia y seguridad de nirsevimab, un anticuerpo monoclonal, empleado para prevenir las infecciones de vías respiratorias bajas (IVRB) por virus respiratorio sincitial (VRS) en el lactante a término. Encontramos un ensayo clínico aleatorizado controlado con placebo doble ciego que incluyó 3012 lactantes, nacidos a término o pretérmino tardío, menores de un año con un seguimiento de al menos 150 días. La calidad de la evidencia se clasificó como baja para IVRB muy grave y moderada para IVRB que precisara asistencia o ingreso. La evidencia se sustenta sobre un escaso número de eventos (para ingresos hospitalarios sólo 29 casos, para IVRB con atención médica 78), por lo que cualquier estimación debe considerarse imprecisa. La eficacia, estimada como reducción relativa del riesgo (RRR) fue del 76,4% (intervalo de confianza del 95% [IC 95]: 62,3 a 85,2) para IVRB por VRS y del 76,8% (IC 95: 49,4 a 89,4%) para ingreso. No se encontraron diferencias en cuanto a seguridad. Existen dudas sobre la importancia clínica, por los criterios de gravedad empleados, y sobre su impacto, con un número necesario a tratar para evitar una IVRB con ingreso de 63 y que requiera asistencia médica de 24. Por la información disponible parece una intervención segura, de la que no esperamos efectos adversos comunes, pero no podemos descartar efectos de baja frecuencia. Asimismo, esperamos contar pronto con estimaciones más precisas de eficacia y seguridad (AU)

We reviewed the published evidence on the efficacy and safety of nirsevimab, a monoclonal antibody, used to prevent respiratory syncytial virus (RSV) associated lower respiratory tract infections (LRTI) in term infants. We have found a randomized double-blind placebo-controlled clinical trial that included 3012 infants, born at term or late preterm, less than one year of age with a follow-up of at least 150 days. The quality of the evidence was classified as low for very severe LRTI and moderate for LRTI requiring medical care or admission. The evidence is based on a small number of events (only 29 cases for hospital admissions, 78 for IVRB with medical care), so any estimate must be considered imprecise. Efficacy, estimated as relative risk reduction (RRR) was 76.4% (95% confidence interval [95 CI]: 62.3 to 85.2) for RSV associated LRTI that required medical care and 76.8% (CI 95: 49.4 to 89.4%) for hospital admission. No differences were found in terms of safety. There are doubts about the clinical importance, due to the severity criteria used, and about its impact, with a number needed to treat of 63 to avoid a LRTI with hospital admission and of 24 to avoid LRTI requiring medical care. Based on the available information, it seems a safe intervention, from which we do not expect common adverse effects, but we cannot rule out low-frequency effects. We also expect to have more precise estimates of efficacy and safety soon. (AU)

Comentario del Comité Asesor de Vacunas de la Asociación Española de Pediatría a Evidencias en Pediatría sobre nirsevimab / Comment by the Advisory Committee on Vaccines of the Spanish Association of Paediatrics on Evidences in Paediatrics about nirsevimab

La bronquiolitis sigue siendo un problema de salud de primer orden en nuestro país, pues genera anualmente miles de consultas en Atención Primaria, colapso en las plantas de hospitalización y cuidados intensivos pediátricas y costes millonarios al Sistema Nacional de Salud. Su interés es máximo, además, porque la mayoría de los que requerirán ingreso hospitalario serán lactantes sanos, sin ningún tipo de factor de riesgo conocido. La altísima incidencia de la enfermedad y la ausencia de un tratamiento específico hace que los pediatras asistamos impasibles a esta epidemia anual, sin poder ofrecer una opción ni preventiva ni terapéutica a nuestros pacientes. En noviembre de 2022, la Agencia Europea de Medicamentos autorizó la comercialización de un anticuerpo monoclonal específico contra la proteína F del virus respiratorio sincitial (VRS), tras los resultados de los ensayos iniciales realizados en más de 3000 lactantes en los que se demostró una eficacia en la prevención de hospitalizaciones por VRS superior al 75%. En mayo de 2023 se comunicaron los resultados preliminares del estudio HARMONIE, llevado a cabo en más de 8000 individuos, representando la primera experiencia en vida real con el uso de nirsevimab y obteniéndose una eficacia superior al 80% en la prevención de hospitalización por bronquiolitis. En este texto se exponen los argumentos del Comité Asesor de Vacunas de la Asociación Española de Pediatría que sustentan la recomendación que hizo este organismo para su uso sistemático en recién nacidos y lactantes menores de 6 meses en España (AU)

Bronchiolitis continues to be a major health problem in Spain, as it generates thousands of consultations in primary care every year, a backlog in paediatric hospitalisation and intensive care wards, and millions in costs to the National Health System. Most of those who require hospital admission are healthy infants, without any known risk factor. The very high incidence of the disease and the absence of a specific treatment means that paediatricians are impassive in the face of this annual epidemic, unable to offer our patients either a preventive or therapeutic option. In November 2022, the European Medicines Agency granted marketing authorisation for a monoclonal antibody specific against respiratory syncytial virus (RSV) F protein, following results from initial trials in more than 3,000 infants that demonstrated greater than 75% efficacy in preventing RSV hospitalisations. Preliminary results from the HARMONIE study, conducted in over 8000 individuals, were reported in May 2023, representing the first real-life experience with the use of nirsevimab and showing greater than 80% efficacy in preventing hospitalisations for bronchiolitis. This text presents the arguments of the Vaccine Advisory Committee of the Spanish Association of Paediatrics to support the recommendation made by this group for its routine use in newborns and infants under 6 months of age in Spain(AU)

Bronchiolitis guidelines: what about the Italian situation in a primary care setting?

Acute viral bronchiolitis is the most common cause of hospitalization in children under 12 months of age. The variable clinical presentation and the potential for sudden deterioration of the clinical conditions require a close monitoring by healthcare professionals.In Italy, first access care for children is provided by primary care physicians (PCPs) who often must face to a heterogeneous disease presentation that, in some cases, make the management of patient with bronchiolitis challenging. Consequently, Italian studies report poor adherence to national and international guidelines processed to guide the clinicians in decision making in acute viral bronchiolitis.This paper aims to identify the potential factors contributing to the lack of adherence to the suggested guidelines derived by clear and evidence-based recommendations among primary care physicians operating in an outpatient setting, with a specific focus on the context of Italy. Particularly, we focus on the prescription of medications such as ß2-agonists, systemic steroids, and antibiotics which are commonly prescribed by PCPs to address conditions that can mimic bronchiolitis.

Multilevel analysis identifying the factors associated with RSV detection in infants admitted for viral bronchiolitis in the era of the COVID-19 pandemic.

OBJECTIVES: To identify factors independently associated with respiratory syncytial virus (RSV) detection in infants admitted for viral bronchiolitis during 3 consecutive years, before and during the COVID-19 pandemic, in Bogota, Colombia, a middle-income country with a subtropical highland climate. METHODS: An analytical cross-sectional study was conducted before and during the COVID-19 pandemic, including patients with a diagnosis of viral bronchiolitis admitted to all the hospitals of the city between January 2019 and November 2021. We evaluated a set of a priori-selected predictor variables that included individual, healthcare system, meteorological, air pollutant, and COVID-19 variables. Since the variables analyzed are hierarchical in nature, multilevel modeling was used to identify factors independently associated with detection of RSV as the causative agent of viral bronchiolitis. RESULTS: A total of 13,177 patients were included in the study. After controlling for potential confounders, it was found that age (odds ratio [OR] 0.86; 95% confidence interval [CI] 0.76-0.97), a third level of medical care institution (OR 3.05; 95% CI 1.61-5.76), temperature (OR 1.60; 95% CI 1.24-2.07), rainfall (OR 1.003, 95% CI 1.001, 1.005), NO2 (OR 0.97; 95% CI 0.95-0.99), CO (OR 0.99; 95% CI 0.99-0.99), and COVID-19 pandemic period (OR 0.84, 95% CI 0.71-0.99) were independently associated with RSV detection in our sample of patients. CONCLUSIONS: The identified factors associated with RSV detection provide additional scientific evidence that may be useful in the development of specific interventions aimed at ameliorating or preventing the impact of RSV in Bogota and probably other similar low- to middle-income countries in high-risk infants.

Variation in Early Pediatric Intensive Care Management Strategies and Duration of Invasive Mechanical Ventilation for Acute Viral Bronchiolitis in the United Kingdom: A Retrospective Multicenter Cohort Study.

OBJECTIVES: Management of mechanically ventilated patients with bronchiolitis is not standardized and duration of mechanical ventilation has been shown to vary widely between centers. The aim of this study was to examine practice in a large number of U.K. PICUs with a view to identify if early management choices relating to fluid prescription, sedative agent use, and endotracheal tube (ETT) placement were associated with differences in duration of invasive mechanical ventilation (IMV). DESIGN: Retrospective multicenter cohort study. Primary outcome was duration of IMV. A hierarchical gamma generalized linear model was used to test for associations between practice variables (sedative and neuromuscular blocking agents, route of endotracheal intubation at 24 hr and fluid balance at 48 hr) and duration of IMV after adjustment for known confounders. SETTING: Thirteen U.K. PICUs. Duration of 2 months between November and December 2019. PATIENTS: Three hundred fifty infants receiving IMV for bronchiolitis. Excluded were patients receiving long-term ventilation, extracorporeal life support, or who died before separation from IMV. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After adjustment for confounders, several variables were associated with an increase in the geometric mean duration of IMV (expressed as a percentage) including: nasal ETT use, 16% (95% CI, 1-32%); neuromuscular blockade use, 39% (95% CI, 21-61%); and fluid balance at 48 hr, 13% per 100 mL/kg positive fluid balance (95% CI, -1% to 28%). The association of sedative use varied with class of agent. The use of an alpha-2 agonist alone was associated with a reduction in duration of IMV by 19% in relation to no sedative agent (95% CI, -31 to -5%), whereas benzodiazepine uses alone or with alpha-2 agonist in combination were similar to using neither agent. CONCLUSIONS: Early management strategies for bronchiolitis were associated with the duration of IMV across U.K. centers after adjustment for confounders. Future work should prospectively assess the impact of fluid restriction, route of endotracheal intubation, and alpha-2 agonist use on duration of IMV in infants with bronchiolitis, with the aim of reducing seasonal bed pressure.

Bronchiolitis versus bronchopneumonia: navigating antibiotic use within the LRTI spectrum.

Bronchiolitis, a common reason for infant hospitalisation in South Africa (SA), is caused by viral pathogens. Bronchiolitis is typically an illness of mild to moderate severity that occurs in well-nourished children. Hospitalised SA infants frequently have severe disease and/or coexisting medical conditions, and these cases of bronchiolitis may have bacterial co-infection that requires antibiotic therapy. However, the existence of widespread antimicrobial resistance in SA warrants the judicious use of antibiotics. This commentary describes: (i) common clinical pitfalls leading to an incorrect diagnosis of bronchopneumonia; and (ii) considerations for antibiotic therapy in hospitalised infants with bronchiolitis. If antibiotics are prescribed, the indication for their use should be clearly stated, and antibiotic therapy must be stopped promptly if investigations indicate that bacterial co-infection is unlikely. Until more robust data emerge, we recommend a pragmatic management strategy to inform antibiotic use in hospitalised SA infants with bronchiolitis in whom bacterial co-infection is suspected.

Severe bronchiolitis profiling as the first step towards prevention of asthma.

Bronchiolitis is the most common respiratory infection leading to hospitalization and constitutes a significant healthcare burden. The two main viral agents causing bronchiolitis, respiratory syncytial virus (RSV) and rhinovirus (RV), have distinct cytopathic, immune response, and clinical characteristics. Different approaches have been suggested for subtyping bronchiolitis based on viral etiology, atopic status, transcriptome profiles in blood, airway metabolome, lipidomic data, and airway microbiota. The highest risk of asthma at school age has been in a subgroup of bronchiolitis characterized by older age, high prevalence of RV infection, previous breathing problems, and/or eczema. Regarding solely viral etiology, RV-bronchiolitis in infancy has been linked to a nearly three times higher risk of developing asthma than RSV-bronchiolitis. Although treatment with betamimetics and systemic corticosteroids has been found ineffective in bronchiolitis overall, it can be beneficial for infants with severe RV bronchiolitis. Thus, there is a need to develop a more individualized therapeutic approach for bronchiolitis and follow-up strategies for infants at higher risk of asthma in the future perspective.

Acute kidney injury in infants hospitalized for viral bronchiolitis.

We investigated prevalence of and factors associated with acute kidney injury (AKI) in a group of patients hospitalized with viral bronchiolitis. We retrospectively enrolled 139 children (mean age = 3.2 ± 2.1 months; males = 58.9%) hospitalized for viral bronchiolitis in a non-pediatric intensive care unit (PICU) setting. The Kidney Disease/Improving Global Outcomes creatinine criterion was used to diagnose AKI. We estimated basal serum creatinine by back-calculating it by Hoste (age) equation assuming that basal eGFR were the median age-based eGFR normative values. Univariate and multivariate logistic regression models were used to explore associations with AKI. Out of 139 patients, AKI was found in 15 (10.8%). AKI was found in 13 out of 74 (17.6%) patients with and in 2 out of 65 (3.1%) without respiratory syncytial virus (RSV) infection (p = 0.006). No patient required renal replacement therapies, while 1 out of 15 (6.7%) developed AKI stage 3, 1 (6.7%) developed AKI stage 2, and 13 (86.6%) developed AKI stage 1. Among the 15 patients with AKI, 13 (86.6%) reached the maximum AKI stage at admission, 1 (6.7%) at 48 h, and 1 (6.7%) at 96 h. At multivariate analysis, birth weight < 10th percentile (odds ratio, OR = 34.1; 95% confidence interval, CI = 3.6-329.4; p = 0.002), preterm birth (OR = 20.3; 95% CI = 3.1-129.5; p = 0.002), RSV infection (OR = 27.0; 95% CI = 2.6-279.9; p = 0.006), and hematocrit levels > 2 standard deviation score (SDS) (OR = 22.4; 95% CI = 2.8-183.6; p = 0.001) were significantly associated with AKI. CONCLUSION: About 11% of patients hospitalized with viral bronchiolitis in a non-PICU setting develop an AKI (frequently mild in degree). Preterm birth, birth weight < 10th percentile, hematocrit levels > 2SDS, and RSV infection are significantly associated with AKI in the setting of viral bronchiolitis. WHAT IS KNOWN: • Viral bronchiolitis affects children in the first months of life and in 7.5% of cases it can be complicated by acute kidney injury (AKI). • No studies investigated associations with AKI in infants hospitalized for viral bronchiolitis. WHAT IS NEW: • About 11% of patients hospitalized with viral bronchiolitis can develop an AKI (frequently mild in degree). • Preterm birth, birth weight <10th percentile, hematocrit levels > 2 standard deviation score, and respiratory syncytial virus infection are associated with AKI development in infants with viral bronchiolitis.

Respiratory effort during noninvasive positive pressure ventilation and continuous positive airway pressure in severe acute viral bronchiolitis.

OBJECTIVES: To assess if noninvasive positive pressure ventilation (NIPPV) is associated with a greater reduction in respiratory effort as compared to continuous positive airway pressure (CPAP) during severe acute bronchiolitis, with both supports set either clinically or physiologically. METHODS: Twenty infants (median [IQR] age 1.2 [0.9; 3.2] months) treated <24 h with noninvasive respiratory support (CPAP Clin, set at 7 cmH2 O, or NIPPV Clin) for bronchiolitis were included in a prospective single-center crossover study. Esogastric pressures were measured first with the baseline support, then with the other support. For each support, recordings were performed with the clinical setting and a physiological setting (CPAP Phys and NIPPV Phys), aiming at normalising respiratory effort. Patients were then treated with the optimal support. The primary outcome was the greatest reduction in esophageal pressure-time product (PTPES /min). Other outcomes included improvement of the other components of the respiratory effort. RESULTS: NIPPV Clin and Phys were associated with a lower PTPES /min (164 [105; 202] and 106 [78; 161] cmH2 O s/min, respectively) than CPAP Clin (178 [145; 236] cmH2 O s/min; p = 0.01 and 2 × 10-4 , respectively). NIPPV Clin and Phys were also associated with a significant reduction of all other markers of respiratory effort as compared to CPAP Clin. PTPES /min with NIPPV (Clin or Phys) was not different from PTPES /min with CPAP Phys. There was no significant difference between physiological and clinical settings. CONCLUSION: NIPPV is associated with a significant reduction in respiratory effort as compared to CPAP set at +7 cmH2 O in infants with severe acute bronchiolitis. CPAP Phys performs as well as NIPPV Clin.

Temporal-spatial analysis of hospitalizations for bronchiolitis in Brazil: prediction of epidemic regions and periods for immunization against the Respiratory Syncytial Virus.

OBJECTIVE: Due to the high cost and short term of passive immunization against the respiratory syncytial virus, the main virus causing acute viral bronchiolitis, predicting epidemic regions and epidemic months is extremely important. The objective of this study is to identify both the month when the seasonal peak begins and Brazilian regions and states with the highest incidence of monthly hospitalizations due acute viral bronchiolitis. METHODS: Based on data obtained from DATASUS, monthly hospitalization rates due acute viral bronchiolitis were calculated for every 10,000 live births to children under 12 months of age in all Brazilian states and the Federal District between 2000 and 2019. Seasonal autoregressive integrated moving average models were estimated to forecast monthly hospitalization rates in 2020. RESULTS: A higher incidence of hospitalizations was found for male children, especially under six months of age. As for Brazilian regions, between 2000 and 2019, the South region registered the highest incidence of hospitalizations, followed by the Southeast, Midwest, North and Northeast regions, in this order. Considering the seasonal peak, the period between March and July 2020 comprised the highest expected hospitalization rates. CONCLUSIONS: Palivizumab is suggested to be started between February/March and June/July for most Brazilian states, with the exception of Rio Grande do Sul, which, in addition to presenting the highest rates of hospitalizations for acute viral bronchiolitis per 10,000 live births, has the longest seasonal peak between May and September.

Oxygen saturation thresholds for bronchiolitis at high altitudes: a cost-effectiveness analysis.

BACKGROUND: There is evidence suggesting that exaggerated reliance on pulse oximetry (SpO2) and the use of arbitrary/inadequate thresholds of SpO2 might drive unnecessary hospitalizations for viral bronchiolitis, especially among high-altitude residents. The aim of the present study was to compare the cost-effectiveness of two oxygen SpO2 thresholds for deciding whether infants with viral bronchiolitis living at high altitudes need hospital admission or can be discharged home. METHODS: A cost-effectiveness study was performed to compare the cost and clinical outcomes of two oxygen SpO2 thresholds, adjusted or not, to an altitude above the sea level of Bogota, Colombia (2640 m), for deciding whether infants with viral bronchiolitis need hospitalization or can be discharged home. The principal outcome was avoidance of hospital admission. RESULTS: Compared to the use of an SpO2 threshold of 90%, using an SpO2 threshold of 85% in infants with viral bronchiolitis was associated with lower overall costs (US$130.4 vs. US$194.0 average cost per patient) and a higher probability of hospitalization avoided (0.7500 vs. 0.5900), thus leading to dominance. CONCLUSIONS: The use of an SpO2 threshold below 90% for deciding on hospitalization in infants with viral bronchiolitis living at high altitudes appears to be logical, secure, and cost-effective.

Bronchiolitis therapies and misadventures.

Viral bronchiolitis, which is most commonly caused by an infection with the respiratory syncytial virus (RSV), can lead to respiratory difficulties in young children which may require hospitalization. Despite years of research and medical trials, the mainstay of bronchiolitis treatment remains supportive only. This review provides an overview of the history of different treatments for bronchiolitis, including those that failed, as well as new therapies that are under study. Future studies for the treatment of bronchiolitis should consider different age-groups, important subgroups (i.e., those with a prior history of wheezing, those with a family history of asthma and those with non-RSV viral etiologies) whose response to treatment may differ from that of the composite group.