Assessment of Peak Inspiratory Flow in Young Infants with Acute Viral Bronchiolitis: Physiological Basis for Initial Flow Setting in Patients Supported with High-Flow Nasal Cannula.

OBJECTIVE: To assess the inspiratory demand in young infants with acute viral bronchiolitis to provide a physiological basis for initial flow setting for patients supported with high flow nasal cannula. STUDY DESIGN: Prospective study in 44 infants up to 6 months old with acute viral bronchiolitis, admitted to a pediatric intensive care unit from November 2017 to March 2019. Airflow measurements were performed using spirometry. The primary endpoint was the inspiratory demand as measured by peak tidal inspiratory flow (PTIF). The secondary endpoints were the relationships determined between PTIF, patient weight, and disease severity. RESULTS: Median (Q25-Q75) age and weight of the patients were 37 (20-67) days and 4.3 (3.5-5.0) kg, respectively. Mean PTIF was 7.45 (95% CI 6.51-8.39, min-max: 2.40-16.00) L/minute. PTIF indexed to weight was 1.68 (95% CI 1.51-1.85, min-max: 0.67-3.00) L/kg/minute. PTIF was <2.5 L/kg/minute in 89% (95% CI 75-96) of infants. PTIF was correlated with weight (ρ= 0 .55, P < .001) but not with markers of disease severity, including modified Woods clinical asthma score, Silverman-Andersen score, respiratory rate, fraction of inspired oxygen, and PCO2. CONCLUSIONS: High flow nasal cannula therapy is used commonly to support infants with acute viral bronchiolitis. The efficiency of the device is optimal if the flow setting matches the patient's inspiratory demand. According to our results, a flow rate of <2.5 L/kg/minute would be appropriate in most situations.

Lack of association between viral load and severity of acute bronchiolitis in infants.

OBJECTIVE:: To investigate the correlation between respiratory syncytial viral load and length of hospitalization in infants with acute wheezing episodes. METHODS:: This was a two-year, cross-sectional study of infants ≤ 12 months of age with bronchiolitis at the time of admission to a tertiary hospital. For the identification of respiratory viruses, nasopharyngeal secretions were collected. Samples were analyzed (throughout the study period) by direct immunofluorescence and (in the second year of the study) by quantitative real-time PCR. We screened for three human viruses: rhinovirus, respiratory syncytial virus, and metapneumovirus. RESULTS:: Of 110 samples evaluated by direct immunofluorescence, 56 (50.9%) were positive for a single virus, and 16 (14.5%) were positive for two or more viruses. Among those 72 samples, the most prevalent virus was respiratory syncytial virus, followed by influenza. Of 56 samples evaluated by quantitative real-time PCR, 24 (42.8%) were positive for a single virus, and 1 (1.7%) was positive for two viruses. Among those 25 samples, the most prevalent virus was again respiratory syncytial virus, followed by human rhinovirus. Coinfection did not influence the length of the hospital stay or other outcome s. In addition, there was no association between respiratory syncytial virus load and the length of hospitalization. CONCLUSIONS:: Neither coinfection nor respiratory syncytial viral load appears to influence the outcomes of acute bronchiolitis in infants. OBJETIVO:: Investigar a correlação entre a carga viral do vírus sincicial respiratório e o tempo de internação hospitalar em lactentes com episódios de sibilância aguda. MÉTODOS:: Este foi um estudo transversal de dois anos envolvendo lactentes de até 12 meses de idade com bronquiolite no momento da internação em um hospital terciário. Para a identificação dos vírus respiratórios foram coletadas secreções nasofaríngeas. As amostras foram analisadas (por todo o período do estudo) por imunofluorescência direta e (no segundo ano do estudo) por PCR quantitativa em tempo real para três vírus humanos (rinovírus, vírus sincicial respiratório e metapneumovírus). RESULTADOS:: Das 110 amostras avaliadas por imunofluorescência direta, 56 (50,9%) foram positivas para um único vírus, e 16 (14,5%) foram positivas para dois ou mais vírus. Nessas 72 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por influenza. Das 56 amostras avaliadas por PCR quantitativa em tempo real, 24 (42,8%) foram positivas para um único vírus, e 1 (1,7%) foi positiva para dois vírus. Nessas 25 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por rinovírus humano. A coinfecção não influenciou o tempo de internação ou outros desfechos. Além disso, não houve associação entre a carga viral de vírus sincicial respiratório e o tempo de internação. CONCLUSÕES:: A coinfecção e a carga viral do vírus sincicial respiratório não parecem influenciar os desfechos em lactentes com bronquiolite aguda.

Rhinopharyngeal Retrograde Clearance Induces Less Respiratory Effort and Fewer Adverse Effects in Comparison With Nasopharyngeal Aspiration in Infants With Acute Viral Bronchiolitis.

BACKGROUND: Acute viral bronchiolitis is an inflammatory disease of the lower respiratory tract. This study aimed to compare the immediate effects of retrograde rhinopharyngeal clearance with nasopharyngeal aspiration in children admitted with acute viral bronchiolitis. METHODS: This was a randomized controlled clinical trial with children admitted for acute viral bronchiolitis up to 12 months old. Subjects were divided into a nasopharyngeal aspiration group and a clearance group, submitted to retrograde rhinopharyngeal clearance with physiological solution (0.9%) instillation. In both groups, there were 3 evaluations on the same day (data collections 1, 2, and 3), including cardiorespiratory parameters, clinical score of respiratory dysfunction, and adverse effects. RESULTS: One hundred children were included, with no statistical differences between groups regarding the characteristics of the sample. There was a significant reduction (P < .05) in heart rate in data collections 1 and 2 after 10 and 30 min. The number of episodes of nasal bleeding (28 vs 1) and vomiting (11 vs 7) was higher in the aspiration group compared with the clearance group. Children classified as moderate showed a significant reduction of retractions (100% vs 84.6%) and nasal bleeding (44.8% vs 0%). An increase of 6.7 and 19.5% in wheezing and retractions, respectively, was shown for the aspiration group, whereas the clearance group showed only 4.6% for both parameters. CONCLUSIONS: The use of retrograde rhinopharyngeal clearance in the management of infants with acute viral bronchiolitis can be an alternative for the clearance of the upper airways, since it showed immediate positive effects on the occurrence of complications and signs of respiratory effort compared with nasopharyngeal aspiration. Children classified with a moderate clinical score appear to benefit the most. (ClinicalTrials.gov registration NCT02460614.).

Lack of association between viral load and severity of acute bronchiolitis in infants / Falta de associação entre carga viral e gravidade da bronquiolite aguda em lactentes

ABSTRACT Objective: To investigate the correlation between respiratory syncytial viral load and length of hospitalization in infants with acute wheezing episodes. Methods: This was a two-year, cross-sectional study of infants ≤ 12 months of age with bronchiolitis at the time of admission to a tertiary hospital. For the identification of respiratory viruses, nasopharyngeal secretions were collected. Samples were analyzed (throughout the study period) by direct immunofluorescence and (in the second year of the study) by quantitative real-time PCR. We screened for three human viruses: rhinovirus, respiratory syncytial virus, and metapneumovirus. Results: Of 110 samples evaluated by direct immunofluorescence, 56 (50.9%) were positive for a single virus, and 16 (14.5%) were positive for two or more viruses. Among those 72 samples, the most prevalent virus was respiratory syncytial virus, followed by influenza. Of 56 samples evaluated by quantitative real-time PCR, 24 (42.8%) were positive for a single virus, and 1 (1.7%) was positive for two viruses. Among those 25 samples, the most prevalent virus was again respiratory syncytial virus, followed by human rhinovirus. Coinfection did not influence the length of the hospital stay or other outcome s. In addition, there was no association between respiratory syncytial virus load and the length of hospitalization. Conclusions: Neither coinfection nor respiratory syncytial viral load appears to influence the outcomes of acute bronchiolitis in infants.

RESUMO Objetivo: Investigar a correlação entre a carga viral do vírus sincicial respiratório e o tempo de internação hospitalar em lactentes com episódios de sibilância aguda. Métodos: Este foi um estudo transversal de dois anos envolvendo lactentes de até 12 meses de idade com bronquiolite no momento da internação em um hospital terciário. Para a identificação dos vírus respiratórios foram coletadas secreções nasofaríngeas. As amostras foram analisadas (por todo o período do estudo) por imunofluorescência direta e (no segundo ano do estudo) por PCR quantitativa em tempo real para três vírus humanos (rinovírus, vírus sincicial respiratório e metapneumovírus). Resultados: Das 110 amostras avaliadas por imunofluorescência direta, 56 (50,9%) foram positivas para um único vírus, e 16 (14,5%) foram positivas para dois ou mais vírus. Nessas 72 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por influenza. Das 56 amostras avaliadas por PCR quantitativa em tempo real, 24 (42,8%) foram positivas para um único vírus, e 1 (1,7%) foi positiva para dois vírus. Nessas 25 amostras, o vírus mais prevalente foi o vírus sincicial respiratório, seguido por rinovírus humano. A coinfecção não influenciou o tempo de internação ou outros desfechos. Além disso, não houve associação entre a carga viral de vírus sincicial respiratório e o tempo de internação. Conclusões: A coinfecção e a carga viral do vírus sincicial respiratório não parecem influenciar os desfechos em lactentes com bronquiolite aguda.

Actualización en el tratamiento de bronquiolitis aguda: menos es más / Update in the treatment of acute bronchiolitis: less is more

Viral bronchiolitis is a major worldwide cause of morbidity and mortality in children under two years old. Evidence-based management guidelines suggest that there is no effective treatment for bronchiolitis and that supportive care - hydration and oxygenation - remains the cornerstone of clinical management. In this review we describe the current guidelines of treatment with emphasis in the limitation of unnecessary testing and intervention. Also, we discuss the future directions in the research of new therapies for bronchiolitis.

La bronquiolitis viral es una causa importante de morbilidad y mortalidad en niños de menos de dos años de edad en todo el mundo. Las guías clínicas basadas en la evidencia sugieren que no existe un tratamiento efectivo para la bronquiolitis y que la hidratación y una adecuada oxigenación, siguen siendo la base del manejo clínico. En esta revisión, se describen las actuales guías de tratamiento haciendo énfasis en limitar los exámenes e intervenciones innecesarias. También discutimos la investigación en nuevas terapias para la bronquiolitis.

Predictors of severity and mortality in children hospitalized with respiratory syncytial virus infection in a tropical region.

INTRODUCTION: Respiratory syncytial virus (RSV) is one of the leading causes of acute lower respiratory infection (ALRI) in infants and young children. Although ALRI is a major public health problem in developing countries located in tropical areas, studies about RSV epidemiology in these regions are scarce. METHODS: In a retrospective cohort study, we investigated the epidemiology and predictive variables that reflect disease severity and mortality in young children hospitalized with ALRI due to RSV in Colombia, South-America, during a 2-year period (2009-2011). RESULTS: Of a total of 6,344 children with a diagnosis of ALRI, we selected 2,147 (33.8%) that were positive for RSV. After controlling for pre-existing conditions, we found that independent predictors of severe disease in our population included age <6 months (RR 2.01; CI 95% 1.70-2.38; P < 0.001), prematurity (RR 1.61; CI 95% 1.20-2.17; P = 0.001), congenital heart disease (RR 2.03; CI 95% 1.16-3.54; P = 0.013), and mixed RSV-adenovirus infection (RR 2.09; CI 95% 1.60-2.73; P < 0.001). Multivariate analysis identified that cancer (RR 31.60; CI 95% 5.97-167.13; P < 0.001) is a predictor of mortality in our RSV-infected pediatric population independently of age and other co-morbidities. CONCLUSIONS: RSV is an important cause of ALRI in infants and young children living in tropical regions, especially during the rainy season. The identified predictors of severe disease and mortality should be taken into account when planning interventions to reduce the burden of ALRI in young children living in these regions.

Intravenous fluids versus gastric-tube feeding in hospitalized infants with viral bronchiolitis: a randomized, prospective pilot study.

The American Academy of Pediatrics recommends intravenous fluids for infants with bronchiolitis who are unable to sustain oral feedings. Our randomized, prospective pilot study shows that gastric tube feeding (in 31 infants) is feasible and demonstrated comparable clinical outcomes with intravenous fluids (in 20 infants) among hospitalized infants ≤6 months of age with moderate bronchiolitis.

A randomized, controlled trial of nasal phenylephrine in infants hospitalized for bronchiolitis.

OBJECTIVE: To examine the hypothesis that pharmacologic treatment of nasal obstruction, specifically alpha-adrenergic nose drops, will decrease objective signs of respiratory distress in infants with bronchiolitis. STUDY DESIGN: Forty-one infants aged 3 weeks to 12 months hospitalized for viral bronchiolitis were enrolled in this double-blinded, placebo-controlled trial of topical 0.5% phenylephrine drops. The primary outcome measure was change in oxygen saturation. Secondary outcomes were changes in respiratory scores and vital signs. RESULTS: There were no statistical differences in any of the outcome measures between groups. No adverse events were observed. Overall, participants showed an average 1.6 percentage point increase in their oxygen saturations (P = .002) and a 0.5-point improvement in respiratory score (P = .003) over the 30 minutes of the study. CONCLUSIONS: Topical nasal phenylephrine did not produce significant short-term improvements in clinical status in infants hospitalized for acute bronchiolitis.

Feeding efficiency and respiratory integration in infants with acute viral bronchiolitis.

OBJECTIVE: To examine the effects of bronchiolitis on feeding efficiency and respiratory integration. STUDY DESIGN: We studied 21 infants with bronchiolitis and 21 bottle-fed healthy infants who formed a comparison group. Repeat evaluations of half the bronchiolitis group were performed during recovery. During each feeding study we measured the duration and frequency of sucking, the frequency of single and multiple swallows, the respiratory rate, the postswallow respiratory direction, and the suck and swallow volumes. RESULTS: The infants with bronchiolitis devoted significantly less time to sucking than their healthy peers (P <.05), and the mean suck volume was reduced. Although the frequency of swallowing was slightly higher, the volume of milk consumed per swallow was almost half the amount consumed by the comparison group (P <.01). Coordination of breathing with swallowing was also less effective (P <.01). CONCLUSION: Although most aspects of feeding are less efficient during periods of respiratory illness, others are preserved or recover rapidly. Coordination of breathing during feeding is also significantly impaired.

Epidemiologic evidence of increased airway reactivity in children with a history of bronchiolitis.

Airway hyper-responsiveness, or hyper-reactivity, can be identified on clinical evaluation in a number of ways, including a history of wheezing, physician-diagnosed asthma, or the bronchial response to challenge with nonspecific stimuli such as methacholine or histamine. However, wheezing and the responses to these stimuli are not uniform within or across individuals, and in the general population there is a wide range of bronchial responsiveness that follows a normal distribution. Airway hyper-reactivity occurs in a number of settings, including acute viral bronchiolitis. Some, but not all, studies of children years after hospitalization during infancy for respiratory syncytial virus bronchiolitis or another lower respiratory tract infection demonstrate the presence of airway hyper-responsiveness. In contrast, infants studied who are <12 months of age do not have airway hyper-responsiveness after episodes of bronchiolitis. Discrepancies in the study results may reflect the bronchial challenge procedure used and the pulmonary function studies performed. Viral lower respiratory tract infections might alter immune responses to favor immunoglobulin E production, but the results of studies relating respiratory syncytial virus bronchiolitis with subsequent immunoglobulin E production again have been discrepant. Host and environmental factors such as exposure to tobacco smoke or a family history of atopy may be more important than viral lower respiratory tract infections as determinants of bronchial reactivity.

Bronquiolitis en el lactante pequeño: evolución y factores de riesgo durante su internación / Bronchiolitis in infant under four months: evolution and risk factors during hospitalization

Objetivos: Conocer las características clinicoepidemiologicas y los factores de riesgo de la bronquiolitis aguda en los lactantes menores de cuatro meses hospitalizados durante un brote estacional. Materiales y Métodos: Estudio retrospectivo de 49 historias clínicas de lactantes menores de cuatro meses ingresados en el hospital escuela del litoral de Paysandú (Uruguay) durante el período comprendido entre los meses de julio a setiembre de 1995. Resultados: El análisis de los factores de riesgo al ingreso solo mostró una relación estadísticamente significativa (p<0.05) de la hipoxia y el grado de sindrome funcional respiratorio al ingreso con una peor evolución, valorada por las necesidades de oxígeno y la persistencia de hiperactividad en los dos meses subsiguientes. Ninguno de los restantes factores de riesgo analizados (edad, prematuridad, antecedentes familiares o personales y consolidación en la radiografía de tórax) se asoció estadísticamente a un peor pronóstico, si bien se detectaron diferencias entre los grupos no estadísticamente significativas. Se administraron antibióticos en un 32,5 por ciento (n= 17) de los pacientes y broncodilatadores en un 69,3 por ciento (n=34) de los casos. Recibieron corticoides un 40,8 por ciento de pacientes (n=20), a pesar de que este tratamiento es controvertido en la entidad. Más de la mitad de los lactantes sometidos a exámen radiológico mostraron imágenes de consolidación en la radiografía de torax. Precisaron internación en unidad de cuidados intensivos 3 pacientes (6,1 por ciento) requiriendo ventilación mecánica solamente uno de ellos. No se produjo ningún exitus en nuestra serie. Conclusiones: La bronquiolitis aguda en el lactante pequeño presenta unas características especiales que marcan su evolución y tratamiento. Se halla una relación clara entre la dificultad respiratoria a su ingreso y su evolución posterior, no detectándose esta relación con otros factores de riesgo debido, probablemente al pequeño tamaño de muestra. Creemos conveniente la realización rutinaria de estudios radiográficos a todo lactante menor de cuatro meses ingresado por esta patología

Bronquiolitis en el lactante pequeño: evolución y factores de riesgo durante su internación / Bronchiolitis in infant under four months: evolution and risk factors during hospitalization

Objetivos: Conocer las características clinicoepidemiologicas y los factores de riesgo de la bronquiolitis aguda en los lactantes menores de cuatro meses hospitalizados durante un brote estacional. Materiales y Métodos: Estudio retrospectivo de 49 historias clínicas de lactantes menores de cuatro meses ingresados en el hospital escuela del litoral de Paysandú (Uruguay) durante el período comprendido entre los meses de julio a setiembre de 1995. Resultados: El análisis de los factores de riesgo al ingreso solo mostró una relación estadísticamente significativa (p<0.05) de la hipoxia y el grado de sindrome funcional respiratorio al ingreso con una peor evolución, valorada por las necesidades de oxígeno y la persistencia de hiperactividad en los dos meses subsiguientes. Ninguno de los restantes factores de riesgo analizados (edad, prematuridad, antecedentes familiares o personales y consolidación en la radiografía de tórax) se asoció estadísticamente a un peor pronóstico, si bien se detectaron diferencias entre los grupos no estadísticamente significativas. Se administraron antibióticos en un 32,5 por ciento (n= 17) de los pacientes y broncodilatadores en un 69,3 por ciento (n=34) de los casos. Recibieron corticoides un 40,8 por ciento de pacientes (n=20), a pesar de que este tratamiento es controvertido en la entidad. Más de la mitad de los lactantes sometidos a exámen radiológico mostraron imágenes de consolidación en la radiografía de torax. Precisaron internación en unidad de cuidados intensivos 3 pacientes (6,1 por ciento) requiriendo ventilación mecánica solamente uno de ellos. No se produjo ningún exitus en nuestra serie. Conclusiones: La bronquiolitis aguda en el lactante pequeño presenta unas características especiales que marcan su evolución y tratamiento. Se halla una relación clara entre la dificultad respiratoria a su ingreso y su evolución posterior, no detectándose esta relación con otros factores de riesgo debido, probablemente al pequeño tamaño de muestra. Creemos conveniente la realización rutinaria de estudios radiográficos a todo lactante menor de cuatro meses ingresado por esta patología(AU)

Bronquiolite viral aguda: terapêutica medicamentosa atual / Acute viral bronchiolitis

O papel que broncodiltadores e glicocorticóides ocupam na terapêutica atual da bronqiolite viral aguda é ainda discutido. A metodologia empregada nas publicaçöes disponíveis sobre o assunto é analisada criticamente. Os mecanismos etiopatogênicos desta doença säo abordados para um melhor entendimento e justificativa de uma proposta terapêutica. Recentes artigos permitem-nos opinar que toda criança com diagnóstico de bronquiolite aguda, de moderada a grave intensidade, deve receber o benefício de uma tentativa terapêutica inicial com broncodilatadores simpaticomiméticos. Da mesma forma, em casos severos refratários a esta primeira medida, é recomendável o uso de aminofilina intravenosa. A açäo dos glicocorticóides é ainda discutível, havendo necessidaade de novos estudos para que se possa fazer alguma afirmaçäo definitiva sobre seu uso nessa afecçäo. Tem sido aceito, no entanto, por alguns autores, sua associaçäo aos broncodilatadores, naqueles casos de agravamento progressivo refratários a terapêutica prévia

Thoracoabdominal asynchrony in infants with airflow obstruction.

Thoracoabdominal asynchrony (TAA) has long been thought clinically useful in the assessment of airflow obstruction (AO) in infants. To test the hypothesis that the measurement of TAA is useful in the assessment of lung mechanics in infants with AO, we have used respiratory inductive plethysmography (RIP) to quantity TAA. We compared changes in TAA to changes in lung mechanics before and after aerosolized bronchodilator (BD) administration in 13 infants. Abdominal wall (AB) and rib cage (RC) motion were displayed on an X-Y recorder in a Lissajous figure. Asynchrony between RC and AB motion was quantified by comparing the width m of the Lissajous figure (difference between AB inspiratory and expiratory positions) at mid-RC excursion with the total AB excursion at its extremes (s). Phase angle phi ws computed as sin phi = m/s (or phi = 180 degrees - mu, where sin mu = m/s for phase angles greater than 90 degrees) and was taken as a measure of TAA. Lung resistance RL and elastance EL were calculated from esophageal pressure (Pes), mouth pressure, tidal volume, and tidal flow. All infants displayed TAA at baseline. After BD administration, TAA decreased in those infants in whom RL decreased. The percentage decrease in the phase angle from baseline after BD administration was significantly correlated with the decrease in peak-to-peak Pes (delta Pes) and the percentage decrease in RL and EL. We conclude that AO in infants leads to TAA through altered pleural pressure swings acting on the compliant chest wall. Changes in lung mechanics induced by bronchodilators are reflected in changes in TAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronquiolitis / Bronchiolitis

Se presenta la revisión actualizada de la bronquiolitis, considerándola como una enfermedad infecciosa aguda obstructiva del tramo respiratorio bronquilar, muy frecuente en niños menores de dos años de edad, en particular lactantes menores y causa importante de hospitalización. Enfasis especial se hace en su etiología viral (virus sincicial respiratorio, parainfluenza 3, adenovirus, mycoplasma) describiéndose en detalle anatomía patológica, fisiopatogenia, alteraciones fisiopatológicas, manifestaciones clínicas, repercusiones locales y generales, metodología, diagnóstico y control médico, preferente o necesariamente en hospitalización, con medidas básicas de enfermería, oxigenación, humidificación, hidratación y corrección del equilibrio acidobase, señalándose la ineficacia y peligro de los broncodilatadores y los aerosoles mucolíticos y la muy limitada indicación para el empleo de antibióticos, antiinflamatorios, cardiotónicos y respiración asistida. Finalmente se formulan consideraciones sobre autolimitación habitual del padecimiento y sus posibles complicaciones así como sobre pronóstico y medidas preventivas.

Normal pulmonary function measurements and airway reactivity in childhood after mild bronchiolitis.

Concern about the long-term sequelae of bronchiolitis has been raised through studies of children hospitalized for bronchiolitis, but the long-term sequelae of mild bronchiolitis have not been studied. We assessed the hypothesis that 25 children with mild bronchiolitis (index subjects) were at greater risk for abnormalities of pulmonary function or airway reactivity to cold air between the ages of 8 and 12 years than were randomly selected, matched controls. There were no consistent differences in pulmonary function or airway reactivity between index and control groups. Airway hyperreactivity was found in five control subjects and three index subjects, and all children with symptomatic asthma were identified by cold air challenge. Our data suggest that children with a history of mild bronchiolitis are not at increased risk between ages 8 and 12 years for airway hyperreactivity or for abnormalities in pulmonary function.