Bronchodilators for bronchiolitis

Asthma pharmacotherapy: an update on leukotriene treatments

Introduction: Asthma is a chronic inflammatory disease of the airways with a large heterogeneity of clinical phenotypes. There has been increasing interest regarding the role of cysteinyl leukotriene (LT) and leukotriene receptor antagonists (LTRA) in asthma treatment.Areas covered: This review summarized the data (published in PubMed during 1984-2019) regarding LTRA treatment in asthma and LTs-related airway inflammation mechanisms. Involvement of LTs C₄/D₄/E₄ has been demonstrated in the several aspects of airway inflammation and remodeling. Novel pathways related to LTE₄, the most potent mediator, and its respective receptors have recently been studied. Antagonists against cysteinyl leukotriene receptor (CysLTR) type 1, including montelukast, pranlukast and zafirlukast, have been widely prescribed in clinical practices; however, some clinical trials have shown insignificant responses to LTRAs in adult asthmatics, while some phenotypes of adult asthma showed more favorable responses to LTRAs including aspirin-exacerbated respiratory disease, elderly asthma, asthma associated with smoking, obesity and allergic rhinitis.Expert opinion: Further investigations are needed to understand the role of LTs in airway inflammation and remodeling of the asthmatic airways. There is a lack of biomarkers to predict responsiveness to LTRA, especially in adult asthmatics. Besides CysLTR1 antagonists, targets aiming other LT pathways should be considered.

Lung ultrasound in infants with bronchiolitis

Lung ultrasound (LUS) is nowadays a fast-growing field of study since the technique has been widely acknowledged as a cost-effective, radiation free, and ready available alternative to standard X-ray imaging. However, despite extensive acoustic characterization studies and documented medical evidences, a lot is still unknown about how ultrasounds interact with lung tissue. One of the most discussed lung artifacts are the B-lines [in all ages] and the subpleural consolidations (in young infants). Recently, LUS has been claimed to be able to detect pneumonia in infants with bronchiolitis, although this can be an overestimation due to the peculiar physiology of small peripheral airways of the pediatric lung (particularly in neonate/infants). Distinguishing consolidations from atelectasis in young infants with bronchiolitis can be challenging and those criteria well defined for adults and older children (size and bronchogram) cannot easily translated in this specific subset. Therefore, if decades of studies clearly defined the low risk of SBI in bronchiolitis, we need to be careful before stating that LUS may confirm pneumonia in such a high number of cases and, importantly, new and promising techniques such as LUS should give us new insights bringing us to improvements and not back to overuse of antibiotics. More studies are surely need on this topic.

A systematic review of the psychometric properties of bronchiolitis assessment tools

AIM

The aim of this study was to assess the psychometric properties of tools developed for the purpose of assessing infants with bronchiolitis.

BACKGROUND

Bronchiolitis is the leading cause of hospitalization in infants under the age of 1 year. Several bronchiolitis assessment tools have been developed primarily for use in randomized control trials of medical treatments for infants with bronchiolitis, however, the reliability and validity of many of these tools is not well reported.

DESIGN

Systematic review.

DATA SOURCES

CINAHL, MEDLINE, EMBASE and PubMed electronic databases were searched between January 1960-December 2015 using the key words 'bronchiolitis' and 'assessment' or 'screen' or 'tool' or 'scale' or 'score'.

REVIEW METHODS

A systematic review of the psychometric properties of bronchiolitis assessment tools was undertaken using the COSMIN checklist.

RESULTS

Fourteen studies meeting the inclusion criteria were reviewed and the methodological quality of the studies and reported psychometric properties of 11 instruments were assessed. Overall, the reliability and validity of bronchiolitis assessment tools was poorly established. Although several studies reported that their tools had good inter-rater reliability, the methodological quality of these studies was generally poor. Only one study underwent psychometric testing that was assessed as being of excellent quality. The Respiratory Distress Assessment Index was deemed to have undergone the most rigorous psychometric testing but had poor to moderate construct validity and considerable test-retest error.

CONCLUSION

Current bronchiolitis assessment tools lack clearly established reliability and validity and may not be sensitive to clinically meaningful outcomes for patients.

Prevention of Respiratory Syncytial Virus Infection: From Vaccine to Antibody

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract disease in infants and young children. Initial efforts to develop a vaccine to prevent RSV lower respiratory tract disease in children were halted because of serious adverse events that occurred when children were infected with RSV following vaccination, including vaccine-related deaths. Subsequently, a major focus for researchers was to understand what led to these adverse events. Investment in a vaccine for RSV continues, and new strategies are under development. Success to prevent RSV disease was met by the development of immunoprophylaxis, first with intravenous immunoglobulin and then with recombinant monoclonal antibody. The story of immunoprophylaxis for RSV includes the first-in-class use of antibody technology for infectious disease, and palivizumab currently remains the only way to prevent serious lower respiratory tract disease due to RSV infection.

Nebulized Magnesium Sulfate in Acute Bronchiolitis: A Randomized Controlled Trial

OBJECTIVE

To assess the efficacy of nebulized magnesium sulfate as a bronchodilator in infants hospitalized with acute bronchiolitis.

METHODS

This three-center double masked randomized clinical trial comprised 120 children with moderate to severe bronchiolitis. They were randomly assigned into two groups: the first group was treated with nebulized magnesium sulfate (40 mg/kg) and nebulized epinephrine (0.1 ml/kg) and the second group (control) was treated with nebulized epinephrine (0.1 ml/kg). The primary outcome was the length of hospital stay. The use of oxygen, temperature, oxygen saturation (SPO2), pulse rate (PR), respiratory rate (RR) and respiratory distress assessment instrument (RDAI) score were measured in the beginning of the study and during hospitalization.

RESULTS

The mean (SD) age of 120 infants was 5.1(± 2.6) mo and 60% were boys. The length of hospital stay was not different between the two groups (P > 0.01). Use of oxygen supplementation, SPO2 and vital signs were similar in the two groups. Improvement in RDAI score was significantly better in infants treated with nebulized magnesium sulfate than in the other group (P 0.01).

CONCLUSIONS

Thus, in infants with acute bronchiolitis, the effect of nebulized magnesium sulfate is comparable to nebulized epinephrine. However nebulized magnesium sulfate can improve the clinical score so it may have additive effect to reduce symptoms during hospitalization.

Effect of combined dexamethasone therapy with nebulized r-epinephrine or salbutamol in infants with bronchiolitis: A randomized, double-blind, controlled trial

Background:

This study investigated the effect of combining oral dexamethasone with either nebulized racemic epinephrine or salbutamol compared to bronchodilators alone for the treatment of infants with bronchiolitis.

Materials and Methods:

This was a double-blind, randomized controlled trial on infants (1 to 12 months) who were diagnosed in the emergency department with moderate-to-severe bronchiolitis. The primary outcome was the rate of hospital admission within 7 days of the first dose of treatment, and the secondary outcomes were changes in respiratory distress assessment instrument score, heart rate, respiratory rate, and oxygen saturation (O₂ Sat) over a 4-hour observation period. Infants (n = 162) were randomly assigned to four groups: A (dexamethasone + racemic epinephrine) = 45, B (placebo and racemic epinephrine) =39, C (dexamethasone and salbutamol) = 40, or D (placebo and salbutamol) = 38.

Results:

Patients who had received dexamethasone + epinephrine exhibited similar admission rates compared to placebo + epinephrine or salbutamol (P = 0.64). Similarly, no statistically significant difference was observed in the rate of hospitalization for patients who received dexamethasone + salbutamol compared to those who received placebo + epinephrine or salbutamol (P = 0.51). Clinical parameters were improved at the end of the 4-hour observation period for all treatment groups. Treatment with dexamethasone + epinephrine resulted in a statistically significant change in HR over time (P < 0.005) compared to the other groups.

Conclusions:

This study adds to a body of evidence suggesting that corticosteroids have no role in the management of bronchiolitis for young infants who are first time wheezers with no risk of atopy.

Respiratory syncytial virus: current and emerging treatment options

Respiratory syncytial virus (RSV) is an important respiratory pathogen in infants and children worldwide. Although RSV typically causes mild upper respiratory infections, it frequently causes severe morbidity and mortality, especially in premature infants and children with other chronic diseases. Treatment of RSV is limited by a lack of effective antiviral treatments; however, ribavirin has been used in complicated cases, along with the addition of intravenous immune globulin in specific patients. Vaccination strategies for RSV prevention are heavily studied, but only palivizumab (Synagis^®) has been approved for use in the United States in very select patient populations. Research is ongoing in developing additional vaccines, along with alternative therapies that may help prevent or decrease the severity of RSV infections in infants and children. To date, we have not seen a decrement in RSV morbidity and mortality with our current options; therefore, there is a clear need for novel RSV preventative and therapeutic strategies. In this review, we discuss the current and evolving trends in RSV treatment for infants and children.

Clinical profile of bronchiolitis in infants younger than 90 days in Saudi Arabia

Background:

Bronchiolitis is a self-limiting disease of children caused by viral infections of the small airways with a wide spectrum of illness severity. Search of the literature reveals a need for refinement of criteria for testing for concomitant severe bacterial infections as well as appropriate therapeutic interventions for patients <90-day-old diagnosed with clinical bronchiolitis. We believe that a better understanding of the disease spectrum will help optimize health-care delivery to these patients.

Aims:

The aim of this study was to determine the clinical profile at presentation, disease course and outcome of bronchiolitis in <3-month-old infants who presented to our Pediatric Emergency Department (PED) during one disease season.

Settings:

Retrospective chart review during one bronchiolitis season, from November 1, 2011 to April 20, 2012.

Subjects:

All <90-day-old infants presenting with clinical bronchiolitis presenting to Urban PED of a tertiary care university hospital during one bronchiolitis season.

Materials and Methods:

A retrospective chart review based on computer records of all emergency department visits of infants less than 90 days with a clinical diagnosis of bronchiolitis, covering the period between November 1, 2011 and April 30, 2012.

Results:

Out of the total of 1895 infants <90 days of age, 141 had a clinical diagnosis of bronchiolitis and 35 needed admission to hospital. Blood for culture was obtained from 47 infants, urine for culture was obtained from 46 infants and cerebrospinal fluid for culture was obtained from eight infants. One case of bacteremia was documented, but this was found to be a contaminant. No cases of meningitis occurred among these infants. However, one infant had a positive urine culture consistent with infection (Escherichia coli).

Conclusion:

Based on the results, it can be conclude that the risk of bacteremia or meningitis among infants <90 days of age with fever and bronchiolitis is low. The risk of urinary tract infection in this age group is also low, but it is higher than the risk for meningitis or bacteremia. Our data for admission and treatment guidelines are similar to those published from other countries.

Acute bronchiolitis in a paediatric emergency department of Northern Greece. Comparisons between two decades

INTRODUCTION

Acute bronchiolitis is the most common lower respiratory tract infection in infants and toddlers concerning small bronchi or bronchioli. This retrospective study aimed to evaluate the incidence of acute bronchiolitis and the use of β(2)-agonists between two different decades.

MATERIAL AND METHODS

During 1990-1991 and 2001-2002, the files of the 2(nd) Paediatric Emergency Department of Aristotle University of Thessaloniki, AHEPA Hospital were reviewed and cases of acute bronchiolitis were recorded and analysed.

RESULTS

During 1990-1991, 14 538 children were identified with respiratory infections and bronchiolitis was diagnosed in 519/14 538 children (3.56%). Only 34 out of 519 patients received nebulised salbutamol (6.6%) and 221/519 were hospitalized (42.6%). During 2001-2002, 9001 children were found to have respiratory tract infections and acute bronchiolitis was diagnosed in 641/9001 of them (7.12%). In total, 411/641 children (64.1%) received salbutamol and ipratropium, and 89/641 patients (13.88%) were hospitalized. There was a predominance of male sex in both decades (p = 0.509). There was a statistically significant difference (p < 0.001) concerning the use of nebulised salbutamol with nebulised ipratropium between the two decades. Finally, during 2001-2002, the use of bronchodilators with or without corticosteroids was more frequent and it appears to be correlated with the reduced number of admissions to hospital (p < 0.05) compared with 1990-1991.

CONCLUSIONS

There was an increase in the incidence of acute bronchiolitis during the last decade. The admission rate decreased probably due to the use of nebulized salbutamol and ipratropium, but further multicentre comparative trials are required to define the role of bronchodilators in the treatment of acute bronchiolitis.

Variability in the diagnostic labeling of nonbacterial lower respiratory tract infections: a multicenter study of children who presented to the emergency department

OBJECTIVE

The diagnostic labeling of presumed nonbacterial lower respiratory tract infection is unclear. Our objective was to identify patterns of specific diagnoses and treatments that were given to children who presented with lower respiratory tract infection to US academic emergency departments.

METHODS

Data were collected on all children who were aged <2 years and had lower respiratory tract infection symptoms during a similar 2- to 3-week winter period at 4 pairs of emergency departments from the same state or region. The children were identified by using relevant International Classification of Diseases, Ninth Revision, Clinical Modification codes in the primary diagnosis field. Data were collected by using standardized chart review forms for the index emergency department visit and also for 1 month before through 1 year after the index visit.

RESULTS

Among the 928 children who presented with lower respiratory tract infection symptoms, 676 (73%) were younger than 12 months and 624 (67%) had a primary diagnosis of bronchiolitis. When comparing the assigned diagnoses between emergency department pairs, bronchiolitis was the more common diagnosis at certain hospitals, whereas asthma, cough, and wheeze were more frequent at others. Independent predictors of corticosteroid treatment were visiting specific emergency departments, older age, an asthma diagnosis (compared with bronchiolitis), documented history of wheezing, observed wheezing during the index visit, eosinophil values >4%, previous use of corticosteroids, and parental history of asthma.

CONCLUSIONS

For children who are age <2 years and present to an emergency department with lower respiratory tract infection symptoms, there is large variability in the assigned diagnosis. Children who present to emergency departments that more commonly diagnose lower respiratory tract infection as "asthma" are more likely to receive corticosteroids. As clinicians, we need to develop evidence- and outcome-based definitions for lower respiratory tract infections to guide diagnosis and treatment better.

A double-blind, placebo-controlled, randomized trial of montelukast for acute bronchiolitis

BACKGROUND

Cysteinyl leukotrienes are implicated in the inflammation of bronchiolitis. Recently, a specific cysteinyl leukotriene receptor antagonist, montelukast (Singulair [MSD, Haarlem, Netherlands]), has been approved for infants in granule sachets.

OBJECTIVE

Our goal was to evaluate the effect of montelukast on clinical progress and on cytokines in acute bronchiolitis.

METHODS

This was a randomized, placebo-controlled, double-blind, parallel-group study in 2 medical centers. Fifty-three infants (mean age: 3.8+/-3.5 months) with a first episode of acute bronchiolitis were randomly assigned to receive either 4-mg montelukast sachets or placebo, every day, from hospital admission until discharge. The primary outcome was length of stay, and secondary outcomes included clinical severity score (maximum of 12) and changes in type 1 and 2 cytokine levels (including interleukin4/IFN-gamma ratio as a surrogate for the T-helper 2/T-helper 1 ratio) in nasal lavage.

RESULTS

Both groups were comparable at baseline, and cytokine levels correlated positively with disease severity. There were neither differences in length of stay (4.63+/-1.88 [placebo group] vs 4.65+/-1.97 days [montelukast group]) nor in clinical severity score and cytokine levels between the 2 groups. No differences in interleukin 4/IFN-gamma ratio between the 2 groups were seen. There was a slight tendency for infants in the montelukast group to recover more slowly than those in the placebo group (clinical severity score at discharge: 6.1+/-2.4 vs 4.8+/-2.2, respectively).

CONCLUSIONS

Montelukast did not improve the clinical course in acute bronchiolitis. No significant effect of montelukast on the T-helper 2/T-helper 1 cytokine ratio when given in the early acute phase could be demonstrated.

Challenges to improving case management of childhood pneumonia at health facilities in resource-limited settings

Effective case management is an important strategy to reduce pneumonia-related morbidity and mortality in children. Guidelines based on sound evidence are available but are used variably. This review outlines current guidelines for childhood pneumonia management in the setting where most child pneumonia deaths occur and identifies challenges for improved management in a variety of settings and different "at-risk" groups. These include appropriate choice of antibiotic, clinical overlap with other conditions, prompt and appropriate referral for inpatient care, and management of treatment failure. Management of neonates, and of HIV-infected or severely malnourished children is more complicated. The influence of co-morbidities on pneumonia outcome means that pneumonia case management must be integrated within strategies to improve overall paediatric care. The greatest potential for reducing pneumonia-related deaths in health facilities is wider implementation of the current guidelines built around a few core activities: training, antibiotics and oxygen. This requires investment in human resources and in equipment for the optimal management of hypoxaemia. It is important to provide data from a variety of epidemiological settings for formal cost-effectiveness analyses. Improvements in the quality of case management of pneumonia can be a vehicle for overall improvements in child health-care practices.

Epidemiologic, experimental, and clinical links between respiratory syncytial virus infection and asthma

Virtually all children experience respiratory syncytial virus (RSV) infection at least once during the first 2 years of life, but only a few develop bronchiolitis and more severe disease requiring hospitalization, usually in the first 6 months of life. Children who recover from RSV-induced bronchiolitis are at increased risk for the development of recurrent wheeze and asthma in later childhood. Recent studies suggest that there is an association between RSV-induced bronchiolitis and asthma within the first decade of life but that this association is not significant after age 13. Despite the considerable progress made in our understanding of several aspects of respiratory viral infections, further work needs to be done to clarify the molecular mechanisms of early interactions between virus and host cell and the role of host gene products in the infection process. This review provides a critical appraisal of the literature in epidemiology and experimental research which links RSV infection to asthma. Studies to date demonstrate that there is a significant association between RSV infection and childhood asthma and that preventing severe primary RSV infections can decrease the risk of childhood asthma.

Computerized acoustic assessment of treatment efficacy of nebulized epinephrine and albuterol in RSV bronchiolitis

Aim

We evaluated the use of computerized quantification of wheezing and crackles compared to a clinical score in assessing the effect of inhaled albuterol or inhaled epinephrine in infants with RSV bronchiolitis.

Methods

Computerized lung sounds analysis with quantification of wheezing and crackles and a clinical score were used during a double blind, randomized, controlled nebulized treatment pilot study. Infants were randomized to receive a single dose of 1 mgr nebulized l-epinephrine or 2.5 mgr nebulized albuterol. Computerized quantification of wheezing and crackles (PulmoTrack^®) and a clinical score were performed prior to, 10 minutes post and 30 minutes post treatment. Results were analyzed with Student's t-test for independent samples, Mann-Whitney U test and Wilcoxon test.

Results

15 children received albuterol, 12 received epinephrine. The groups were identical at baseline. Satisfactory lung sounds recording and analysis was achieved in all subjects. There was no significant change in objective quantification of wheezes and crackles or in the total clinical scores either within the groups or between the groups. There was also no difference in oxygen saturation and respiratory distress.

Conclusion

Computerized lung sound analysis is feasible in young infants with RSV bronchiolitis and provides a non-invasive, quantitative measure of wheezing and crackles in these infants.

Trial registration number: ClinicalTrials.gov NCT00361452

Recombinant Human Deoxyribonuclease in Infants With Respiratory Syncytial Virus Bronchiolitis

BACKGROUND

Treatment of hospitalized infants with respiratory syncytial virus (RSV) bronchiolitis is mainly supportive. Bronchodilators and systemic steroids are often used but do not reduce the length of hospital stay. Because hypoxia and airways obstruction develop secondary to viscous mucus in infants with RSV bronchiolitis, and because free DNA is present in RSV mucus, we tested the efficacy of the mucolytic drug recombinant human deoxyribonuclease (rhDNase).

METHODS

In a multicenter, randomized, double-blind, controlled clinical trial, 225 oxygen-dependent infants admitted to the hospital for RSV bronchiolitis were randomly assigned to receive 2.5 mg bid of nebulized rhDNase or placebo until discharge. The primary end point was length of hospital stay. Secondary end points were duration of supplemental oxygen, improvement in symptom score, and number of intensive care admissions.

RESULTS

There were no significant differences between the groups with regard to the length of hospital stay (p = 0.19) or the duration of supplemental oxygen (p = 0.07). The ratio (rhDNase/placebo) of geometric means of length of stay was 1.12 (95% confidence interval, 0.96 to 1.33); for the duration of supplemental oxygen, the ratio was 1.28 (95% confidence interval, 0.97 to 1.68). There were no significant differences in the rate of improvement of the symptom score or in the number of intensive care admissions.

CONCLUSIONS

Administration of rhDNase did not reduce the length of hospital stay or the duration of supplemental oxygen in oxygen-dependent infants with RSV bronchiolitis.

Beta2-agonists for asthma: the pediatric perspective

Inhaled beta-agonists are commonly prescribed for the treatment of wheezing disorders in infants and children. Despite this, there are concerns that these medications have potentially detrimental effects on lung health and symptoms. We will review the ontogeny of beta-agonist receptor and smooth muscle development from fetal life through infancy and childhood as well as the evidence supporting the clinical utility of beta-agonists in wheezing infants and asthmatic children. Finally, the potential detrimental effects of long- and short-acting beta-agonists in infants and children are discussed.

Treatment in the pediatric emergency department is evidence based: a retrospective analysis

BACKGROUND

Our goal was to quantify the evidence that is available to the physicians of a pediatric emergency department (PED) in making treatment decisions. Further, we wished to ascertain what percentage of evidence for treatment provided in the PED comes from pediatric studies.

METHODS

We conducted a retrospective chart review of randomly selected patients seen in the PED between January 1 and December 31, 2002. The principal investigator identified a primary diagnosis and primary intervention for each chart. A thorough literature search was then undertaken with respect to the primary intervention. If a randomized control trial (RCT) or a systematic review was found, the intervention was classified as level I evidence. If no RCT was found, the intervention was assessed by an expert committee who determined its appropriateness based on face validity (RCTs were unanimously judged to be both unnecessary and, if a placebo would have been involved, unethical). These interventions were classified as level II evidence. Interventions that did not fall into either above category were classified as level III evidence.

RESULTS

Two hundred and sixty-two patient charts were reviewed. Of these, 35.9% did not receive a primary intervention. Of the 168 interventions assessed, 80.4% were evidence-based (level I), 7.1% had face validity (level II) and 12.5% had no supporting evidence (level III). Of the evidence-based interventions, 83.7% were supported by studies with mostly pediatric patients.

CONCLUSION

Our study demonstrates that a substantial proportion of PED treatment decisions are evidence-based, with most based on studies in pediatric patients. Also, a large number of patients seen in the PED receive no intervention.

Diagnosis and management of bronchiolitis

Bronchiolitis is a disorder most commonly caused in infants by viral lower respiratory tract infection. It is the most common lower respiratory infection in this age group. It is characterized by acute inflammation, edema, and necrosis of epithelial cells lining small airways, increased mucus production, and bronchospasm. The American Academy of Pediatrics convened a committee composed of primary care physicians and specialists in the fields of pulmonology, infectious disease, emergency medicine, epidemiology, and medical informatics. The committee partnered with the Agency for Healthcare Research and Quality and the RTI International-University of North Carolina Evidence-Based Practice Center to develop a comprehensive review of the evidence-based literature related to the diagnosis, management, and prevention of bronchiolitis. The resulting evidence report and other sources of data were used to formulate clinical practice guideline recommendations. This guideline addresses the diagnosis of bronchiolitis as well as various therapeutic interventions including bronchodilators, corticosteroids, antiviral and antibacterial agents, hydration, chest physiotherapy, and oxygen. Recommendations are made for prevention of respiratory syncytial virus infection with palivizumab and the control of nosocomial spread of infection. Decisions were made on the basis of a systematic grading of the quality of evidence and strength of recommendation. The clinical practice guideline underwent comprehensive peer review before it was approved by the American Academy of Pediatrics. This clinical practice guideline is not intended as a sole source of guidance in the management of children with bronchiolitis. Rather, it is intended to assist clinicians in decision-making. It is not intended to replace clinical judgment or establish a protocol for the care of all children with this condition. These recommendations may not provide the only appropriate approach to the management of children with bronchiolitis.

Chest radiography in children aged 2-59 months diagnosed with non-severe pneumonia as defined by World Health Organization: descriptive multicentre study in Pakistan

OBJECTIVES

To evaluate the chest radiographs of children diagnosed with non-severe pneumonia on the basis of the current World Health Organization guidelines (fast breathing alone) for radiological evidence of pneumonia.

DESIGN

Descriptive analysis.

SETTING

Outpatient departments of six hospitals in four cities in Pakistan.

PARTICIPANTS

2000 children with non-severe pneumonia were enrolled; 1932 children were selected for chest radiography.

INTERVENTIONS

Two consultant radiologists used standardised WHO definitions to evaluate chest radiographs; no clinical information was made available to them. If they disagreed, the radiographs were read by a third radiologist; the final classification was based on agreement between two of the three radiologists.

MAIN OUTCOME MEASURES

Presence or absence of pneumonia on radiographs.

RESULTS

Chest radiographs were reported normal in 1519 children (82%). Radiological evidence of pneumonia was reported in only 263 (14%) children, most of whom had interstitial pneumonitis. Lobar consolidation was present in only 26 children. The duration of illness did not correlate significantly with the presence of radiological changes (relative risk 1.17, 95% confidence interval 0.91 to 1.49).

CONCLUSION

Most children diagnosed with non-severe pneumonia on the basis of the current WHO definition had normal chest radiographs.

Pathogenesis of respiratory syncytial virus infection in the murine model

There is a wide spectrum of illness caused by respiratory syncytial virus (RSV) infection that is caused in large part by host-related factors, such as age of the patient and degree of host immunocompetency. Although the vast majority of persons infected with RSV experience symptoms of mild upper respiratory tract infection, in some people these infections cause significant morbidity and are sometimes fatal. Although a great deal of investigation in both humans and animals has explained the timing and tropism of RSV infection and the general principles by which the immune system responds to this infection, at present we only partially understand the disparity in illness severity that can occur. This article briefly reviews the clinical sequelae of RSV infection and then focuses on the mechanisms of viral pathogenesis.

Racemic epinephrine compared to salbutamol in hospitalized young children with bronchiolitis; a randomized controlled clinical trial [ISRCTN46561076]

BACKGROUND

Bronchiolitis is the most common cause of lower respiratory tract illness in infancy, and hospital admission rates appear to be increasing in Canada and the United States. Inhaled beta agonists offer only modest short-term improvement. Trials of racemic epinephrine have shown conflicting results. We sought to determine if administration of racemic epinephrine during hospital stay for bronchiolitis improved respiratory distress, was safe, and shortened length of stay.

METHODS

The study was a randomized, double-blind controlled trial of aerosolized racemic epinephrine compared to salbutamol every one to 4 hours in previously well children aged 6 weeks to < or = 2 years of age hospitalized with bronchiolitis. The primary outcome was symptom improvement as measured by the Respiratory Distress Assessment Instrument (RDAI); secondary outcomes were length of stay in hospital, adverse events, and report of symptoms by structured parental telephone interview one week after discharge.

RESULTS

62 children with a mean age of 6.4 months were enrolled; 80% of children had Respiratory Syncytial Virus (RSV). Racemic epinephrine resulted in significant improvement in wheezing and the total RDAI score on day 2 and over the entire stay (p < 0.05). The mean LOS in the epinephrine arm was 2.6 days (95% CI 2, 3.2) v. 3.4 days in those in the salbutamol group (95% CI 2.6, 4.2) (p > 0.05). Adverse events were not significantly different in the two arms. At one week post-discharge, over half of parents reported that their child still had a respiratory symptom and 40% had less than normal feeding.

CONCLUSION

Racemic epinephrine relieves respiratory distress in hospitalized infants with bronchiolitis and is safe but does not abbreviate hospital stay. Morbidity associated with bronchiolitis as identified by parents persists for at least one week after hospital discharge in most infants.

The response to β-agonists in wheezy infants: three methods compared

BACKGROUND

Studies into the effects of salbutamol in the treatment of wheeze in infancy have been conflicting, possibly due to differences in outcome variables. We aimed to assess the response to salbutamol using indices derived from passive and forced expiration.

METHODS

We recruited 39 infants who had a history of wheezing (mean age 43 weeks) and measured maximum flow at functional residual capacity (V'(max FRC)) by rapid thoracoabdominal compression (RTC), and forced expired volume at 0.4s (FEV0.4) using the raised-volume RTC technique (RV-RTC). We calculated passive compliance (C(rs)), resistance (R(rs)) and time constant (tau) from relaxed expirations that followed the augmented inspirations delivered during RV-RTC. Measurements were repeated after aerosol salbutamol (800 mcg).

RESULTS

Data were obtained in 32 infants for V'(max FRC), 22 for FEV0.4 and 19 for passive mechanics. There were no mean changes in any index of forced expiration after salbutamol. Some individuals showed significant changes (improvement or worsening) in one or other index. Overall, there was a small increase in C(rs) after salbutamol but no change in R(rs) or tau.

CONCLUSIONS

We found no consistent pattern of response in either index of forced expiration. Validated clinical scores or alternative physiological techniques may be preferable to respiratory mechanics in assessing bronchodilator response.

Bronchiolitis management preferences and the influence of pulse oximetry and respiratory rate on the decision to admit

OBJECTIVE

High incidence, rising admission rates, and relatively ineffective therapies make the management of bronchiolitis controversial. Since 1980, the rate of hospitalization for children with bronchiolitis has increased by nearly 250%, whereas mortality rates for the disease have remained constant. It has been speculated that the increasing use of pulse oximetry has lowered the threshold for admission and may have contributed to the rise in bronchiolitis-related admissions. The objective of this study was to describe pediatric emergency medicine physicians' management preferences regarding infants with moderately severe bronchiolitis and to assess the influence of specific differences in oxygen saturation as measured by pulse oximetry (SpO2) and respiratory rate (RR) on the decision to admit.

METHODS

Physicians who are members of the American Academy of Pediatrics Section of Emergency Medicine and living in the United States were randomized into 4 groups and mailed a survey that contained 1 of 4 vignettes. Vignettes were identical except for given SpO2 values (94% or 92%) and RR (50/min or 65/min). Subjects were asked to answer questions regarding laboratory tests, treatment options, and the decision to admit for the patient in their vignette.

RESULTS

We received completed surveys from 519 (64%) of the 812 physicians contacted. Most respondents recommended use of bronchodilators (96%), nasal suction (82%), and supplemental oxygen (57%). Few respondents recommended decongestants (9%), steroids (8%), or antibiotics (2%). When asked to rank therapies, respondents gave nasal suction 182 number 1 votes; bronchodilators received 164. The decision to admit varied with SpO2 and RR. Forty-three percent of respondents who received a vignette featuring SpO2 of 94% and a RR of 50/min recommended admission for the infant in their vignette. Fifty-eight percent recommended admission when the vignette SpO2 was 94% and RR was 65/min (chi2 = 5.021). Respondents who received a vignette with SpO2 of 92% were nearly twice as likely to recommend admission: 83% recommended admission when vignette RR was 50/min, and 85% recommended admission when vignette RR was 65/min (chi2 = 0.126).

CONCLUSIONS

When treating infants with moderately severe bronchiolitis, pediatricians who work in emergency departments frequently use bronchodilators and nasal suction, 2 practices for which supporting data are either conflicting (bronchodilators) or nonexistent (nasal suction). In addition, their decisions to admit differ markedly on the basis of only a 2% difference in SpO2. It is possible that increased reliance on pulse oximetry has contributed to the increase in bronchiolitis hospitalization rates seen during the past 2 decades.

Acute viral bronchiolitis and its sequelae in developing countries

Acute viral bronchiolitis (AVB) is a common disease found throughout the world. Various aspects of it are being studied: its epidemiology, diagnosis, prognosis and treatment. Most of these studies are being conducted in developed countries, with only a few taking place in developing countries. Risk factors such as poor nutrition, an adverse environment and early weaning should be studied where these features are common. Treatment aspects such as cost-effectiveness in low income settings need further study. Use of ribavirin and respiratory syncytial virus (RSV)-immunoglobulin are good examples. Post-bronchiolitic sequelae also need to be studied in low income countries. There is evidence that bronchiolitis obliterans is unusually frequent in some Latin-American countries such as Argentina and Brazil. It will be helpful to undertake combined studies in countries with the same socio-economics, investigating the preventive and management aspects of AVB and its sequelae to reduce the morbidity and mortality.