Respiratory syncytial virus bronchiolitis: supportive care and therapies designed to overcome airway obstruction

Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children

BACKGROUND

Respiratory syncytial virus (RSV) is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years, representing a major global healthcare burden. There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life. A multidisciplinary consensus development group comprising experts in epidemiology, infectious diseases, respiratory medicine, and methodology aims to develop the current consensus to address clinical issues of RSV infections in children.

DATA SOURCES

The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, using variations in terms for "respiratory syncytial virus", "RSV", "lower respiratory tract infection", "bronchiolitis", "acute", "viral pneumonia", "neonatal", "infant" "children", and "pediatric".

RESULTS

Evidence-based recommendations regarding diagnosis, treatment, and prevention were proposed with a high degree of consensus. Although supportive care remains the cornerstone for the management of RSV infections, new monoclonal antibodies, vaccines, drug therapies, and viral surveillance techniques are being rolled out.

CONCLUSIONS

This consensus, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections. Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

Nebulised hypertonic saline solution for acute bronchiolitis in infants

BACKGROUND

Airway oedema (swelling) and mucus plugging are the principal pathological features in infants with acute viral bronchiolitis. Nebulised hypertonic saline solution (≥ 3%) may reduce these pathological changes and decrease airway obstruction. This is an update of a review first published in 2008, and updated in 2010, 2013, and 2017.

OBJECTIVES

To assess the effects of nebulised hypertonic (≥ 3%) saline solution in infants with acute bronchiolitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily, Embase, CINAHL, LILACS, and Web of Science on 13 January 2022. We also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 13 January 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs using nebulised hypertonic saline alone or in conjunction with bronchodilators as an active intervention and nebulised 0.9% saline or standard treatment as a comparator in children under 24 months with acute bronchiolitis. The primary outcome for inpatient trials was length of hospital stay, and the primary outcome for outpatients or emergency department (ED) trials was rate of hospitalisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction, and assessment of risk of bias in included studies. We conducted random-effects model meta-analyses using Review Manager 5. We used mean difference (MD), risk ratio (RR), and their 95% confidence intervals (CI) as effect size metrics.

MAIN RESULTS

We included six new trials (N = 1010) in this update, bringing the total number of included trials to 34, involving 5205 infants with acute bronchiolitis, of whom 2727 infants received hypertonic saline. Eleven trials await classification due to insufficient data for eligibility assessment. All included trials were randomised, parallel-group, controlled trials, of which 30 were double-blinded. Twelve trials were conducted in Asia, five in North America, one in South America, seven in Europe, and nine in Mediterranean and Middle East regions. The concentration of hypertonic saline was defined as 3% in all but six trials, in which 5% to 7% saline was used. Nine trials had no funding, and five trials were funded by sources from government or academic agencies. The remaining 20 trials did not provide funding sources. Hospitalised infants treated with nebulised hypertonic saline may have a shorter mean length of hospital stay compared to those treated with nebulised normal (0.9%) saline or standard care (mean difference (MD) -0.40 days, 95% confidence interval (CI) -0.69 to -0.11; 21 trials, 2479 infants; low-certainty evidence). Infants who received hypertonic saline may also have lower postinhalation clinical scores than infants who received normal saline in the first three days of treatment (day 1: MD -0.64, 95% CI -1.08 to -0.21; 10 trials (1 outpatient, 1 ED, 8 inpatient trials), 893 infants; day 2: MD -1.07, 95% CI -1.60 to -0.53; 10 trials (1 outpatient, 1 ED, 8 inpatient trials), 907 infants; day 3: MD -0.89, 95% CI -1.44 to -0.34; 10 trials (1 outpatient, 9 inpatient trials), 785 infants; low-certainty evidence). Nebulised hypertonic saline may reduce the risk of hospitalisation by 13% compared with nebulised normal saline amongst infants who were outpatients and those treated in the ED (risk ratio (RR) 0.87, 95% CI 0.78 to 0.97; 8 trials, 1760 infants; low-certainty evidence). However, hypertonic saline may not reduce the risk of readmission to hospital up to 28 days after discharge (RR 0.83, 95% CI 0.55 to 1.25; 6 trials, 1084 infants; low-certainty evidence). We are uncertain whether infants who received hypertonic saline have a lower number of days to resolution of wheezing compared to those who received normal saline (MD -1.16 days, 95% CI -1.43 to -0.89; 2 trials, 205 infants; very low-certainty evidence), cough (MD -0.87 days, 95% CI -1.31 to -0.44; 3 trials, 363 infants; very low-certainty evidence), and pulmonary moist crackles (MD -1.30 days, 95% CI -2.28 to -0.32; 2 trials, 205 infants; very low-certainty evidence). Twenty-seven trials presented safety data: 14 trials (1624 infants; 767 treated with hypertonic saline, of which 735 (96%) co-administered with bronchodilators) did not report any adverse events, and 13 trials (2792 infants; 1479 treated with hypertonic saline, of which 416 (28%) co-administered with bronchodilators and 1063 (72%) hypertonic saline alone) reported at least one adverse event such as worsening cough, agitation, bronchospasm, bradycardia, desaturation, vomiting and diarrhoea, most of which were mild and resolved spontaneously (low-certainty evidence).

AUTHORS' CONCLUSIONS

Nebulised hypertonic saline may modestly reduce length of stay amongst infants hospitalised with acute bronchiolitis and may slightly improve clinical severity score. Treatment with nebulised hypertonic saline may also reduce the risk of hospitalisation amongst outpatients and ED patients. Nebulised hypertonic saline seems to be a safe treatment in infants with bronchiolitis with only minor and spontaneously resolved adverse events, especially when administered in conjunction with a bronchodilator. The certainty of the evidence was low to very low for all outcomes, mainly due to inconsistency and risk of bias.

Application of aerosol therapy in respiratory diseases in children: A Saudi expert consensus

The Saudi Pediatric Pulmonology Association (SPPA) is a subsidiary of the Saudi Thoracic Society (STS), which consists of a group of Saudi experts with well-respected academic and clinical backgrounds in the fields of asthma and other respiratory diseases. The SPPA Expert Panel realized the need to draw up a clear, simple to understand, and easy to use guidance regarding the application of different aerosol therapies in respiratory diseases in children, due to the high prevalence and high economic burden of these diseases in Saudi Arabia. This statement was developed based on the available literature, new evidence, and experts' practice to come up with such consensuses about the usage of different aerosol therapies for the management of respiratory diseases in children (asthma and nonasthma) in different patient settings, including outpatient, emergency room, intensive care unit, and inpatient settings. For this purpose, SPPA has initiated and formed a national committee which consists of experts from concerned specialties (pediatric pulmonology, pediatric emergency, clinical pharmacology, pediatric respiratory therapy, as well as pediatric and neonatal intensive care). These committee members are from different healthcare sectors in Saudi Arabia (Ministry of Health, Ministry of Defence, Ministry of Education, and private healthcare sector). In addition to that, this committee is representing different regions in Saudi Arabia (Eastern, Central, and Western region). The subject was divided into several topics which were then assigned to at least two experts. The authors searched the literature according to their own strategies without central literature review. To achieve consensus, draft reports and recommendations were reviewed and voted on by the whole panel.

Exploring the efficacy of using hypertonic saline for nebulizing treatment in children with bronchiolitis: a meta-analysis of randomized controlled trials

BACKGROUND

Inhaled hypertonic saline (HS) has shown benefit in decreasing airway edema in acute bronchiolitis which is the most common lower respiratory infection resulting in dyspnea among infants under 2 years old. The aim of this systematic review and meta-analysis was to evaluate the efficacy and safety of HS in the implementation of treatment with nebulized HS among children with bronchiolitis.

METHODS

A systematic literature search was conducted using Cochrane Library, PubMed, EMBASE and Airiti Library (Chinese Database) for randomized controlled trials from inception to July 2019. We calculated pooled risk ratios (RR), mean difference (MD) and 95% CI using RevMan 5.3 for meta-analysis.

RESULTS

There were 4186 children from 32 publications included. Compared to the control group, the HS group exhibited significant reduction of severity of respiratory distress, included studies used the Clinical Severity Score (n = 8; MD, - 0.71; 95% CI, - 1.15 to - 0.27; I2 = 73%) and full stop after Respiratory Distress Assessment Instrument (n = 5; MD, - 0.60; 95% CI, - 0.95 to - 0.26; I2 = 0%) for evaluation respectively. Further, the HS group decreased the length of hospital stay 0.54 days (n = 20; MD, - 0.54; 95% CI, - 0.86 to - 0.23; I2 = 81%).

CONCLUSIONS

We conclude that nebulization with 3% saline solution is effective in decreasing the length of hospital stay and the severity of symptoms as compared with 0.9% saline solution among children with acute bronchiolitis. Further rigorous randomized controlled trials with large sample size are needed.

Antibodies in lymphocyte supernatants can distinguish between neutralising antibodies induced by RSV vaccination and pre-existing antibodies induced by natural infection

INTRODUCTION

Respiratory syncytial virus (RSV) is the single most important cause of severe respiratory illness in infants. There is no effective vaccine and the only effective treatment available is the monoclonal antibody palivizumab which reduces the risk of severe RSV disease in prematurely born infants. However, palivizumab is too costly to allow for wide implementation and thus treatment is restricted to supportive care. Despite extensive efforts to develop a vaccine, progress has been hindered by the difficulty in measuring and assessing immunological correlates of RSV vaccine efficacy in the presence of high levels of pre-existing RSV antibodies.

METHODS

Here we describe a new method for measuring the functional activity of antibodies induced by vaccination distinct from pre-existing antibodies. Antibodies in lymphocyte supernatants (ALS) from the cultured peripheral blood mononuclear cells (PBMCs) of young adults who had recently been vaccinated with a novel RSV candidate vaccine were directly assayed for virus neutralising activity. An ELISA method was used to measure antibodies in nasal and serum samples and then compared with the adapted ALS based method.

RESULTS

There was a wide background distribution of RSV-specific antibodies in serum and nasal samples that obscured vaccine-specific responses measured two weeks after vaccination. No RSV-specific antibodies were observed at baseline in ALS samples, but a clear vaccine-specific antibody response was observed in ALS seven days after the administration of each dose of vaccine. These vaccine-specific antibodies in ALS displayed functional activity in vitro, and quantification of this functional activity was unperturbed by pre-existing antibodies from natural exposure. The results demonstrate a promising new approach for assessing functional immune responses attributed to RSV vaccines.

Nebulised hypertonic saline solution for acute bronchiolitis in infants

BACKGROUND

Airway oedema (swelling) and mucus plugging are the principal pathological features in infants with acute viral bronchiolitis. Nebulised hypertonic saline solution (≥ 3%) may reduce these pathological changes and decrease airway obstruction. This is an update of a review first published in 2008, and previously updated in 2010 and 2013.

OBJECTIVES

To assess the effects of nebulised hypertonic (≥ 3%) saline solution in infants with acute bronchiolitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily, Embase, CINAHL, LILACS, and Web of Science on 11 August 2017. We also searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov on 8 April 2017.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised controlled trials using nebulised hypertonic saline alone or in conjunction with bronchodilators as an active intervention and nebulised 0.9% saline, or standard treatment as a comparator in children under 24 months with acute bronchiolitis. The primary outcome for inpatient trials was length of hospital stay, and the primary outcome for outpatients or emergency department trials was rate of hospitalisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction, and assessment of risk of bias in included studies. We conducted random-effects model meta-analyses using Review Manager 5. We used mean difference (MD), risk ratio (RR), and their 95% confidence intervals (CI) as effect size metrics.

MAIN RESULTS

We identified 26 new trials in this update, of which 9 await classification due to insufficient data for eligibility assessment, and 17 trials (N = 3105) met the inclusion criteria. We included a total of 28 trials involving 4195 infants with acute bronchiolitis, of whom 2222 infants received hypertonic saline.Hospitalised infants treated with nebulised hypertonic saline had a statistically significant shorter mean length of hospital stay compared to those treated with nebulised 0.9% saline (MD -0.41 days, 95% CI -0.75 to -0.07; P = 0.02, I² = 79%; 17 trials; 1867 infants) (GRADE quality of evidence: low). Infants who received hypertonic saline also had statistically significant lower post-inhalation clinical scores than infants who received 0.9% saline in the first three days of treatment (day 1: MD -0.77, 95% CI -1.18 to -0.36, P < 0.001; day 2: MD -1.28, 95% CI -1.91 to -0.65, P < 0.001; day 3: MD -1.43, 95% CI -1.82 to -1.04, P < 0.001) (GRADE quality of evidence: low).Nebulised hypertonic saline reduced the risk of hospitalisation by 14% compared with nebulised 0.9% saline among infants who were outpatients and those treated in the emergency department (RR 0.86, 95% CI 0.76 to 0.98; P = 0.02, I² = 7%; 8 trials; 1723 infants) (GRADE quality of evidence: moderate).Twenty-four trials presented safety data: 13 trials (1363 infants, 703 treated with hypertonic saline) did not report any adverse events, and 11 trials (2360 infants, 1265 treated with hypertonic saline) reported at least one adverse event, most of which were mild and resolved spontaneously.

AUTHORS' CONCLUSIONS

Nebulised hypertonic saline may modestly reduce length of stay among infants hospitalised with acute bronchiolitis and improve clinical severity score. Treatment with nebulised hypertonic saline may also reduce the risk of hospitalisation among outpatients and emergency department patients. However, we assessed the quality of the evidence as low to moderate.

Multicenter Observational Study of the Use of Nebulized Hypertonic Saline to Treat Children Hospitalized for Bronchiolitis From 2008 to 2014

OBJECTIVES

Among children hospitalized for bronchiolitis, we examined temporal trends in the use of hypertonic saline (HTS) and the characteristics associated with receiving this treatment.

METHODS

We conducted a secondary analysis of data from 2 large, multicenter prospective cohort studies that included young children hospitalized with bronchiolitis during 5 winter seasons (2008-2014). Our outcome was receipt of HTS any time during the preadmission visit or hospitalization. For comparison with the observed trends in HTS use, we conducted a PubMed literature review of studies evaluating HTS use for bronchiolitis. We classified publications according to their assessment of HTS efficacy (positive, negative, or neutral).

RESULTS

Among 2709 hospitalized children, 241 (8.9%) received HTS. There was marked variability in HTS use by site (0%-91%), with use more common among children admitted to the ICU than those treated on the ward (31% vs 15%). Over the study period, administration of HTS increased from 2% during the 2008-2009 season to 27% during the 2011-2012 season, but then it decreased to 11% during the 2013-2014 season. Before 2010, the number of PubMed HTS publications ranged from 0 to 3 articles per year, with all classified as either positive or neutral. The number of positive publications increased in 2010 (n = 5), whereas negative publications peaked in 2014 (n = 4).

CONCLUSIONS

Use of HTS in children hospitalized with bronchiolitis increased during the 2008 to 2012 winter seasons and then declined. These findings paralleled trends in the HTS literature, with positive articles encouraging HTS use in early years followed by a growing number of neutral and negative articles after 2012.

Heliox inhalation therapy for bronchiolitis in infants

BACKGROUND

Bronchiolitis is the leading cause of hospitalisation among infants in high-income countries. Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing. In this review, we selected trials that objectively assessed the effect of the addition of heliox to standard medical care for acute bronchiolitis.

OBJECTIVES

To assess heliox inhalation therapy in addition to standard medical care for acute bronchiolitis in infants with respiratory distress, as measured by clinical endpoints (in particular the rate of endotracheal intubation, the rate of emergency department discharge, the length of treatment for respiratory distress) and pulmonary function testing (mainly clinical respiratory scores).

SEARCH METHODS

We searched CENTRAL (2015, Issue 2), MEDLINE (1966 to March week 3, 2015), EMBASE (1974 to March 2015), LILACS (1982 to March 2015) and the National Institutes of Health (NIH) website (May 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

We included seven trials involving 447 infants younger than two years with respiratory distress secondary to viral bronchiolitis. All children were recruited from a paediatric intensive care unit (PICU; 378 infants), except in one trial (emergency department; 69 infants). All children were younger than two (under nine months in two trials and under three months in one trial). Positive tests for respiratory syncytial virus (RSV) were required for inclusion in five trials. The two other trials were carried out in the bronchiolitis seasons. Seven different protocols were used for inhalation therapy with heliox.When heliox was used in the PICU, we observed no significant reduction in the rate of intubation: risk ratio (RR) 2.73 (95% confidence interval (CI) 0.96 to 7.75, four trials, 408 infants, low quality evidence). When heliox inhalation was used in the emergency department, we observed no increase in the rate of discharge: RR 0.51 (95% CI 0.17 to 1.55, one trial, 69 infants, moderate quality evidence).There was no decrease in the length of treatment for respiratory distress: mean difference (MD) -0.19 days (95% CI -0.56 to 0.19, two trials, 320 infants, moderate quality evidence). However, in the subgroup of infants who were started on nasal continuous positive airway pressure (nCPAP) right from the start, because of severe respiratory distress, heliox therapy reduced the length of treatment: MD -0.76 days (95% CI -1.45 to -0.08, one trial, 21 infants, low quality evidence). No adverse events related to heliox inhalation were reported.We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation: MD -1.04 (95% CI -1.60 to -0.48, four trials, 138 infants, moderate quality evidence). This outcome had statistical heterogeneity, which remained even after removing the study using a standard high-concentration reservoir mask. Several factors may explain this heterogeneity, including first the limited number of patients in each trial, and the wide differences in the baseline severity of disease between studies, with the modified Wood Clinical Asthma Score (m-WCAS) in infants treated with heliox ranging from less than two to more than seven.

AUTHORS' CONCLUSIONS

Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. We noticed this beneficial effect regardless of which heliox inhalation protocol was used. Nevertheless, there was no reduction in the rate of intubation, in the rate of emergency department discharge, or in the length of treatment for respiratory distress. Heliox could reduce the length of treatment in infants requiring CPAP for severe respiratory distress. Further studies with homogeneous logistics in their heliox application are needed. Inclusion criteria must include a clinical severity score that reflects severe respiratory distress to avoid inclusion of children with mild bronchiolitis who may not benefit from heliox inhalation. Such studies would provide the necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.

The impact of viral dynamics on the clinical severity of infants with respiratory syncytial virus bronchiolitis

The impact of dynamic respiratory syncytial virus (RSV) load on the clinical severity of hospitalized infants with bronchiolitis has not been clarified. Nasopharyngeal aspirates were obtained from 60 infants who were diagnosed with bronchiolitis within 96 hr of wheezing onset upon admission and on days 3, 5, and 7 in the hospital, and 17 respiratory viruses were detected. The RSV load was quantified by real‐time qPCR for RSV subtypes A and B at different time points. Scoring criteria were used to evaluate the degree of severity. A total of 40 infants were determined to be RSV‐positive, nine were identified as RSV subtype A (RSVA), and 31 were RSV subtype B (RSVB). The peak RSV load was observed upon admission, and the RSV load decreased significantly over time; in addition, this decrease began to have significant differences on day 5. There was a positive correlation between the RSV load and the clinical score (r² = 0.121 and P < 0.001). According to the clinical scores, the infants in the severe group tended to have higher RSV loads than those in the moderate and mild groups. Multivariate logistic regression models revealed that the viral load on day 3 was independently associated with the degree of severity. This study elucidated that a higher mean RSV load was associated with a more severe disease and a longer duration of hospitalization and symptoms. This study also clarified RSV replication in infants and provides a theoretical basis for specifying an anti‐RSV therapy strategy. J. Med. Virol. 87:1276–1284, 2015. © 2015 Wiley Periodicals, Inc.

Epidemiology of respiratory syncytial virus in children in Cyprus during three consecutive winter seasons (2010-2013): age distribution, seasonality and association between prevalent genotypes and disease severity

This study reports the epidemiology of respiratory syncytial virus (RSV) in hospitalized children in Cyprus over three successive seasons (2010-2013) and the association between prevalent genotypes and disease severity. RSV infections had a circulation pattern from December to March. Most RSV-positive children (83%) were aged <2 years. Genotyping of RSV isolates showed that during the first winter season of the study (2010-2011), the only RSV genotype circulating was GA2 (RSV-A), followed by genotype BA (RSV-B) in the next winter season with only few sporadic cases of GA2. During the last winter season of the study (2012-2013) the newly emerged RSV genotype ON1 (RSV-A) was virtually the only circulating genotype. Children infected with genotype ON1 suffered a significantly milder illness compared to infections with genotypes GA2 and BA with a higher percentage of BA-infected children requiring oxygen. Our findings are in contrast to the majority of published reports that suggest RSV-A causes more severe illness than RSV-B. Therefore, further investigation of the association between RSV genotypes and disease severity is required, as it might affect treatment strategies in the future.

Nebulised hypertonic saline solution for acute bronchiolitis in infants

BACKGROUND

Airway oedema and mucus plugging are the predominant pathological features in infants with acute viral bronchiolitis. Nebulised hypertonic saline solution may reduce these pathological changes and decrease airway obstruction.

OBJECTIVES

To assess the effects of nebulised hypertonic (≥ 3%) saline solution in infants with acute viral bronchiolitis.

SEARCH METHODS

We searched CENTRAL 2013, Issue 4, OLDMEDLINE (1951 to 1965), MEDLINE (1966 to April week 4, 2013), EMBASE (1974 to May 2013), LILACS (1985 to May 2013) and Web of Science (1955 to May 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs using nebulised hypertonic saline alone or in conjunction with bronchodilators as an active intervention and nebulised 0.9% saline as a comparator in infants up to 24 months of age with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction and assessment of risk of bias in included studies. We conducted meta-analyses using the Cochrane statistical package RevMan 5.2. We used the random-effects model for meta-analyses. We used mean difference (MD) and risk ratio (RR) as effect size metrics.

MAIN RESULTS

We included 11 trials involving 1090 infants with mild to moderate acute viral bronchiolitis (500 inpatients, five trials; 65 outpatients, one trial; and 525 emergency department patients, four trials). All but one of the included trials were of high quality with a low risk of bias. A total of 560 patients received hypertonic saline (3% saline n = 503; 5% saline n = 57). Patients treated with nebulised 3% saline had a significantly shorter mean length of hospital stay compared to those treated with nebulised 0.9% saline (MD -1.15 days, 95% confidence interval (CI) -1.49 to -0.82, P < 0.00001). The hypertonic saline group also had a significantly lower post-inhalation clinical score than the 0.9% saline group in the first three days of treatment (day 1: MD -0.88, 95% CI -1.36 to -0.39, P = 0.0004; day 2: MD -1.32, 95% CI -2.00 to -0.64, P = 0.001; day 3: MD -1.51, 95% CI -1.88 to -1.14, P < 0.00001). The effects of improving clinical score were observed in both outpatients and inpatients. Four emergency department-based trials did not show any significant short-term effects (30 to 120 minutes) of up to three doses of nebulised 3% saline in improving clinical score and oxygen saturation. No significant adverse events related to hypertonic saline inhalation were reported.

AUTHORS' CONCLUSIONS

Current evidence suggests nebulised 3% saline may significantly reduce the length of hospital stay among infants hospitalised with non-severe acute viral bronchiolitis and improve the clinical severity score in both outpatient and inpatient populations.

Suctioning and length of stay in infants hospitalized with bronchiolitis

IMPORTANCE

Hospitalizations of infants for bronchiolitis are common and costly. Despite the high incidence and resource burden of bronchiolitis, the mainstay of treatment remains supportive care, which frequently includes nasal suctioning.

OBJECTIVE

To examine the association between suctioning device type and suctioning lapses greater than 4 hours within the first 24 hours after hospital admission on length of stay (LOS) in infants with bronchiolitis.

DESIGN

Retrospective cohort study. Data were extracted from the electronic health record.

SETTING

Main hospital and satellite facility of a large quaternary care children's hospital from January 10, 2010, through April 30, 2011.

PARTICIPANTS

A total of 740 infants aged 2 to 12 months and hospitalized with bronchiolitis.

MAIN OUTCOME MEASURE

Hospital LOS.

RESULTS

In the multivariable model adjusted for inverse weighting for propensity to receive deep suctioning, increased deep suction as a percentage of suction events was associated with increased LOS with a geometric mean of 1.75 days (95% CI, 1.56-1.95 days) in patients with no deep suction and 2.35 days (2.10-2.62 days) in patients with more than 60% deep suction. An increased number of suctioning lapses was also associated with increased LOS in a dose-dependent manner with a geometric mean of 1.62 days (95% CI, 1.43-1.83 days) in patients with no lapses and 2.64 days (2.30-3.04 days) in patients with 3 or 4 lapses.

CONCLUSIONS AND RELEVANCE

For patients admitted with bronchiolitis, the use of deep suctioning in the first 24 hours after admission and lapses greater than 4 hours between suctioning events were associated with longer LOS.

Respiratory syncytial virus infection in children with neuromuscular impairment

Clinically obvious reasons why children with neurological impairment (NMI) may be more severely affected in case of a viral respiratory tract infection include reduced vital capacity due to muscular weakness or spastic scoliosis, disturbed clearance of respiratory excretions (weak coughing and dysphagia), inability to comply actively with physiotherapeutic interventions, recurrent micro-aspirations (gastroesophageal reflux disease, vomiting related to coughing), a history of frequent exposure to antibiotics and health care institutions, colonization with resistant pathogens, impaired immunologic defence mechanisms due to severe malnutrition and cachexia, and early clinical deterioration in case of high fever with metabolic acidosis and hypercapnia, and maybe associated seizures or febrile convulsions.

Data from the literature suggests that in all children with NMI, who have to be hospitalized with severe clinical deterioration due to an airway infection, at least one specimen of nasopharyngeal secretions should be sent as soon as possible to a virologic laboratory to detect viral pathogens. Children with severe NMI and those mechanically ventilated for other reasons being hospitalized during the RSV season must be strictly protected against nosocomial RSV infection by means of standard and droplet precautions. Finally, children with severe NMI and age below 24 months of life should receive passive immunization with palivizumab following international recommendations.

Heliox inhalation therapy for bronchiolitis in infants

BACKGROUND

Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing.

OBJECTIVES

To assess heliox in addition to standard medical care for acute bronchiolitis in infants.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2), which includes the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, MEDLINE (1966 to June 2009), EMBASE (June 2009), LILACS (May 2009) and the NIH web site (May 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. We pooled data from individual trials.

MAIN RESULTS

We included four trials involving 84 infants under two years of age with respiratory distress secondary to bronchiolitis caused by respiratory syncytial virus (RSV) and requiring paediatric intensive care unit (PICU) hospitalisation. We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation (mean difference (MD) -1.15, 95% confidence interval (CI) -1.98 to -0.33, P = 0.006, n = 69). There was no clinically significant reduction in the rate of intubation (risk ratio (RR) 1.38, 95% CI 0.41 to 4.56, P = 0.60, n = 58), in the need for mechanical ventilation (RR 1.11, 95% CI 0.36 to 3.38, P = 0.86, n = 58), or in the length of stay in a PICU (MD = -0.15 days, 95% CI -0.92 to 0.61, P = 0.69, n = 58). No adverse events related to heliox inhalation were reported.

AUTHORS' CONCLUSIONS

Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. Nevertheless, there was no reduction in the rate of intubation, in the need for mechanical ventilation, or in the length of PICU stay. Further studies with homogeneous logistics in their heliox application are needed. Such studies would provide necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.

Small Airways Disease

Small airways diseases are best defined pathologically as a diverse group of conditions that primarily involve bronchioles and acartilagenous airways 2 mm or less in diameter, which include membranous bronchioles, respiratory bronchioles, and alveolar ducts. Small airways can be involved with disease primarily or secondarily. The concept of small airways disease varies among specialties, with clinicians generally considering them in terms of terminal airway changes causing airflow obstruction, radiologists considering them in the context of direct signs and indirect signs identified on high-resolution computed tomography scans, and pathologists evaluating them based entirely or almost entirely on the histologic changes present in the bronchioles, with or without associated changes involving bronchi and alveoli. The histologic features of small airways diseases may be confusing because they overlap. There may be incomplete assessment of the histologic process with limited biopsy. Other disease processes may occur along with a small airways disease, and may obscure or confound its histologic features. This article focuses on the histologic changes diagnostic of a variety of primary and secondary small airways diseases. Because the histologic features involve bronchioles, gross findings are often minimal and/or nonspecific. The article provides a nonexhaustive examination of conditions and diseases involving the small airways, focusing on the microscopic features, with emphasis on the limitations of histologic diagnosis and differential diagnosis.

Nebulized hypertonic saline solution for acute bronchiolitis in infants

BACKGROUND

Airway edema and mucus plugging are the predominant pathological features in infants with acute viral bronchiolitis. Nebulized hypertonic saline solution may reduce these pathological changes and decrease airway obstruction.

OBJECTIVES

To assess the effects of nebulized hypertonic saline solution in infants with acute viral bronchiolitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 4), which contains the Cochrane Acute Respiratory Infections Group Specialized Register; OLDMEDLINE (1951 to 1965); MEDLINE (1966 to November 2007); EMBASE (1974 to November 2007); and LILACS (November 2007).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs using nebulized hypertonic saline alone or in conjunction with bronchodilators as an active intervention in infants up to 24 months of age with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors (ZL, MRA) independently performed data extraction and study quality assessment. We pooled the data from individual trials using the Cochrane statistical package Review Manager (RevMan).

MAIN RESULTS

We included four trials involving 254 infants with acute viral bronchiolitis (189 inpatients and 65 outpatients) in this review. Patients treated with nebulized 3% saline had a significantly shorter mean length of hospital stay compared to those treated with nebulized 0.9% saline (mean difference (MD) -0.94 days, 95% CI -1.48 to -0.40, P = 0.0006). The 3% saline group also had a significantly lower post-inhalation clinical score than the 0.9% saline group in the first three days of treatment (day 1: MD -0.75, 95% CI -1.38 to -0.12, P = 0.02; day 2: MD -1.18, 95% CI -1.97 to -0.39, P = 0.003; day 3: MD -1.28, 95% CI -2.57 to 0.00, P = 0.05). The effect of nebulized hypertonic saline in improving clinical score was greater among outpatients than inpatients. No adverse events related to 3% saline inhalation were reported.

AUTHORS' CONCLUSIONS

Current evidence suggests nebulized 3% saline may significantly reduce the length of hospital stay and improve the clinical severity score in infants with acute viral bronchiolitis.

Combined fluticasone propionate and salmeterol reduces RSV infection more effectively than either of them alone in allergen-sensitized mice

BACKGROUND

Respiratory syncytial virus (RSV) infection is the major cause of bronchiolitis in infants and is a risk factor for the development of asthma. Allergic asthmatics are more susceptible to RSV infection and viral exacerbation.

METHODS

Since the effectiveness of corticosteroids in treating RSV infection has been controversial, we tested fluticasone propionate (FP) and salmeterol (Sal) alone versus FP plus Sal (FPS) on RSV-induced airway inflammation. Mice were sensitized and challenged with ovalbumin (OVA) and infected with RSV. Following infection they were treated with FP, Sal, or FPS intranasally and airway hyperreactivity (AHR), inflammation and RSV titers were examined.

RESULTS

The group treated with FPS showed significantly lower AHR compared to the group treated with FP or Sal alone. The group treated with FP alone showed slightly decreased (non-significant) AHR compared to controls. Treatment with FPS resulted in significant decreases in the percentage of eosinophils and neutrophils in bronchoalveolar lavage fluid and in lung pathology compared to FP or Sal. FP alone decreased eosinophils but not neutrophils or lymphocytes, while Sal alone decreased eosinophils and neutrophils but not lymphocytes. FPS treatment of mice infected with RSV in the absence of allergen sensitization resulted in a 50% decrease of RSV titer in the lung and a reduction in neutrophils compared to FP or Sal.

CONCLUSION

Together, these results indicate that fluticasone in combination with salmeterol is a more effective treatment for decreasing airway hyperreactivity and inflammation than either of them alone in allergen-sensitized, RSV-infected mice.

Guidelines for evaluating chronic cough in pediatrics: ACCP evidence-based clinical practice guidelines

OBJECTIVES

To review relevant literature and present evidence-based guidelines to assist general and specialist medical practitioners in the evaluation and management of children who present with chronic cough.

METHODOLOGY

The Cochrane, MEDLINE, and EMBASE databases, review articles, and reference lists of relevant articles were searched and reviewed by a single author. The date of the last comprehensive search was December 5, 2003, and that of the Cochrane database was November 7, 2004. The authors' own databases and expertise identified additional articles.

RESULTS/CONCLUSIONS

Pediatric chronic cough (ie, cough in children aged <15 years) is defined as a daily cough lasting for >4 weeks. This time frame was chosen based on the natural history of URTIs in children and differs from the definition of chronic cough in adults. In this guideline, only chronic cough will be discussed. Chronic cough is subdivided into specific cough (ie, cough associated with other symptoms and signs suggestive of an associated or underlying problem) and nonspecific cough (ie, dry cough in the absence of an identifiable respiratory disease of known etiology). The majority of this section focuses on nonspecific cough, as specific cough encompasses the entire spectrum of pediatric pulmonology. A review of the literature revealed few randomized controlled trials for treatment of nonspecific cough. Management guidelines are summarized in two pathways. Recommendations are derived from a systematic review of the literature and were integrated with expert opinion. They are a general guideline only, do not substitute for sound clinical judgment, and are not intended to be used as a protocol for the management of all children with a coughing illness. Children (aged <15 years) with cough should be managed according to child-specific guidelines, which differ from those for adults as the etiologic factors and treatments for children are sometimes different from those for adults. Cough in children should be treated based on etiology, and there is no evidence for using medications for the symptomatic relief of cough. If medications are used, it is imperative that the children are followed up and therapy with the medications stopped if there is no effect on the cough within an expected time frame. An evaluation of the time to response is important. Irrespective of diagnosis, environmental influences and parental expectations should be discussed and managed accordingly. Cough often impacts the quality of life of both children and parents, and the exploration of parental expectations and fears is often valuable in the management of cough in children.

Reduced clearance of respiratory syncytial virus infection in a preterm lamb model

Respiratory syncytial virus (RSV) causes significant respiratory disease in children worldwide. For the study of severe RSV disease seen in preterm infants, a suitable animal model is lacking. The novel hypothesis of this study was that preterm lambs are susceptible to bovine RSV (bRSV) infection, an analogous pneumovirus with ruminant host specificity, and that there would be age-dependent differences in select RSV disease parameters. During RSV infection, preterm lambs had elevated temperatures and respiration rates with mild anorexia and cough compared to controls. Gross lesions included multifocal consolidation and atelectasis with foci of hyperinflation. Microscopic lesions included multifocal alveolar septal thickening and bronchiolitis. Immunohistochemistry localized the RSV antigen to all layers of bronchiolar epithelium from a few basal cells to numerous sloughing epithelia. A few mononuclear cells were also immunoreactive. To assess for age-dependent differences in RSV infection, neonatal lambs were infected similarly to the preterm lambs or with a high-titer viral inoculum. Using morphometry at day 7 of infection, preterm lambs had significantly more cellular immunoreactivity for RSV antigen (P <0.05) and syncytial cell formation (P <0.05) than either group of neonatal lambs. This work suggests that perinatal RSV clearance is age-dependent, which may explain the severity of RSV infection in preterm infants. The preterm lamb model is useful for assessing age-dependent mechanisms of severe RSV infection.

Epinephrine for bronchiolitis

BACKGROUND

Bronchodilators are commonly used in the management of bronchiolitis. A recent systematic review showed that bronchodilators produce modest short-term benefit among patients with mild or moderate bronchiolitis.

OBJECTIVES

To compare epinephrine versus placebo and other bronchodilators in infants less than 2 years of age with bronchiolitis.

SEARCH STRATEGY

Electronic searches were conducted on the following bibliographic databases: The Cochrane Central Register of Controlled Trials (CENTRAL) (issue 1, 2003), MEDLINE (January 1966 to May 2003), and EMBASE (January 1988 to May 2003). The reference lists of all selected articles were examined for relevant studies. Primary authors were contacted for information on additional trials.

SELECTION CRITERIA

Studies were included if they: 1) were RCTs comparing epinephrine with placebo or other bronchodilator; 2) involved children less than two years with bronchiolitis; 3) presented at least one quantitative outcome.

DATA COLLECTION AND ANALYSIS

Searches were screened and inclusion criteria applied independently by two reviewers. Quality was assessed by two reviewers using the Jadad scale and allocation concealment. Data were extracted by one reviewer using a structured form and checked by a second. Separate analyses were conducted for the two types of control groups (placebo, non-epinephrine bronchodilators) and for patient status (inpatient, outpatient).

MAIN RESULTS

Fourteen studies were included. Quality ranged from one to five (Jadad scale) with a median of three (inter-quartile range: two to three). Allocation concealment was adequate in six trials and unclear in eight. Among inpatient studies comparing epinephrine and placebo (n = five), there was one significant outcome favouring epinephrine: change in clinical score at 60 minutes post-treatment (SMD -0.52; 95% CI -1.00,-0.03). For outpatient studies (n = three), change in clinical score at 60 minutes (SMD -0.81; -1.56,-0.07), change in oxygen saturation at 30 minutes (WMD 2.79;1.50,4.08), respiratory rate at 30 minutes (WMD -4.54;-8.89-0.19), and "improvement" (OR 25.06; 4.95,126.91) favoured epinephrine. Heart rate at 60 minutes post-treatment favoured placebo (WMD 11.80; 5.20,18.40). Admission rates and change in oxygen saturation at 60 minutes post-treatment were not significantly different. For inpatient studies comparing epinephrine and salbutamol (n = four), only one of the seven outcomes was statistically significant: respiratory rate at 30 minutes favoured epinephrine (WMD -5.12; -6.83;-3.41). Among outpatient studies (n = four), change in oxygen saturation at 60 minutes (WMD 1.91; 0.38,3.44), heart rate at 90 minutes (WMD -14.00; -22.95;-5.05), respiratory rate at 60 minutes (WMD -7.76; -11.35,-4.17) post-treatment and "improvement" (OR 4.51; 1.93,10.53) favoured epinephrine. Admission rates were not significantly different (OR 0.40; 0.12,1.33). Pallor at 30 minutes post-treatment was significantly higher in the epinephrine group (OR 6.00; 1.33,27.00).

REVIEWER'S CONCLUSIONS

There is insufficient evidence to support the use of epinephrine for the treatment of bronchiolitis among inpatients. There is some evidence to suggest that epinephrine may be favourable to salbutamol and placebo among outpatients. A number of large, multi-centered trials are required to examine the effectiveness of epinephrine compared to placebo and salbutamol for infants presenting to outpatient settings. There is a need to develop a validated, reliable scoring system that is sensitive to important clinical changes in patients with bronchiolitis.