Nebulized hypertonic saline in the treatment of viral bronchiolitis in infants

Effects of nebulized hypertonic saline on inflammatory mediators in patients with severe COVID-19 pneumonia: A double-blinded randomized controlled trial

INTRODUCTION

An exaggerated immune response is considered the most important aspect of COVID-19 pathogenesis. Hypertonic saline (HS) has shown promise in combating inflammation in several respiratory diseases. We investigated the effects of nebulized HS on clinical symptoms and inflammatory status in patients with severe novel coronavirus infection (COVID-19) pneumonia.

MATERIALS AND METHODS

We randomly assigned 60 adults admitted to the intensive care unit (ICU) due to severe COVID-19 pneumonia to the experimental (received nebulized 5% saline) and control (received nebulized distilled water) groups. All interventions were applied 4 times daily for 5 days. The levels of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and other clinical factors from venous blood were evaluated before and after intervention application. Mortality rate, intubation rate, and durations of ICU and hospital stay were also compared between groups.

RESULTS

The levels of TNF-α (MD: -21.35 [-32.29, -10.40], P  =  0.000) and IL-6 (-9.94 [-18.86, -1.02], P  =  0.003) were lower in the experimental group compared to the control group after applying the interventions. The levels of white blood cell count, PO2, and serum sodium were also statistically significant differences between groups. However, we did not observe significant differences in terms of hospitalization durations and mortality rates.

CONCLUSION

Nebulization of HS in patients with severe COVID-19 pneumonia appears to be effective in reducing inflammation, but does not appear to affect intubation rates, mortality, hospitalization, or length of stay in ICU.

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.

3% nebulized hypertonic saline versus normal saline for infants with acute bronchiolitis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This study evaluated the efficacy and safety of 3% nebulized hypertonic saline (NHS) in infants with acute bronchiolitis (AB).

METHODS

We systematically searched the PUBMED, EMBASE, Cochrane Library, China National Knowledge Infrastructure Database, WANFANG, and VIP databases from inception to June 1, 2022. We included randomized controlled trials comparing NHS with 0.9% saline. Outcomes included the length of hospital stay (LOS), rate of hospitalization (ROH), clinical severity score (CSS), rate of readmission, respiratory distress assessment instrument, and adverse events. RevMan V5.4 software was used for statistical analysis.

RESULTS

A total of 27 trials involving 3495 infants were included in this study. Compared to normal saline, infants received 3% NHS showed better outcomes in LOS reduction (MD = -0.60, 95% CI [-1.04, -0.17], I2 = 92%, P = .007), ROH decrease (OR = 0.74, 95% CI [0.59, 0.91], I2 = 0%, P = .005), CSS improvement at day 1 (MD = -0.79, 95% CI [-1.23, -0.34], I2 = 74%, P < .001), day 2 (MD = -1.26, 95% CI [-2.02, -0.49], I2 = 91%, P = .001), and day 3 and over (MD = -1.27, 95% CI [-1.92, -0.61], I2 = 79%, P < .001), and respiratory distress assessment instrument enhancement (MD = -0.60, 95% CI [-0.95, -0.26], I2 = 0%, P < .001). No significant adverse events related to 3% NHS were observed.

CONCLUSION

This study showed that 3% NHS was better than 0.9% normal saline in reducing LOS, decreasing ROH, improving CSS, and in enhancing the severity of respiratory distress. Further studies are needed to validate these findings.

The Role of Seawater and Saline Solutions in Treatment of Upper Respiratory Conditions

The history of saline nasal irrigation (SNI) is indeed a long one, beginning from the ancient Ayurvedic practices and gaining a foothold in the west at the beginning of the 20th century. Today, there is a growing number of papers covering the effects of SNI, from in vitro studies to randomized clinical trials and literature overviews. Based on the recommendations of most of the European and American professional associations, seawater, alone or in combination with other preparations, has its place in the treatment of numerous conditions of the upper respiratory tract (URT), primarily chronic (rhino)sinusitis, allergic rhinitis, acute URT infections and postoperative recovery. Additionally, taking into account its multiple mechanisms of action and mounting evidence from recent studies, locally applied seawater preparations may have an important role in the prevention of viral and bacterial infections of the URT. In this review we discuss results published in the past years focusing on seawater preparations and their use in clinical and everyday conditions, since such products provide the benefits of additional ions vs. saline, have an excellent safety profile and are recommended by most professional associations in the field of otorhinolaryngology.

Exploring the appropriate dose of nebulized hypertonic saline for bronchiolitis: a dose-response meta-analysis

Nebulized hypertonic saline (HS) has gathered increasing attention in bronchiolitis. This study aims to evaluate the relationship between the dose of nebulized HS and the effects on bronchiolitis. Five electronic databases-PubMed, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and ISRCTN-were searched until May 2021. Randomized controlled trials (RCTs) that investigated the effect of HS on bronchiolitis were included. A total of 35 RCTs met the eligibility criteria. HS nebulization may shorten the length of stay (LOS) in hospital (mean difference -0.47, 95% CI -0.71 to -0.23) and improve the 24-hour, 48-hour, and 72-hour Clinical Severe Score (CSS) in children with bronchiolitis. The results showed that there was no significant difference between 3% HS and the higher doses (>3%) of HS in LOS and 24-hour CSS. Although the dose-response meta-analysis found that there may be a linear relationship between different doses and effects, the slope of the linear model changed with different included studies. Besides, HS nebulization could reduce the rate of hospitalization of children with bronchiolitis (risk ratio 0.88, 95% CI 0.78 to 0.98), while the trial sequential analysis indicated the evidence may be insufficient and potentially false positive. This study showed that nebulized HS is an effective and safe therapy for bronchiolitis. More studies are necessary to be conducted to evaluate the effects of different doses of HS on bronchiolitis.

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.

Nebulised normal saline in moderate acute bronchiolitis and pneumonia in a low- to middle-income country: a randomised trial in Papua New Guinea

BACKGROUND

Acute lower respiratory tract infections are the commonest cause of hospitalisation in young children and supportive care remains the cornerstone of management. A randomised open trial was undertaken at the Port Moresby General Hospital Children's Emergency Department (CED) to determine whether nebulised normal saline had beneficial effects.

METHODS

Children <2 years of age presenting with a clinical diagnosis of moderate acute bronchiolitis or moderate pneumonia were randomised to receive standard care alone or with nebulised normal saline administered hourly. The outcomes were the difference in respiratory distress scores (RDS) and oxygen saturation between 0 and 4 hours, and admission rates.

RESULTS

A total of 199 patients participated; 100 patients were randomised to normal saline and 99 to standard care. At 4 hours there was a significant difference in the change of the respiratory distress scores: mean RDS reduced by 3.41 (95% CI 3.0-3.8) in the normal saline group, and for the standard group, the RDS reduced by 1.96 (95% CI 1.5-2.4, p < 0.0001). In those receiving normal saline oxygen saturation measured by pulse oximetry (SpO₂) increased by a mean of 7% (95% CI 6.0-7.9) to 90.7% at 4 hours. For those receiving standard care, the SpO₂ increased by a mean of 4% (95% CI 2.8-5.2) to 87.5% at 4 hours (p < 0.001). Of 100 patients, 58 (58%) in the normal saline group and 24 of 99 (24.2%) in the standard arm were discharged from the Children's Emergency Department (p < 0.001).

CONCLUSIONS

This study supports the use of nebulised normal saline in the treatment of moderate acute bronchiolitis or pneumonia in an emergency department setting in a low- to middle-income country.

ABBREVIATIONS

ALRI, acute lower respiratory infection; CED, Children's Emergency Department; NaCl, sodium chloride; PMGH, Port Moresby General Hospital; PNG, Papua New Guinea; RDS, respiratory distress score; SpO₂, oxygen saturation by pulse oximetry.

Nebulized hypertonic saline 3% for 1 versus 3 days in hospitalized bronchiolitis: a blinded non-inferiority randomized controlled trial

Background

The use and optimal duration of treatment with nebulized hypertonic saline (HS) in infants hospitalized for acute bronchiolitis is unclear. The objective was to compare the efficacy of 1 versus 3 days of nebulized 3% HS at 72 h of treatment. We conducted a blinded non-inferiority randomized controlled trial including infants aged less than 12 months old, hospitalized for a moderate bronchiolitis.

Methods

Nebulisations of 3% HS for 1 day were followed by either the continuation of 3% HS (HS3d group) or switched to 0.9% normal isotonic saline (HS1d group) for 2 days Randomization was performed according to a predefined list with a 1:1 ratio, obtained with a random generator number with blocks.. Main outcome was mean Wang clinical severity score (CSS) after 72 h of treatment.

Results

One hundred sixteen infants (HS1d n = 59 and HS3d n = 57), were included over two epidemic seasons from 2014 to 2016, but recruitement did not reach the planned sample size. The difference for the Wang CSS score in the HS3d vs HS1d group was 0.71 [IC 90% 0.1; 1.3], above the precluded value of 0.4 set in the protocol defining the non-inferiority of shorter treatment duration. Clinical remission was more rapidly obtained in the HS3d than in HS1d (2.3 ± 1.6 vs 2.9 ± 1.4 days, p = 0.04), with a non-significant tendency for less need of nutritional support and supplemental oxygen in HS3d group. Clinical worsening and treatment intolerance were similar in the 2 groups.

Conclusions

Despite being underpowered, results seem not to be in favour of reducing the duration of nebulised HS treatment from 3 to 1 day in acute moderate bronchiolitis.

Trial registration

Clinical trials NCT 02538458, October 2014.

Efficacy of 3% hypertonic saline in bronchiolitis: A meta-analysis

A meta-analysis was performed to analyze the efficacy of 3% hypertonic saline (HS) in bronchiolitis. Pubmed and MEDLINE databases were searched for relevant articles. A total of 2 authors selected the articles according to the inclusion criteria and then data were carefully extracted. Weighted mean difference (WMD) with 95% confidence interval (95% CI) values were used to pool continuous data, including length of stay and clinical severity score (CSS). Relative risk (RR) with 95% CI was calculated to determine the association between 3% HS and re-admission. The pooled data revealed that infants treated with 3% HS exhibited shorter durations of hospitalization compared with those treated with normal saline (NS; WMD=-0.43; 95% CI=-0.70, -0.15). Subgroup analysis examining the combination of HS or NS with additional medication demonstrated that 3% HS with epinephrine significantly decreased the length of hospital stay, with a WMD=-0.62 (95% CI=-0.90, -0.33). The results indicated a lower CSS score in the 3% HS group compared with the NS group (SMD=-0.80; 95% CI=-1.06, -0.54). The pooled outcome indicated a beneficial effect of 3% HS on decreasing re-admission rates compared with NS (RR=0.93; 95% CI=0.70, 1.23). No potential publication bias was observed (Begg's, P=0.133; Egger's, P=0.576). In conclusion, 3% HS was demonstrated to be a more successful therapy compared with NS for infants with bronchiolitis.

Hypertonic Saline in Bronchiolitis and Type I Error: A Trial Sequential Analysis

: media-1vid110.1542/5799873875001PEDS-VA_2018-1144Video Abstract BACKGROUND AND OBJECTIVES: Meta-analyses of nebulized hypertonic saline (HS) for acute viral bronchiolitis have yielded disparate conclusions. Trial sequential analysis (TSA) is a novel method designed to account for potential sources of error in conventional meta-analysis. We sought to use TSA to determine if the existing literature base is sufficient to draw firm conclusions about the effectiveness of HS in bronchiolitis.

METHODS

We used the cohort of studies identified in previously published conventional meta-analyses. Included studies were those in which authors compared treatment with HS versus normal saline (or supportive care) in children with bronchiolitis to reduce hospital length of stay (LOS) or hospitalizations. TSA results are used to provide a required information size and monitoring boundaries for statistical significance.

RESULTS

For the LOS outcome, 17 studies including 1866 patients analyzed in which authors used conventional meta-analysis reveal a statistically significant benefit (mean difference = -0.41 days; 95% confidence interval = -0.07 to -0.75); however, TSA suggests that those conclusions are premature because of failure to reach the adequate information size of 2665 individuals. For the risk of hospitalization outcome, 8 studies including 1728 patients analyzed in which authors used conventional meta-analysis reveal a reduction in the relative risk of hospitalization (relative risk = 0.86; 95% confidence interval = 0.76 to 0.98); however, TSA suggests these conclusions are premature because of failure to reach the adequate information size of 4770. Both LOS and hospitalization results from conventional meta-analysis would be considered potentially false-positives by TSA.

CONCLUSIONS

TSA reveals that concluding benefit from HS for children with bronchiolitis potentially represents type I error.

Bronchiolitis in children: The Saudi initiative of bronchiolitis diagnosis, management, and prevention (SIBRO)

Bronchiolitis is the leading cause of admissions in children less than two years of age. It has been recognized as highly debated for many decades. Despite the abundance of literature and the well-recognized importance of palivizumab in the high risk groups, and despite the existence of numerous, high-quality, recent guidelines on bronchiolitis, the number of admissions continues to increase. Only supportive therapy and few therapeutic interventions are evidence based and proved to be effective. Since Respiratory Syncytial Virus (RSV) is the major cause of bronchiolitis, we will focus on this virus mostly in high risk groups like the premature babies and children with chronic lung disease and cardiac abnormalities. Further, the prevention of RSV with palivizumab in the high risk groups is effective and well known since 1998; we will discuss the updated criteria for allocating infants to this treatment, as this medication is expensive and should be utilized in the best condition. Usually, diagnosis of bronchiolitis is not challenging, however there has been historically no universally accepted and validated scoring system to assess the severity of the condition. Severe RSV, especially in high risk children, is unique because it can cause serious respiratory sequelae. Currently there is no effective curative treatment for bronchiolitis. The utility of different therapeutic interventions is worth a discussion.

Intermittent versus continuous oxygen saturation monitoring for infants hospitalised with bronchiolitis: study protocol for a pragmatic randomised controlled trial

INTRODUCTION

Bronchiolitis is the most common reason for hospitalisation in infants in developed countries. The main focus of hospital care is on supportive care, such as monitoring for hypoxia and supplemental oxygen administration, as active therapies lack effectiveness. Pulse oximetry is used to monitor hypoxia in hospitalised infants and is used either intermittently or continuously. Observational studies have suggested that continuous pulse oximetry use leads to a longer length of hospital stay in stable infants. The use of continuous pulse oximetry may lead to unnecessary clinical intervention due to readings that are of little clinical significance, false-positive readings and less reliance on the clinical status. There is a lack of high-quality evidence to guide which pulse oximetry monitoring strategy, intermittent or continuous, is superior in infants hospitalised with bronchiolitis with respect to patient and policy-relevant outcomes.

METHODS AND ANALYSIS

This is a multicentre, pragmatic randomised controlled trial comparing two strategies for pulse oximetry monitoring in infants hospitalised for bronchiolitis. Infants aged 1 month to 2 years presenting to Canadian tertiary and community hospitals will be randomised after stabilisation to receive either intermittent or continuous oxygen saturation monitoring on the inpatient unit until discharge. The primary outcome is length of hospital stay. Secondary outcomes include additional measures of effectiveness, acceptability, safety and cost. We will need to enrol 210 infants in order to detect a 12-hour difference in length of stay with a type 1 error rate of 5% and a power of 90%.

ETHICS AND DISSEMINATION

Research ethics approval has been obtained for this trial. This trial will provide data to guide hospitals and clinicians on the optimal pulse oximetry monitoring strategy in infants hospitalised with bronchiolitis. We will disseminate the findings of this study through peer-reviewed publication, professional societies and meetings.

TRIAL REGISTRATION NUMBER

NCT02947204.

Nebulized hypertonic saline in infants hospitalized with moderately severe bronchiolitis due to RSV infection: A multicenter randomized controlled trial

INTRODUCTION

The efficacy of nebulized hypertonic saline (HS) therapy for shortening hospital length of stay (LOS) or improving bronchiolitic symptoms remains controversial. Most studies enrolled small numbers of subjects and did not consider the role of respiratory syncytial virus (RSV), the most common cause of acute bronchiolitis. Our aim was to evaluate the efficacy and safety of nebulized HS therapy for acute bronchiolitis due to RSV in moderately ill hospitalized infants.

MATERIALS AND METHODS

This was an open-label, multicenter, randomized controlled trial comparing a nebulized HS treatment group with a normal saline (NS) group. The subjects, 128 infants with bronchiolitis due to RSV, were admitted to five hospitals in Tokyo, Japan. Three-percent HS or NS was administered via bronchodilator four times daily post-admission. The primary outcome was LOS, defined as the time until the patients fulfilled the discharge criteria, namely, absence of fever, no need for supplemental oxygen, and adequate feeding. Survival analysis was conducted in accordance with the intention-to-treat principle.

RESULTS

The baseline characteristics were similar between the two groups. There was no significant overall difference in LOS between the groups (4.81 ± 2.14 days in HS vs 4.61 ± 2.18 days in NS; P = 0.60). Survival analysis by log-rank test also showed no significance (P = 0.62). Multivariate adjustment did not significantly alter the results. The treatment was well-tolerated, with no adverse effects attributable to the use of HS.

CONCLUSIONS

Nebulized HS therapy did not significantly reduce LOS among infants with bronchiolitis due to RSV.

Hypertonic saline inhalations in bronchiolitis-A cumulative meta-analysis

We undertook a cumulative meta-analysis for the efficacy of hypertonic saline (HS) compared to normal saline (NS) inhalations or no inhalations as controls in bronchiolitis. We performed literature searches from PubMed, Scopus, and by hand search until 20 June 2017. We accepted published randomized controlled trials of HS inhalations in children with bronchiolitis aged <24 months. We evaluated the differences between treatment group with HS and control group without HS inhalations for the length-of-stay in hospital (LOS) by cumulative mean difference (MD) and in hospitalization rate by cumulative risk ratio (RR). We identified 18 studies including 2102 children treated in hospital, and the cumulative MD in LOS was -0.471 days (95% confidence interval [CI] -0.765 to -0.177, Higgins heterogeneity test [I² ] 72.9%). The cumulative MD reduced in more recently published papers. In studies with the upper age limit of 12 months, the cumulative MD was -0.408 days (95%CI -0.733 to -0.083) without any important heterogeneity (I²  = 0%). If only studies with a very low risk of bias were included, the cumulative MD was 0.034 (95%CI -0.361 to 0.293) without any important heterogeneity (I²  = 0%). We identified eight studies including 1834 children in the outpatient setting, and the cumulative risk ratio for hospitalization was 0.771 (95%CI 0.619-0.959, I² 55.8%). In conclusion, HS inhalations offered only limited clinical benefits, though the differences between HS and control groups were statistically significant. The heterogeneity between the studies was substantial. Further studies are warranted with consistent definitions of bronchiolitis and comparable research frames.

The cost-effectiveness of hypertonic saline inhalations for infant bronchiolitis: a decision analysis

BACKGROUND

This study evaluated the cost-effectiveness of hypertonic saline (HS) inhalations for infant bronchiolitis, compared to normal saline inhalations or standard treatment without inhalations as controls.

METHODS

The decision tree in the decision analysis was used to calculate the expected costs. Actual cost data were obtained from our retrospective case-control study on bronchiolitis treatment. The effectiveness of treatment, based on the hospitalization rate of those admitted to the emergency department and the length of stay (LOS) of those who were hospitalized, was collected from previous studies. For the effectiveness estimations, we made a meta-analysis summarizing the results of the meta-analysis of the Cochrane review in 2013 and the results of 10 studies published after it.

RESULTS

The mean hospitalization rate was 24.7% in the HS inhalation group and 32.6% in the control group [risk ratio: 0.80, 95% confidence interval (CI) 0.67-0.96] and the mean LOS was 3.736 (HS group) and 4.292 (controls) days (mean difference: - 0.55 days, 95% CI - 0.96 to - 0.15), respectively. The expected costs per patient, when both inpatients and outpatients were included, were €816 ($1111) in the HS inhalation group and €962 ($1310) in the control group. The expected costs per hospitalization, when only inpatients were included, were €2600 ($3540) in the HS inhalation group and €2890 ($3935) in the control group.

CONCLUSIONS

HS inhalations slightly reduced the expected hospitalization costs of infant bronchiolitis. However, the low effectiveness, rather than the cost, is the factor that will limit the use of HS inhalations in infant bronchiolitis.

Systematic review of instruments aimed at evaluating the severity of bronchiolitis

OBJECTIVE

No recent studies have performed a systematic review of all available instruments aimed at evaluating the severity of bronchiolitis. The objective of the present study was to perform a systematic review of instruments aimed at evaluating the severity of bronchiolitis and to evaluate their measurement properties.

METHODS

A systematic search of the literature was performed in order to identify studies in which an instrument for evaluating the severity of bronchiolitis was described. Instruments were evaluated based on their reliability, validity, utility, endorsement frequency, restrictions in range, comprehension, and lack of ambiguity.

RESULTS

A total of 77 articles, describing a total of 32 different instruments were included in the review. The number of items included in the instruments ranged from 2 to 26. Upon analyzing their content, respiratory rate turned out to be the most frequently used item (in 26/32, 81.3% of the instruments), followed by wheezing (in 25/32, 78.1% of the instruments). In 18 (56.3%) instruments, there was a report of at least one of their measurement properties, mainly reliability and utility. Taking into consideration the information contained in the instruments, as well as their measurement properties, one was considered to be the best one available.

CONCLUSIONS

Among the 32 instruments aimed at evaluating the severity of bronchiolitis that were identified and systematically examined, one was considered to be the best one available. However, there is an urgent need to develop better instruments and to validate them in a more comprehensive and proper way.

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.

Real-life comparison of three general paediatric wards showed similar outcomes for children with bronchiolitis despite different treatment regimens

AIM

This study evaluated the effectiveness of three different treatments for bronchiolitis in a tertiary paediatric facility.

METHODS

Patients with bronchiolitis who were younger than two years of age and were randomly allocated to three general wards at Schneider Children's Medical Center, Israel, after admission were included. Different treatment protocols in the wards were retrospectively compared.

RESULTS

The study comprised 286 children. The clinical and laboratory parameters on admission were similar between the wards. In Ward C where nebulised hypertonic saline was infrequently administered (6.7%), the mean number of days with oxygen saturation under 92% and the meanlength of hospital stay (1.8 and 3.8 days) were significantly lower than Ward A (2.8 and 5.3 days) and Ward B, (2.9 and 4.7 days) where nebulised hypertonic saline was given more frequently (38.7%-74.7%). Multivariate analysis indicated that low saturation on admission, leukocytosis and use of nebulised hypertonic saline or adrenalin were independent predictors of a longer period of desaturation and hospital stay.

CONCLUSION

Different treatment protocols for bronchiolitis were used in three paediatric wards in this real-life study. No treatment regimen proved superior. Inhalations of hypertonic saline or adrenaline were associated with a longer hospital stay.

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.

The role of mucoactive agents in the mechanically ventilated patient: a review of the literature

INTRODUCTION

The management of airway secretions in the mechanically ventilated patient is a routine task throughout all intensive care units. The current treatment strategies are primarily based on anecdotal experiences rather than statistical evidence. Areas covered: This review article evaluates the data from published trials surrounding mucoactive agents and their use in the critically ill patient population. We completed an extensive search through PUBMED and CINAHL via EBSCO, along with the Cochran library to find all trials using mucoactive agents in the critically ill patient population. Expert commentary: Overall, the role of mucoactive agents in the intensive care unit is a field within pulmonary critical care that is in need of evidence-based recommendations. We feel that there is great opportunity for investigators to evaluate different mucoactive therapies in this patient population and to determine their effect on clinical outcomes.

Viral bronchiolitis

Viral bronchiolitis is a common clinical syndrome affecting infants and young children. Concern about its associated morbidity and cost has led to a large body of research that has been summarised in systematic reviews and integrated into clinical practice guidelines in several countries. The evidence and guideline recommendations consistently support a clinical diagnosis with the limited role for diagnostic testing for children presenting with the typical clinical syndrome of viral upper respiratory infection progressing to the lower respiratory tract. Management is largely supportive, focusing on maintaining oxygenation and hydration of the patient. Evidence suggests no benefit from bronchodilator or corticosteroid use in infants with a first episode of bronchiolitis. Evidence for other treatments such as hypertonic saline is evolving but not clearly defined yet. For infants with severe disease, the insufficient available data suggest a role for high-flow nasal cannula and continuous positive airway pressure use in a monitored setting to prevent respiratory failure.

A randomized trial of nebulized 3% hypertonic saline with salbutamol in the treatment of acute bronchiolitis in hospitalized infants

OBJECTIVE

Acute bronchiolitis is a common disorder of infants that often results in hospitalization. Apart from supportive care, no therapy has been shown to influence the course of the disease, except for a possible effect of nebulized hypertonic saline (HS). To determine whether this does have beneficial effects on length of stay in hospital or on severity scores, we undertook a double-blind, randomized, controlled trial in a pediatric department of a Portuguese hospital.

METHODS

Previously healthy infants, younger than 12 months, hospitalized with mild-to-moderate acute viral bronchiolitis were randomized to receive either nebulized 3% (hypertonic, HS) or 0.9% (normal, NS) saline during their entire hospital stay. Primary endpoints were: length of hospital stay and severity scores on each day of hospitalization. Need for supplemental oxygen, further add-on medications and adverse effects were also analyzed.

RESULTS

Sixty-eight patients completed the study (HS: 33; NS: 35). The median length of hospital stay did not differ between groups: HS: 5.6 ± 2.3 days; NS: 5.4 ± 2.1 days (P = 0.747). We found no difference between groups in severity scores from day 1 to day 4. There were no differences in need for supplemental oxygen or add-on medications. Patients in HS group had significantly more cough (46% vs. 20%, P = 0.025) and rhinorrhoe (58% vs. 31%, P = 0.30).

CONCLUSION

This study does not support the use of nebulized HS over NS in therapy of hospitalized children with mild-to-moderate acute viral bronchiolitis.

Effectiveness of 3% hypertonic saline nebulization in acute bronchiolitis among Indian children: A quasi-experimental study

OBJECTIVE

To compare the effects of 3% hypertonic saline (HS) and 0.9% normal saline with nebulized 0.9% normal saline with salbutamol in patients of acute viral bronchiolitis.

MATERIALS AND METHODS

Participants were divided into three groups, that is, 3% HS group, 0.9% normal saline group and 0.9% saline with salbutamol group. Four doses at interval of 6 h were given daily until discharge. Average CS score and length of hospital stay were compared. One-way analysis of variance paired t-test and Chi-square test were utilized for statistical analysis.

RESULTS

The mean ages of the patients in three groups were 6.03 ± 3.71, 5.69 ± 3.34 and 5.48 ± 3.35 respectively. The 3(rd) day CS scores for all the groups were 1.0 ± 1.1, 1.9 ± 1.1 and 3.3 ± 0.5 respectively (P = 0.000). The average length of hospital stay was 3.4 ± 1.7, 3.7 ± 1.9 and 4.9 ± 1.4 days respectively (P = 0.001).

CONCLUSION

The present study concludes that 3% HS nebulization (without additional bronchodilators) is an effective and safe treatment for nonasthmatic, moderately ill patients of acute bronchiolitis. The economic benefit of this comparably priced modality of treatment can be enormous in terms of hospital costs with parents returning to work sooner.

Latest options for treatment of bronchiolitis in infants

Bronchiolitis is the most frequent pathology associated with lower respiratory tract infection in newborns and young infants. The treatment of bronchiolitis is essentially supportive therapy for respiratory distress, hypoxia and dehydration. To date, no specific antiviral drug is used on a routine basis for the treatment of RSV infections. Currently, the only antiviral drug approved for the infection is ribavirin; however, its use is limited due to adverse side effects and the risks it poses to healthcare providers. Moreover, several drugs have been routinely administered for years in infants with acute RSV bronchiolitis, even if their efficacy is often not confirmed by clinical evidence, and studies on emerging antiviral drugs are still ongoing. In the present paper we review the recent literature about the drugs used during acute bronchiolitis and we summarize the main recommendations of national and international guidelines and the latest options for the treatment of bronchiolitis.

Comparing the Efficacy of 7%, 3% and 0.9% Saline in Moderate to Severe Bronchiolitis in Infants

BACKGROUND

There is no standard treatment option in acute bronchiolitis. 3-7% hypertonic saline (HS) seems to be the effective treatment choice for reducing the hospitalization day.

AIMS

To compare the effect of nebulized 7% HS/salbutamol and 3% HS/salbutamol to 0.9% saline/salbutamol. The primary outcome measure was the effect of study drugs on the length of hospital stay (LOS). Secondary outcome measures were safety and efficacy in reducing the clinical severity score (CSS) at the 24 hours of the study.

STUDY DESIGN

Prospective, double-blinded randomized clinical study.

METHODS

The study consists of 104 infants. Groups were constituted according to the treatment they received: These are, group A - 0.9% saline/salbutamol, group B -3% HS/salbutamol and group C-7% HS/salbutamol. Heart beat, Bronchiolitis CSS and oxygen saturation of the patients were determined before and after nebulization. The patients were monitored for adverse reactions.

RESULTS

Length of hospital stay in group A, B and C were as follows; 72.0 (20-288) hours in group A, 64.0 (12-168) hours in group B and 60.0 (12-264) hours in group C. No significant differences was observed among three groups (p>0.05).

CONCLUSION

7% HS and 3% HS does not have any effect to decrease LOS for infants with bronchiolitis.

Hypertonic saline (HS) for acute bronchiolitis: Systematic review and meta-analysis

BACKGROUND

Acute bronchiolitis is the commonest cause of hospitalisation in infancy. Currently management consists of supportive care and oxygen. A Cochrane review concluded that, "nebulised 3 % saline may significantly reduce the length of hospital stay". We conducted a systematic review of controlled trials of nebulised hypertonic saline (HS) for infants hospitalised with primary acute bronchiolitis.

METHODS

Searches to January 2015 involved: Cochrane Central Register of Controlled Trials; Ovid MEDLINE; Embase; Google Scholar; Web of Science; and, a variety of trials registers. We hand searched Chest, Paediatrics and Journal of Paediatrics on 14 January 2015. Reference lists of eligible trial publications were checked. Randomised or quasi-randomised trials which compared HS versus either normal saline (+/- adjunct treatment) or no treatment were included. Eligible studies involved children less than 2 years old hospitalised due to the first episode of acute bronchiolitis. Two reviewers extracted data to calculate mean differences (MD) and 95 % Confidence Intervals (CIs) for length of hospital stay (LoS-primary outcome), Clinical Severity Score (CSS) and Serious Adverse Events (SAEs). Meta-analysis was undertaken using a fixed effect model, supplemented with additional sensitivity analyses. We investigated statistical heterogeneity using I(2). Risk of bias, within and between studies, was assessed using the Cochrane tool, an outcome reporting bias checklist and a funnel plot.

RESULTS

Fifteen trials were included in the systematic review (n = 1922), HS reduced mean LoS by 0.36, (95 % CI 0.50 to 0.22) days, but with considerable heterogeneity (I(2) = 78 %) and sensitivity to alternative analysis methods. A reduction in CSS was observed where assessed [n = 516; MD -1.36, CI -1.52, -1.20]. One trial reported one possible intervention related SAE, no other studies described intervention related SAEs.

CONCLUSIONS

There is disparity between the overall combined effect on LoS as compared with the negative results from the largest and most precise trials. Together with high levels of heterogeneity, this means that neither individual trials nor pooled estimates provide a firm evidence-base for routine use of HS in inpatient acute bronchiolitis.

Epinephrine Improves the Efficacy of Nebulized Hypertonic Saline in Moderate Bronchiolitis: A Randomised Clinical Trial

Background and Aims

There is no evidence that the epinephrine-3% hypertonic saline combination is more effective than 3% hypertonic saline alone for treating infants hospitalized with acute bronchiolitis. We evaluated the efficacy of nebulized epinephrine in 3% hypertonic saline.

Patients and Methods

We performed a randomized, double-blind, placebo-controlled clinical trial in 208 infants hospitalized with acute moderate bronchiolitis. Infants were randomly assigned to receive nebulized 3% hypertonic saline with either 3 mL of epinephrine or 3 mL of placebo, administered every four hours. The primary outcome measure was the length of hospital stay.

Results

A total of 185 infants were analyzed: 94 in the epinephrine plus 3% hypertonic saline group and 91 in the placebo plus 3% hypertonic saline group. Baseline demographic and clinical characteristics were similar in both groups. Length of hospital stay was significantly reduced in the epinephrine group as compared with the placebo group (3.94 ±1.88 days vs. 4.82 ±2.30 days, P = 0.011). Disease severity also decreased significantly earlier in the epinephrine group (P = 0.029 and P = 0.036 on days 3 and 5, respectively).

Conclusions

In our setting, nebulized epinephrine in 3% hypertonic saline significantly shortens hospital stay in hospitalized infants with acute moderate bronchiolitis compared to 3% hypertonic saline alone, and improves the clinical scores of severity from the third day of treatment, but not before.

Trial Registration

EudraCT 2009-016042-57

Nebulized Hypertonic Saline for Acute Bronchiolitis: A Systematic Review

BACKGROUND AND OBJECTIVE

The mainstay of treatment for acute bronchiolitis remains supportive care. The objective of this study was to assess the efficacy and safety of nebulized hypertonic saline (HS) in infants with acute bronchiolitis.

METHODS

Data sources included PubMed and the Virtual Health Library of the Latin American and Caribbean Center on Health Sciences Information up to May 2015. Studies selected were randomized or quasi-randomized controlled trials comparing nebulized HS with 0.9% saline or standard treatment.

RESULTS

We included 24 trials involving 3209 patients, 1706 of whom received HS. Hospitalized patients treated with nebulized HS had a significantly shorter length of stay compared with those receiving 0.9% saline or standard care (15 trials involving 1956 patients; mean difference [MD] -0.45 days, 95% confidence interval [CI] -0.82 to -0.08). The HS group also had a significantly lower posttreatment clinical score in the first 3 days of admission (5 trials involving 404 inpatients; day 1: MD -0.99, 95% CI -1.48 to -0.50; day 2: MD -1.45, 95% CI -2.06 to -0.85; day 3: MD -1.44, 95% CI -1.78 to -1.11). Nebulized HS reduced the risk of hospitalization by 20% compared with 0.9% saline among outpatients (7 trials involving 951 patients; risk ratio 0.80, 95% CI 0.67-0.96). No significant adverse events related to HS inhalation were reported. The quality of evidence is moderate due to inconsistency in results between trials and study limitations (risk of bias).

CONCLUSIONS

Nebulized HS is a safe and potentially effective treatment of infants with acute bronchiolitis.

Nebulised hypertonic saline (3%) among children with mild to moderately severe bronchiolitis--a double blind randomized controlled trial

BACKGROUND

To Assess the efficacy of nebulised hypertonic saline (HS) (3%) among children with mild to moderately severe bronchiolitis.

METHODS

Infants aged 6 weeks to 24 months, with a first episode of wheezing and Clinical Severity scores (Arch Dis Child 67:289-93, 1992) between 1 and 8, were enrolled over 4 months duration. Those with severe disease, co-morbidities, prior wheezing, recent bronchodilator and steroid use were excluded. Patients were randomized in a double-blind fashion, to receive two doses of nebulized 3% HS (Group 1) or 0.9% normal saline (Group 2) with 1.5 mg of L-Epineprine, delivered 30 min apart. Parents were contacted at 24 h and 7 days. The principal outcome measure was the mean change in clinical severity score at the end of 2 h of observation.

RESULTS

A total of 100 infants (mean age 9.6 months, range 2-23 months; 61 % males) were enrolled. Patients in both groups had mild to moderately severe disease at presentation. On an intention-to-treat basis, the infants in the HS group had a significant reduction (3.57 ± 1.41) in the mean clinical severity score compared to those in the NS group (2.26 ± 1.15); [p < 0.001; CI: 0.78-1.82]. More children in the HS group (n = 35/50; 70.0%) were eligible for ER/OPD discharge at the end of 2 h than those in the NS group (n = 15/50; 30%; p < 0.001), and less likely to need a hospital re-visit (n = 5/50; 10.0%) in the next 24 h as compared to the NS group (n = 15/50, 30.0%; p < 0.001). The treatment was well tolerated, with no adverse effects.

CONCLUSIONS

Nebulized 3% HS is effective, safe and superior to normal saline for outpatient management of infants with mild to moderately severe viral bronchiolitis in improving Clinical Severity Scores, facilitating early Out-Patient Department discharge and preventing hospital re-visits and admissions in the 24 h of presentation.

TRIAL REGISTRATION

Clinicaltrials.gov NCTID012766821. Registered on January 12, 2011.

Saline in acute bronchiolitis RCT and economic evaluation: hypertonic saline in acute bronchiolitis - randomised controlled trial and systematic review

BACKGROUND

Acute bronchiolitis is the most common cause of hospitalisation in infancy. Supportive care and oxygen are the cornerstones of management. A Cochrane review concluded that the use of nebulised 3% hypertonic saline (HS) may significantly reduce the duration of hospitalisation.

OBJECTIVE

To test the hypothesis that HS reduces the time to when infants were assessed as being fit for discharge, defined as in air with saturations of > 92% for 6 hours, by 25%.

DESIGN

Parallel-group, pragmatic randomised controlled trial, cost-utility analysis and systematic review.

SETTING

Ten UK hospitals.

PARTICIPANTS

Infants with acute bronchiolitis requiring oxygen therapy were allocated within 4 hours of admission.

INTERVENTIONS

Supportive care with oxygen as required, minimal handling and fluid administration as appropriate to the severity of the disease, 3% nebulised HS every ± 6 hours.

MAIN OUTCOME MEASURES

The trial primary outcome was time until the infant met objective discharge criteria. Secondary end points included time to discharge and adverse events. The costs analysed related to length of stay (LoS), readmissions, nebulised saline and other NHS resource use. Quality-adjusted life-years (QALYs) were estimated using an existing utility decrement derived for hospitalisation in children, together with the time spent in hospital in the trial.

DATA SOURCES

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and other databases from inception or from 2010 onwards, searched ClinicalTrials.gov and other registries and hand-searched Chest, Paediatrics and Journal of Paediatrics to January 2015.

REVIEW METHODS

We included randomised/quasi-randomised trials which compared HS versus saline (± adjunct treatment) or no treatment. We used a fixed-effects model to combine mean differences for LoS and assessed statistical heterogeneity using the I (2) statistic.

RESULTS

The trial randomised 158 infants to HS (n = 141 analysed) and 159 to standard care (n = 149 analysed). There was no difference between the two arms in the time to being declared fit for discharge [median 76.6 vs. 75.9 hours, hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.75 to 1.20] or to actual discharge (median 88.5 vs. 88.7 hours, HR 0.97, 95% CI 0.76 to 1.23). There was no difference in adverse events. One infant developed bradycardia with desaturation associated with HS. Mean hospital costs were £2595 and £2727 for the control and intervention groups, respectively (p = 0.657). Incremental QALYs were 0.0000175 (p = 0.757). An incremental cost-effectiveness ratio of £7.6M per QALY gained was not appreciably altered by sensitivity analyses. The systematic review comprised 15 trials (n = 1922) including our own. HS reduced the mean LoS by -0.36 days (95% CI -0.50 to -0.22 days). High levels of heterogeneity (I (2) = 78%) indicate that the result should be treated cautiously.

CONCLUSIONS

In this trial, HS had no clinical benefit on LoS or readiness for discharge and was not a cost-effective treatment for acute bronchiolitis. Claims that HS achieves small reductions in LoS must be treated with scepticism.

FUTURE WORK

Well-powered randomised controlled trials of high-flow oxygen are needed.

STUDY REGISTRATION

This study is registered as NCT01469845 and CRD42014007569.

FUNDING DETAILS

This project was funded by the NIHR Health Technology Assessment (HTA) programme and will be published in full in Health Technology Assessment; Vol. 19, No. 66. See the HTA programme website for further project information.

Effect of inhaled hypertonic saline on hospital admission rate in children with viral bronchiolitis: a randomized trial

Objective:

We sought to determine whether inhaled 3% hypertonic saline (HS) reduces admission to hospital in ambulatory children with moderately severe viral bronchiolitis. Secondary objectives compared changes in respiratory scores before and after treatment and assessed the need for unscheduled medical intervention within 7 days.

Methods:

Children under the age of 2 years presenting with moderately severe viral bronchiolitis to the emergency department of 4 general hospitals from November 2008 to March 2009 were randomly assigned to receive 3 consecutive 4-mL doses of nebulized 3% HS (treatment group) or 0.9% normal saline (NS; control group) in a double blind fashion, each coadministered with 1 mg salbutamol. Outcome measures included the difference in hospital admission rate and changes in respiratory distress scores.

Results:

A total of 81 children (mean age 8.9 mo, range 0.7–22 mo) were assessed over 88 visits on an intention-to-treat basis. No statistically significant differences were found between treatment groups. Children in the HS group had a nonsignificant trend toward greater improvement compared with NS controls with a same-day admission rate of 18% (95% confidence interval [CI] 9%–32%) versus 27% (95% CI 16%–42%), respectively. Respiratory Assessment Change Scores (RACS) favoured the HS group over NS controls (mean RACS 4.7 [95% CI 3.6–5.8] v. 3.7 [95% CI 2.5–4.9], respectively), although the CIs overlap and these differences were not statistically significant.

Conclusion:

The short-term use of nebulized 3% HS did not result in any statistically significant benefits, although a nonsignificant trend toward a decrease in admission rate and improvement in respiratory distress was found. A larger study would be required to determine whether these trends arise from a clinically relevant treatment effect.

Nebulized hypertonic saline treatment reduces both rate and duration of hospitalization for acute bronchiolitis in infants: an updated meta-analysis

Nebulized hypertonic saline (HS) treatment reduced the length of hospitalization in infants with acute bronchiolitis in a previous meta-analysis. However, there was no reduction in the admission rate. We hypothesized that nebulized HS treatment might significantly decrease both the duration and the rate of hospitalization if more randomized controlled trials (RCTs) were included. We searched MEDLINE, PubMed, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL) without a language restriction. A meta-analysis was performed based on the efficacy of nebulized HS treatment in infants with acute bronchiolitis. We used weighted mean difference (WMD) and risk ratio as effect size metrics. Eleven studies were identified that enrolled 1070 infants. Nebulized HS treatment significantly decreased the duration and rate of hospitalization compared with nebulized normal saline (NS) [duration of hospitalization: WMD = -0.96, 95% confidence interval (CI) = -1.38 to -0.54, p < 0.001; rate of hospitalization: risk ratio = 0.59, 95% CI = 0.37-0.93, p = 0.02]. Furthermore, nebulized HS treatment had a beneficial effect in reducing the clinical severity (CS) score of acute bronchiolitis infants post-treatment (Day 1: WMD = -0.77, 95% CI = -1.30 to -0.24, p = 0.005; Day 2: WMD = -0.85, 95% CI = -1.30 to -0.39, p < 0.001; Day 3: WMD = -1.14, 95% CI = -1.69 to -0.58, p < 0.001). There was no decrease in the rate of readmission (risk ratio = 1.08, 95% CI = 0.68-1.73, p = 0.74). Nebulized HS treatment significantly decreased both the rate and the duration of hospitalization. Due to the efficacy and cost-effectiveness, HS should be considered for the treatment of acute bronchiolitis in infants.

Inter-society consensus document on treatment and prevention of bronchiolitis in newborns and infants

Acute bronchiolitis is the leading cause of lower respiratory tract infection and hospitalization in children less than 1 year of age worldwide. It is usually a mild disease, but some children may develop severe symptoms, requiring hospital admission and ventilatory support in the ICU. Infants with pre-existing risk factors (prematurity, bronchopulmonary dysplasia, congenital heart diseases and immunodeficiency) may be predisposed to a severe form of the disease. Clinical diagnosis of bronchiolitis is manly based on medical history and physical examination (rhinorrhea, cough, crackles, wheezing and signs of respiratory distress). Etiological diagnosis, with antigen or genome detection to identify viruses involved, may have a role in reducing hospital transmission of the infection. Criteria for hospitalization include low oxygen saturation (<90-92%), moderate-to-severe respiratory distress, dehydration and presence of apnea. Children with pre-existing risk factors should be carefully assessed.To date, there is no specific treatment for viral bronchiolitis, and the mainstay of therapy is supportive care. This consists of nasal suctioning and nebulized 3% hypertonic saline, assisted feeding and hydration, humidified O2 delivery. The possible role of any pharmacological approach is still debated, and till now there is no evidence to support the use of bronchodilators, corticosteroids, chest physiotherapy, antibiotics or antivirals. Nebulized adrenaline may be sometimes useful in the emergency room. Nebulized adrenaline can be useful in the hospital setting for treatment as needed. Lacking a specific etiological treatment, prophylaxis and prevention, especially in children at high risk of severe infection, have a fundamental role. Environmental preventive measures minimize viral transmission in hospital, in the outpatient setting and at home. Pharmacological prophylaxis with palivizumab for RSV bronchiolitis is indicated in specific categories of children at risk during the epidemic period. Viral bronchiolitis, especially in the case of severe form, may correlate with an increased incidence of recurrent wheezing in pre-schooled children and with asthma at school age.The aim of this document is to provide a multidisciplinary update on the current recommendations for the management and prevention of bronchiolitis, in order to share useful indications, identify gaps in knowledge and drive future research.

Seven percent hypertonic saline--0.1% hyaluronic acid in infants with mild-to-moderate bronchiolitis

OBJECTIVES

Our study was aimed to evaluate the efficacy of 7% hypertonic saline and 0.1% hyaluronic acid (7% HS-HA) given by inhalation, in infants hospitalized for mild-to-moderate bronchiolitis.

METHODS

In a double-blind controlled study, 39 infants (23 boys) <7 months of age (median age 2 months) were enrolled and randomly assigned to receive either nebulized 7% HS-HA (7%NaCl + 0.1%HA) (n:21) or 0.9 normal saline (NS) (n:18) at a dose of 2.5 ml twice a day for 3 days. All infants were assigned a clinical severity score at admission and four times daily during hospitalization. Main outcome measures were number of days hospitalization, safety and daily reduction in the severity score.

RESULTS

No difference was found between the two groups for clinical severity score at admission. One child in the study group and two in the NS group interrupted the study protocol; 19% of infants in the study group and 11% in the NS group had mild cough after the aerosol. The length of stay in the control group and treatment groups were 4.8 ± 1.5 versus 4.1 ± 1.9 days, respectively (P = 0.09). There was a trend for shortening the hospitalization days in the treatment group by 14.6%. The use of NS in the control group was identified as an independent risk factor for length of hospital stay using the multivariate logistic regression model (P = 0.04). No difference was observed between the two groups for the clinical score reduction during the first 3 days hospitalization.

CONCLUSIONS

7% HS-HA is a safe and effective therapy in treating infants hospitalized for mild-to-moderate bronchiolitis.

Bronchiolitis

This article discusses and evaluates the management options for children with bronchiolitis, and identifies children at high risk of a clinically severe illness.

The effect of 3% and 6% hypertonic saline in viral bronchiolitis: a randomised controlled trial

Bronchiolitis is a common disorder in young children that often results in hospitalisation. Except for a possible effect of nebulised hypertonic saline (sodium chloride), no evidence-based therapy is available. This study investigated the efficacy of nebulised 3% and 6% hypertonic saline compared with 0.9% hypertonic saline in children hospitalised with viral bronchiolitis.

In this multicentre, double-blind, randomised, controlled trial, children hospitalised with acute viral bronchiolitis were randomised to receive either nebulised 3%, 6% hypertonic saline or 0.9% normal saline during their entire hospital stay. Salbutamol was added to counteract possible bronchial constriction. The primary endpoint was the length of hospital stay. Secondary outcomes were need for supplemental oxygen and tube feeding.

From the 292 children included in the study (median age 3.4 months), 247 completed the study. The median length of hospital stay did not differ between the groups: 69 h (interquartile range 57), 70 h (IQR 69) and 53 h (IQR 52), for 3% (n=84) and 6% (n=83) hypertonic saline and 0.9% (n=80) normal saline, respectively, (p=0.29). The need for supplemental oxygen or tube feeding did not differ significantly. Adverse effects were similar in the three groups.

Nebulisation with hypertonic saline (3% or 6% sodium chloride) although safe, did not reduce the length of stay in hospital, duration of supplemental oxygen or tube feeding in children hospitalised with moderate-to-severe viral bronchiolitis.

Validity of respiratory scores in bronchiolitis

OBJECTIVE

The primary objective of this study was to establish the validity and reliability of 2 respiratory scores, the Respiratory Distress Assessment Instrument (RDAI) and the Children's Hospital of Wisconsin Respiratory Score (CHWRS), in bronchiolitis. A secondary objective was to identify the respiratory score components that most determine overall respiratory status.

METHODS

This was a prospective cohort study in infants aged < 1 year seen at Children's Hospital of Wisconsin for bronchiolitis. We evaluated: (1) discriminative validity (the score's ability to discriminate between 2 different outcomes) of the respiratory scores to identify emergency department (ED) disposition by using receiver operating characteristic curves; and (2) construct validity (the score's ability to measure what it is thought to measure, overall respiratory status) by using length of stay (LOS) as a proxy for disease severity and comparing correlations between changes in respiratory scores and LOS. Interrater reliability was established by using intraclass correlation. The contribution of individual respiratory score components to determine ED disposition was studied by using multivariate logistic regression.

RESULTS

A total of 195 infants were included. The area under the receiver operating characteristic curve was 0.68 for CHWRS versus 0.51 for RDAI in predicting disposition. There was no correlation between initial respiratory scores or change in respiratory scores over the first 24 hours and LOS. Item analysis revealed that oxygen delivery, subcostal retractions, and respiratory rate were independently correlated with ED disposition. The CHWRS was more reliable than the RDAI.

CONCLUSIONS

The CHWRS had modest discriminative validity in predicting ED disposition. Neither the CHWRS nor the RDAI had good construct validity. Respiratory rate, oxygen need, and presence of retractions were most useful in predicting ED disposition.

A model of the costs of community and nosocomial pediatric respiratory syncytial virus infections in Canadian hospitals

BACKGROUND

Approximately one in 10 hospitalized patients will acquire a nosocomial infection (NI) after admission to hospital, of which 71% are due to respiratory viruses, including the respiratory syncytial virus (RSV). NIs are concerning and lead to prolonged hospitalizations. The economics of NIs are typically described in generalized terms and specific cost data are lacking.

OBJECTIVE

To develop an evidence-based model for predicting the risk and cost of nosocomial RSV infection in pediatric settings.

METHODS

A model was developed, from a Canadian perspective, to capture all costs related to an RSV infection hospitalization, including the risk and cost of an NI, diagnostic testing and infection control. All data inputs were derived from published literature. Deterministic sensitivity analyses were performed to evaluate the uncertainty associated with the estimates and to explore the impact of changes to key variables. A probabilistic sensitivity analysis was performed to estimate a confidence interval for the overall cost estimate.

RESULTS

The estimated cost of nosocomial RSV infection adds approximately 30.5% to the hospitalization costs for the treatment of community-acquired severe RSV infection. The net benefits of the prevention activities were estimated to be equivalent to 9% of the total RSV-related costs. Changes in the estimated hospital infection transmission rates did not have a significant impact on the base-case estimate.

CONCLUSIONS

The risk and cost of nosocomial RSV infection contributes to the overall burden of RSV. The present model, which was developed to estimate this burden, can be adapted to other countries with different disease epidemiology, costs and hospital infection transmission rates.

Respiratory syncytial virus bronchiolitis in children

Respiratory syncytial virus is a highly infectious virus that commonly causes bronchiolitis and leads to high morbidity and a low, but important, incidence of mortality. Supportive therapy is the foundation of management. Hydration/nutrition and respiratory support are important evidence-based interventions. For children with severe disease, continuous positive airway pressure or mechanical ventilation may be necessary. Ribavirin may be used for treatment of patients with severe disease. Palivizumab provides important ongoing immunoprophylaxis during epidemic months for high-risk infants. Caregiver education and incorporating an explanation of all therapies and anticipatory guidance, including strategies for reducing the risk of infection, are vital.

Acute bronchiolitis

Bronchiolitis is the most common lower respiratory tract infection to affect infants and toddlers. High-risk patients include infants younger than 3 months, premature infants, children with immunodeficiency, children with underlying cardiopulmonary or neuromuscular disease, or infants prone to apnea, severe respiratory distress, and respiratory failure. Bronchiolitis is a self-limited disease in healthy infants and children. Treatment is usually symptomatic, and the goal of therapy is to maintain adequate oxygenation and hydration. Use of a high-flow nasal cannula is becoming common for children with severe bronchiolitis.

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.

Inhaled Mucoactive Drugs for Treating Non-Cystic Fibrosis Bronchiectasis in Children

Non-cystic fibrosis bronchiectasis (nCFb) is an acquired condition of variable etiology. Medical treatment basically involves antibiotics and chest physiotherapy. An impaired mucociliary clearance seems to be one of the mechanisms behind nCFb, and inhaled therapy with mucoactive agents has frequently been used to try to correct it. The most often used mucoactive agents in this setting are N-acetylcysteine, hypertonic saline solution (HS), mannitol powder and recombinant human DNase (rhDNase). Reviewing the international medical literature on the use of these drugs for patients with nCFb from 1992 to the present day, we retrieved 88 articles, only 12 of which met our selection criteria for this analysis. We found only 2 papers and 2 reviews on the use of rhDNase in children, and in adults 3 trials on HS, 5 on mannitol powder and 2 on rhDNase. In conclusion, no observational or randomized controlled trials (RCT) have been published on the use of these drugs in children with nCFb, while the few conducted on adult patients report some evidence of their effects. Further studies are needed on inhaled mucoactive drugs for the treatment of children with nCFb.

[Inhalation therapy: provocation tests, infectious risks, acute bronchiolitis and ENT diseases. GAT aerosolstorming, Paris 2011]

Communications from the 2011 meeting of the GAT are reported in this second article on the practical management of bronchial provocation tests and infectious risks associated with the use of nebulization. Recent advances on the role of nebulized hypertonic saline in the treatment of acute bronchiolitis in infants and of the nebulization in sinusal diseases are also reported.

Hypertonic (3%) saline vs 0.93% saline nebulization for acute viral bronchiolitis: a randomized controlled trial

OBJECTIVE

To compare the length of hospital stay (primary) and improvement in clinical severity scores (secondary) among children with bronchiolitis nebulized with 3 % hypertonic saline or 0.9% saline.

DESIGN

Randomized double blind controlled trial.

SETTINGS

Tertiary care teaching hospital.

PATIENTS

Hospitalized children (1-24 months) with acute bronchiolitis of moderate severity.

INTERVENTION

Nebulization of 4 ml of 3% hypertonic saline or 4 mL of 0.9% saline, along with 2.5 mg salbutamol, at 4-hourly intervals till the patient was ready for discharge.

RESULTS

Baseline characteristics were similar in two groups. Median clinical severity score at admission was 6 (IQR-1) in both the groups. Clinical severity scores monitored afterwards 12-hourly till discharge (132 h) did not show statistically significant differences in 3% and 0.9% saline groups. Mean length of hospital stay (time to reach predefined clinical severity score<3) was 63.93 ± 22.43 h in 3% saline group and 63.51 ± 21.27 h in 0.9% saline group (P=0.878). No adverse events were reported by the parents, caregivers or treating medical attendants in both groups.

CONCLUSION

Nebulized 3 % saline is not superior to 0.9% saline in infants with clinically diagnosed acute bronchiolitis.

Nebulized hypertonic saline attenuates acute lung injury following trauma and hemorrhagic shock via inhibition of matrix metalloproteinase-13

OBJECTIVE

We hypothesized that aerosolized inhaled hypertonic saline given at the onset of resuscitation will decrease acute lung injury following hemorrhagic shock, by inhibiting the release of epithelial derived proinflammatory mediators.

DESIGN

Animal study.

SETTING

Animal-care facility procedure room in a medical center.

SUBJECTS

Adult male Sprague-Dawley rats.

INTERVENTIONS

Rats underwent hemorrhagic shock followed by 2 hrs of resuscitation and 1 hr of observation. In the study group, nebulized hypertonic saline was delivered at the end of the shock period and after 1 hr and 2 hrs of resuscitation.

MEASUREMENTS AND MAIN RESULTS

Shock provoked acute lung injury, which was attenuated with inhaled hypertonic saline (1.56 ± 0.2 mg protein/mL vs. 0.95 ± 0.3 mg protein/mL bronchoalveolar lavage fluid, shock vs. shock + hypertonic saline, p < .01). Nebulized hypertonic saline reduced inflammation (cytokine-induced neutrophil chemoattractant-1 accumulation in bronchoalveolar lavage fluid 5999 ± 1267 pg/mL vs. 3342 ± 859 pg/mL, shock vs. shock + hypertonic saline, p = .006). Additionally, nebulized hypertonic saline inhibited matrix -metalloproteinase-13 accumulation in the bronchoalveolar lavage fluid (1513 ± 337 pg/mL bronchoalveolar lavage fluid vs. 230 ± 19 pg/mL, shock vs. shock + hypertonic saline, p = .009) and pretreatment with a matrix metalloproteinase-13 inhibitor was sufficient to attenuate postshock acute lung injury (1.42 ± 0.09 mg/mL vs. 0.77 ± 0.23 mg/mL bronchoalveolar lavage protein, shock vs. shock + matrix metalloproteinase-13 inhibitor CL-82198, p = .002).

CONCLUSION

Inhaled hypertonic saline attenuates postshock acute lung injury by exerting an anti-inflammatory effect on the pulmonary epithelium, suggesting a new clinical strategy to treat acute lung injury/acute respiratory distress syndrome.

Prospective multicenter study of viral etiology and hospital length of stay in children with severe bronchiolitis

OBJECTIVE

To determine whether hospital length of stay(LOS) for acute bronchiolitis is influenced by the infecting pathogen.

DESIGN

A prospective observational cohort study was performed during 3 consecutive years.

SETTING

Sixteen US hospitals participated in the study.

PARTICIPANTS

Children younger than 2 years hospitalized with bronchiolitis were included.

MAIN EXPOSURE

The results of nasopharyngeal aspirate polymerase chain reaction pathogen testing served as the main exposure.

MAIN OUTCOME MEASURE

Hospital LOS was determined.

RESULTS

Of 2207 participants, 72.0% had respiratory syncytial virus (RSV) and 25.6% had human rhinovirus(HRV); the incidence of each of the other viruses and bacteria was 7.8% or less. Multiple pathogen infections were present in 29.8% of the children. There were 1866 children(84.5%) with RSV and/or HRV. Among these 1866 children, the median age was 4 months and 59.5% were male. The median LOS was 2 days (interquartile range,1-4 days). Compared with children who had only RSV,an LOS of 3 or more days was less likely among children with HRV alone (adjusted odds ratio [AOR], 0.36; 95%CI, 0.20-0.63; P.001) and those with HRV plus non-RSV pathogens (AOR, 0.39; 95% CI, 0.23-0.66; P.001)but more likely among children with RSV plus HRV(AOR,1.33; 95% CI, 1.02-1.73; P=.04), controlling for 15 demographic and clinical factors.

CONCLUSIONS

In this multicenter study of children hospitalized with bronchiolitis, RSV was the most common virus detected, but HRV was detected in one-quarter of the children. Since 1 in 3 children had multiple virus infections and HRV was associated with LOS, these data challenge the effectiveness of current RSV-based cohorting practices, the sporadic testing for HRV in bronchiolitis research, and current thinking that the infectious etiology of severe bronchiolitis does not affect short-term outcomes.