Hypertonic saline or high volume normal saline for viral bronchiolitis: mechanisms and rationale

7% Hypertonic saline in acute bronchiolitis: a randomized controlled trial

BACKGROUND

Research suggests that hypertonic saline (HS) may improve mucous flow in infants with acute bronchiolitis. Data suggest a trend favoring reduced length of hospital stay and improved pulmonary scores with increasing concentration of nebulized solution to 3% and 5% saline as compared with 0.9% saline mixed with epinephrine. To our knowledge, 7% HS has not been previously investigated.

METHODS

We conducted a prospective, double-blind, randomized controlled trial in 101 infants presenting with moderate to severe acute bronchiolitis. Subjects received either 7% saline or 0.9% saline, both with epinephrine. Our primary outcome was a change in bronchiolitis severity score (BSS), obtained before and after treatment, and at the time of disposition from the emergency department (ED). Secondary outcomes measured were hospitalization rate, proportion of admitted patients discharged at 23 hours, and ED and inpatient length of stay.

RESULTS

At baseline, study groups were similar in demographic and clinical characteristics. The decrease in mean BSS was not statistically significant between groups (2.6 vs 2.4 for HS and control groups, respectively). The difference between the groups in proportion of admitted patients (42% in HS versus 49% in normal saline), ED or inpatient length of stay, and proportion of admitted patients discharged at 23 hours was not statistically significant.

CONCLUSIONS

In moderate to severe acute bronchiolitis, inhalation of 7% HS with epinephrine does not appear to confer any clinically significant decrease in BSS when compared with 0.9% saline with epinephrine.

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.

Treatment of bronchiolitis: state of the art

Bronchiolitis is a leading cause of acute illness and hospitalization for infants and young children worldwide. It is usually a mild disease, but the few children developing severe symptoms need to be hospitalized and some will need ventilatory support. To date, the mainstay of therapy has been supportive care, i.e. assisted feeding and hydration, minimal handling, nasal suctioning and oxygen therapy. In recent years the delivery of oxygen has been improved by using a high-flow nasal cannula. At the same time, the discovery of nebulized hypertonic saline enables better airway cleaning with a benefit for respiratory function. The possible role of any pharmacological approach is still debated: many pharmacological therapies tried in the past, ranging from bronchodilators to corticosteroids, were found to offer no benefit in this disease. More recently, nebulized adrenaline demonstrated a short-term benefit. Prophylaxis and prevention, especially in children at high risk of severe infection, such as prematurely born infants and children with bronchopulmonary dysplasia, have a fundamental role in dealing with this disease. In this review, we focus on current recommendations for the management and prevention of bronchiolitis, paying particular attention to the latest literature in search of answers to the questions that remain open.

High-flow nasal cannula oxygen for bronchiolitis in a pediatric ward: a pilot study

High-flow nasal cannula (HFNC) is a widely used ventilatory support in children with bronchiolitis in the intensive care setting. No data is available on HFNC use in the general pediatric ward. The aim of this study was to evaluate the feasibility of HFNC oxygen therapy in infants hospitalized in a pediatric ward for moderate-severe bronchiolitis and to assess the changes in ventilatory parameters before and after starting HFNC support. This prospective observational pilot study was carried out during the bronchiolitis season 2011-2012 in a pediatric tertiary care academic center in Italy. Interruptions of HFNC therapy and possible side effects or escalation to other forms of respiratory support were recorded. Oxygen saturation (SpO2), end-tidal carbon dioxide (ETCO2), and respiratory rate (RR), measured for a baseline period of 1 h before and at specific time intervals in 48 h after the start of HFNC were recorded. Twenty-seven infants were included (median age 1.3 months; absolute range 0.3-8.5). No adverse events, no premature HFNC therapy termination, and no escalation to other forms of respiratory support were recorded. Median SpO2 significantly increased by 1-2 points after changing from standard oxygen to HFNC (p <0.001). Median ETCO2 and RR rapidly decreased by 6-8 mmHg and 13-20 breaths per minute, respectively, in the first 3 h of HFNC therapy (p <0.001) and remained steady thereafter.

CONCLUSIONS

Use of HFNC for oxygen administration is feasible for infants with moderate-severe bronchiolitis in a general pediatric ward. In these children, HFNC therapy improves oxygen saturation levels and seems to be associated with a decrease in both ETCO2 and RR.

[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 saline and acute wheezing in preschool children

BACKGROUND

Most acute wheezing episodes in preschool children are associated with rhinovirus. Rhinovirus decreases extracellular adenosine triphosphate levels, leading to airway surface liquid dehydration. This, along with submucosal edema, mucus plaques, and inflammation, causes failure of mucus clearance. These preschool children do not respond well to available treatments, even oral steroids. This calls for pro-mucus clearance and prohydration treatments such as hypertonic saline in wheezing preschool children.

METHODS

Randomized, controlled, double-blind study. Forty-one children (mean age 31.9 ± 17.4 months, range 1-6 years) presented with wheezing to the emergency department were randomized after 1 albuterol inhalation to receive either 4 mL of hypertonic saline 5% (HS) (n = 16) or 4 mL of normal saline (NS) (n = 25), both with 0.5 mL albuterol, twice every 20 minutes in the emergency department and 4 times a day thereafter if hospitalized. The primary outcome measured was length of stay (LOS) and the secondary outcomes were admission rate (AR) and clinical severity score.

RESULTS

The LOS was significantly shorter in the HS than in the NS group: median 2 days (range 0-6) versus 3 days (range 0-5) days (P = .027). The AR was significantly lower in the HS than the NS group: 62.2% versus 92%. Clinical severity score improved significantly in both groups but did not reach significance between them.

CONCLUSIONS

Using HS inhalations significantly shortens LOS and lowers AR in preschool children presenting with an acute wheezing episode to the emergency department.

Treatment of acute viral bronchiolitis

Acute viral bronchiolitis represents the most common lower respiratory tract infection in infants and young children and is associated with substantial morbidity and mortality. Respiratory syncytial virus is the most frequently identified virus, but many other viruses may also cause acute bronchiolitis. There is no common definition of acute viral bronchiolitis used internationally, and this may explain part of the confusion in the literature. Most children with bronchiolitis have a self limiting mild disease and can be safely managed at home with careful attention to feeding and respiratory status. Criteria for referral and admission vary between hospitals as do clinical practice in the management of acute viral bronchiolitis, and there is confusion and lack of evidence over the best treatment for this condition. Supportive care, including administration of oxygen and fluids, is the cornerstone of current treatment. The majority of infants and children with bronchiolitis do not require specific measures. Bronchodilators should not be routinely used in the management of acute viral bronchiolitis, but may be effective in some patients. Most of the commonly used management modalities have not been shown to have a clear beneficial effect on the course of the disease. For example, inhaled and systemic corticosteroids, leukotriene receptor antagonists, immunoglobulins and monoclonal antibodies, antibiotics, antiviral therapy, and chest physiotherapy should not be used routinely in the management of bronchiolitis. The potential effect of hypertonic saline on the course of the acute disease is promising, but further studies are required. In critically ill children with bronchiolitis, today there is little justification for the use of surfactant and heliox. Nasal continuous positive airway pressure may be beneficial in children with severe bronchiolitis but a large trial is needed to determine its value. Finally, very little is known on the effect of the various interventions on the development of post-bronchiolitic wheeze.

Inhaled hypertonic saline in infants and toddlers with cystic fibrosis: short-term tolerability, adherence, and safety

BACKGROUND

Inhaled hypertonic saline (HS) is an attractive agent for chronic maintenance therapy in infants and toddlers with cystic fibrosis (CF) because it improves defective mucociliary clearance. Prior to undertaking a clinical trial of HS efficacy in young children with CF, tolerability, adherence, and safety must be established.

METHODS

Three-center, open label evaluation of the short-term tolerability, adherence, and safety of 7% HS administered twice daily for 14 days in children with CF 12-30 months of age. The primary objective was to evaluate the proportion of participants unable to tolerate single and repeated doses of 7% HS according to protocol-defined criteria. Participants inhaled a test dose of HS at the enrollment visit; test dose intolerance was defined as fulfillment of at least one of 4 criteria. Participants who tolerated the test dose inhaled 7% HS twice daily for 14±2 days.

RESULTS

Twenty children were enrolled. One was withdrawn due to maternal concern over fussiness with application of the facemask for the test dose. Of the 19 participants administered the test dose, 1 was withdrawn due to test dose intolerance (5%, 95% confidence interval 0, 26%). Eighteen participants completed the study; 1 was intolerant (95% CI 0, 27%) at the final visit due to new wheezes on exam in association with an upper respiratory infection and otitis media. Home symptom diaries demonstrated cough as the main symptom in the hour following inhalation, which decreased in frequency over the study period. Adherence as assessed by daily home diary and returned study drug ampoules was high. Participants reported receiving both treatments on a median of 100% of days; a median of 25 ampoules were used during a median of 13 days.

CONCLUSIONS

7% HS appears well tolerated for up to 14 days in infants and toddlers with CF, with high adherence. These results provide encouraging short-term tolerability and adherence data for future trials assessing the safety and efficacy of 7% HS in young children with CF.

Update on management of bronchiolitis

PURPOSE OF REVIEW

Bronchiolitis impacts millions of infants worldwide. Although several therapeutic options stem from highly plausible theoretical rationales for success and some may even offer modest short-term symptom relief, none has been conclusively shown to alter the course of the disease or its major outcomes. However, several recent papers shed light on which treatments show promising preliminary evidence and offer insight into future research endeavors on this topic. This review will summarize bronchiolitis therapy in view of this recent evidence.

RECENT FINDINGS

The agents in which theory promises but treatment does not deliver include systemic corticosteroids alone, inhaled bronchodilators alone and antileukotrienes. The most promising combination to date appears to be that of oral dexamethasone and inhaled epinephrine but numerous related issues need to be clarified further. Caretakers need to be counselled about the usual protracted clinical course of bronchiolitis.

SUMMARY

Because bronchiolitis is a highly heterogeneous entity, future research challenges should include detailed characterization of infants most likely to benefit from given interventions. In the meantime, stick with the good old time-honored supportive route!

Nebulized hypertonic-saline vs epinephrine for bronchiolitis; proof of concept study of cumulative sum (CUSUM) analysis

OBJECTIVE

To apply cumulative sum (CUSUM) to monitor a drug trial of nebulized hypertonic-saline in bronchiolitis. To test if monitoring with CUSUM control lines is practical and useful as a prompt to stop the drug trial early, if the study drug performs significantly worse than the comparator drug.

DESIGN

Prospective, open label, controlled trial using standard therapy (epinephrine) and study drug (hypertonic-saline) sequentially in two groups of patients.

SETTING

Hospital offering tertiary-level pediatric care.

PATIENTS

Children, 2 months to 2 years, with first episode of bronchiolitis, excluding those with cardiac disease, immunodeficiency and critical illness at presentation.

INTERVENTIONS

Nebulized epinephrine in first half of the bronchiolitis season (n = 35) and hypertonic saline subsequently (n = 29). Continuous monitoring of response to hypertonic-saline using CUSUM control charts developed with epinephrine-response data.

MAIN OUTCOME MEASURES

Clinical score, tachycardia and total duration of hospital stay.

RESULTS

In the epinephrine group, the maximum CUSUM was +2.25 (SD 1.34) and minimum CUSUM was -2.26 (SD 1.34). CUSUM score with hypertonic saline group stayed above the zero line throughout the study. There was no statistical difference in the post-treatment clinical score at 24 hours between the treatment groups {Mean (SD) 3.516 (2.816): 3.552 (2.686); 95% CI: -1.416 to 1.356}, heart rate {Mean (SD) 136 (44): 137(12); 95% CI: -17.849 to 15.849) or duration of hospital stay (Mean (SD) 96.029 (111.41): 82.914 (65.940); 95% CI: -33.888 to 60.128}.

CONCLUSIONS

The software we developed allows for drawing of control lines to monitor study drug performance. Hypertonic saline performed as well or better than nebulized epinephrine in bronchiolitis.

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.