Nebulised hypertonic saline in moderate-to-severe bronchiolitis: a randomised clinical trial

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.

UPDATE - 2022 Italian guidelines on the management of bronchiolitis in infants

Bronchiolitis is an acute respiratory illness that is the leading cause of hospitalization in young children. This document aims to update the consensus document published in 2014 to provide guidance on the current best practices for managing bronchiolitis in infants. The document addresses care in both hospitals and primary care. The diagnosis of bronchiolitis is based on the clinical history and physical examination. The mainstays of management are largely supportive, consisting of fluid management and respiratory support. Evidence suggests no benefit with the use of salbutamol, glucocorticosteroids and antibiotics with potential risk of harm. Because of the lack of effective treatment, the reduction of morbidity must rely on preventive measures. De-implementation of non-evidence-based interventions is a major goal, and educational interventions for clinicians should be carried out to promote high-value care of infants with bronchiolitis. Well-prepared implementation strategies to standardize care and improve the quality of care are needed to promote adherence to guidelines and discourage non-evidence-based attitudes. In parallel, parents' education will help reduce patient pressure and contribute to inappropriate prescriptions. Infants with pre-existing risk factors (i.e., prematurity, bronchopulmonary dysplasia, congenital heart diseases, immunodeficiency, neuromuscular diseases, cystic fibrosis, Down syndrome) present a significant risk of severe bronchiolitis and should be carefully assessed. This revised document, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of acute bronchiolitis.

Prevention and Treatment Strategies for Respiratory Syncytial Virus (RSV)

Respiratory syncytial virus (RSV) is a leading cause of severe lower respiratory tract disease, especially in young children. Despite its global impact on healthcare, related to its high prevalence and its association with significant morbidity, the current therapy is still mostly supportive. Moreover, while more than 50 years have passed since the first trial of an RSV vaccine (which unfortunately caused enhanced RSV disease), no vaccine has been approved for RSV prevention. In the last two decades, our understanding of the pathogenesis and immunopathology of RSV have continued to evolve, leading to significant advancements in RSV prevention strategies. These include both the development of new potential vaccines and the successful implementation of passive immunization, which, together, will provide coverage from infancy to old age. In this review, we provide an update of the current treatment options for acute disease (RSV-specific and -non-specific) and different therapeutic approaches focusing on RSV prevention.

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.

Bronchiolitis

Viral bronchiolitis is the most common cause of admission to hospital for infants in high-income countries. Respiratory syncytial virus accounts for 60-80% of bronchiolitis presentations. Bronchiolitis is diagnosed clinically without the need for viral testing. Management recommendations, based predominantly on high-quality evidence, advise clinicians to support hydration and oxygenation only. Evidence suggests no benefit with use of glucocorticoids or bronchodilators, with further evidence required to support use of hypertonic saline in bronchiolitis. Evidence is scarce in the intensive care unit. Evidence suggests use of high-flow therapy in bronchiolitis is limited to rescue therapy after failure of standard subnasal oxygen only in infants who are hypoxic and does not decrease rates of intensive care unit admission or intubation. Despite systematic reviews and international clinical practice guidelines promoting supportive rather than interventional therapy, universal de-implementation of interventional care in bronchiolitis has not occurred and remains a major challenge.

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.

Inhaled hypertonic saline after pediatric lung transplant-Caution required?

Management of pulmonary infection following lung transplant is multifaceted and includes respiratory physiotherapy. Inhaled hypertonic saline (HTS) has been introduced as an adjunct to physiotherapy in pediatric transplant patients. There are no published studies investigating the use of HTS in this population. This study aimed to evaluate the effect of inhaled HTS, in the acute post-operative period, in pediatric lung transplant patients. A retrospective case-note review was completed at a single UK pediatric transplant center. An intervention group who received HTS was compared to a historical control group. Participants were frequency matched for age, gender, and diagnosis (14 per group); median age in years was 13.7(IQR 12.7-15.3) in the controls and 14.8(IQR 12.4-16.1) in the intervention group. Primary outcome was the requirement of invasive and non-invasive ventilation. Secondary outcomes included oxygen use and length of stay. Median days of invasive ventilation were shorter in the control group (1, 95% CI 1-1) compared to the intervention group (2, 95% CI 1-2.5) (P < .05). Days of non-invasive ventilation and oxygen were higher in the HTS group, but this was not statistically significant. The controls displayed shorter median length of stay (23 days, 95% CI 20-24) compared to the intervention group (31 days, 95% CI 24.5-39) (P < .05). The results of this small study provide uncertainty regarding the safety of inhaled hypertonic saline after lung transplant. There was a trend of poorer acute outcomes in patients who received HTS. However, the findings should be interpreted with caution and further investigation using larger samples is required.

Rational use of mucoactive medications to treat pediatric airway disease

Many airway diseases in children, notably bronchiolitis, cystic fibrosis (CF), non-CF bronchiectasis including primary ciliary dyskinesia, pneumonia, and severe asthma are associated with retention of airway secretions. Medications to improve secretions clearance, the mucoactive medications, are employed to treat these diseases with varying degrees of success. This manuscript reviews evidence for the use of these medications and future directions of study.