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

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.

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.

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.

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.

Hyaluronic Acid Molecular Weight Determines Lung Clearance and Biodistribution after Instillation

Hyaluronic acid (HA) has emerged as a versatile polymer for drug delivery. Multiple commercial products utilize HA, it can be obtained in a variety of molecular weights, and it offers chemical handles for cross-linkers, drugs, or imaging agents. Previous studies have investigated multiple administration routes, but the absorption, biodistribution, and pharmacokinetics of HA after delivery to the lung is relatively unknown. Here, pharmacokinetic parameters were investigated by delivering different molecular weights of HA (between 7 and 741 kDa) to the lungs of mice. HA was labeled with either a near-infrared dye or with iodine-125 conjugated to HA using a tyrosine linker. In initial studies, dye-labeled HA was instilled into the lungs and fluorescent images of organs were collected at 1, 8, and 24 h post administration. Data suggested longer lung persistence of higher molecular weight HA, but signal diminished for all molecular weights at 8 h. To better quantitate pharmacokinetic parameters, different molecular weights of iodine-125 labeled HA were instilled and organ radioactivity was determined after 1, 2, 4, 6, and 8 h. The data showed that, after instillation, the lungs contained the highest levels of HA, as expected, followed by the gastrointestinal tract. Smaller molecular weights of HA showed more rapid systemic distribution, while 67 and 215 kDa HA showed longer persistence in the lungs. Lung exposure appeared to be optimum in this size range due to the rapid absorption of <67 kDa HA and the poor lung penetration and mucociliary clearance of viscous solutions of HA > 215 kDa. The versatility of HA molecular weight and conjugation chemistries may, therefore, provide new opportunities to extend pulmonary drug exposure and potentially facilitate access to lymph nodes draining the pulmonary bed.

Hypertonic Saline for the Treatment of Bronchiolitis in Infants and Young Children: A Critical Review of the Literature

Bronchiolitis, an infection of the lower respiratory tract, is the leading cause of infant and child hospitalization in the United States. Therapeutic options for management of bronchiolitis are limited. Hypertonic saline inhalation therapy has been studied in numerous clinical trials with mixed results. In 2014, the American Academy of Pediatrics (AAP) published updated guidelines on the diagnosis and management of bronchiolitis, which include new recommendations on the use of hypertonic saline. We reviewed all published clinical trials mentioned in the 2014 AAP guidelines, as well as additional trials published since the guidelines, and critically evaluated each trial to determine efficacy, safety, and expectations of hypertonic saline inhalation therapy. A total of 2682 infants were studied over the course of 22 clinical trials. Nine trials were carried out in the outpatient/clinic/emergency department and 13 in the inpatient setting. We agree with the AAP guidelines regarding the recommendation to use nebulized hypertonic saline for infants hospitalized with bronchiolitis, with the expectation of reducing bronchiolitis scores and length of stay when it is expected to last more than 72 hours. However, we also believe there might be an advantage for hypertonic saline in reducing admission rates from the emergency department, based on close examination of the results of recent trials. This review also highlights important gaps in the available literature that need to be addressed in order to define the role of inhaled hypertonic saline therapy.

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.

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.