Hypertonic saline for acute viral bronchiolitis: take the evidence with a grain of salt

Acute bronchiolitis in Switzerland - Current management and comparison over the last two decades

BACKGROUND

Although international guidelines and Cochrane reviews emphasize that therapies do not alter the natural course of acute viral bronchiolitis (AVB), they are still prescribed frequently. This survey evaluated self-reported management of AVB by Swiss pediatricians in 2019 and compared it with previous surveys.

METHODS

We performed a cross-sectional online survey of all board-certified pediatricians in Switzerland in November 2019 and compared the reported use of therapies with that reported in the 2001 and 2006 surveys. We used multivariable ordered logistic regression to assess factors associated with reported prescription of bronchodilators, corticosteroids, antibiotics, and physiotherapy.

RESULTS

Among 1618 contacted board-certified pediatricians, 884 returned the questionnaires (55% response rate). After exclusions were applied, 679 were included in the final analysis. Pediatricians working in primary care reported using therapeutics more frequently than those working in a hospital setting, either always or sometimes: bronchodilators 53% versus 38%, corticosteroids 37% versus 23%, and antibiotics 39% versus 22%. The opposite occurred with physiotherapy: 53% reported prescribing it in hospital and 44% in primary care. There was an overall decrease in the prescription of therapeutics and interventions for AVB from 2001 to 2019. The proportion who reported "always" prescribing corticosteroids decreased from 71% to 2% in primary care, and of those "always" prescribing bronchodilators from 55% to 1% in hospitals.

CONCLUSION

Although we observed a significant decrease since 2001, more effort is required to reduce the use of unnecessary therapies in children with AVB.

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.

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.

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.

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.

CPAP and High-Flow Nasal Cannula Oxygen in Bronchiolitis

Severe respiratory failure develops in some infants with bronchiolitis because of a complex pathophysiologic process involving increased airways resistance, alveolar atelectasis, muscle fatigue, and hypoxemia due to mismatch between ventilation and perfusion. Nasal CPAP and high-flow nasal cannula (HFNC) oxygen may improve the work of breathing and oxygenation. Although the mechanisms behind these noninvasive modalities of respiratory support are not well understood, they may help infants by way of distending pressure and delivery of high concentrations of warmed and humidified oxygen. Observational studies of varying quality have suggested that CPAP and HFNC may confer direct physiologic benefits to infants with bronchiolitis and that their use has reduced the need for intubation. No trials to our knowledge, however, have compared CPAP with HFNC in bronchiolitis. Two randomized trials compared CPAP with oxygen delivered by low-flow nasal cannula or face mask and found some improvements in blood gas results and some physiologic parameters, but these trials were unable to demonstrate a reduction in the need for intubation. Two trials evaluated HFNC in bronchiolitis (one comparing it with headbox oxygen, the other with nebulized hypertonic saline), with the results not seeming to suggest important clinical or physiologic benefits. In this article, we review the pathophysiology of respiratory failure in bronchiolitis, discuss these trials in detail, and consider how future research studies may be designed to best evaluate CPAP and HFNC in bronchiolitis.