Trial launched to identify optimum breathing support for babies with bronchiolitis

23rd October 2023

A new trial aims to determine the most effective breathing support for babies hospitalised with bronchiolitis in order to aid quicker recovery, limit discomfort and reduce hospital stays.

Led by researchers at Imperial College London and clinicians at Imperial College Healthcare NHS Trust, in collaboration with experts across the UK, the BACHbtrial will recruit 1,508 infants (924 with moderate and 584 with severe bronchiolitis) over a 30-month period from children’s emergency departments and wards in 50 hospitals.

It is hoped that the trial will help to inform national and international guidelines on the care of infants with bronchiolitis.

Dr Padmanabhan Ramnarayan, chief investigator of the trial from the Department of Surgery and Cancer at Imperial College London, and honorary consultant in paediatric intensive care at Imperial College Healthcare NHS Trust, said: ‘There are a range of options to treat breathing difficulties in babies with bronchiolitis but there is a lack of evidence about which patients would benefit most from each type of treatment. This has led to varying approaches to treating the condition, based on little evidence.

‘Our trial aims to answer this question by assessing current treatments and seeing which one provides the most effective breathing support in moderate and severe cases of bronchiolitis.’

The researchers will conduct two simultaneous clinical trials to determine the effectiveness of high-flow nasal cannula (HFNC) therapy in moderate and severe bronchiolitis.

Infants with moderate bronchiolitis will be randomly allocated to start either HFNC or humidified standard oxygen (HSO) and those with severe bronchiolitis with either HFNC or continuous positive airwave pressure (CPAP).

The clinical teams will be responsible for all other treatment decisions, including switching patients to an alternative treatment if the original is not found to be effective.

The researchers will then compare the treatments by measuring how quickly infants are discharged from hospitals. Other outcomes to be considered are patient comfort, parent/carer satisfaction, how often infants need admission to intensive care and their health status one and three months later. The comparative costs of each treatment will also be assessed.

The study design was supported by two parent representatives from the National Institute of Clinical Excellence bronchiolitis guideline committee and an independent parent advisory group with six parents whose children were treated for bronchiolitis will also help to advise the research group throughout the trial.

Each year, nearly 30,000 infants under the age of one are admitted to hospitals in England with bronchiolitis and around half of these need oxygen treatment through nasal cannula.

Effect of high-flow nasal cannula oxygen on COVID-19 mortality

5th October 2022

Whether high-flow nasal cannula oxygen improves mortality in COVID-19 patients with respiratory failure was the subject of a recent RCT

The mortality benefit of high-flow nasal cannula (HFNC) oxygen therapy in those with COVID-19 and respiratory failure remains uncertain and was examined in a recent randomised trial by the SOHO-COVID Study Group.

According to a 2019 meta-analysis, in patients with acute hypoxaemic respiratory failure, high-flow nasal cannula oxygen flow, while not affecting mortality, was found to decrease the risk of requiring intubation or escalation of oxygen therapy. Moreover, a further study in critically ill patients with COVID-19 found that HFNC significantly reduced intubation and subsequent invasive mechanical ventilation but did not affect mortality. Other work among those with severe COVID-19 has also shown that HFNC significantly decreased need for mechanical ventilation support and the time to clinical recovery compared with conventional low-flow oxygen therapy. In contrast, data from the RECOVERY group found that the requirement for tracheal intubation or mortality within 30 days was not significantly different between an initial strategy of HFNO compared with conventional oxygen therapy. Prior to the pandemic, there has been conflicting data on the mortality benefits of HFNO in patients with acute respiratory failure. Some evidence indicates that there is a mortality benefit whereas other data suggests that in critically ill immunocompromised patients with acute respiratory failure, high-flow oxygen therapy did not significantly decrease day-28 mortality compared with standard oxygen therapy.

For the present study, researchers set out to establish if HFNO compared to standard oxygen impacted on 28-day mortality in patients with COVID-19 admitted to an intensive care unit (ICU). Individuals were randomised to HFNO or standard oxygen which was delivered through a non-rebreathing mask. The primary outcome was set as 28-day mortality and there were 13 secondary outcomes including, for example, the proportion of patients who required intubation.

High-flow nasal oxygen and 28-day mortality

A total of 711 patients with respiratory failure and a mean age of 61 years (30% female) were randomised to HFNO (357) or standard oxygen.

For the primary outcome, 28-day mortality occurred in 10% of those receiving HFNO and 11% of patients given standard oxygen and this difference was not significant (adjusted odds ratio, aOR = 0.78, 95% CI 0,48 – 1.28, p = 0.32).

Out of all the secondary outcomes, only the need for intubation at day 28 was significantly different between the two groups, favouring the use of HFNO (aOR = 0.65, 95% CI 0.48 – 0.89, p = 0.007).

The authors concluded that in patients with respiratory failure due to COVID-19, the use of high-flow nasal oxygen was no better than standard oxygen with respect to 28-day mortality.

Citation
Frat JP et al. Effect of High-Flow Nasal Cannula Oxygen vs Standard Oxygen Therapy on Mortality in Patients With Respiratory Failure Due to COVID-19: The SOHO-COVID Randomized Clinical Trial JAMA 2022

Liberation time from respiratory support similar for high-flow nasal cannula and CPAP in acutely ill children

24th June 2022

High-flow nasal cannula therapy is equivalent to continuous positive airway pressure for release time from respiratory support in children

The use of high-flow nasal cannula (HFNC) therapy as a first-line non-invasive respiratory support system appears to be non-inferior to continuous positive airway pressure (CPAP) for the time to liberation of respiratory support in critically ill children. This was the conclusion of a randomised trial by UK researchers.

Respiratory distress is common cause of paediatric intensive care unit admission and strategies to address oxygenation problems in critically ill patients with hypoxemic respiratory failure include use of simple oxygen equipment, use of non-invasive ventilation, or use of invasive ventilation.

Non-invasive mechanical ventilation procedures include CPAP whereas HFNC is considered as a cross over therapy from basic oxygen therapy to non-invasive ventilation. In a systemic review, HFNC was shown to reduce the rate of intubation, mechanical ventilation and the escalation of respiratory support.

However, whether or not HFNC is superior to other forms of non-invasive respiratory support such as CPAP with respect to the length of time required for such respiratory support in acutely ill children remains to be determined.

In a feasibility study in 2018 designed to compare HFNC with CPAP, it was concluded that such a trial would be possible. Following on from this initial study, for the present trial, the UK team set out to determine if HFNC was comparable to CPAP in terms of to the time to liberation from respiratory support in acutely ill children admitted to a paediatric critical care unit.

In their pragmatic, unblinded trial, the researchers randomised children 1:1 to receive either HFNC or CPAP although physicians were permitted to switch from HFNC to CPAP (or visa versa) where they felt it would be clinically appropriate.

The primary outcome of interest was the time from randomisation to liberation from respiratory support, defined as the start of the 48-hour period during which the patient was free from all respiratory support.

For their secondary outcomes, the authors focused on several outcomes including the duration of stay within the critical care unit, mortality and use of sedatives during non-invasive respiratory support.

HFNC therapy outcomes

A total of 573 children with a median age of 9 months (39% girls) were included and randomised to either HFNC (295) or CPAP. The most common reasons for intensive care admission were in the HFNC group were bronchiolitis (48.5%) or another respiratory condition (18.6%) and these proportions were similar in the CPAP group.

The median time to liberation of respiratory support in the HFNC group was 52.9 hours compared to 47.9 hours in the CPAP group and this difference was not statistically significant (hazard ratio, HR = 1.03, 95% CI 0.86 – 1.22).

For the secondary outcomes the use of sedatives during respiratory support were significantly less for children using HFNC (odds ratio, OR = 0.59, 95% CI 0,39 – 0.88), as was the mean duration of their critical care stay (mean difference = – 3 days) and the mean duration of hospital day (mean difference = -7.6 days).

The authors concluded that HFNC was non-inferior to CPAP with respect to the liberation of respiratory support.

Citation
Ramnarayan P et al. Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Therapy on Liberation From Respiratory Support in Acutely Ill Children Admitted to Pediatric Critical Care Units: A Randomized Clinical Trial JAMA 2022