High-Flow Oxygen Therapy in Infants with Bronchiolitis

Comparison of severity scales for acute bronchiolitis in real clinical practice

Several clinical scales have been developed to assess the severity of bronchiolitis as well as the probability of needing in-hospital care. A recent systematic review of 32 validated clinical scores for bronchiolitis concluded that 6 of them (Wood-Downes, M-WCAS, Respiratory Severity Score, Respiratory Clinical Score, Respiratory Score and Bronchiolitis risk of admission score) were the best ones regarding reliability, sensitivity, validity, and usability. However, to the best of our knowledge, no study has compared all of them in a clinical scenario. Also, after this review, three more scales were published: BROSJOD, Tal modified, and one score developed by PERN. Our main aim was to compare the ability of different clinical scales for bronchiolitis to predict any relevant outcome. A prospective observational study was conducted that included patients of up to 12 months old attended to, due to bronchiolitis, in the paediatric Emergency Department of a secondary university hospital from October 2019 to January 2022. For each patient, the attending clinician filled in a form with the items of the scales, decomposed, in order to prevent the clinician from knowing the score of each scale. Then, the patient was managed according to the protocol of our Emergency Department. A phone call was made to each patient in order to check whether the patient ended up being admitted in the next 48 h. In the case of those that were impossible to contact by phone, the clinical history was reviewed. For the purpose of the study, any of the following were considered to be a relevant outcome: admission to ward and need for supplementary oxygen, non-invasive ventilation (NIV) or intravenous fluids, and admission to the paediatric intensive care unit (PICU) within the next 48 h or death. For the aim of the study, the area under the curve (AUC) and the odds ratio (OR) for a relevant outcome were calculated in each scale. Also, the best cut-off point was estimated according to the Youden index, and its sensitivity (Sn) and specificity (Sp) for a relevant outcome were calculated. We included 265 patients (52.1% male) with a median age of 5.3 months (P₂₅-P₇₅ 2.6-7.4). Among them, 46 (17.4%) had some kind of relevant outcome. AUC for prediction of a relevant outcome ranged from 0.705 (Respiratory Score) to 0.786 (BRAS), although no scale performed significantly better than others. A score ≤ 2 in the PERN scale showed a sensitivity of 91.3% (CI95% 79.7-96.6) for a relevant outcome, with only 4 misdiagnosed patients (only 2 of them needed NIV).   Conclusions: There were no differences in the performance of the nine scales to predict relevant outcomes in patients with bronchiolitis. However, the PERN scale might be more useful to select patients at low risk of a severe outcome. What is Known: • Several clinical scales are used to assess the severity of bronchiolitis. Nevertheless, none of them seems to be better than others. What is New: • This is the first study comparing different bronchiolitis scales in a real clinical scenario. None of the nine scales compared performed better than the other. However, the PERN scale might be more useful to select patients at low risk of relevant outcomes.

Bronchiolitis therapies and misadventures

Viral bronchiolitis, which is most commonly caused by an infection with the respiratory syncytial virus (RSV), can lead to respiratory difficulties in young children which may require hospitalization. Despite years of research and medical trials, the mainstay of bronchiolitis treatment remains supportive only. This review provides an overview of the history of different treatments for bronchiolitis, including those that failed, as well as new therapies that are under study. Future studies for the treatment of bronchiolitis should consider different age-groups, important subgroups (i.e., those with a prior history of wheezing, those with a family history of asthma and those with non-RSV viral etiologies) whose response to treatment may differ from that of the composite group.

Changes in Ventilation Practices for Bronchiolitis in the Hospital Ward and Need for ICU Transfer over the Last Decade

There is limited evidence of the potential benefits of the use of high-flow nasal cannula (HFNC) for the management of bronchiolitis in the ward. Our aim is to describe the ventilation trends for bronchiolitis in our hospital along with the introduction of an HFNC ward protocol and to determine the need for respiratory support escalation and transfer to an intensive care unit (ICU). A retrospective analytical observational study of children < 12 months old requiring admission for a first RSV bronchiolitis episode in a single centre from January 2009 to December 2018. The sample was divided into four groups according to the type of respiratory support that would ensure the clinical stability of the infants on admission. A total of 502 infants were recruited. The total number and percentage of patients admitted in the ward grew progressively over time. Simultaneously, there was an increase in HFNC and, paradoxically, an increase in ICU transfers. The risk of failure was higher for those who required HFNC or CPAP for clinical stabilisation in the first 12 h after admission. Moreover, the risk of failure was also higher in children with standard oxygen therapy promptly escalated to HFNC, especially if they had atelectasis/viral pneumonia, coinfections or a history of prematurity. Despite the limitations of a retrospective analysis, our study reflects usual clinical practice and no correlation was found between the usage of HFNC and a shorter length of hospital stay or less time spent on oxygen therapy.

Burden of respiratory syncytial virus bronchiolitis on the Dutch pediatric intensive care units

Respiratory syncytial virus (RSV) bronchiolitis causes substantial morbidity and mortality in young children, but insight into the burden of RSV bronchiolitis on pediatric intensive care units (PICUs) is limited. We aimed to determine the burden of RSV bronchiolitis on the PICUs in the Netherlands. Therefore, we identified all children ≤ 24 months of age with RSV bronchiolitis between 2003 and 2016 from a nationwide PICU registry. Subsequently we manually checked their patient records for correct diagnosis and collected patient characteristics, additional clinical data, respiratory support modes, and outcome. In total, 2161 children were admitted to the PICU for RSV bronchiolitis. The annual number of admissions increased significantly during the study period (β 4.05, SE 1.27, p = 0.01), and this increase was mostly driven by increased admissions in children up to 3 months old. Concomitantly, non-invasive respiratory support significantly increased (β 7.71, SE 0.92, p < 0.01), in particular the use of high flow nasal cannula (HFNC) (β 6.69, SE 0.96, p < 0.01), whereas the use of invasive ventilation remained stable.Conclusion: The burden of severe RSV bronchiolitis on PICUs has increased in the Netherlands. Concomitantly, the use of non-invasive respiratory support, especially HFNC, has increased. What is Known: • RSV bronchiolitis is a major cause of childhood morbidity and mortality and may require pediatric intensive care unit admission. • The field of pediatric critical care for severe bronchiolitis has changed due to increased non-invasive respiratory support options. What is New: • The burden of RSV bronchiolitis for the Dutch PICUs has increased. These data inform future strategic PICU resource planning and implementation of RSV preventive strategies. • There was a significant increase in the use of high flow nasal cannula at the PICU, but the use of invasive mechanical ventilation did not decrease.

Factors associated with treatment failure of high-flow nasal cannula among children with bronchiolitis: a single-centre retrospective study

Objectives

Bronchiolitis is the most common viral lower respiratory tract infection in children under age 2 for which high-flow nasal cannula (HFNC) is increasingly used. Understanding factors associated with HFNC failure is important to identify patients at risk for respiratory deterioration. The objective of this study was to evaluate patient characteristics associated with HFNC failure in bronchiolitis.

Methods

A retrospective review of patients aged 0 to 24 months, with bronchiolitis who received HFNC within a single tertiary paediatric intensive care unit, between January 2014 and December 2018 was conducted. HFNC treatment failure was defined as escalation to non-invasive positive pressure or invasive mechanical ventilation. Multivariable regression analysis was used to identify demographic, clinical, and biochemical parameters associated with HFNC failure.

Results

Two hundred eight patients met inclusion criteria, of which 61 (29.33%) failed HFNC. Risk factors for HFNC failure included younger age (odds ratio [OR] 1.12; 95% confidence interval [CI] 1.03, 1.23; P=0.011) and a Modified Tal score greater than 5 at 4 hours of HFNC therapy (OR 2.81; 95% CI 1.04, 7.64; P=0.042). Duration of HFNC in hours was protective (OR 0.94; 95% CI 0.92, 0.96; P<0.001), such that deterioration is less likely once patients have remained stable on HFNC for a prolonged time.

Conclusion

This is the first study exploring predictors of HFNC failure among Canadian children with bronchiolitis. Patient age, HFNC duration, and Modified Tal score were associated with HFNC failure. These factors should be considered when initiating HFNC for bronchiolitis to identify patients at risk for deterioration.

A randomised trial of high-flow nasal cannula in infants with moderate bronchiolitis

BACKGROUND

The objective was to determine whether high-flow nasal cannula (HFNC), a promising respiratory support in infant bronchiolitis, could reduce the proportion of treatment failure requiring escalation of care.

METHODS

In this randomised controlled trial, we assigned infants aged <6 months who had moderate bronchiolitis to receive either HFNC at 3 L·kg^-1·min^-1 or standard oxygen therapy. Crossover was not allowed. The primary outcome was the proportion of patients in treatment failure requiring escalation of care (mostly noninvasive ventilation) within 7 days following randomisation. Secondary outcomes included rates of transfer to the paediatric intensive care unit (PICU), oxygen, number of artificial nutritional support-free days and adverse events.

RESULTS

The analyses included 268 patients among the 2621 infants assessed for inclusion during two consecutive seasons in 17 French paediatric emergency departments. The percentage of infants in treatment failure was 14% (19 out of 133) in the study group, compared to 20% (27 out of 135) in the control group (OR 0.66, 95% CI 0.35-1.26; p=0.21). HFNC did not reduce the risk of admission to PICU (21 (15%) out of 133 in the study group versus 26 (19%) out of 135 in the control group) (OR 0.78, 95% CI 0.41-1.41; p=0.45). The main reason for treatment failure was the worsening of modified Wood clinical asthma score (m-WCAS). Short-term assessment of respiratory status showed a significant difference for m-WCAS and respiratory rate in favour of HFNC. Three pneumothoraces were reported in the study group.

CONCLUSIONS

In patients with moderate bronchiolitis, there was no evidence of lower rate of escalating respiratory support among those receiving HFNC therapy.

High flow nasal cannula as respiratory support in treating infant bronchiolitis: a systematic review

Bronchiolitis is a common respiratory illness in early childhood, often leading to hospitalization and associated healthcare costs. Low flow 100% oxygen through nasal prongs is the standard therapy for infants with bronchiolitis and hypoxemia. Nasal continuous positive airway pressure (nCPAP) or invasive ventilation is used in case of progressive respiratory failure. High flow heated and humidified oxygen therapy with delivery of an air-oxygen mixture up to 2 L/min/kg body weight via nasal prongs (referred to as high flow nasal cannula or HFNC) is a newer method for respiratory support. Initial data from retrospective studies were promising but should be interpreted with caution. A limited number of prospective randomized controlled trials (RCT) have now compared HFNC with either standard oxygen therapy (SOT) or nCPAP. In this review, we critically summarize the data from these RCTs with the aim to provide advice on how to position HFNC in clinical practice.Conclusion: HFNC is a safe mode of respiratory support that can be positioned between SOT and nCPAP as rescue therapy for children not adequately supported by SOT. It does not seem to shorten the duration of oxygen need nor the duration of hospital admission.What is Known:• HFNC is being used increasingly in the context of infant bronchiolitis. However, evidence on efficacy and safety are limited. Different published studies involve different disease severities and different pediatric settings.What is New:• In this review, we summarize data only from prospective RCTs with the aim to provide guidance on how to use HFNC.

[Factors associated to high-flow nasal cannula treatment failure in pediatric patients with respiratory failure in two pediatric intensive care units at high altitude]

INTRODUCTION

Acute respiratory failure is the leading cause of hospitalization in pediatrics. High-flow nasal cannulas (HFNCs) offer a new alternative, but the evidence and indications are still debated. The performance of HFNCs at high altitude has not been described to date.

OBJECTIVE

To describe the use of HFNCs in pediatric patients admitted with respiratory failure and explore the factors associated with treatment failure.

METHODOLOGY

A prospective cohort study was carried out in patients between 1 month and 18 years of age managed with HFNCs. The demographic and treatment response data were recorded at baseline and after 1, 6 and 24hours. The number of failures was determined, as well as the length of stay, complications and mortality. Patients with treatment failure were compared with the rest.

RESULTS

A total of 539 patients were enrolled. Infants (70.9%) of male sex (58.4%) and airway diseases such as asthma and bronchiolitis (61.2%) were more frequent. There were 53 failures (9.8%), with 21 occurring in the first 24hours. The median length of stay was 4 days (IQR 4); there were 5 deaths (0.9%) and 13 adverse events (epistaxis) (2.2%). Improvement was observed in vital signs and severity over time, with differences in the group that failed, but without interactions. The final logistic model established an independent relationship of failure between the hospital (OR 2.78, 95%CI 1.48-5.21) and the initial respiratory rate (OR 1.56, 95%CI 1.21-2.01).

CONCLUSIONS

HFNCs afford good clinical response, with few complications and a low failure rate. The differences found between institutions suggest a subjective relationship in the decision of therapy failure.

Does high-flow oxygen reduce escalation of care in infants with hypoxaemic bronchiolitis?

Bronchiolitis is an acute, lower respiratory tract disease of viral aetiology that affects infants below 2 years of age [1]. Bronchiolitis is common. One in five children have at least one healthcare visit related to bronchiolitis during infancy and it is a major cause of hospitalisation, accounting for 18% of all hospitalisations in the USA in children younger than 1 year [2]. The diagnosis is clinical and based on viral respiratory infection symptoms and signs such as tachypnoea, wheeze, crackles, rhonchi and respiratory distress [3]. There are no effective medical therapies for bronchiolitis so treatment is based on hydration and respiratory supportive care when necessary [3]. The use of high-flow oxygen through nasal cannula as respiratory support in infants with bronchiolitis has increased in recent years [4]. It provides a high flow of humidified air warmed to body temperature with an adjustable fraction of oxygen, and is usually well tolerated by infants. It may improve oxygenation and breathing effort by producing a positive pressure at the end of the expiration [5]. Franklinet al. [6] examined treatment failure resulting in escalation of care in infants with bronchiolitis and hypoxaemia who were treated in emergency departments or general paediatric wards with either high-flow oxygen or standard therapy with supplemental oxygen through a nasal cannula.

Treatment failure leading to escalation of care occurred less often in infants with hypoxaemic bronchiolitis treated with high-flow oxygen than with standard oxygen therapy, but there were no differences in the proportion needing ICU transfer or intubationhttp://bit.ly/2F3rSi1