Non-invasive positive pressure ventilation for acute asthma in children

Analysis of guideline recommendations for treatment of asthma exacerbations in children: a Pediatric Emergency Research Networks (PERN) study

RATIONALE

There is significant practice variation in acute paediatric asthma, particularly severe exacerbations. It is unknown whether this is due to differences in clinical guidelines.

OBJECTIVES

To describe and compare the content and quality of clinical guidelines for the management of acute exacerbations of asthma in children between geographic regions.

METHODS

Observational study of guidelines for the management of acute paediatric asthma from institutions across a global collaboration of six regional paediatric emergency research networks.

MEASUREMENTS AND MAIN RESULTS

158 guidelines were identified. Half provided recommendations for at least two age groups, and most guidelines provided treatment recommendations according to asthma severity.There were consistent recommendations for the use of inhaled short-acting beta-agonists and systemic corticosteroids. Inhaled anticholinergic therapy was recommended in most guidelines for severe and critical asthma, but there were inconsistent recommendations for its use in mild and moderate exacerbations. Other inhaled therapies such as helium-oxygen mixture (Heliox) and nebulised magnesium were inconsistently recommended for severe and critical illness.Parenteral bronchodilator therapy and epinephrine were mostly reserved for severe and critical asthma, with intravenous magnesium most recommended. There were regional differences in the use of other parenteral bronchodilators, particularly aminophylline.Guideline quality assessment identified high ratings for clarity of presentation, scope and purpose, but low ratings for stakeholder involvement, rigour of development, applicability and editorial independence.

CONCLUSIONS

Current guidelines for the management of acute paediatric asthma exacerbations have substantial deficits in important quality domains and provide limited and inconsistent guidance for severe exacerbations.

Noninvasive Respiratory Support for Pediatric Critical Asthma: A Multicenter Cohort Study

BACKGROUND

Noninvasive respiratory support (NRS) for pediatric critical asthma includes CPAP; bi-level positive airway pressure (BPAP); and heated, humidified, high-flow nasal cannula (HFNC). We used the Virtual Pediatric System database to estimate NRS by prescribing rates for pediatric critical asthma and characterize patient clinical features and in-patient outcomes by the initial NRS device applied.

METHODS

We performed a retrospective cohort study from 125 participating pediatric ICUs among children 2-17 years of age hospitalized for critical asthma and prescribed NRS from 2017 through 2021. The primary outcomes were NRS modality prescribing rates and trends. Secondary outcomes were descriptive and included demographics, comorbidities, severity of illness indices, and NRS failure rates (defined as escalation from the initial NRS modality to invasive ventilation, HFNC to BPAP or CPAP, or CPAP to BPAP).

RESULTS

Of the 10,083 encounters studied, the initial NRS modalities prescribed varied widely by hospital center (HFNC: 69.7 ± 29.6%; BPAP: 27.2 ± 7.1%; CPAP: 3.1 ± 5.9%). The mean rates of HFNC use increased from 59.7% in 2017 to 71.9% in 2021 (+2.5%/y). In contrast, BPAP (-1.6%/y) and CPAP (-0.8%/y) utilization declined throughout the study period. Older children who were obese and with a higher Pediatric Risk of Mortality III-Probability of Mortality score were more frequently prescribed BPAP and CPAP compared with HFNC. Those children on HFNC experienced higher noninvasive respiratory support failure rates versus BPAP (7.3% vs 2.4%; P < .001) but a lower subsequent invasive ventilation rate versus BPAP (0.8% vs 2.4%; P < .001).

CONCLUSIONS

In this multi-center cohort study, we observed that children with critical asthma are increasingly exposed to HFNC compared with BPAP and CPAP. Rates of HFNC failure were greater than those of BPAP failure, but a majority were transitioned to BPAP without subsequent invasive ventilation. The next steps include prospective trials, including practical end points such as patient comfort and optimal delivery of nebulized treatments to distinguish device superiority and suitable NRS utilization.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Noninvasive positive-pressure ventilation for children with acute asthma: a meta-analysis of randomized controlled trials

Background

Noninvasive positive-pressure ventilation (NPPV) can be effective in children with acute asthma. However, clinical evidence remains limited. The objective of the meta-analysis was to systematically assess NPPV's effectiveness and safety in treating children with acute asthma.

Methods

Relevant randomized controlled trials were obtained from electronic resources, including PubMed, Embase, Cochrane's Library, Wanfang, and CNKI databases. The influence of potential heterogeneity was taken into account before using a random-effect model to pool the results.

Results

A total of 10 RCTs involving 558 children with acute asthma were included in the meta-analysis. Compared to conventional treatment alone, additional use of NPPV significantly improved early blood gas parameters such as the oxygen saturation (mean difference [MD]: 4.28%, 95% confidence interval [CI]: 1.51 to 7.04, p = 0.002; I² = 80%), partial pressure of oxygen (MD: 10.61 mmHg, 95% CI: 6.06 to 15.16, p < 0.001; I² = 89%), and partial pressure of carbon dioxide (MD: -6.29 mmHg, 95% CI: -9.81 to -2.77, p < 0.001; I² = 85%) in the arterial blood. Moreover, NPPV was also associated with early reduced respiratory rate (MD: -12.90, 95% CI: -22.21 to -3.60, p = 0.007; I²= 71%), improved symptom score (SMD: -1.85, 95% CI: -3.65 to -0.07, p = 0.04; I² = 92%), and shortened hospital stay (MD: -1.82 days, 95% CI: -2.32 to -1.31, p < 0.001; I²= 0%). No severe adverse events related to NPPV were reported.

Conclusions

NPPV in children with acute asthma is associated with improved gas exchange, decreased respiratory rates, a lower symptom score, and a shorter hospital stay. These results suggest that NPPV may be as effective and safe as conventional treatment for pediatric patients with acute asthma.

Clinical Profile and Outcome of Children Requiring Noninvasive Ventilation (NIV)

OBJECTIVES

To determine the clinical profile and outcome of children requiring noninvasive ventilation (NIV) in a PICU.

METHODS

This prospective observational study was conducted in the PICU at Dayanand Medical College and Hospital, Punjab. Children (1 mo-18 y) with moderate-to-severe respiratory distress who received NIV during one-year period were included. Failure was defined as the need for endotracheal intubation. The patients received bilevel positive airway pressure (BiPAP) with inspiratory and expiratory positive airway pressure (8-18 cm H₂O and 4-8 cm), respectively and indigenous continuous positive airway pressure (CPAP) were included. Vital signs (heart rate, respiratory rate) and gasometric parameters (pH, HCO₃, pCO₂, pO₂) were recorded.

RESULTS

Out of total 115 patients, 81.7% were successfully treated by NIV whereas 18.3% constituted NIV failure group. Two types of NIV were used, 65.2% were started on BiPAP and 34.8% on indigenous bubble CPAP. Most common diagnosis was tropical fever (24.3%), bronchopneumonia (20%), and sepsis with multiple organ dysfunction syndrome (MODS) (7.8%). Commonest indication of NIV was respiratory distress (70.4%) and prevention of postextubation respiratory failure (20.8%). Seven patients (6.9%) died during the study. NIV failure is higher in children with sepsis with MODS, abnormal blood gas (acidosis), and moderate-to-severe acute respiratory distress syndrome (ARDS).

CONCLUSIONS

This study demonstrates that NIV is an effective form of respiratory support for children with acute respiratory distress/failure. Sepsis with MODS, acidosis and ARDS (moderate to severe) were predictors of NIV failure. Careful patient selection may help in judicious use of NIV in PICU.

Management of Children with Acute Asthma Attack: A RAND/UCLA Appropriateness Approach

Bronchial asthma is the most frequent chronic disease in children and affects up to 20% of the pediatric population, depending on the geographical area. Asthma symptoms vary over time and in intensity, and acute asthma attack can resolve spontaneously or in response to therapy. The aim of this project was to define the care pathway for pediatric patients who come to the primary care pediatrician or Emergency Room with acute asthmatic access. The project was developed in the awareness that for the management of these patients, broad coordination of interventions in the pre-hospital phase and the promotion of timely and appropriate assistance modalities with the involvement of all health professionals involved are important. Through the application of the RAND method, which obliges to discuss the statements derived from the guidelines, there was a clear increase in the concordance in the behavior on the management of acute asthma between primary care pediatricians and hospital pediatricians. The RAND method was found to be useful for the selection of good practices forming the basis of an evidence-based approach, and the results obtained form the basis for further interventions that allow optimizing the care of the child with acute asthma attack at the family and pediatric level. An important point of union between the primary care pediatrician and the specialist hospital pediatrician was the need to share spirometric data, also including the use of new technologies such as teleconsultation. Monitoring the progress of asthma through spirometry could allow the pediatrician in the area to intervene early by modifying the maintenance therapy and help the patient to achieve good control of the disease.

[Paediatric Life Support]

The European Resuscitation Council (ERC) Paediatric Life Support (PLS) guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations of the International Liaison Committee on Resuscitation (ILCOR). This section provides guidelines on the management of critically ill or injured infants, children and adolescents before, during and after respiratory/cardiac arrest.

Implementation of a Critical Care Asthma Pathway in the PICU

OBJECTIVES

Acute asthma management has improved significantly across hospitals in the United States due to implementation of standardized care pathways. Management of severe acute asthma in ICUs is less well studied, and variations in management may delay escalation and/or deescalation of therapies and increase length of stay. In order to standardize the management of severe acute asthma in our PICU, a nurse- and respiratory therapist-driven critical care asthma pathway was designed, implemented, and tested.

DESIGN

Cross-sectional study of severe acute asthma at baseline followed by implementation of a critical care asthma pathway.

SETTING

Twenty-six-bed urban quaternary PICU within a children's hospital.

PATIENTS

Patients 24 months to 18 years old admitted to the PICU in status asthmaticus. Patients with severe bacterial infections, chronic lung disease, heart disease, or immune disorders were excluded.

INTERVENTIONS

Implementation of a nurse- and respiratory therapist-driven respiratory scoring tool and critical care asthma pathway with explicit escalation/deescalation instructions.

MEASUREMENTS AND MAIN RESULTS

Primary outcome was PICU length of stay. Secondary outcomes were time to resolution of symptoms and hospital length of stay. Compliance approached 90% for respiratory score documentation and critical care asthma pathway adherence. Severity of illness at admission and clinical baseline characteristics were comparable in both groups. Pre intervention, the median ICU length of stay was 2 days (interquartile range, 1-3 d) with an overall hospital length of stay of 4 days (interquartile range, 3-6 d) (n = 74). After implementation of the critical care asthma pathway, the ICU length of stay was 1 day (interquartile range, 1-2 d) (p = 0.0013; n = 78) with an overall length of stay of 3 days (interquartile range, 2-3.75 d) (p < 0.001). The time to resolution of symptoms was reduced from a median of 66.5 hours in the preintervention group to 21 hours in the postintervention compliant group (p = 0.036).

CONCLUSIONS

The use of a structured critical care asthma pathway, driven by an ICU nurse and respiratory therapist, is associated with faster resolution of symptoms, decreased ICU, and overall hospital lengths of stay in children admitted to an ICU for severe acute asthma.

High-flow nasal cannula and bilevel positive airway pressure for pediatric status asthmaticus: a single center, retrospective descriptive and comparative cohort study

INTRODUCTION

We aimed to describe patient characteristics and clinical outcomes for children hospitalized for status asthmaticus (SA) receiving high-flow nasal cannula (HFNC) or bilevel positive airway pressure (BiPAP).

METHODS

We performed a single center, retrospective cohort study among 39 children admitted for SA aged 5-17 years from January 2016 to May 2019 to a quaternary pediatric intensive care unit (PICU). Cohorts were defined by BiPAP versus HFNC exposure and assessed to determine if differences existed in demographics, anthropometrics, comorbidities, asthma severity indices, historical factors, duration of noninvasive ventilation, and asthma-related clinical outcomes (i.e. length of stay, mechanical ventilation rates, exposure to concurrent sedatives/anxiolysis, and rate of adjunctive therapy exposure).

RESULTS

Thirty-three percent (n = 13) received HFNC (33%) and 67% (n = 26) BiPAP. Children receiving BiPAP had greater age (10.9 ± 3.7 vs. 6.8 ± 2.2 years, P < 0.01), asthma severity (proportion with severe NHLBI classification: 38% vs. 0%, P < 0.01; median pediatric asthma severity score: 13[12,14] vs. 10[9,12], P < 0.01), previous PICU admissions (62% vs. 15%, P = 0.01), frequency of prescribed anxiolysis/sedation (42% vs. 8%, P = 0.02), and median duration of continuous albuterol (1.7[1,3.1] vs. 0.9[0.7,1.6] days, P = 0.03) compared to those on HFNC. Those on HFNC more commonly were treated comorbid bacterial pneumonia (69% vs. 19%, P < 0.01). No differences in NIV duration, mortality, mechanical ventilation rates, or LOS were observed.

CONCLUSIONS

Our data suggest a trial of BiPAP or HFNC appears well tolerated in children with SA. Prospective trials are needed to establish modality superiority and identify patient or clinical characteristics that prompt use of HFNC over BiPAP.

Emergency department treatment of asthma in children: A review

Asthma is the most common chronic illness in children, with >700,000 emergency department (ED) visits each year. Asthma is a respiratory disease characterized by a combination of airway inflammation, bronchoconstriction, bronchial hyperresponsiveness, and variable outflow obstruction, with clinical presentations ranging from mild to life-threatening. Standardized ED treatment can improve patient outcomes, including fewer hospital admissions. Informed by the most recent guidelines, this review focuses on the optimal approach to diagnosis and treatment of children with acute asthma exacerbations who present to the ED.

Interventions for escalation of therapy for acute exacerbations of asthma in children: an overview of Cochrane Reviews

BACKGROUND

Asthma is an illness that commonly affects adults and children, and it serves as a common reason for children to attend emergency departments. An asthma exacerbation is characterised by acute or subacute worsening of shortness of breath, cough, wheezing, and chest tightness and may be triggered by viral respiratory infection, poor compliance with usual medication, a change in the weather, or exposure to allergens or irritants. Most children with asthma have mild or moderate exacerbations and respond well to first-line therapy (inhaled short-acting beta-agonists and systemic corticosteroids). However, the best treatment for the small proportion of seriously ill children who do not respond to first-line therapy is not well understood. Currently, a large number of treatment options are available and there is wide variation in management.

OBJECTIVES

Main objective - To summarise Cochrane Reviews with or without meta-analyses of randomised controlled trials on the efficacy and safety of second-line treatment for children with acute exacerbations of asthma (i.e. after first-line treatments, titrated oxygen delivery, and administration of intermittent inhaled short-acting beta₂-agonists and oral corticosteroids have been tried and have failed) Secondary objectives - To identify gaps in the current evidence base that will inform recommendations for future research and subsequent Cochrane Reviews - To categorise information on reported outcome measures used in trials of escalation of treatment for acute exacerbations of asthma in children, and to make recommendations for development and reporting of standard outcomes in future trials and reviews - To identify relevant randomised controlled trials that have been published since the date of publication of each included review METHODS: We included Cochrane Reviews assessing interventions for children with acute exacerbations of asthma. We searched the Cochrane Database of Systematic Reviews. The search is current to 28 December 2019. We also identified trials that were potentially eligible for, but were not currently included in, published reviews. We assessed the quality of included reviews using the ROBIS criteria (tool used to assess risk of bias in systematic reviews). We presented an evidence synthesis of data from reviews alongside an evidence map of clinical trials. Primary outcomes were length of stay, hospital admission, intensive care unit admission, and adverse effects. We summarised all findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We identified 17 potentially eligible Cochrane Reviews but extracted data from, and rated the quality of, 13 reviews that reported results for children alone. We excluded four reviews as one did not include any randomised controlled trials (RCTs), one did not provide subgroup data for children, and the last two had been updated and replaced by subsequent reviews. The 13 reviews included 67 trials; the number of trials in each review ranged from a single trial up to 27 trials. The vast majority of comparisons included between one and three trials, involving fewer than 100 participants. The total number of participants included in reviews ranged from 40 to 2630. All studies included children; 16 (24%) included children younger than two years of age. Most of the reviews reported search dates older than four years. We have summarised the published evidence as outlined in Cochrane Reviews. Key findings, in terms of our primary outcomes, are that (1) intravenous magnesium sulfate was the only intervention shown to reduce hospital length of stay (high-certainty evidence); (2) no evidence suggested that any intervention reduced the risk of intensive care admission (low- to very low-certainty evidence); (3) the risk of hospital admission was reduced by the addition of inhaled anticholinergic agents to inhaled beta₂-agonists (moderate-certainty evidence), the use of intravenous magnesium sulfate (high-certainty evidence), and the use of inhaled heliox (low-certainty evidence); (4) the addition of inhaled magnesium sulfate to usual bronchodilator therapy appears to reduce serious adverse events during hospital admission (moderate-certainty evidence); (5) aminophylline increased vomiting compared to placebo (moderate-certainty evidence) and increased nausea and nausea/vomiting compared to intravenous beta₂-agonists (low-certainty evidence); and (6) the addition of anticholinergic therapy to short-acting beta₂-agonists appeared to reduce the risk of nausea (high-certainty evidence) and tremor (moderate-certainty evidence) but not vomiting (low-certainty evidence). We considered 4 of the 13 reviews to be at high risk of bias based on the ROBIS framework. In all cases, this was due to concerns regarding identification and selection of studies. The certainty of evidence varied widely (by review and also by outcome) and ranged from very low to high.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on interventions for escalation of therapy for acute exacerbations of asthma in children from Cochrane Reviews of randomised controlled trials. A vast majority of comparisons involved between one and three trials and fewer than 100 participants, making it difficult to assess the balance between benefits and potential harms. Due to the lack of comparative studies between various treatment options, we are unable to make firm practice recommendations. Intravenous magnesium sulfate appears to reduce both hospital length of stay and the risk of hospital admission. Hospital admission is also reduced with the addition of inhaled anticholinergic agents to inhaled beta₂-agonists. However, further research is required to determine which patients are most likely to benefit from these therapies. Due to the relatively rare incidence of acute severe paediatric asthma, multi-centre research will be required to generate high-quality evidence. A number of existing Cochrane Reviews should be updated, and we recommend that a new review be conducted on the use of high-flow nasal oxygen therapy. Important priorities include development of an internationally agreed core outcome set for future trials in acute severe asthma exacerbations and determination of clinically important differences in these outcomes, which can then inform adequately powered future trials.

Non-invasive Ventilation for Children With Chronic Lung Disease

Advances in medical care and supportive care options have contributed to the survival of children with complex disorders, including children with chronic lung disease. By delivering a positive pressure or a volume during the patient's inspiration, NIV is able to reverse nocturnal alveolar hypoventilation in patients who experience hypoventilation during sleep, such as patients with chronic lung disease. Bronchopulmonary dysplasia (BPD) is a common complication of prematurity, and despite significant advances in neonatal care over recent decades its incidence has not diminished. Most affected infants have mild disease and require a short period of oxygen supplementation or respiratory support. However, severely affected infants can become dependent on positive pressure support for a prolonged period. In case of established severe BPD, respiratory support with non-invasive or invasive positive pressure ventilation is required. Patients with cystic fibrosis (CF) and advanced lung disease develop hypoxaemia and hypercapnia during sleep and hypoventilation during sleep usually predates daytime hypercapnia. Hypoxaemia and hypercapnia indicates poor prognosis and prompts referral for lung transplantation. The prevention of respiratory failure during sleep in CF may prolong survival. Long-term oxygen therapy has not been shown to improve survival in people with CF. A Cochrane review on the use NIV in CF concluded that NIV in combination with oxygen therapy improves gas exchange during sleep to a greater extent than oxygen therapy alone in people with moderate to severe CF lung disease. Uncontrolled, non-randomized studies suggest survival benefit with NIV in addition to being an effective bridge to transplantation. Complications of NIV relate mainly to prolonged use of a face or nasal mask which can lead to skin trauma, and neurodevelopmental delay by acting as a physical barrier to social interaction. Another associated risk is pulmonary aspiration caused by vomiting whilst wearing a face mask. Adherence to NIV is one of the major barriers to treatment in children. This article will review the current evidence for indications, adverse effects and long term follow up including adherence to NIV in children with chronic lung disease.

Noninvasive positive pressure ventilation for treating acute asthmatic attacks in three pregnant women with dyspnea and hypoxemia

In our case reports, we mentioned about the utility of NPPV therapy in addition to standard pharmacologic therapy for acute asthma exacerbations in pregnant women with dyspnea and hypoxemia compared with that of oxygen therapy alone. Careful patient selection and clinicians' NPPV experience are crucial in optimizing patient outcomes.

Treatment, outcomes and costs of asthma exacerbations in Chilean children: a prospective multicenter observational study

OBJECTIVE

To describe potential regional variations in therapies for severe asthma exacerbations in Chilean children and estimate the associated health expenditures.

METHODS

Observational prospective cohort study in 14 hospitals over a one-year period. Children five years of age or older were eligible for inclusion. Days with oxygen supply and pharmacological treatments received were recorded from the clinical chart. A basic asthma hospitalization basket was defined in order to estimate the average hospitalization cost for a single patient. Six months after discharge, new visits to the Emergency Room (ER), use of systemic corticosteroids and adherence to the controller treatment were evaluated.

RESULTS

396 patients were enrolled. Patients from the public health system and from the north zone received significantly more days of oxygen, systemic corticosteroids and antibiotics. Great heterogeneity in antibiotic use among the participating hospitals was found, from 0 to 92.3% (ICC 0.34, 95% CI 0.16-0.52). The use of aminophylline, magnesium sulfate and ketamine varied from 0 to 36.4% between the different Pediatric Intensive Care Units (ICC 0.353, 95% CI 0.010-0.608). The average cost per inpatient was of $1910 USD. 290 patients (73.2%) completed the follow-up six months after discharge. 76 patients (26.2%) were not receiving any controller treatment and nearly a fourth had new ER visits and use of systemic corticosteroids due to new asthma exacerbations.

CONCLUSIONS

Considerable practice variation in asthma exacerbations treatment was found among the participating hospitals, highlighting the poor outcome of many patients after hospital discharge, with an important health cost.

Non-invasive positive pressure ventilation for acute asthma in children

BACKGROUND

Asthma is one of the most common reasons for hospital admission among children and constitutes a significant economic burden. Use of non-invasive positive pressure ventilation (NPPV) in the care of children with acute asthma has increased even though evidence supporting the intervention has been considered weak and clinical guidelines do not recommend the intervention. NPPV might be an effective intervention for acute asthma, but no systematic review has been conducted to assess the effects of NPPV as an add-on therapy to usual care in children with acute asthma.

OBJECTIVES

To assess the benefits and harms of NPPV as an add-on therapy to usual care (e.g. bronchodilators and corticosteroids) in children with acute asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR). The Register contains trial reports identified through systematic searches of bibliographic databases, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, AMED and PsycINFO, and by handsearching of respiratory journals and meeting abstracts. We also conducted a search of ClinicalTrials.gov (www.ClinicalTrials.gov) and the WHO trials portal (www.who.int/ictrp/en/). We searched all databases from their inception to February 2016, with no restriction on language of publication.

SELECTION CRITERIA

We included randomised clinical trials (RCTs) assessing NPPV as add-on therapy to usual care versus usual care for children (age < 18 years) hospitalised for an acute asthma attack.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts. We retrieved all relevant full-text study reports, independently screened the full text, identified trials for inclusion and identified and recorded reasons for exclusion of ineligible trials. We resolved disagreements through discussion or, if required, consulted a third review author. We recorded the selection process in sufficient detail to complete a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) flow diagram and 'Characteristics of excluded studies' table. We identified the risk of bias of included studies to reduce the risk of systematic error. We contacted relevant study authors when data were missing.

MAIN RESULTS

We included two RCTs that randomised 20 participants to NPPV and 20 participants to control. We assessed both studies as having high risk of bias; both trials assessed effects of bilateral positive airway pressure (BiPAP). Neither trial used continuous positive airway pressure (CPAP). Controls received standard care. Investigators reported no deaths and no serious adverse events (Grades of Recommendation, Assessment, Development and Evaluation (GRADE): very low quality of evidence due to serious risk of bias and serious imprecision of results). Both trials showed a statistically significant reduction in symptom score. One trial did not report a standard deviation (SD), but by using an estimated SD, we found a statistically significantly reduced asthma symptom score (mean difference (MD) -2.50, 95% confidence interval (CI) -4.70 to -0.30, P = 0.03, 19 participants, GRADE: very low quality of evidence). In the other trial, NPPV was associated with a lower total symptom score (5.6 vs 1.9, 16 participants, very low quality of evidence) before cross-over, but investigators did not report an SD, nor could it be estimated from the first phase of the trial, before the cross-over. These gains could be clinically relevant, as a reduction of three or more points in symptom score is considered a clinically meaningful change. Researchers documented five dropouts (12.5%), four of which were due to intolerance to NPPV, and one to respiratory failure requiring intubation. Owing to insufficient reporting in the latter trial and use of different scoring systems, it was not possible to conduct a meta-analysis nor a Trial Sequential Analysis.

AUTHORS' CONCLUSIONS

Current evidence does not permit confirmation or rejection of the effects of NPPV for acute asthma in children. Large RCTs with low risk of bias are warranted.