Nasal continuous positive airway pressure with heliox versus air oxygen in infants with acute bronchiolitis: a crossover study

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

High-flow nasal cannula therapy for infants with bronchiolitis

BACKGROUND

Bronchiolitis is a common lower respiratory tract illness, usually of viral aetiology, affecting infants younger than 24 months of age and is the most common cause of hospitalisation of infants. It causes airway inflammation, mucus production and mucous plugging, resulting in airway obstruction. Effective pharmacotherapy is lacking and bronchiolitis is a major cause of morbidity and mortality. Conventional treatment consists of supportive therapy in the form of fluids, supplemental oxygen, and respiratory support. Traditionally, oxygen delivery is as a dry gas at 100% concentration via low-flow nasal prongs. However, the use of heated, humidified, high-flow nasal cannula (HFNC) therapy enables delivery of higher inspired gas flows of an air/oxygen blend, at 2 to 3 L/kg per minute up to 60 L/min in children. It can provide some level of continuous positive airway pressure (CPAP) to improve ventilation in a minimally invasive manner. This may reduce the need for invasive respiratory support, thus potentially lowering costs, with clinical advantages and fewer adverse effects.

OBJECTIVES

To assess the effects of HFNC therapy compared with conventional respiratory support in the treatment of infants with bronchiolitis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, and Web of Science (from June 2013 to December 2022). In addition, we consulted ongoing trial registers and experts in the field to identify ongoing studies, checked reference lists of relevant articles, and searched for conference abstracts. Date restrictions were imposed such that we only searched for studies published after the original version of this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs that assessed the effects of HFNC (delivering oxygen or oxygen/room air blend at flow rates greater than 4 L/minute) compared to conventional treatment in infants (< 24 months) with a clinical diagnosis of bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently used a standard template to assess trials for inclusion and extract data on study characteristics, risk of bias elements, and outcomes. We contacted trial authors to request missing data. Outcome measures included the need for invasive respiratory support and time until discharge, clinical severity measures, oxygen saturation, duration of oxygen therapy, and adverse events.

MAIN RESULTS

In this update we included 15 new RCTs (2794 participants), bringing the total number of RCTs to 16 (2813 participants). Of the 16 studies, 11 compared high-flow to low-flow, and five compared high-flow to CPAP. These studies included infants less than 24 months of age as stated in our selection criteria. There were no significant differences in sex. We found that when comparing high-flow to low-flow oxygen therapy for infants with bronchiolitis there may be a reduction in the total length of hospital stay (mean difference (MD) -0.65 days, 95% confidence interval (CI) -1.23 to -0.06; P < 0.00001, I2 = 89%; 7 studies, 1951 participants; low-certainty evidence). There may also be a reduction in the duration of oxygen therapy (MD -0.59 days, 95% CI -1 to -0.18; P < 0.00001, I2 = 86%; 7 studies, 2132 participants; low-certainty evidence). We also found that there was probably an improvement in respiratory rate at one and 24 hours, and heart rate at one, four to six, and 24 hours in those receiving high-flow oxygen therapy when compared to pre-intervention baselines. There was also probably a reduced risk of treatment escalation in those receiving high-flow when compared to low-flow oxygen therapy (risk ratio (RR) 0.55, 95% CI 0.39 to 0.79; P = 0.001, I2 = 43%; 8 studies, 2215 participants; moderate-certainty evidence). We found no difference in the incidence of adverse events (RR 1.2, 95% CI 0.38 to 3.74; P = 0.76, I2 = 26%; 4 studies, 1789 participants; low-certainty evidence) between the two groups. The lack of comparable outcomes in studies comparing high-flow and CPAP, as well as the small numbers of participants, limited our ability to perform meta-analysis on this group.

AUTHORS' CONCLUSIONS

High-flow nasal cannula therapy may have some benefits over low-flow oxygen for infants with bronchiolitis in terms of a greater improvement in respiratory and heart rates, as well as a modest reduction in the length of hospital stay and duration of oxygen therapy, with a reduced incidence of treatment escalation. There does not appear to be a difference in the number of adverse events. Further studies comparing high-flow nasal cannula therapy and CPAP are required to demonstrate the efficacy of one modality over the other. A standardised clinical definition of bronchiolitis, as well as the use of a validated clinical severity score, would allow for greater and more accurate comparison between studies.

Heliox for croup in children

BACKGROUND

Croup is an acute viral respiratory infection with upper airway mucosal inflammation that may cause respiratory distress. Most cases are mild. Moderate to severe croup may require treatment with corticosteroids (the benefits of which are often delayed) and nebulised epinephrine (adrenaline) (the benefits of which may be short-lived and which can cause dose-related adverse effects including tachycardia, arrhythmias, and hypertension). Rarely, croup results in respiratory failure necessitating emergency intubation and ventilation. A mixture of helium and oxygen (heliox) may prevent morbidity and mortality in ventilated neonates by reducing the viscosity of the inhaled air. It is currently used during emergency transport of children with severe croup. Anecdotal evidence suggests that it relieves respiratory distress. This review updates versions published in 2010, 2013, and 2018.

OBJECTIVES

To examine the effect of heliox compared to oxygen or other active interventions, placebo, or no treatment on relieving signs and symptoms in children with croup as determined by a croup score and rates of admission and intubation.

SEARCH METHODS

We searched CENTRAL, which includes the Cochrane Acute Respiratory Infections Group Specialised Register, MEDLINE, Embase, CINAHL, Web of Science, and LILACS, on 15 April 2021. We also searched the World Health Organization International Clinical Trials Registry Platform (apps.who.int/trialsearch/) and ClinicalTrials.gov (clinicaltrials.gov) on 15 April 2021. We contacted the British Oxygen Company, a leading supplier of heliox.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing the effect of heliox in comparison with placebo, no treatment, or any active intervention(s) in children with croup.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Data that could not be pooled for statistical analysis were reported descriptively.

MAIN RESULTS

We included 3 RCTs involving a total of 91 children aged between 6 months and 4 years. Study duration was from 7 to 16 months, and all studies were conducted in emergency departments. Two studies were conducted in the USA and one in Spain. Heliox was administered as a mixture of 70% heliox and 30% oxygen. Risk of bias was low in two studies and high in one study because of its open-label design. We did not identify any new trials for this 2021 update. One study of 15 children with mild croup compared heliox with 30% humidified oxygen administered for 20 minutes. There may be no difference in croup score changes between groups at 20 minutes (mean difference (MD) -0.83, 95% confidence interval (CI) -2.36 to 0.70) (Westley croup score, scale range 0 to 16). The mean croup score at 20 minutes postintervention may not differ between groups (MD -0.57, 95% CI -1.46 to 0.32). There may be no difference between groups in mean respiratory rate (MD 6.40, 95% CI -1.38 to 14.18) and mean heart rate (MD 14.50, 95% CI -8.49 to 37.49) at 20 minutes. The evidence for all outcomes in this comparison was of low certainty, downgraded for serious imprecision. All children were discharged, but information on hospitalisation, intubation, or re-presenting to emergency departments was not reported. In another study, 47 children with moderate croup received one dose of oral dexamethasone (0.3 mg/kg) with either heliox for 60 minutes or no treatment. Heliox may slightly improve Taussig croup scores (scale range 0 to 15) at 60 minutes postintervention (MD -1.10, 95% CI -1.96 to -0.24), but there may be no difference between groups at 120 minutes (MD -0.70, 95% CI -1.56 to 0.16). Children treated with heliox may have lower mean Taussig croup scores at 60 minutes (MD -1.11, 95% CI -2.05 to -0.17) but not at 120 minutes (MD -0.71, 95% CI -1.72 to 0.30). Children treated with heliox may have lower mean respiratory rates at 60 minutes (MD -4.94, 95% CI -9.66 to -0.22), but there may be no difference at 120 minutes (MD -3.17, 95% CI -7.83 to 1.49). There may be a difference in hospitalisation rates between groups (odds ratio 0.46, 95% CI 0.04 to 5.41). We assessed the evidence for all outcomes in this comparison as of low certainty, downgraded due to imprecision and high risk of bias related to an open-label design. Information on heart rate and intubation was not reported. In the third study, 29 children with moderate to severe croup all received continuous cool mist and intramuscular dexamethasone (0.6 mg/kg). They were then randomised to receive either heliox (given as a mixture of 70% helium and 30% oxygen) plus one to two doses of nebulised saline or 100% oxygen plus nebulised epinephrine (adrenaline), with gas therapy administered continuously for three hours. Heliox may slightly improve croup scores at 90 minutes postintervention, but may result in little or no difference overall using repeated-measures analysis. We assessed the evidence for all outcomes in this comparison as of low certainty, downgraded due to high risk of bias related to inadequate reporting. Information on hospitalisation or re-presenting to the emergency department was not reported. The included studies did not report on adverse events, intensive care admissions, or parental anxiety. We could not pool the available data because each comparison included data from only one study.

AUTHORS' CONCLUSIONS

Given the very limited available evidence, uncertainty remains regarding the effectiveness and safety of heliox. Heliox may not be more effective than 30% humidified oxygen for children with mild croup, but may be beneficial in the short term for children with moderate croup treated with dexamethasone. The effect of heliox may be similar to 100% oxygen given with one or two doses of adrenaline. Adverse events were not reported, and it is unclear if these were monitored in the included studies. Adequately powered RCTs comparing heliox with standard treatments are needed to further assess the role of heliox in the treatment of children with moderate to severe croup.

Assessment of Peak Inspiratory Flow in Young Infants with Acute Viral Bronchiolitis: Physiological Basis for Initial Flow Setting in Patients Supported with High-Flow Nasal Cannula

OBJECTIVE

To assess the inspiratory demand in young infants with acute viral bronchiolitis to provide a physiological basis for initial flow setting for patients supported with high flow nasal cannula.

STUDY DESIGN

Prospective study in 44 infants up to 6 months old with acute viral bronchiolitis, admitted to a pediatric intensive care unit from November 2017 to March 2019. Airflow measurements were performed using spirometry. The primary endpoint was the inspiratory demand as measured by peak tidal inspiratory flow (PTIF). The secondary endpoints were the relationships determined between PTIF, patient weight, and disease severity.

RESULTS

Median (Q₂₅-Q₇₅) age and weight of the patients were 37 (20-67) days and 4.3 (3.5-5.0) kg, respectively. Mean PTIF was 7.45 (95% CI 6.51-8.39, min-max: 2.40-16.00) L/minute. PTIF indexed to weight was 1.68 (95% CI 1.51-1.85, min-max: 0.67-3.00) L/kg/minute. PTIF was <2.5 L/kg/minute in 89% (95% CI 75-96) of infants. PTIF was correlated with weight (ρ= 0 .55, P < .001) but not with markers of disease severity, including modified Woods clinical asthma score, Silverman-Andersen score, respiratory rate, fraction of inspired oxygen, and PCO₂.

CONCLUSIONS

High flow nasal cannula therapy is used commonly to support infants with acute viral bronchiolitis. The efficiency of the device is optimal if the flow setting matches the patient's inspiratory demand. According to our results, a flow rate of <2.5 L/kg/minute would be appropriate in most situations.

Criteria for Critical Care Infants and Children: PICU Admission, Discharge, and Triage Practice Statement and Levels of Care Guidance

OBJECTIVES

To update the American Academy of Pediatrics and Society of Critical Care Medicine's 2004 Guidelines and levels of care for PICU.

DESIGN

A task force was appointed by the American College of Critical Care Medicine to follow a standardized and systematic review of the literature using an evidence-based approach. The 2004 Admission, Discharge and Triage Guidelines served as the starting point, and searches in Medline (Ovid), Embase (Ovid), and PubMed resulted in 329 articles published from 2004 to 2016. Only 21 pediatric studies evaluating outcomes related to pediatric level of care, specialized PICU, patient volume, or personnel. Of these, 13 studies were large retrospective registry data analyses, six small single-center studies, and two multicenter survey analyses. Limited high-quality evidence was found, and therefore, a modified Delphi process was used. Liaisons from the American Academy of Pediatrics were included in the panel representing critical care, surgical, and hospital medicine expertise for the development of this practice guidance. The title was amended to "practice statement" and "guidance" because Grading of Recommendations, Assessment, Development, and Evaluation methodology was not possible in this administrative work and to align with requirements put forth by the American Academy of Pediatrics.

METHODS

The panel consisted of two groups: a voting group and a writing group. The panel used an iterative collaborative approach to formulate statements on the basis of the literature review and common practice of the pediatric critical care bedside experts and administrators on the task force. Statements were then formulated and presented via an online anonymous voting tool to a voting group using a three-cycle interactive forecasting Delphi method. With each cycle of voting, statements were refined on the basis of votes received and on comments. Voting was conducted between the months of January 2017 and March 2017. The consensus was deemed achieved once 80% or higher scores from the voting group were recorded on any given statement or where there was consensus upon review of comments provided by voters. The Voting Panel was required to vote in all three forecasting events for the final evaluation of the data and inclusion in this work. The writing panel developed admission recommendations by level of care on the basis of voting results.

RESULTS

The panel voted on 30 statements, five of which were multicomponent statements addressing characteristics specific to PICU level of care including team structure, technology, education and training, academic pursuits, and indications for transfer to tertiary or quaternary PICU. Of the remaining 25 statements, 17 reached consensus cutoff score. Following a review of the Delphi results and consensus, the recommendations were written.

CONCLUSIONS

This practice statement and level of care guidance manuscript addresses important specifications for each PICU level of care, including the team structure and resources, technology and equipment, education and training, quality metrics, admission and discharge criteria, and indications for transfer to a higher level of care. The sparse high-quality evidence led the panel to use a modified Delphi process to seek expert opinion to develop consensus-based recommendations where gaps in the evidence exist. Despite this limitation, the members of the Task Force believe that these recommendations will provide guidance to practitioners in making informed decisions regarding pediatric admission or transfer to the appropriate level of care to achieve best outcomes.

Helium-oxygen mixture: clinical applicability in an intensive care unit

Objective

To evaluate if distress respiratory decreases after using helium-oxygen mixture in pediatric patients diagnosed with bronchospasm.

Methods

This is a retrospective, non-randomized study that included patients diagnosed with bronchospasm, who received a helium-oxygen mixture at three time points (30, 60, and 120 minutes) according to the organization protocol singular, and were admitted to the intensive care unit, from January 2012 to December 2013. This protocol includes patients with bronchospasm who sustained a modified Wood score of moderate to severe, even after one hour of conventional treatment.

Results

Twenty children were included in the study. The mean score of severity of the disease at the initial moment was 5.6 (SD:2.0), and at moment 120 minutes, it was 3.4 (SD: 2.0). The severity score showed a significant improvement as of 30 minutes (p<0.001).

Conclusion

The use of helium-oxygen mixture proved to be effective in diminishing the respiratory distress score for children with airway obstructions; it should be considered a supplementary therapeutic option, together with drug therapy, in specific clinical situations.

[Does heliox administered by low-flow nasal cannula improve respiratory distress in infants with respiratory syncytial virus acute bronchiolitis? A randomized controlled trial]

OBJECTIVES

The aim of our study is to evaluate whether the use of heliox (79:21) delivered through a low flow nasal cannula would improve respiratory distress in infants with acute bronchiolitis caused by respiratory syncytial virus.

METHODS

We have conducted a prospective randomized controlled study. All patients fulfilled inclusion criteria were randomized to either heliox (79:21) or air via NC at 2 L/min for a continuous 24hours. Measurements were taken at baseline, after 2hours and at the end of the 24hours.

RESULTS

We have included 104 patients into our study. The MCA-S did not show any significant difference between the two groups after 2hours 4.3 vs. 4.1 (P =.78), or at 24hours after 4.2 vs. 4.3 (P =.89). No difference was found in the proportion of participants progressed to MV, n-CPAP or oxygen via nasal cannula (RR 1.0, 0.86 and 0.89) (P= 1.0, .77 and .73). There was no notable reduction in length of treatment in Heliox group 2.42 days vs. 2.79 days in air group P =.65. The in oxygen saturation, PaO₂, and PaCO₂ did not to have any statistical difference between the two studied groups after 2hours and 24hours of treatment.

CONCLUSION

Our data showed absence of any beneficial effect of heliox in a concentration (79:21) delivered through low flow nasal cannula in terms of respiratory distress improvement in infants with RSV acute bronchiolitis.

Heliox delivered by high flow nasal cannula improves oxygenation in infants with respiratory syncytial virus acute bronchiolitis

OBJECTIVE

The objective of this study is to evaluate the hypothesis that use of heliox would result in improvement of gas exchange when used with high flow nasal cannula in infants with RSV acute bronchiolitis.

METHODS

All patients that met the inclusion criteria were randomized to either heliox (70:30) or air-oxygen mixture 30% via high flow nasal cannula at 8L/min for a continuous 24h. Measurements were taken at baseline, after 2h, and at the end of the 24h.

RESULTS

This prospective study included 48 patients. After 2h of treatment with heliox, the oxygen saturation and PaO₂ significantly improved when compared with the air-oxygen group, 98.3% vs. 92.9%, 62.0mmHg vs. 43.6mmHg (p=0.04 and 0.01), respectively. Furthermore, PaO₂/FiO₂ ratio was significantly higher in the heliox group when compared with the air-oxygen group, 206.7 vs. 145.3. Nevertheless, CO₂ showed better elimination when heliox was used, without significance. MWCA score dropped significantly in the heliox group, 2.2 points vs. 4.0 points in air-oxygen (p=0.04), 2h after starting the therapy.

CONCLUSION

Transient improvement of oxygenation in infants with RSV acute bronchiolitis during the initial phase of the therapy is associated with heliox when provided with HFNC, may provide a precious time for other therapeutic agents to work or for the disease to resolve naturally, avoiding other aggressive interventions.

[High flow nasal cannula oxygen therapy in the treatment of acute bronchiolitis in neonates]

OBJECTIVE

To determine whether the availability of heated humidified high-flow nasal cannula (HFNC) therapy was associated with a decrease in need for mechanical ventilation in neonates hospitalised with acute bronchiolitis.

METHODS

A combined retrospective and prospective (ambispective) cohort study was performed in a type II-B Neonatal Unit, including hospitalised neonates with acute bronchiolitis after the introduction of HFNC (HFNC-period; October 2011-April 2015). They were compared with a historical cohort prior to the availability of this technique (pre-HFNC; January 2008-May 2011). The need for mechanical ventilation between the two study groups was analysed. Clinical parameters and technique-related complications were evaluated in neonates treated with HFNC.

RESULTS

A total of 112 neonates were included, 56 after the introduction of HFNC and 56 from the period before the introduction of HFNC. None of patients in the HFNC-period required intubation, compared with 3.6% of the patients in the pre-HFNC group. The availability of HFNC resulted in a significant decrease in the need for non-invasive mechanical ventilation (30.4% vs 10.7%; P=.01), with a relative risk (RR) of .353 (95% CI; .150-.829), an absolute risk reduction (ARR) of 19.6% (95% CI; 5.13 - 34.2), yielding a NNT of 5. In the HFNC-period, 22 patients received high flow therapy, and 22.7% (95% CI; 7.8 to 45.4) required non-invasive ventilation. Treatment with HFNC was associated with a significant decrease in heart rate (P=.03), respiratory rate (P=.01), and an improvement in the Wood-Downes Férres score (P=.00). No adverse effects were observed.

CONCLUSIONS

The availability of HFNC reduces the need for non-invasive mechanical ventilation, allowing a safe and effective medical management of neonates with acute bronchiolitis.

Heliox inhalation therapy for bronchiolitis in infants

BACKGROUND

Bronchiolitis is the leading cause of hospitalisation among infants in high-income countries. Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing. In this review, we selected trials that objectively assessed the effect of the addition of heliox to standard medical care for acute bronchiolitis.

OBJECTIVES

To assess heliox inhalation therapy in addition to standard medical care for acute bronchiolitis in infants with respiratory distress, as measured by clinical endpoints (in particular the rate of endotracheal intubation, the rate of emergency department discharge, the length of treatment for respiratory distress) and pulmonary function testing (mainly clinical respiratory scores).

SEARCH METHODS

We searched CENTRAL (2015, Issue 2), MEDLINE (1966 to March week 3, 2015), EMBASE (1974 to March 2015), LILACS (1982 to March 2015) and the National Institutes of Health (NIH) website (May 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

We included seven trials involving 447 infants younger than two years with respiratory distress secondary to viral bronchiolitis. All children were recruited from a paediatric intensive care unit (PICU; 378 infants), except in one trial (emergency department; 69 infants). All children were younger than two (under nine months in two trials and under three months in one trial). Positive tests for respiratory syncytial virus (RSV) were required for inclusion in five trials. The two other trials were carried out in the bronchiolitis seasons. Seven different protocols were used for inhalation therapy with heliox.When heliox was used in the PICU, we observed no significant reduction in the rate of intubation: risk ratio (RR) 2.73 (95% confidence interval (CI) 0.96 to 7.75, four trials, 408 infants, low quality evidence). When heliox inhalation was used in the emergency department, we observed no increase in the rate of discharge: RR 0.51 (95% CI 0.17 to 1.55, one trial, 69 infants, moderate quality evidence).There was no decrease in the length of treatment for respiratory distress: mean difference (MD) -0.19 days (95% CI -0.56 to 0.19, two trials, 320 infants, moderate quality evidence). However, in the subgroup of infants who were started on nasal continuous positive airway pressure (nCPAP) right from the start, because of severe respiratory distress, heliox therapy reduced the length of treatment: MD -0.76 days (95% CI -1.45 to -0.08, one trial, 21 infants, low quality evidence). No adverse events related to heliox inhalation were reported.We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation: MD -1.04 (95% CI -1.60 to -0.48, four trials, 138 infants, moderate quality evidence). This outcome had statistical heterogeneity, which remained even after removing the study using a standard high-concentration reservoir mask. Several factors may explain this heterogeneity, including first the limited number of patients in each trial, and the wide differences in the baseline severity of disease between studies, with the modified Wood Clinical Asthma Score (m-WCAS) in infants treated with heliox ranging from less than two to more than seven.

AUTHORS' CONCLUSIONS

Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. We noticed this beneficial effect regardless of which heliox inhalation protocol was used. Nevertheless, there was no reduction in the rate of intubation, in the rate of emergency department discharge, or in the length of treatment for respiratory distress. Heliox could reduce the length of treatment in infants requiring CPAP for severe respiratory distress. Further studies with homogeneous logistics in their heliox application are needed. Inclusion criteria must include a clinical severity score that reflects severe respiratory distress to avoid inclusion of children with mild bronchiolitis who may not benefit from heliox inhalation. Such studies would provide the necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.

Continuous positive airway pressure with helmet versus mask in infants with bronchiolitis: an RCT

BACKGROUND

Noninvasive continuous positive airway pressure (CPAP) is usually applied with a nasal or facial mask to treat mild acute respiratory failure (ARF) in infants. A pediatric helmet has now been introduced in clinical practice to deliver CPAP. This study compared treatment failure rates during CPAP delivered by helmet or facial mask in infants with respiratory syncytial virus-induced ARF.

METHODS

In this multicenter randomized controlled trial, 30 infants with respiratory syncytial virus-induced ARF were randomized to receive CPAP by helmet (n = 17) or facial mask (n = 13). The primary endpoint was treatment failure rate (defined as due to intolerance or need for intubation). Secondary outcomes were CPAP application time, number of patients requiring sedation, and complications with each interface.

RESULTS

Compared with the facial mask, CPAP by helmet had a lower treatment failure rate due to intolerance (3/17 [17%] vs 7/13 [54%], P = .009), and fewer infants required sedation (6/17 [35%] vs 13/13 [100%], P = .023); the intubation rates were similar. In successfully treated patients, CPAP resulted in better gas exchange and breathing pattern with both interfaces. No major complications due to the interfaces occurred, but CPAP by mask had higher rates of cutaneous sores and leaks.

CONCLUSIONS

These findings confirm that CPAP delivered by helmet is better tolerated than CPAP delivered by facial mask and requires less sedation. In addition, it is safe to use and free from adverse events, even in a prolonged clinical setting.

Bronchiolitis

Everyone on the planet is exposed to respiratory syncytial virus (RSV) infection by the age of 2 years. Most infants admitted to the pediatric intensive care unit (PICU) for respiratory support during this infection are previously healthy, but their principal risk for needing PICU treatment is young age. That is, if you are born in October/November in the northern hemisphere, then your first winter exposure to RSV is likely to be when you are less than 4 months of age and vulnerable because of poor respiratory mechanical reserve (Alonso et al. 2007). However, if you are born in May/June, then you will be 7–8 months during your first winter exposure to RSV, much bigger and stronger and have more efficient thoracic and diaphragmatic mechanics. In the PICU, the main predictors of severe outcome in previously well infants appear to be young age, presence of apnea, and pulmonary consolidation on admission chest radiograph (Tasker et al. 2000; Lopez Guinea et al. 2007). Taken together, we can say that more severe RSV bronchiolitis in PICU practice is typically a problem of pulmonary consolidation, poor respiratory mechanics, and poor reserve, in the younger infant.

Acute bronchiolitis in infants, a review

Acute viral bronchiolitis is one of the most common medical emergency situations in infancy, and physicians caring for acutely ill children will regularly be faced with this condition. In this article we present a summary of the epidemiology, pathophysiology and diagnosis, and focus on guidelines for the treatment of bronchiolitis in infants. The cornerstones of the management of viral bronchiolitis are the administration of oxygen and appropriate fluid therapy, and overall a “minimal handling approach” is recommended. Inhaled adrenaline is commonly used in some countries, but the evidences are sparse. Recently, inhalation with hypertonic saline has been suggested as an optional treatment. When medical treatment fails to stabilize the infants, non-invasive and invasive ventilation may be necessary to prevent and support respiratory failure. It is important that relevant treatment algorithms exist, applicable to all levels of the treatment chain and reflecting local considerations and circumstances.

Heliox for mechanically ventilated newborns with bronchopulmonary dysplasia

OBJECTIVE

We assessed the safety and studied the influence of short-term helium-oxygen (heliox) mechanical ventilation (MV) on respiratory function, gas exchange and oxygenation in infants with bronchopulmonary dysplasia (BPD) or at high risk for BPD.

DESIGN

A pilot, time-series study.

SETTING

Neonatal intensive care unit.

PATIENTS

Infants with severe BPD who required MV.

INTERVENTIONS

MV with helium-oxygen and air-oxygen mixtures.

MAIN OUTCOME MEASURES

Respiratory parameters, acid-base balance, oxygenation and vital signs were recorded at five time points: initially during MV with air-oxygen, after 15 and 60 min of helium-oxygen MV, and 15 and 60 min after return to air-oxygen MV.

RESULTS

15 infants with BPD were enrolled. Helium-oxygen MV was well tolerated and was associated with a statistically significant increase in tidal volume, dynamic compliance and peak expiratory flow rate. An improvement in oxygenation and a decrease in fraction of inspired oxygen was also observed. During helium-oxygen MV there was a significant decrease in the oxygenation index and alveolar-arterial oxygen tension difference. The PaO2/fraction of inspired oxygen (FiO2) ratio increased significantly during helium-oxygen ventilation. A decrease in PaCO2 and an increase in pH were also observed during helium-oxygen administration, however this was not statistically significant. After ventilation with helium-oxygen was discontinued, the infants' respiratory function and oxygenation deteriorated and supplemental oxygen requirements increased accordingly.

CONCLUSIONS

Helium-oxygen MV is safe and resulted in improvement of respiratory function and oxygenation in infants with severe BPD requiring MV.

High-flow nasal cannula therapy for infants with bronchiolitis

BACKGROUND

Bronchiolitis is a common lower respiratory tract illness, usually of viral aetiology, affecting infants younger than 24 months of age and is a frequent cause of hospitalisation. It causes airway inflammation, mucus production and mucous plugging, resulting in airway obstruction. Effective pharmacotherapy is lacking and bronchiolitis is a major cause of morbidity and mortality.Conventional treatment consists of supportive therapy in the form of fluids, supplemental oxygen and respiratory support. Traditionally oxygen delivery is as a dry gas at 100% concentration via low-flow nasal prongs. However, the use of heated, humidified, high-flow nasal cannula (HFNC) therapy enables delivery of higher inspired gas flows of an air/oxygen blend, up to 12 L/min in infants and 30 L/min in children. Its use provides some level of continuous positive airway pressure to improve ventilation in a minimally invasive manner. This may reduce the need for invasive respiratory support thus potentially lowering costs, with clinical advantages and fewer adverse effects.

OBJECTIVES

To assess the effects of HFNC therapy compared with conventional respiratory support in the treatment of infants with bronchiolitis.

SEARCH METHODS

We searched CENTRAL (2013, Issue 4), MEDLINE (1946 to May week 1, 2013), EMBASE (January 2010 to May 2013), CINAHL (1981 to May 2013), LILACS (1982 to May 2013) and Web of Science (1985 to May 2013). In addition we consulted ongoing trial registers and experts in the field to identify ongoing studies, checked reference lists of relevant articles and searched conference abstracts.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs which assessed the effects of HFNC (delivering oxygen or oxygen/room air blend at flow rates greater than 4 L/min) compared to conventional treatment in infants (< 24 months) with a clinical diagnosis of bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently used a standard template to assess trials for inclusion and extract data on study characteristics, 'Risk of bias' elements and outcomes. We contacted trial authors to request missing data. Outcome measures included the need for invasive respiratory support and time until discharge, clinical severity measures, oxygen saturation, duration of oxygen therapy and adverse events.

MAIN RESULTS

We included one RCT which was a pilot study with 19 participants that compared HFNC therapy with oxygen delivery via a head box. In this study, we judged the risk of selection, attrition and reporting bias to be low, and we judged the risk of performance and detection bias to be unclear due to lack of blinding. The median oxygen saturation (SpO2) was higher in the HFNC group at eight hours (100% versus 96%, P = 0.04) and at 12 hours (99% versus 96%, P = 0.04) but similar at 24 hours. There was no clear evidence of a difference in total duration of oxygen therapy, time to discharge or total length of stay between groups. No adverse events were reported in either group and no participants in either group required further respiratory support. Five ongoing trials were identified but no data were available in May 2013. We were not able to perform a meta-analysis.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the effectiveness of HFNC therapy for treating infants with bronchiolitis. The current evidence in this review is of low quality, from one small study with uncertainty about the estimates of effect and an unclear risk of performance and detection bias. The included study provides some indication that HFNC therapy is feasible and well tolerated. Further research is required to determine the role of HFNC in the management of bronchiolitis in infants. The results of the ongoing studies identified will contribute to the evidence in future updates of this review.

Respiratory syncytial virus bronchiolitis in children

Respiratory syncytial virus is a highly infectious virus that commonly causes bronchiolitis and leads to high morbidity and a low, but important, incidence of mortality. Supportive therapy is the foundation of management. Hydration/nutrition and respiratory support are important evidence-based interventions. For children with severe disease, continuous positive airway pressure or mechanical ventilation may be necessary. Ribavirin may be used for treatment of patients with severe disease. Palivizumab provides important ongoing immunoprophylaxis during epidemic months for high-risk infants. Caregiver education and incorporating an explanation of all therapies and anticipatory guidance, including strategies for reducing the risk of infection, are vital.

Heliox therapy in bronchiolitis: phase III multicenter double-blind randomized controlled trial

BACKGROUND AND OBJECTIVE

Supportive care remains the mainstay of therapy in bronchiolitis. Earlier studies suggest that helium-oxygen therapy may be beneficial, but evidence is limited. We aimed to compare efficacy of 2 treatment gases, Heliox and Airox (21% oxygen + 79% helium or nitrogen, respectively), on length of hospital treatment for bronchiolitis.

METHODS

This was a multicenter randomized blinded controlled trial of 319 bronchiolitic infant subjects randomly assigned to either gas; 281 subjects completed the study (140 Heliox, 141 Airox), whose data was analyzed. Treatment was delivered via facemask (nasal cannula, if the facemask intolerant) ± continuous positive airway pressure (CPAP). Severe bronchiolitics received CPAP from the start. Primary end point was length of treatment (LoT) required to alleviate hypoxia and respiratory distress. Secondary end-points were proportion of subjects needing CPAP; CPAP (LoT); and change in respiratory distress score.

RESULTS

Analysis by intention to treat (all subjects); median LoT (inter-quartile range, days): Heliox 1.90 (1.08-3.17), Airox 1.87 (1.11-3.34), P = .41. Facemask tolerant subgroup: Heliox 1.46 (0.85-1.95), Airox 2.01 (0.93-2.86), P = .03. Nasal cannula subgroup: Heliox 2.51 (1.21-4.32), Airox 2.81 (1.45-4.78), P = .53. Subgroup started on CPAP: Heliox 1.55 (1.38-2.01), Airox 2.26 (1.84-2.73), P = .02. Proportion of subjects needing CPAP: Heliox 17%, Airox 19%, O.R. 0.87 (0.47-1.60), P = .76. Heliox reduced respiratory distress score after 8 hours (mixed models estimate, -0.1298; P < .001). The effect was greater for facemask compared with nasal cannula (mixed models estimate, 0.093; P = .04).

CONCLUSIONS

Heliox therapy does not reduce LoT unless given via a tight-fitting facemask or CPAP. Nasal cannula heliox therapy is ineffective.

6 cmH2O continuous positive airway pressure versus conventional oxygen therapy in severe viral bronchiolitis: a randomized trial

OBJECTIVE

To compare the effects of nasal continuous positive airway pressure (nCPAP) and conventional oxygen therapy on the clinical signs of respiratory distress and the respiratory muscle workload in acute viral bronchiolitis.

DESIGN

Prospective, randomized, monocentric study carried out in the pediatric intensive care unit (PICU) of a university hospital.

PATIENTS

Infants <6 months old, admitted to the PICU with severe respiratory syncytial virus bronchiolitis.

INTERVENTION

The patients were randomized into two groups for 6 hr. The nCPAP group (n = 10) received 6 cmH(2)O pressure support delivered by a jet flow generator and the control group (n = 9) received an air/oxygen mixture from a heated humidifier. Respiratory distress was assessed by the modified Wood's clinical asthma score (m-WCAS), and inspiratory muscle work was evaluated by calculating the pressure-time product per breath (PTP(insp) /breath) and per minute (PTP(insp) /min) from the esophageal pressure (Pes) recordings.

MEASUREMENTS AND MAIN RESULTS

Compared with control condition, nCPAP decreased m-WCAS [-2.4 (1.05) vs. -0.5 (1.3), P = 0.03], PTPes(insp)/breath [-9.7 (5.7) vs. -1.4 (8.2), P = 0.04], PTPes(insp) /min [-666 (402) vs. -116 (352), P = 0.015], and FiO(2) [-7 (10) vs. +5 (15), P = 0.05]. Significant worsening of m-WCAS was only observed in the control group (4/9 vs. 0/10, P = 0.03).

CONCLUSIONS

nCPAP rapidly decreased inspiratory work in young infants with acute bronchiolitis. Improvement in the respiratory distress score at 6 hr was proportional to the initial clinical severity, suggesting the importance of rapid nCPAP initiation in the more severe forms of the disease.

Nasal continuous positive airway pressure with heliox in preterm infants with respiratory distress syndrome

OBJECTIVE

To assess the therapeutic effects of breathing a low-density helium and oxygen mixture (heliox, 80% helium and 20% oxygen) in premature infants with respiratory distress syndrome (RDS) treated with nasal continuous positive airway pressure (NCPAP).

METHODS

Infants born between 28 and 32 weeks of gestational age with radiologic findings and clinical symptoms of RDS and requiring respiratory support with NCPAP within the first hour of life were included. These infants were randomly assigned to receive either standard medical air (control group) or a 4:1 helium and oxygen mixture (heliox group) during the first 12 hours of enrollment, followed by medical air until NCPAP was no longer needed.

RESULTS

From February 2008 to September 2010, 51 newborn infants were randomly assigned to two groups, 24 in the control group and 27 in the heliox group. NCPAP with heliox significantly decreased the risk of mechanical ventilation in comparison with NCPAP with medical air (14.8% vs 45.8%).

CONCLUSIONS

Heliox increases the effectiveness of NCPAP in the treatment of RDS in premature infants.

Acute Pulmonary Infections

Acute lower respiratory infection is a common cause of morbidity in infants and children, and at times, requires intensive care and mechanical ventilation. Viral bronchiolitis and bacterial pneumonia account for the majority of lower respiratory tract infections that lead to respiratory insufficiency and pediatric intensive care admission. Twenty-seven percent of children who require mechanical ventilation for at least 24 h in pediatric intensive care units are diagnosed with bronchiolitis and 16% have the diagnosis of pneumonia. The median length of time intubated for an acute pulmonary infection leading to respiratory failure is approximately 7 days.

Care of infants and children with bronchiolitis: a systematic review

Bronchiolitis is the most frequent cause of hospitalization in the infant population. Management varies widely, and the efficacy of many routinely implemented therapies is not supported by evidence. The purpose of the systematic review was to identify the best evidence available regarding the care of infants and children with bronchiolitis. A two-phase literature search was performed, and 20 publications were appraised. An abundance of evidence regarding management of bronchiolitis was revealed resulting in numerous recommendations. Use of a clinical pathway is proposed as a possible solution for moving this evidence into practice.

Non-invasive ventilation in pediatric status asthmaticus: a prospective observational study

OBJECTIVE

Non-invasive ventilation (NIV) has been shown to be effective in different causes of respiratory failure in both adult and pediatric patients. However, its role in status asthmaticus (SA) remains unclear. We designed a prospective study to assess the feasibility of NIV in children with SA.

STUDY DESIGN

Prospective observational study, over a 4.5-year period.

PATIENT SELECTION

Children with SA unresponsive to conventional therapy with a modified Wood's clinical asthma score (m-WCAS) ≥4 and marked increased work of breathing, were included.

METHODOLOGY

Patients were placed on pressure support NIV. During NIV therapy, salbutamol was nebulized continuously and ipratropium bromide every 2 hr; methyl-prednisolone was given at a dose of 1-2 mg/kg/6 hr. Clinical variables were measured at baseline and at 1, 6, 12, 24, and 48 hr.

RESULTS

During the study period, there were 122 PICU admissions due to SA; 72 episodes fulfilled inclusion criteria. Baseline mean values were as follows: m-WCAS of 5.7 points, heart rate (HR) of 166.7 beats/min, respiratory rate (RR) of 49.5 breaths/min and FiO(2) of 45.3%. In the first hour m-WCAS fell 2.3 ± 1.5 points, HR 13.5 ± 14 beats/min, and RR 9.8 ± 10 breaths/min (P < 0.01). After institution of NIV therapy, 5 children required intubation due to increasing respiratory distress. There was one case of massive subcutaneous emphysema, with no other serious adverse effects associated with NIV.

CONCLUSIONS

These results show that NIV is a feasible therapy in children with SA unresponsive to conventional treatment. Pediatr. Pulmonol. 2011; 46:949-955. © 2011 Wiley-Liss, Inc.

Noninvasive ventilation with helium-oxygen in children

Most existing literature on noninvasive ventilation (NIV) in combination with helium-oxygen (HELIOX) mixtures focuses on its use in adults, basically for treatment of acute exacerbations of chronic obstructive pulmonary disease. This article reviews and summarizes the theoretical basis, existing clinical evidence, and practical aspects of the use of NIV with HELIOX in children. There is only a small body of literature on HELIOX in pediatric NIV but with positive results. The reported experience focuses on treatment for patients with severe acute bronchiolitis who cannot be treated with standard therapies. The inert nature of helium adds no biological risk to NIV performance. Noninvasive ventilation with HELIOX is a promising therapeutic option for children with various respiratory pathologies who do not respond to conventional treatment. Further controlled studies should be warranted.

Use of continuous positive airway pressure (CPAP) in acute viral bronchiolitis: a systematic review

INTRODUCTION

Continuous positive airway pressure (CPAP), used either alone or associated with heliox (CPAP-He), has become a popular therapeutic option for bronchiolitis. This systematic review assesses the impact of CPAP on endotracheal intubation, carbon dioxide pressure (PCO(2) ) and respiratory distress in patients with bronchiolitis.

METHODS

Systematic search including studies that used CPAP or CPAP-He in infants with bronchiolitis admitted to a PICU. Data analysis included descriptive statistics and the GRADE system.

RESULTS

Five CPAP (one crossover randomized controlled trial [RCT] and four before-after studies) and three CPAP-He (one quasi-RCT and two before-after) studies were included. CPAP was reported to reduce PCO(2) (-6.9 to -11.7 mmHg, respectively, P < 0.015), respiratory rate (-12 to -16 breaths/min after 2 hr, P < 0.01) and the modified Wood clinical asthma score (mWCAS, -2.2 points after 1 hr, P < 0.01). CPAP-He studies observed decreases in PCO(2) (-9.7 mmHg, P < 0.05), mWCAS (-2.12 points, P < 0.001), and respiratory rate (-8 to -13.7 breaths/min, P < 0.05) after 1 hr of treatment. Endotracheal intubation rates ranged from 0-12.5% (CPAP-He) to 17-27% (CPAP). After applying the GRADE system, the quality of evidence for a beneficial effect of CPAP and CPAP-He was classified as low.

CONCLUSIONS

The evidence supporting the use of CPAP to reduce PCO(2) and respiratory distress in bronchiolitis is of low methodological quality, and there is no conclusive evidence that CPAP reduces the need for intubation. No definitive conclusions could be drawn about the CPAP-He effect. Further research using higher quality methodology is needed to clarify the beneficial role of these interventions.

Helmet-delivered heliox-CPAP in severe upper airway obstruction caused by PHACES syndrome

We present the case of a 4-month-old girl with PHACES syndrome and severe upper respiratory airway obstruction secondary to multiple subglottic and tracheal hemangiomas effectively treated with heliox-CPAP delivered by helmet (HH-CPAP).

Use of heliox in the management of neonates with meconium aspiration syndrome

BACKGROUND

Helium-oxygen mixture (heliox) ventilation has been known as an alternative treatment in patients with airway obstruction. Because of the physical properties of heliox, mechanical ventilation with this gas mixture may offer advantages in the management of respiratory failure associated with meconium aspiration syndrome (MAS).

OBJECTIVES

The purpose of this pilot study was to assess the effect of short-term mechanical ventilation with heliox in newborns with MAS on vital signs, oxygenation, acid-base balance and respiratory function parameters.

METHODS

The study was carried out in newborns with respiratory failure requiring mechanical ventilation due to MAS. Eight patients were ventilated using pressure-controlled synchronized intermittent mandatory ventilation. Parameters of respiratory function, oxygenation, acid-base balance and vital signs were recorded at baseline, then twice during 1 h of heliox ventilation and finally twice during 1 h after switching back to air-oxygen ventilation.

RESULTS

Mechanical ventilation with heliox did not affect vital signs and the infants' clinical condition remained stable during the study. Heliox ventilation was associated with a nonsignificant increase in tidal volume, minute ventilation and peak expiratory flow rate values. Mechanical ventilation with heliox allowed the use of significantly lower FiO(2), with a significant decrease in alveolar-arterial oxygen tension difference and a decrease in the oxygenation index which was not statistically significant. There was also a significant increase in the PaO(2)/FiO(2) ratio during heliox ventilation.

CONCLUSIONS

Ventilation with a helium and oxygen mixture had a positive effect on the selected parameters of oxygenation, while its effects on other respiratory parameters were relatively small.

Treatment of acute hypoxemic respiratory failure with continuous positive airway pressure delivered by a new pediatric helmet in comparison with a standard full face mask: a prospective pilot study

OBJECTIVES

To evaluate the feasibility and efficacy of continuous positive airway pressure delivered by a new pediatric helmet in comparison with a standard facial mask in infants with acute hypoxemic respiratory failure.

DESIGN

A single-center prospective case-control study.

SETTING

Pediatric intensive care unit in a tertiary children hospital.

PATIENTS AND INTERVENTIONS

Twenty consecutive infants treated with continuous positive airway pressure by a helmet matched with a control patient treated with continuous positive airway pressure by facial mask and selected by age, weight, PaO2:Fio2, and PaCO2 on pediatric intensive care unit admission.

MEASUREMENTS AND MAIN RESULTS

Feasibility was defined as the incidence of continuous positive airway pressure protocol failure secondary to 1) failure to administer continuous positive airway pressure because of intolerance to the interface; 2) deterioration in gas exchange soon after continuous positive airway pressure institution; and 3) major clinical adverse events such as pneumothorax or any hemodynamic instability related to the continuous positive airway pressure safety system device's failure. Evaluation of feasibility included also the total application time of respiratory treatment, the number of continuous positive airway pressure discontinuations/first 24 hrs. Interface-related complications included air leaks, cutaneous pressure sores, eye irritation, inhalation, and gastric distension. The 20 patients and control subjects had similar matching characteristics. Continuous positive airway pressure delivered by a helmet compared with a facial mask reduced continuous positive airway pressure trial failure rate (p = .02), increased application time (p = .001) with less discontinuations (p = .001), and was not associated with an increased rate of major adverse events, resulting in decreased air leaks (p = .04) and pressure sores (p = .002). Both continuous positive airway pressure systems resulted in early and sustained improvement in oxygenation.

CONCLUSIONS

The helmet might be considered a viable and safe alternative to a standard facial mask to deliver continuous positive airway pressure in hypoxemic infants in the pediatric intensive care unit setting. In our study, the helmet allowed more prolonged application of continuous positive airway pressure compared with a facial mask, ensuring similar improvement in oxygenation without any adverse events and clinical intolerance.

Heliox inhalation therapy for bronchiolitis in infants

BACKGROUND

Acute viral bronchiolitis is associated with airway obstruction and turbulent gas flow. Heliox, a mixture of oxygen and the inert gas helium, may improve gas flow through high-resistance airways and decrease the work of breathing.

OBJECTIVES

To assess heliox in addition to standard medical care for acute bronchiolitis in infants.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2), which includes the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register, MEDLINE (1966 to June 2009), EMBASE (June 2009), LILACS (May 2009) and the NIH web site (May 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs of heliox in infants with acute bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial quality. We pooled data from individual trials.

MAIN RESULTS

We included four trials involving 84 infants under two years of age with respiratory distress secondary to bronchiolitis caused by respiratory syncytial virus (RSV) and requiring paediatric intensive care unit (PICU) hospitalisation. We found that infants treated with heliox inhalation had a significantly lower mean clinical respiratory score in the first hour after starting treatment when compared to those treated with air or oxygen inhalation (mean difference (MD) -1.15, 95% confidence interval (CI) -1.98 to -0.33, P = 0.006, n = 69). There was no clinically significant reduction in the rate of intubation (risk ratio (RR) 1.38, 95% CI 0.41 to 4.56, P = 0.60, n = 58), in the need for mechanical ventilation (RR 1.11, 95% CI 0.36 to 3.38, P = 0.86, n = 58), or in the length of stay in a PICU (MD = -0.15 days, 95% CI -0.92 to 0.61, P = 0.69, n = 58). No adverse events related to heliox inhalation were reported.

AUTHORS' CONCLUSIONS

Current evidence suggests that the addition of heliox therapy may significantly reduce a clinical score evaluating respiratory distress in the first hour after starting treatment in infants with acute RSV bronchiolitis. Nevertheless, there was no reduction in the rate of intubation, in the need for mechanical ventilation, or in the length of PICU stay. Further studies with homogeneous logistics in their heliox application are needed. Such studies would provide necessary information as to the appropriate place for heliox in the therapeutic schedule for severe bronchiolitis.

Effects of nasal continuous positive airway pressure and cannula use in the neonatal intensive care unit setting

OBJECTIVE

To investigate the effects of nasal continuous positive airway pressure (CPAP) and cannula use in the neonatal intensive care unit.

DESIGN

Cross-sectional study.

SETTING

Tertiary care children's hospital.

PATIENTS

One hundred patients (200 nasal cavities), younger than 1 year, who received at least 7 days of nasal CPAP (n = 91) or cannula supplementation (n = 9) in the neonatal intensive care unit.

INTERVENTIONS

External nasal examination and anterior nasal endoscopy with photographic documentation.

MAIN OUTCOME MEASURES

The incidence and characteristics of internal and external nasal findings of patients with nasal CPAP or cannula use.

RESULTS

Nasal complications were seen in 12 of the 91 patients (13.2%) with at least 7 days of nasal CPAP exposure, while no complications were seen in the 9 patients with nasal cannula use alone. The external nasal finding of columellar necrosis, seen in 5 patients (5.5%), occurred as early as 10 days after nasal CPAP use. Incidence of intranasal findings attributed to CPAP use, in the 182 nostrils examined, included ulceration in 6 nasal cavities (3.3%), granulation in 3 nasal cavities (1.6%), and vestibular stenosis in 4 nasal cavities (2.2%). Intranasal complications were seen as early as 8 to 9 days after nasal CPAP administration. Nasal complications from CPAP were associated with lower Apgar scores at 1 (P = .02) and 5 (P = .06) minutes.

CONCLUSIONS

External or internal complications of nasal CPAP can be relatively frequent (13.2%) and can occur early, and patients with lower Apgar scores may be at higher risk. Close surveillance for potential complications should be considered during nasal CPAP use.

High flow nasal cannulae therapy in infants with bronchiolitis

OBJECTIVES

To determine whether the introduction of heated humidified high-flow nasal cannulae (HFNC) therapy was associated with decreased rates of intubation for infants <24 months old with bronchiolitis admitted to a pediatric intensive care unit (PICU).

STUDY DESIGN

A retrospective chart review of infants with bronchiolitis admitted before and in the season after introduction of HFNC.

RESULTS

In the season after the introduction of HFNC, only 9% of infants admitted to the PICU with bronchiolitis required intubation, compared with 23% in the prior season (P=.043). This 68% decrease in need for intubation persisted in a logistic regression model controlling for age, weight, and RSV status. HFNC therapy resulted in a greater decrease in respiratory rate compared with other forms of respiratory support, and those infants with the greatest decrease in respiratory rate were least likely to be intubated. In addition, median PICU length of stay for children with bronchiolitis decreased from 6 to 4 days after the introduction of HFNC.

DISCUSSION

We hypothesize that HFNC decreases rates of intubation in infants with bronchiolitis by decreasing the respiratory rate and work of breathing by providing a comfortable and well-tolerated means of noninvasive ventilatory support.

Acute viral bronchiolitis in children- a very common condition with few therapeutic options

Acute viral bronchiolitis remains a cause of substantial morbidity and health care costs in young infants. It is the most common lower respiratory tract condition and most common reason for admission to hospital in infants. Many respiratory viruses have been associated with acute viral bronchiolitis although respiratory syncytial virus (RSV) remains the most frequently identified virus. Most infants have a mild self limiting illness while others have more severe illness and require hospital admission and some will need ventilatory support. Differences in innate immune function in response to the respiratory viral insult as well as differences in the geometry of the airways may explain some of the variability in clinical pattern. Young age and history of prematurity remain the most important risk factors although male gender, indigenous status, exposure to tobacco smoke, poor socioeconomic factors and associated co-morbidities such as chronic lung disease and congenital heart disease increase the risks of more severe illness. Supportive therapy remains the major treatment option as no specific treatments to date have been shown to provide clinically important benefits except for inhaled hypertonic saline. Prophylaxis of high risk infants with palivizumab should be considered although the cost effectiveness is still unclear. Many questions remain regarding optimal management approaches for infants requiring hospitalisation with bronchiolitis including use of nasogastric feeding, the optimal role of supplemental oxygen, optimal use of hypertonic saline and the role of combinations of therapies, the use of heliox or modern physiotherapy approaches.

Helmet-delivered continuous positive airway pressure with heliox in respiratory syncytial virus bronchiolitis

AIM

The objective of this study was to check the feasibility and efficacy of helmet-delivered heliox-continuous positive airway pressure (CPAP) in infants with bronchiolitis.

METHODS

Children <3 months of age diagnosed with respiratory syncytial virus bronchiolitis and recurrent apnoeas or a venous PCO(2) >55 mmHg or a transcutaneous oxygen saturation <92% in room air were eligible for inclusion in the study. CPAP was delivered by a noninvasive ventilator connected to a heliox port. The interface was a helmet.

RESULTS

Eight consecutive infants fulfilled the inclusion criteria. Apnoeas were present in six children before respiratory support was started; they disappeared in five of them. Two infants had to be changed to pressure support noninvasive ventilation, and one of them required intubation. No side effects were recorded.

CONCLUSION

We propose a relatively new device to deliver heliox-CPAP in small infants with bronchiolitis. Although this is just a descriptive study with a short sample, this system seems to be feasible and effective.

The Effects of helium/oxygen mixture (heliox) before and after extubation in long-term mechanically ventilated very low birth weight infants

OBJECTIVES

Our goal was to evaluate the effects of a helium/oxygen mixture (heliox) on pulmonary mechanics and gas exchange in preterm infants during both conventional and noninvasive ventilation.

PATIENTS AND METHODS

Ten preterm infants, ventilated from birth, were enrolled. Resistive work of breathing, pulmonary compliance, static compliance, respiratory rate, minute ventilation, ventilatory support, and gas exchange were measured before and during treatment. One hour after heliox therapy, subjects who showed a decrease of peak inspiratory pressure of >20% of the initial value were extubated and shifted to nasal bilevel positive airway pressure with heliox for the following 3 hours. Pulmonary mechanics and ventilatory parameters were measured during air/oxygen ventilation and again 10 minutes and 1 hour after starting heliox. Transcutaneous pressure of O(2) and CO(2), oxygen saturation, and respiratory rate were recorded continuously. Arterial blood gases were measured immediately before and 1 hour after initiating bilevel positive airway pressure. To maintain oxygen saturation at >92% during the bilevel positive airway pressure phase, the mean fraction of inspired oxygen was increased from 0.34 to 0.36.

RESULTS

Mean peak inspiratory pressure decreased from 21.4 to 17.4 cmH(2)O, work of breathing decreased from 0.46 to 0.22 joule/L, and transcutaneous pressure of CO(2) decreased from 52.3 to 49.1 mmHg. Mean transcutaneous pressure of O(2) improved from 42.8 to 46.7 mmHg, and minute ventilation improved from 332 to 478 mL/kg per minute. No significant differences were observed in mean airway pressure, respiratory rate, oxygen saturation, pulmonary compliance, and static compliance. Eight infants were extubated. One of them needed to be reintubated after 5 hours.

CONCLUSIONS

Our data show that mechanical ventilation with heliox reduces resistive work of breathing and ventilatory support requirements and improves gas exchange in preterm infants.

Role of ventilation in RSV disease: CPAP, ventilation, HFO, ECMO

Respiratory syncytial virus (RSV) lower respiratory tract disease may present as bronchiolitis, an obstructive lung disease with hyperinflation, or pneumonitis, a restrictive parenchymal disease with diffuse consolidation, a large intrapulmonary shunt and acute respiratory distress syndrome (ARDS). Although a significant proportion of those admitted to hospital will require some form of respiratory support, there have been few randomised studies to determine which is the most beneficial. Studies on the use of continuous positive airway pressure (CPAP), heliox, inhaled nitric oxide, and natural surfactant are reviewed. Current practice regarding ventilator support is largely based on clinical judgment and case reports. Multicentre randomised trials with long-term follow-ups are urgently required.

[Success and failure predictors of non-invasive ventilation in acute bronchiolitis]

INTRODUCTION

The objective was to identify predictive factors for non-invasive ventilation (NIV) failure and to describe its use in bronchiolitis.

PATIENTS AND METHODS

Prospective observational study that included patients diagnosed with bronchiolitis with a modified Wood's Clinical Asthma Score 5, or oxygen saturation <92%, or venous CO(2) partial pressure (PCO(2)) 60 mm Hg, with no response to medical treatment, who received NIV from December 2005 to May 2008. We collected clinical data before NIV began and at 1, 6, 12, 24 and 48 h. Need for intubation was considered as NIV failure.

RESULTS

NIV was successful in 83% of 47 cases included. Patients in whom NIV failed had lower weight (5.2+/-2.2 vs. 3.5+/-0.8 kg, P=.011), lower age [1.8 (0.3-12.3) vs. 0.8 (0.4-4.3) months, P=.038)], lower heart rate (HR) before NIV began (176.3+/-19.1 vs. 160.4+/-9.7 beats/minute, P=.010), lower HR decrease at hours 1 (-16.0+/-17.3 vs.+1.1+/-11.6, P=.005) and 12 (-31.5+/-19.7 vs. -0.75+/-12.2, P=.002), presence of apnoeas (23.1% vs. 75%; P=.004) and of a predisposing condition (84.6% vs. 50%; P=.029). Multivariate analysis identified the absence of a predisposing condition, and a greater HR decrease during the first hour as success-associated independent factors (OR 0.004; 95% CI 0.000-0.664 and OR 0.896; 95% CI: 0.809-0.993, respectively).

CONCLUSIONS

NIV has a high success rate in bronchiolitis. The main parameters which can predict NIV success are the absence of a predisposing condition and a higher HR decrease in the first hour.