High-flow support in very preterm infants in Australia and New Zealand

Nasal high frequency oscillatory highflow therapy in preterm infants: A randomized crossover trial

OBJECTIVES

To assess the clinical efficacy, safety, and potential physiological mechanisms of highflow therapy with superimposed high frequency oscillations ("osciflow").

STUDY DESIGN

In this prospective, randomized, single center crossover trial, 30 preterm infants were randomized to receive osciflow or highflow therapy first, each for 180 min. During osciflow, an oscillatory amplitude of 20 mbar and a frequency of 6 Hz were set. The flow rate was 4 L/min during both interventions. Primary outcome was the paired difference in the combined number of desaturations (SpO2  < 80%) and bradycardia (heart rate <80 beats per min) between interventions. Safety outcomes included nasal trauma, pneumothorax and treatment failure, and a pain score was assessed. In 20 infants, electrical impedance tomography (EIT) recordings were performed to evaluate oscillatory (VOsc ) and tidal volumes (VT ) at the lung level.

RESULTS

Infants with a mean (SD) postnatal age of 33.1 ± 1.2 weeks were included. The median (IQR) number of episodes of desaturation and bradycardia was 19.5 (6-49) during osciflow and 26 (6-44) during highflow therapy (paired difference -2; IQR -10 to 9; p = .37). There were no differences in safety outcomes and pain scores. During osciflow, EIT recordings showed a signal at 6 Hz, which was not detectable during highflow. Corresponding mean (SD) VOsc /VT ratio was 9% (±5%).

CONCLUSIONS

In preterm infants, osciflow did not reduce the number of desaturations and bradycardia compared with highflow therapy. Although VOsc were transmitted to the lung during osciflow, their magnitude was small. Osciflow was safe and well tolerated.

Guidelines for high-flow nasal cannula oxygen therapy in neonates (2022)

High-flow nasal cannula (HFNC) oxygen therapy, which is important in noninvasive respiratory support, is increasingly being used in critically ill neonates with respiratory failure because it is comfortable, easy to setup, and has a low incidence of nasal trauma. The advantages, indications, and risks of HFNC have been the focus of research in recent years, resulting in the development of the application. Based on current evidence, we developed guidelines for HFNC in neonates using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The guidelines were formulated after extensive consultations with neonatologists, respiratory therapists, nurse specialists, and evidence-based medicine experts. We have proposed 24 recommendations for 9 key questions. The guidelines aim to be a source of evidence and reference of HFNC oxygen therapy in clinical practice, and so that more neonates and their families will benefit from HFNC.

Use of high flow nasal cannula in Spanish neonatal units

INTRODUCTION

The use of high-flow cannula therapy (HFNC) in neonatal units has increased in recent years, but there are no consensus guidelines on its indications and application strategies. Our aim was to know the rate of use of HFNC, their indications and the management variability among Spanish neonatal units.

MATERIAL AND METHODS

Twenty-five-question survey for medical and nursing staff. Level II and III units were contacted by phone and sent in Google forms between September 2016 and December 2018.

RESULTS

Ninety-seven responses (63.9% medical, 36.1% nursing), from 69 neonatal units representing 15 autonomous communities (87% level of care III; 13% level II). All units except one have HFNC with a humidified and heated system. Their most frequent indications are: non-invasive ventilation weaning (79.4%), bronchiolitis (69.1%), respiratory distress of the term newborn (58.8%), after extubation (50.5%). Minimum flow (1-5 L/min) and maximum flow (5-15 L/min) are variable between units. 22.7% have experienced some adverse effect from its use (9 air leak, 12 nasal trauma). Less than half have an employment protocol, but all the answers agree on the usefulness of national recommendations.

CONCLUSIONS

HFNC therapy is widely used in Spanish units, but there is great variability in its indications and strategies of use. National recommendations would be applicable in most units and would allow unifying its use.

Observational cohort study of changing trends in non-invasive ventilation in very preterm infants and associations with clinical outcomes

OBJECTIVE

To determine the change in non-invasive ventilation (NIV) use over time in infants born at <32 weeks' gestation and the associated clinical outcomes.

STUDY DESIGN

Retrospective cohort study using routinely recorded data from the National Neonatal Research Database of infants born at <32 weeks admitted to neonatal units in England and Wales from 2010 to 2017.

RESULTS

In 56 537 infants, NIV use increased significantly between 2010 and 2017 (continuous positive airway pressure (CPAP) from 68.5% to 80.2% in 2017 and high flow nasal cannula (HFNC) from 14% to 68%, respectively) (p<0.001)). Use of NIV as the initial mode of respiratory support also increased (CPAP, 21.5%-28.0%; HFNC, 1%-7% (p<0.001)).HFNC was used earlier, and for longer, in those who received CPAP or mechanical ventilation. HFNC use was associated with decreased odds of death before discharge (adjusted OR (aOR) 0.19, 95% CI 0.17 to 0.22). Infants receiving CPAP but no HFNC died at an earlier median chronological age: CPAP group, 22 (IQR 10-39) days; HFNC group 40 (20-76) days (p<0.001). Among survivors, HFNC use was associated with increased odds of bronchopulmonary dysplasia (BPD) (aOR 2.98, 95% CI 2.81 to 3.15) and other adverse outcomes.

CONCLUSIONS

NIV use is increasing, particularly as initial respiratory support. HFNC use has increased significantly with a sevenfold increase soon after birth which was associated with higher rates of BPD. As more infants survive with BPD, we need robust clinical evidence, to improve outcomes with the use of NIV as initial and ongoing respiratory support.

High-flow nasal cannula versus continuous positive airway pressure in primary respiratory support for preterm infants: A systematic review and meta-analysis

Respiratory support is crucial for the survival of preterm infants, and High-flow Nasal Cannula Oxygen Therapy (HFNC) and Continuous Positive Airway Pressure (CPAP) are commonly used for neonatal respiratory support. This meta-analysis aimed to compare the effects of HFNC and CPAP in primary respiratory support for preterm infants, to provide evidence-based support for clinical practice. PubMed, Embase, Cochrane Library, ClinicalTrials.gov, CNKI, VIP, WANFANG and SinoMed were searched for eligible studies. The primary outcomes included the incidence of treatment failure and the application of mechanical ventilation. A total of 27 eligible studies with 3,351 participants were included. There was no significant difference in the incidence of respiratory support failure [RR = 1.17, 95%CI (0.88-1.56)] and the application of mechanical ventilation [RR = 1.00, 95%CI (0.84-1.19)] between HFNC group and CPAP group. HFNC resulted in lower rate of air leaks [RR = 0.65, 95%CI (0.46-0.92)], nasal trauma [RR = 0.36, 95%CI (0.29-0.45)] and abdominal distension [RR = 0.39, 95%CI (0.27-0.58)], and later time of mechanical ventilation initiating [SMD = 0.60, 95%CI (0.21-0.99)], less duration of oxygen therapy [SMD = -0.35, 95%CI (-0.68 to -0.02)] and earlier enteral feeding [SMD = -0.54, 95%CI (-0.95 to -0.13)]. Alternative non-invasive respiratory support after initial treatment failure resulted in no difference in the application of mechanical ventilation between the two groups [RR = 0.99, 95%CI (0.52-1.88)]. HFNC might be more effective and safer in primary respiratory support for preterm infants. Using CPAP as a remedy for the treatment failure of HFNC could not avoid intubation. For premature infants with the gestational age <28 weeks, HFNC as primary respiratory support still needs to be further elucidated. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022313479, identifier: CRD42022313479.

Modified setting of negative pressure in children with mild respiratory disease

BACKGROUND

Continuous negative extra-thoracic pressure (CNEP) can prevent children with apnea developing severe respiratory infection with endotracheal intubation. Little is known about children with mild acute respiratory disease, especially with a focus on clinical respiratory symptoms.

METHODS

We conducted a prospective, observational study between July 2014 and July 2017 to evaluate the safety of a modified setting of CNEP in hospitalized children with symptoms of chest-wall retraction or nasal alar breathing without the requirement for immediate intubation therapy in a single center. A modified setting of CNEP was defined as 4 h of treatment comprising 3 consecutive hours of CNEP followed by 1 h of rest.

RESULTS

We studied 19 hospitalized children with retraction or nasal breathing but no possible state of endotracheal intubation. The median age at admission was 0.9 years and the duration of CNEP was 6 days. No sedative drugs were used. The percentage of children with retraction or nasal breathing after 24 h from initiation of CNEP was significantly decreased compared with that just before CNEP (68% vs 100%, P = 0.02). Logistic regression showed no statistical evidence of contributing factors for pulmonary symptoms. No patients were transferred to receive intubation, but one boy reinitiated respiratory support within 6 months after discharge. No children had adverse events of upper airway obstruction, skin injury, interfering with access, hypothermia, discomfort from fitting a cuirass, and neck excoriation.

CONCLUSIONS

Our results suggest that a modified setting of CNEP management can be tolerated and continued without concern of adverse events.

[Use of high flow nasal cannula in Spanish neonatal units]

INTRODUCTION

The use of high-flow cannula therapy (HFNC) in neonatal units has increased in recent years, but there are no consensus guidelines on its indications and application strategies. Our aim was to know the rate of use of HFNC, their indications and the management variability among Spanish neonatal units.

MATERIAL AND METHODS

Twenty-five-question survey for medical and nursing staff. Level II and III units were contacted by phone and sent in Google forms between September 2016 and December 2018.

RESULTS

Ninety-seven responses (63.9% medical, 36.1% nursing), from 69 neonatal units representing 15 autonomous communities (87% level of care III; 13% level II). All units except one have HFNC with a humidified and heated system. Their most frequent indications are: non-invasive ventilation weaning (79.4%), bronchiolitis (69.1%), respiratory distress of the term newborn (58.8%), after extubation (50.5%). Minimum flow (1-5 L/min) and maximum flow (5-15 L/min) are variable between units. 22.7% have experienced some adverse effect from its use (9 air leak, 12 nasal trauma). Less than half have an employment protocol, but all the answers agree on the usefulness of national recommendations.

CONCLUSIONS

HFNC therapy is widely used in Spanish units, but there is great variability in its indications and strategies of use. National recommendations would be applicable in most units and would allow unifying its use.

Implementation of a protocol-based strategy for weaning nasal high flow therapy in preterm infants

OBJECTIVE

We compared protocolized weaning versus nonprotocolized weaning practice from nasal high flow therapy (nHFT) in preterm infants.

STUDY DESIGN

A before-and- after observational study.

METHODS

The study was conducted in three phases; Phase 1: infants were weaned according to usual practice for 6 months (nonprotocolized), Phase 2: education and training physicians and nursing staff for the protocol for 1 month, and Phase 3: protocol of weaning from nHFT was applied for the following 6 months with specified criteria for readiness to wean, weaning failure and weaning technique. The primary outcome was failure to wean off nHFT.

RESULTS

One hundred and four preterm infants were enrolled, 51 preterm infants in the protocol group and 53 in the nonprotocol group. The groups were similar in demographic and clinical characteristics at baseline. There were significantly lower number of patients who failed weaning from nHFT in the protocol group compared to nonprotocol group (4 [7.8%] versus 15 [28.3%], p = .007]. There was shorter time to reach full enteral feeding in the protocol group compared with nonprotocol group (p = .03). There were no significant differences between groups regarding other outcomes including total durations of respiratory support, nHFT and oxygen therapy, duration of nHFT after decision of weaning, and neonatal mortality and morbidity.

CONCLUSION

Implementation of a standardized protocol for weaning from nHFT in preterm infants reduced weaning failure and reduced the time to full feeds. Larger trials are recommended to detect the impact of weaning protocols on other outcomes.

Practical aspects on the use of non-invasive respiratory support in preterm infants

Preterm infants frequently present with respiratory insufficiency requiring respiratory assistance. Invasive mechanical ventilation has been associated with several short and long term complications. Therefore, the practice of early use of non-invasive ventilation has been adopted. Nasal CPAP proved efficacy as an initial therapy for preterm infants. Non-invasive positive pressure ventilation is an alternative used to mitigate CPAP failure in infants with apnea or increased work of breathing. High flow nasal cannula gained popularity primarily due to the ease of its use, despite multiple prominent trials that demonstrated its inferiority. Bi-level positive airway pressure and neurally adjusted non-invasive ventilatory are used in infants with apnea and increased work of breathing. The effectiveness of non invasive ventilation tools can be augmented by having a proper protocol for initiation, weaning, skin care, positioning, and developmental care during their application.

Predictors and Outcomes of Early Intubation in Infants Born at 28-36 Weeks of Gestation Receiving Noninvasive Respiratory Support

OBJECTIVE

To identify predictors and outcomes of early intubation in preterm infants with respiratory distress, and predictors of need for brief respiratory support (≤1 day).

STUDY DESIGN

Secondary analysis of data from a randomized trial comparing nasal high-flow with continuous positive airway pressure as primary respiratory support in preterm infants born at 28-36 weeks of gestation. Intubation was assessed within 72 hours of randomization.

RESULTS

There were 564 included infants with a mean (SD) gestational age of 32.0 (2.2) weeks and birth weight 1744 (589) g; 76 infants (13.5%) received early intubation. On multivariable analysis, lower gestational age and higher pre-randomization fraction of inspired oxygen (FiO₂) predicted intubation. A test based on gestational age of <30 weeks and an FiO₂ of ≥0.30 produced a likelihood ratio of 9.1. Intubation was associated with prolonged duration of respiratory support and supplemental oxygen, with pneumothorax and nasal trauma, and in infants born at <32 weeks of gestational, with bronchopulmonary dysplasia and patent ductus arteriosus requiring treatment. Greater gestational age and lower FiO₂ predicted the need for ≤1 day of respiratory support. A test based on a gestational age of ≥34 weeks and an FiO₂ of 0.21 produced a likelihood ratio of 4.7.

CONCLUSIONS

In preterm infants 28-36 week of gestation receiving primary noninvasive respiratory support, lower gestational age, and higher FiO₂ predicted need for intubation within 72 hours. Intubation was associated with adverse respiratory outcomes. Greater gestational age and lower FiO₂ predicted need for ≤1 day of respiratory support. It may be reasonable to defer the use of respiratory support in more mature infants with low FiO₂ requirements. TRIAL REGISTRATION AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY: ACTRN12613000303741.

Lost in Transition: Is Early Respiratory Support in Newborn Infants the Best Option?

BACKGROUND

Late preterm and term newborns with respiratory distress are increasingly treated with non-invasive ventilation (NIV) including nasal high-flow or continuous positive airway pressure. For infants with mild distress, NIV may be unnecessary.

OBJECTIVES

We speculated that treatment with supplemental oxygen (SO) prior to NIV could help clinicians select infants for NIV treatment, and examined this hypothesis using data from a recently completed trial.

METHOD

Post hoc analysis of data from a subset of infants enrolled in the HUNTER trial. Infants born at ≥36 weeks' gestation were categorized by whether they were receiving SO prior to randomization. The 2 groups were compared for illness severity (indicated by treatment failure at 72 h, mechanical ventilation, need for up-transfer, SO requirement post-randomization, and length of time receiving respiratory support), use of selected medical interventions (antibiotics, intravenous fluids), and breastfeeding at discharge.

RESULTS

Analysis included 380 infants. Infants not receiving SO had less severe illness; lower rates of treatment failure (7.3 vs. 17.2%), mechanical ventilation (0.6 vs. 5.9%), need for transfer (6.8 vs. 13.8%), and more often did not receive any SO post-randomization (75.1 vs. 3.0%). Most infants in both groups received intravenous fluids (93 and 98%) and antibiotics (81 and 93%); the rate of full breastfeeding was low in both groups (51 and 45%).

CONCLUSIONS

Late preterm and term newborn infants without SO requirement at the time of commencing NIV for respiratory distress are at lower risk of requiring treatment escalation. Close observation of these infants (watch and wait strategy) may avoid unnecessary treatment.

Is Nasal High Flow Inferior to Continuous Positive Airway Pressure for Neonates?

Nasal high-flow therapy (nHF) is increasingly used for neonates, with perceived benefits including reduced rates of nasal trauma and parent and nursing staff preference. Current evidence suggests that although nHF is a reasonable alternative for postextubation support of preterm infants, continuous positive airway pressure is a superior modality for primary support of respiratory distress syndrome. Minimal evidence exists for use of nHF in extremely preterm infants less than 28 weeks' gestation. Depending on clinician preference, units may still choose nHF in some settings, although careful choice of appropriate patients, and availability of rescue continuous positive airway pressure, is essential.

Nasal High-Flow Therapy for Newborn Infants in Special Care Nurseries

BACKGROUND

Nasal high-flow therapy is an alternative to nasal continuous positive airway pressure (CPAP) as a means of respiratory support for newborn infants. The efficacy of high-flow therapy in nontertiary special care nurseries is unknown.

METHODS

We performed a multicenter, randomized, noninferiority trial involving newborn infants (<24 hours of age; gestational age, ≥31 weeks) in special care nurseries in Australia. Newborn infants with respiratory distress and a birth weight of at least 1200 g were assigned to treatment with either high-flow therapy or CPAP. The primary outcome was treatment failure within 72 hours after randomization. Infants in whom high-flow therapy failed could receive CPAP. Noninferiority was determined by calculating the absolute difference in the risk of the primary outcome, with a noninferiority margin of 10 percentage points.

RESULTS

A total of 754 infants (mean gestational age, 36.9 weeks, and mean birth weight, 2909 g) were included in the primary intention-to-treat analysis. Treatment failure occurred in 78 of 381 infants (20.5%) in the high-flow group and in 38 of 373 infants (10.2%) in the CPAP group (risk difference, 10.3 percentage points; 95% confidence interval [CI], 5.2 to 15.4). In a secondary per-protocol analysis, treatment failure occurred in 49 of 339 infants (14.5%) in the high-flow group and in 27 of 338 infants (8.0%) in the CPAP group (risk difference, 6.5 percentage points; 95% CI, 1.7 to 11.2). The incidences of mechanical ventilation, transfer to a tertiary neonatal intensive care unit, and adverse events did not differ significantly between the groups.

CONCLUSIONS

Nasal high-flow therapy was not shown to be noninferior to CPAP and resulted in a significantly higher incidence of treatment failure than CPAP when used in nontertiary special care nurseries as early respiratory support for newborn infants with respiratory distress. (Funded by the Australian National Health and Medical Research Council and Monash University; HUNTER Australian and New Zealand Clinical Trials Registry number, ACTRN12614001203640.).

Efficacy and Safety of Nasal High-Flow Therapy for Neonatal Transport

OBJECTIVE

Noninvasive ventilation, including nasal high-flow therapy (nHFT), provides effective neonatal respiratory support. There are limited data on nHFT use during neonatal transport. Our objective was to assess the efficacy and safety of nHFT during neonatal transport.

METHODS

One hundred ninety-five neonates transported on nHFT via a Neo-Pod "T" system (Westmed Inc, Tucson, AZ) were identified from Life Flight transport data. Data included demographics, transport location, distance, indication, and mode as well as pretransport and intratransport respiratory support data. We compared neonates who successfully tolerated nHFT transport with those who required support escalation (defined as increase in flow ≥2 L/min or fraction of inspired oxygen [FiO₂] ≥20%).

RESULTS

Eighty-seven percent of neonates (170/195) were effectively transported on nHFT. Infants requiring escalation of nHFT support had a significantly higher pretransport FiO₂ (median = 0.60 [interquartile range, 0.36-1.00] vs. 0.36 [0.23-0.56]; P < .05) and a longer ground time for stabilization (56 ± 25 vs. 39 ± 18 minutes, P < .05) and were more frequently transported by air.

CONCLUSION

Nasal HFT can be an effective mode of respiratory support in the transport of selected neonates. FiO₂ at the time of transport may be a key parameter to aid in determining neonates who can be safely transported on nHFT.

3D airway model to assess airway dead space

High flow therapy works partly by washout of airway dead space, the volume of which has not been quantified in newborns. This observational study aimed to quantify airway dead space in infants and to compare efficacy of washout between high flow devices in three-dimensional (3D) printed airway models of infants weighing 2.5-3.8 kg. Nasopharyngeal airway dead space volume was 1.5-2.0 mL/kg in newborns. A single cannula device produced lower carbon dioxide (CO₂) levels than a dual cannula device (33.7, 31.2, 23.1, 15.9, 10.9 and 6.3 mm Hg vs 36.8, 35.5, 32.1, 26.8, 23.1 and 18.8 mm Hg at flow rates of 1, 2, 3, 4, 6 and 8 L/min, respectively; p<0.0001 at all flow rates). Airway pressure was 1 mm Hg at all flow rates with the single cannula but increased at higher flow rates with the dual cannula.Relative nasopharyngeal airway dead space volume is increased in newborns. In 3D-printed airway models, a single cannula high flow device produces improved CO₂ washout with lower airway pressure.

Rapid systematic review shows that using a high-flow nasal cannula is inferior to nasal continuous positive airway pressure as first-line support in preterm neonates

AIM

We reviewed using a high-flow nasal cannula (HFNC) as first-line support for preterm neonates with, or at risk of, respiratory distress.

METHODS

This rapid systematic review covered biomedical databases up to June 2017. We included randomised controlled trials (RCTs) published in English. The reference lists of the studies and relevant reviews we included were also screened. We performed the study selection, data extraction, study quality assessment, meta-analysis and quality of evidence assessment following the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

Pooled results from six RCTs covering 1227 neonates showed moderate-quality evidence that HFNC was associated with a higher rate of failure than nasal continuous positive airway pressure (NCPAP) in preterm neonates of at least 28 weeks of gestation, with a risk ratio of 1.57. Low-quality evidence showed no significant differences between HFNC and NCPAP in the need for intubation and bronchopulmonary dysplasia rate. HFNC yielded a lower rate of nasal injury (risk ratio 0.50). When HFNC failed, intubation was avoided in some neonates by switching them to NCPAP.

CONCLUSION

HFNC had higher failure rates than NCPAP when used as first-line support. Subsequently switching to NCPAP sometimes avoided intubation. Data on the most immature neonates were lacking.

High-Flow Nasal Cannula Practice Patterns Reported by Neonatologists and Neonatal Nurse Practitioners in the United States

BACKGROUND

High-flow nasal cannula (HFNC) is widely used to treat neonatal respiratory conditions. Significant evidence emerged in recent years to guide practice, yet current practice patterns and their alignment with the evidence remain unknown.

PURPOSE

To examine current HFNC practice patterns and availability of clinical practice guidelines used in neonatal intensive care units in the United States.

METHODS/ANALYSIS

A nonexperimental, descriptive study was designed using a web-based survey to elicit a convenience sample of US neonatal providers. Quantitative data were analyzed using descriptive statistics, χ tests were used to test for differences among the categories, and post hoc comparisons among each combination of categories were conducted using a Bonferroni-corrected α of .05 to determine significance as appropriate.

RESULTS

A total of 947 responses were analyzed (626 neonatologists and 321 neonatal nurse practitioners). Univariate analyses suggested wide variations in practice patterns. One-third of the respondents used clinical guidelines, the majority utilized HFNC devices in conjunction with nasal continuous positive airway pressure, more than two-thirds used HFNC as a primary respiratory support treatment, and among all respondents, significant differences related to HFNC device types were reported.

IMPLICATIONS FOR PRACTICE

US providers revealed wide practice variations related to HFNC therapy. In addition, type of device used appears to impact practice patterns and approaches. Use of standardized guidelines was reported by one third of the respondents, and as such may be the contributing factor for wide practice variations.

IMPLICATIONS FOR RESEARCH

Future Research is needed to target aspects of practice where practice variations exist, or practice is not supported by evidence. Significant practice differences related to the device types should be considered in future research design.

Nasal high flow treatment in preterm infants

Nasal High Flow (HF) is a mode of ‘non-invasive’ respiratory support for preterm infants, with several potential modes of action, including generation of distending airway pressure, washout of the nasopharyngeal dead space, reduction of work of breathing, and heating and humidification of inspired gas. HF has several potential advantages over continuous positive airway pressure (CPAP), the most commonly applied form of non-invasive support, such as reduced nasal trauma, ease of use, and infant comfort, which has led to its rapid adoption into neonatal care. In recent years, HF has become a well-established and commonly applied treatment in neonatal care.

Recent trials comparing HF and CPAP as primary support have had differing results. Meta-analyses suggest that primary HF results in an increased risk of treatment failure, but that ‘rescue’ CPAP use in those infants with HF failure results in no greater risk of mechanical ventilation. Even in studies with higher rates of HF failure, the majority of infants were successfully treated with HF, and rates of important neonatal morbidities did not differ between treatment groups. Importantly, these studies have included only infants born at ≥28 weeks’ gestational age (GA). The decision whether to apply primary HF will depend on the value placed on its advantages over CPAP by clinicians, the approach to surfactant treatment, and the severity of respiratory disease in the relevant population of preterm infants.

Post-extubation HF use results in similar rates of treatment failure, mechanical ventilation, and adverse events compared to CPAP. Post-extubation HF appears most suited to infants ≥28 weeks; there are few published data for infants below this gestation, and available evidence suggests that these infants are at high risk of HF failure, although rates of intubation and other morbidities are similar to those seen with CPAP. There is no evidence that using HF to ‘wean’ off CPAP allows for respiratory support to be ceased more quickly, but given its advantages it would appear to be a suitable alternative in infants who require ongoing non-invasive support. Safety data from randomised trials are reassuring, although more evidence in extremely preterm infants (<28 weeks’ GA) is required.

A multicentre, randomised controlled, non-inferiority trial, comparing nasal high flow with nasal continuous positive airway pressure as primary support for newborn infants with early respiratory distress born in Australian non-tertiary special care nurseries (the HUNTER trial): study protocol

INTRODUCTION

Nasal high-flow (nHF) therapy is a popular mode of respiratory support for newborn infants. Evidence for nHF use is predominantly from neonatal intensive care units (NICUs). There are no randomised trials of nHF use in non-tertiary special care nurseries (SCNs). We hypothesise that nHF is non-inferior to nasal continuous positive airway pressure (CPAP) as primary support for newborn infants with respiratory distress, in the population cared for in non-tertiary SCNs.

METHODS AND ANALYSIS

The HUNTER trial is an unblinded Australian multicentre, randomised, non-inferiority trial. Infants are eligible if born at a gestational age ≥31 weeks with birth weight ≥1200 g and admitted to a participating non-tertiary SCN, are <24 hours old at randomisation and require non-invasive respiratory support or supplemental oxygen for >1 hour. Infants are randomised to treatment with either nHF or CPAP. The primary outcome is treatment failure within 72 hours of randomisation, as determined by objective oxygenation, apnoea or blood gas criteria or by a clinical decision that urgent intubation and mechanical ventilation, or transfer to a tertiary NICU, is required. Secondary outcomes include incidence of pneumothorax requiring drainage, duration of respiratory support, supplemental oxygen and hospitalisation, costs associated with hospital care, cost-effectiveness, parental stress and satisfaction and nursing workload.

ETHICS AND DISSEMINATION

Multisite ethical approval for the study has been granted by The Royal Children's Hospital, Melbourne, Australia (Trial Reference No. 34222), and by each participating site. The trial is currently recruiting in eight centres in Victoria and New South Wales, Australia, with one previous site no longer recruiting. The trial results will be published in a peer-reviewed journal and will be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614001203640; pre-results.