Review finds insufficient evidence to support the routine use of heated, humidified high-flow nasal cannula use in neonates

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.

[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.

Physiological effects of high-flow nasal cannula therapy in preterm infants

OBJECTIVE

High-flow nasal cannula (HFNC) therapy is increasingly used in preterm infants despite a paucity of physiological studies. We aimed to investigate the effects of HFNC on respiratory physiology.

STUDY DESIGN

A prospective randomised crossover study was performed enrolling clinically stable preterm infants receiving either HFNC or nasal continuous positive airway pressure (nCPAP). Infants in three current weight groups were studied: <1000 g, 1000-1500 g and >1500 g. Infants were randomised to either first receive HFNC flows 8-2 L/min and then nCPAP 6 cm H₂O or nCPAP first and then HFNC flows 8-2 L/min. Nasopharyngeal end-expiratory airway pressure (pEEP), tidal volume, dead space washout by nasopharyngeal end-expiratory CO₂ (pEECO₂), oxygen saturation and vital signs were measured.

RESULTS

A total of 44 preterm infants, birth weights 500-1900 g, were studied. Increasing flows from 2 to 8 L/min significantly increased pEEP (mean 2.3-6.1 cm H₂O) and reduced pEECO₂ (mean 2.3%-0.9%). Tidal volume and transcutaneous CO₂ were unchanged. Significant differences were seen between pEEP generated in open and closed mouth states across all HFNC flows (difference 0.6-2.3 cm H₂O). Infants weighing <1000 g received higher pEEP at the same HFNC flow than infants weighing >1000 g. Variability of pEEP generated at HFNC flows of 6-8 L/min was greater than nCPAP (2.4-13.5 vs 3.5-9.9 cm H₂O).

CONCLUSIONS

HFNC therapy produces clinically significant pEEP with large variability at higher flow rates. Highest pressures were observed in infants weighing <1000 g. Flow, weight and mouth position are all important determinants of pressures generated. Reductions in pEECO₂ support HFNC's role in dead space washout.

The clinical effectiveness and cost-effectiveness of heated humidified high-flow nasal cannula compared with usual care for preterm infants: systematic review and economic evaluation

BACKGROUND

Respiratory problems are one of the most common causes of morbidity in preterm infants and may be treated with several modalities for respiratory support such as nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive-pressure ventilation. The heated humidified high-flow nasal cannula (HHHFNC) is gaining popularity in clinical practice.

OBJECTIVES

To address the clinical effectiveness of HHHFNC compared with usual care for preterm infants we systematically reviewed the evidence of HHHFNC with usual care following ventilation (the primary analysis) and with no prior ventilation (the secondary analysis). The primary outcome was treatment failure defined as the need for reintubation (primary analysis) or intubation (secondary analysis). We also aimed to assess the cost-effectiveness of HHHFNC compared with usual care if evidence permitted.

DATA SOURCES

The following databases were searched: MEDLINE (2000 to 12 January 2015), EMBASE (2000 to 12 January 2015), The Cochrane Library (issue 1, 2015), ISI Web of Science (2000 to 12 January 2015), PubMed (1 March 2014 to 12 January 2015) and seven trial and research registers. Bibliographies of retrieved citations were also examined.

REVIEW METHODS

Two reviewers independently screened all titles and abstracts to identify potentially relevant studies for inclusion in the review. Full-text copies were assessed independently. Data were extracted and assessed for risk of bias. Summary statistics were extracted for each outcome and, when possible, data were pooled. A meta-analysis was only conducted for the primary analysis, using fixed-effects models. An economic evaluation was planned.

RESULTS

Clinical evidence was derived from seven randomised controlled trials (RCTs): four RCTs for the primary analysis and three RCTs for the secondary analysis. Meta-analysis found that only for nasal trauma leading to a change of treatment was there a statistically significant difference, favouring HHHFNC over NCPAP [risk ratio (RR) 0.21, 95% confidence interval (CI) 0.10 to 0.42]. For the following outcomes, there were no statistically significant differences between arms: treatment failure (reintubation < 7 days; RR 0.76, 95% CI 0.54 to 1.09), bronchopulmonary dysplasia (RR 0.92, 95% CI 0.72 to 1.17), death (RR 0.56, 95% CI 0.22 to 1.44), pneumothorax (RR 0.33, 95% CI 0.03 to 3.12), intraventricular haemorrhage (grade ≥ 3; RR 0.41, 95% CI 0.15 to 1.15), necrotising enterocolitis (RR 0.41, 95% CI 0.15 to 1.14), apnoea (RR 1.08, 95% CI 0.74 to 1.57) and acidosis (RR 1.16, 95% CI 0.38 to 3.58). With no evidence to support the superiority of HHHFNC over NCPAP, a cost-minimisation analysis was undertaken, the results suggesting HHHFNC to be less costly than NCPAP. However, this finding is sensitive to the lifespan of equipment and the cost differential of consumables.

LIMITATIONS

There is a lack of published RCTs of relatively large-sized populations comparing HHHFNC with usual care; this is particularly true for preterm infants who had received no prior ventilation.

CONCLUSIONS

There is a lack of convincing evidence suggesting that HHHFNC is superior or inferior to usual care, in particular NCPAP. There is also uncertainty regarding whether or not HHHFNC can be considered cost-effective. Further evidence comparing HHHFNC with usual care is required.

STUDY REGISTRATION

This review is registered as PROSPERO CRD42015015978.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Nasal injury in preterm infants receiving non-invasive respiratory support: a systematic review

OBJECTIVE

Binasal prongs are the most commonly used interface for the delivery of nasal positive airway pressure (CPAP) to preterm infants. However, they are associated with pressure-related nasal injury, which causes pain and discomfort. Nasal injury may necessitate a change in interface and occasionally damage is severe enough to require surgical repair. We aim to determine the incidence and risk factors for nasal injury in preterm infants, and to provide clinicians with strategies to effectively prevent and treat it.

DESIGN

We conducted a systematic search of databases including MEDLINE (PubMed including the Cochrane Library), EMBASE, CINAHL and Scopus. Included studies enrolled human preterm infants and were published prior to 20 February 2017.

RESULTS

Forty-five studies were identified, including 14 ra ndomised controlled trials, 10 observational studies, two cohort studies, eight case reports and 11 reviews. The incidence of nasal injury in preterm infants ranged from 20-100%. Infants born <30 weeks' gestation are at highest risk. Strategies shown to reduce nasal injury included: nasal barrier dressings (2 studies, n=244, risk ratio (RD) -0.12, 95%, CI - 0.20 to -0.04), nasal high flow therapy as an alternative to binasal prong CPAP (7 studies, n=1570, risk difference (RD) -0.14, 95% CI -0.17 to -0.10), and nasal masks rather than binasal prongs (5 studies, n=544, RR 0.80, 95% CI 0.64 to 1.00).

CONCLUSIONS AND RELEVANCE

Nasal injury is common in preterm infants born <30 weeks' gestational age receiving CPAP via binasal prongs. Larger randomised trials are required to fully evaluate strategies to reduce nasal injury.

The Role of Heated Humidified High-flow Nasal Cannula as Noninvasive Respiratory Support in Neonates

Recently, heated humidified high-flow nasal cannula (HHHFNC) has been introduced and applied as a noninvasive respiratory support in neonates. Although HHHFNC is widely used in neonates presenting with respiratory distress, the efficiency and safety when compared with nasal continuous positive airway pressure or noninvasive positive pressure ventilation are still controversial. This review aims to evaluate the performance and applications of HHHFNC in neonates.

Non-invasive respiratory support for infants with bronchiolitis: a national survey of practice

Background

Bronchiolitis is a common respiratory illness of early childhood. For most children it is a mild self-limiting disease but a small number of children develop respiratory failure. Nasal continuous positive airway pressure (nCPAP) has traditionally been used to provide non-invasive respiratory support in these children, but there is little clinical trial evidence to support its use. More recently, high-flow nasal cannula therapy (HFNC) has emerged as a novel respiratory support modality. Our study aims to describe current national practice and clinician preferences relating to use of non-invasive respiratory support (nCPAP and HFNC) in the management of infants (<12 months old) with acute bronchiolitis.

Methods

We performed a cross-sectional web-based survey of hospitals with inpatient paediatric facilities in England and Wales. Responses were elicited from one senior doctor and one senior nurse at each hospital. We analysed the proportion of hospitals using HFNC and nCPAP; clinical thresholds for their initiation; and clinician preferences regarding first-line support modality and future research.

Results

The survey was distributed to 117 of 171 eligible hospitals; 97 hospitals provided responses (response rate: 83%). The majority of hospitals were able to provide nCPAP (89/97, 91.7%) or HFNC (71/97, 73.2%); both were available at 65 hospitals (67%). nCPAP was more likely to be delivered in a ward setting in a general hospital, and in a high dependency setting in a tertiary centre. There were differences in the oxygenation and acidosis thresholds, and clinical triggers such as recurrent apnoeas or work of breathing that influenced clinical decisions, regarding when to start nCPAP or HFNC. More individual respondents with access to both modalities (74/106, 69.8%) would choose HFNC over nCPAP as their first-line treatment option in a deteriorating child with bronchiolitis.

Conclusions

Despite lack of randomised trial evidence, nCPAP and HFNC are commonly used in British hospitals to support infants with acute bronchiolitis. HFNC appears to be currently the preferred first-line modality for non-invasive respiratory support due to perceived ease of use.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0785-0) contains supplementary material, which is available to authorized users.

Key paediatric messages from the 2016 European Respiratory Society International Congress

In this article, the Group Chairs of the Paediatric Assembly of the European Respiratory Society (ERS) highlight some of the most interesting abstracts presented at the 2016 ERS International Congress, which was held in London.

Safety and Efficacy of High-Flow Nasal Cannula Therapy in Preterm Infants: A Meta-analysis

BACKGROUND AND OBJECTIVE

High-flow therapy is the most recent, and popular, mode of respiratory support in neonates. However, the evidence supporting its efficacy and safety has not yet been established. We conducted a systematic review and meta-analysis of clinical trials comparing efficacy and safety of high-flow therapy compared with other modes of noninvasive ventilation (NIV) in preterm infants.

METHODS

Articles were indexed by using Medline, Embase, Scopus, OpenSIGLE, Health Management Information Consortium, and Cochrane Central Register of Controlled Trials. Randomized or quasi-randomized clinical trials involving preterm infants, comparing high-flow therapy with other modes of NIV, and reporting extractable data on relevant outcomes, were selected. Data on efficacy, safety, and other common neonatal outcomes were extracted on predesigned forms.

RESULTS

In this analysis, we included 1112 preterm infants, participating in 9 clinical trials. High-flow therapy was similar in efficacy to other modes of NIV in preterm infants when used as primary support (odds ratio of failure of therapy, 1.02 [95% confidence interval: 0.55 to 1.88]), as well as after extubation (1.09 [0.58 to 2.02]). There were no significant differences in odds of death (0.48 [0.18 to 1.24]) between the groups. Preterm infants supported on high-flow had significantly lower odds of nasal trauma (0.13 [0.02 to 0.69]).

CONCLUSIONS

High-flow therapy appears to be similar in efficacy and safety to other conventional modes of NIV in preterm infants. It is associated with significantly lower odds of nasal trauma. Caution needs to be exercised in extreme preterm infants because of the paucity of published data.

Assessment of pain during application of nasal-continuous positive airway pressure and heated, humidified high-flow nasal cannulae in preterm infants

OBJECTIVE

To assess pain and compare its severity in preterm infants during application of nasal-continuous positive airway pressure (nCPAP) and heated, humidified high-flow nasal cannulae (HHHFNC).

STUDY DESIGN

An observational cross-sectional study. Sixty preterm infants, categorized into nCPAP (n=37) and HHHFNC groups (n=23). Pain response was assessed using Premature Infant Pain Profile (PIPP), duration of first cry and salivary-cortisol concentrations.

RESULT

The PIPP scores were significantly higher in the nCPAP compared with HHHFNC group (10 (7-12) vs 4 (2-6), P<0.01). None of the infants in the HHHFNC group had severe pain defined as a PIPP score >12, compared with 5 (13.5%) infants in the nCPAP group. Salivary-cortisol concentrations were significantly higher in nCPAP group compared with the HHHFNC group (5.0 (3.6-5.9) vs 1.6 (1.0-2.3) nmol l(-1), P<0.01). A lower incidence of cry was observed for infants in the HHHFNC group compared with the nCPAP group (11 (47.8%) vs 30 (81.1%), P<0.001), however, the duration of first cry was not significantly different between groups. The respiratory rate was significantly lower after application of HHHFNC compared with nCPAP (P<0.001). There were no significant differences between groups with regard to fraction of inspired oxygen (FiO2), oxygen saturation by pulse oximeter (SpO2) and heart rate.

CONCLUSION

The application of HHHFNC in preterm infants is associated with less pain compared with nCPAP, as it is associated with less PIPP scores and lower salivary-cortisol concentrations.

Neonatal ventilation strategies and long-term respiratory outcomes

Long-term respiratory morbidity is common, particularly in those born very prematurely and who have developed bronchopulmonary dysplasia (BPD), but it does occur in those without BPD and in infants born at term. A variety of neonatal strategies have been developed, all with short-term advantages, but meta-analyses of randomized controlled trials (RCTs) have demonstrated that only volume-targeted ventilation and prophylactic high-frequency oscillatory ventilation (HFOV) may reduce BPD. Few RCTs have incorporated long-term follow-up, but one has demonstrated that prophylactic HFOV improves respiratory and functional outcomes at school age, despite not reducing BPD. Results from other neonatal interventions have demonstrated that any impact on BPD may not translate into changes in long-term outcomes. All future neonatal ventilation RCTs should have long-term outcomes rather than BPD as their primary outcome if they are to impact on clinical practice.