High-flow nasal cannulae and nasal continuous positive airway pressure use in non-tertiary special care nurseries in Australia and New Zealand

Authors

  • Brett J Manley,

    Corresponding author
    1. Department of Newborn Research, The Royal Women's Hospital
    2. Department of Obstetrics and Gynaecology, The University of Melbourne
    3. Murdoch Childrens Research Institute
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  • Louise Owen,

    1. Department of Newborn Research, The Royal Women's Hospital
    2. Murdoch Childrens Research Institute
    3. Faculty of Medicine and Dentistry, The University of Bristol, Bristol, United Kingdom
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  • Lex W Doyle,

    1. Department of Obstetrics and Gynaecology, The University of Melbourne
    2. Research Office, The Royal Women's Hospital
    3. Department of Paediatrics, The University of Melbourne, Melbourne, Victoria, Australia
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  • Peter G Davis

    1. Department of Newborn Research, The Royal Women's Hospital
    2. Department of Obstetrics and Gynaecology, The University of Melbourne
    3. Murdoch Childrens Research Institute
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  • Conflict of interest: None declared.

Dr Brett Manley, Department of Newborn Research, The Royal Women's Hospital, 20 Flemington Road, Parkville, Vic. 3052, Australia. Fax: +613 8345 3789; email: brett.manley@thewomens.org.au

Abstract

Aim:  Non-tertiary centres (NTCs) in Australia and New Zealand are increasingly providing non-invasive respiratory support, including high-flow nasal cannulae (HFNC) and nasal continuous positive airway pressure (nCPAP), to newborn infants. We aimed to determine the proportion of NTCs in these countries treating newborn infants with HFNC and nCPAP, and how these therapies are used.

Methods:  We surveyed public and private NTCs in Australia and public NTCs in New Zealand. The survey, directed at senior medical and nursing staff, consisted of questions regarding unit demographics, HFNC and nCPAP use.

Results:  One hundred seventeen responses were received regarding HFNC use, from 88% (80/91) of public hospitals and 64% (37/58) of private hospitals surveyed. Ten (8.5%) responders (nine public and one private) used HFNC; all used the Fisher & Paykel system. HFNC was used for respiratory distress syndrome from birth (9/10 units), as a weaning mode from nCPAP (5/10 units) and as treatment for apnoea (3/10 units). Flow rates used ranged from 1 to 8 L/min, with typical minimum flow of 1 L/min and maximum of 4–6 L/min. The main perceived advantage of HFNC was ‘ease of use’. In the units treating newborn infants with nCPAP, it was used either in an ongoing fashion (43 units), short term or episodically (four units), or only for stabilisation prior to transfer (11 units). Excluding those units using nCPAP only for stabilisation and non-responders, 47/108 (44%) units were using nCPAP.

Conclusions:  HFNC is being used in NTCs in Australia and New Zealand, and the use of nCPAP has increased over time.

Newborn infants with respiratory distress who are cared for in non-tertiary centres (NTCs) receive supportive measures such as supplemental oxygen, intravenous fluids and antibiotics. Oxygen may be administered directly into the cot, into a ‘head box’ or via small nasal prongs. If the infant requires additional respiratory support, then transfer to a tertiary neonatal intensive care unit (NICU) is often required. Transfer of newborn infants carries not only a financial cost but also an emotional cost and is not without risk to the infant. The 2005 Australian and New Zealand Neonatal Network (ANZNN) report1 indicated that 25.5% (1942 infants) of level III registrants were born in a NTC and then transferred to a NICU.

NTCs around Australia and New Zealand are increasingly providing higher levels of respiratory support, including nasal continuous positive airway pressure (nCPAP). A randomised, controlled trial by Buckmaster et al.2 of Hudson prong nCPAP versus head-box oxygen in Australian NTCs showed that nCPAP reduces the need for transfer of newborn infants with respiratory distress from these units to a tertiary centre. However, the effective administration of nCPAP requires maintenance of a high level of medical and nursing expertise. Difficulties with the administration of nCPAP include the need for bulky fixation devices, infant positioning issues and the potential to cause nasal septal trauma. Despite these problems, 17% of Australian NTCs surveyed in 2004 were using nCPAP to treat newborn infants.3

The development of humidified, heated, high-flow nasal cannulae (HFNC) systems, such as the Fisher & Paykel Optiflow system (Fisher & Paykel Healthcare, Auckland, New Zealand) or the Vapotherm 2000i (Vapotherm, Stevensville, MD, USA), may provide a safe and effective alternative to nCPAP in the newborn infant, and these are gaining popularity in NICUs in Australia and around the world.4 When these systems are used in tertiary centres, oxygen or air is delivered via small calibre nasal prongs at flow rates greater than 1 L/min,5 typically up to a maximum of 6–8 L/min.

The aim of our survey was to determine the proportion of NTCs in Australia and New Zealand using HFNC and nCPAP to treat newborn infants, and the manner in which they are used.

What is already known on this topic

  • 1Nasal continuous positive airway pressure (nCPAP) is in use in some non-tertiary centres (NTCs) in Australia and New Zealand, and is known to reduce the need for transfer of newborn infants with early respiratory distress to a tertiary unit.
  • 2Humidified, heated, high-flow nasal cannulae (HFNC) systems are gaining popularity in tertiary units around the world and may represent an alternative to nCPAP.
  • 3There is a paucity of evidence for the safety and efficacy of HFNC compared with nCPAP in newborn infants.

What this paper adds

  • 1Despite a lack of guidelines for its use, HFNC is being used in NTCs in Australia and New Zealand, and is perceived as easy to administer and comfortable for infants.
  • 2HFNC flow rates used in NTCs are in the range of 1–8 L/min, and HFNC is used to treat early respiratory distress, apnoea and as a weaning mode from nCPAP.
  • 3The use of nCPAP to treat newborn infants in Australian and New Zealand NTCs has greatly increased in the last 6 years.

Methods

We surveyed 149 eligible public and private NTCs in Australia and public NTCs in New Zealand via an electronic survey (http://SurveyMonkey.com, LLC Copyright © 2010). The survey questions and choice of responses are shown in Appendix I. The first surveys were distributed in April, 2010, and the last responses received in August, 2010. Public units were selected on the basis that they were ‘non-tertiary’ but still staffed by specialist paediatricians (equivalent to a ‘level 2’ nursery in Victoria, Australia). Australian private hospitals were also surveyed, in the knowledge that they are not classified equivalently but are staffed by experienced paediatricians who may be comfortable using non-invasive respiratory support to treat newborn infants. A database of eligible NTCs was compiled from multiple sources, including the local neonatal transport services and the ANZNN report, 2005.1

An emailed invitation with a link to the survey was sent to a senior nurse and/or a senior paediatrician working in the nursery at each centre. The survey consisted of questions regarding demographic information and the use of HFNC and nCPAP. If respondents stated that they used HFNC for respiratory support in newborn infants, they were asked to answer a series of questions pertaining to its use, including in which clinical scenarios it was used, the flow rates commonly employed, the gestational age of infants treated and any complications experienced while using HFNC. All respondents were asked about their perceptions of HFNC, even if HFNC was not currently in use on their unit. If no response was received within 2–3 weeks, a reminder email was sent. Hard copies of the survey were mailed or faxed to the NTC if requested. If more than one response was received from a unit, the results were compared and any differences resolved in a telephone interview or email with the respondents; only one composite response is presented from these centres. The survey did not examine the use of HFNC in older infants or children, for example to treat bronchiolitis on the paediatric ward. Follow-up emails were sent to the NTCs who stated that they used nCPAP to treat newborn infants to clarify how it was being used.

Results

HFNC use

Responses (total of 117) were received from each Australian state and territory and from New Zealand. Table 1 details the number of responders and total number of surveys sent to each region, both for public and private NTCs. The response rate regarding HFNC use was 88% (80/91) for public hospitals and 64% (37/58) for private hospitals. Not all online surveys were complete, and six units replied by email only to confirm that they did not use HFNC; however, all did not respond regarding CPAP use.

Table 1.  Type, number and percentage of responses from New Zealand and each Australian state and territory regarding the use of high-flow nasal cannulae
RegionTypeResponses/requests, no. (%)
  1. N/A, not applicable.

New ZealandPublic14/15 (93)
VictoriaPublic19/19 (100)
Private15/17 (88)
New South WalesPublic21/27 (78)
Private10/17 (59)
QueenslandPublic14/14 (100)
Private7/12 (58)
Western AustraliaPublic7/11 (64)
Private0/6 (0)
TasmaniaPublic2/2 (100)
Private2/2 (100)
South AustraliaPublic1/1 (100)
Private3/3 (100)
Australian Capital TerritoryPublic1/1 (100)
Private0/1 (0)
Northern TerritoryPublic1/1 (100)
PrivateN/A
OverallPublic80/91 (88)
Private37/58 (64)

Ten NTCs (8.5% of total respondents regarding HFNC use), based in Victoria, New South Wales, Tasmania or New Zealand, stated that they use HFNC in the care of newborn infants (Table 2). Of these, nine are public hospitals and one is a private hospital. These units ranged between one to five beds and 16–20 beds in capacity. All 10 units used the Fisher & Paykel circuit to deliver HFNC; none used the Vapotherm circuit. The duration of HFNC use on the units varied from less than 1 year to greater than 4 years.

Table 2.  Non-tertiary centres using high-flow nasal cannulae to treat newborn infants
 Type of hospitalLocationCapacity (no. of beds)Years of useRange of flow rates used (L/min)Also use CPAP for ‘ongoing care’?
  1. CPAP, continuous positive airway pressure; NSW, New South Wales.

 1PublicVictoria6–101–21–4No
 2PublicVictoria1–52–32–7Yes
 3PublicNSW6–10<11–4No
 4PublicNSW1–5<11–8No
 5PublicTasmaniaUnclear<11–6Yes
 6PrivateTasmania1–53–41–6Yes
 7PublicNew Zealand16–20<12–8Yes
 8PublicNew Zealand11–151–2(Lowest flow rate to maintain SpO2 > 95%)–6Yes
 9PublicNew Zealand11–15>41–(No maximum flow rate specified)Yes
10PublicNew Zealand11–15<11–6Yes

In these 10 units, HFNC is used for the following clinical scenarios: respiratory distress syndrome from birth (9/10 units), as a weaning mode from nCPAP therapy (5/10 units) and for treatment of apnoea (3/10 units). Only one unit stated that they used HFNC as post-extubation support, likely indicating that infants were not ventilated on these units in an ongoing fashion. Flow rates used were in the range of 1–8 L/min, with typical minimum flow rate of 1 L/min and maximum flow rates of 4–6 L/min. HFNC was used on infants of ‘any gestation’ at 3/10 units and on term infants only at 2/10; >32 weeks gestation at 2/10; and >28, >30 and >34 weeks gestation at the other units. Of the 10 units using HFNC, seven stated that they also used nCPAP on their unit to treat newborn infants. With regards to complications from HFNC experienced in these units, problems with condensation in the circuit had occurred in three units, treatment failure in three units, nasal trauma in one unit and infant pain or discomfort in one unit. No units had experienced any pneumothoraces or complications from incorrect prong selection or equipment failure.

nCPAP use

By comparison, of those hospitals that responded to the question regarding nCPAP use, 52/73 (71%) public hospital and 12/35 (34%) private hospital units (overall 59%) stated that they use nCPAP to treat newborn infants. Of note, all 13 respondents from public New Zealand units stated that they used nCPAP to treat newborn infants, as 13/14 units in Queensland and 13/17 units in Victoria did. Additionally, 8/10 private Queensland NTCs stated that nCPAP was used. As this result was higher than expected, a follow-up email was sent to each unit using CPAP to try to clarify how it was being used. This email was not sent to five NTCs in Victoria, where the use of nCPAP to treat newborn infants in an ongoing fashion was well known to the authors (these centres are included in the data later).

Responses were received to the follow-up nCPAP email from 58/64 units, 47/52 public and 11/12 private. Responses fell into three distinct groups: nCPAP used to treat infants in an ongoing fashion (43/58 units); nCPAP used short term (e.g. 24–72 h) or used episodically depending on staff resources (4/58 units); and nCPAP only used for stabilisation prior to transfer (11/58 units). If the NTCs using nCPAP only for stabilisation and non-responders to the follow-up email are defined as not using nCPAP, this produces an overall total of 47/108 (approximately 44%) units, 39/73 (53%) public NTCs and 8/35 (23%) private NTCs.

Perceptions of HFNC

Ease of use for staff and improved comfort for infants with HFNC were the most common responses. Comments included ‘easier for staff to manage (who) are not dealing with CPAP regularly’, ‘easy nursing care’, ‘easier to set up and nurse’, ‘sounds easy to do’ and ‘no real training required on set up compared with CPAP’. Respondents also felt that HFNC provided positioning, mobility and comfort benefits to the infant: ‘more settled (infants)’, ‘better tolerated interface’, ‘babies less traumatized’, ‘easier to position’, ‘(better) parental access to baby’, ‘easier handling of the baby’, ‘less threatening to parents’ and ‘assists. . . mum to breast feed’. There was also the perception that HFNC would result in fewer complications (‘less nasal trauma’ and ‘may be fewer pneumothoraces’) and that HFNC would be cheaper than CPAP. One respondent suggested that HFNC could ‘(keep babies) in a (NTC) if the unit doesn't (normally) keep CPAP babies’.

Respondents were also asked their opinion on what questions remained to be answered about HFNC use in newborn infants. Despite the overwhelmingly positive assessment of HFNC as outlined earlier, many hospitals also had concerns about the lack of evidence around HFNC use in newborn infants. These included: ‘does it carry the same risks (as CPAP)?’, ‘does (using) it require 24-h registrar cover?’, ‘does it replace the use of CPAP?’, ‘how much pressure is generated?’, ‘does it improve work of breathing?’, ‘effects on gut distension (or) feed intolerance’, ‘whether it has any role in (NTCs) at all?’, ‘lack of clearly demonstrated efficacy compared with nCPAP’, ‘what level of medical and nursing experience would be needed on site?’, ‘need larger studies on outcomes’, ‘whether it can be used to stabilise term babies with respiratory distress in place of head-box or CPAP’ and ‘worry that the babies on HFNC will stay in the (NTC) and not be transferred to (a tertiary centre) at the appropriate time’. Concerns that were specifically related to private hospitals included: ‘not (having) a neonatal registrar, which means that the nursing staff are reliant on calling in a consultant for referral’, and ‘nursing staff do not do arterial blood gases in our unit’.

Several units stated that they were considering introducing HFNC after information sessions from the manufacturers, and several requested a protocol for the safe introduction of HFNC to their units. There was considerable interest in being involved in research into the use of HFNC in NTCs; none of the responders were currently involved in such research.

Discussion

Non-invasive respiratory support has become widely used in tertiary neonatal centres around the world. Humidified, heated, HFNC represents a possible alternative to nCPAP that is gaining popularity in these same centres due to its perceived ease of use.

The results of this study demonstrate that HFNC is being used in NTCs in Australia and New Zealand, albeit in only 9/80 (11%) public hospital responders and one private hospital. This is despite a lack of published clinical research into the use of HFNC in newborn infants, although there are several NICU trials currently underway in Australia (including in our unit) and internationally comparing HFNC with CPAP as post-extubation support for premature infants or as early therapy for respiratory distress or apnoea. While some evidence exists as to the in vivo pressures generated by HFNC,6–10 further data are still required on pressure generation at different flow rates.

The potential advantages of the introduction of HFNC into selected NTCs might include a reduction in need for transfer of newborn infants to tertiary units, thus keeping babies and parents together. Anecdotally, HFNC has been easy to administer for NICU nursing staff and has been well liked. The barriers to the use of HFNC in NTCs include lack of experience and specialist neonatologist support, and the training of both medical and nursing staff that is required. The responses from NTCs regarding their perceptions of HFNC use in newborn infants were generally very positive, however some responses were concerning. For example when compared with nCPAP, there is minimal evidence that HFNC can reduce the incidence of pneumothoraces or nasal trauma, and it is difficult to say whether HFNC is as efficacious as nCPAP based on the available literature. The perception that less nursing expertise or training is required for the safe use of HFNC is also interesting, as local experience indicates that nursing expertise is critical to achieve effective HFNC therapy.

nCPAP has been much more rigorously studied than HFNC and is known to reduce the risk of death or need for assisted ventilation in preterm infants11 and to prevent the need for re-intubation after extubation of newborn infants.12 It was interesting to note the large proportion of NTCs using nCPAP to treat newborn infants: at least 11/15 New Zealand public hospital units and 11/14 Queensland public units surveyed use nCPAP. If a conservative estimate is taken, at least 44% of all NTCs who responded are using nCPAP to treat newborn infants and 36/94 (38%) of Australian units. This proportion is still 32% (47/149 units), even when all non-responders are presumed to not use CPAP. This is a notable increase from the 17% found in a previous survey by Buckmaster et al. in 2004,3 when 24/143 (17%) Australian respondents were using nCPAP and a further 38% were considering its use. Buckmaster et al. did not distinguish between nCPAP used only as a temporary measure prior to up-transfer of the infant and nCPAP used in an ongoing fashion, and thus may have overestimated the proportion of units willing to provide ongoing care to infants requiring nCPAP.

Our results demonstrate the rapid rate of uptake of non-invasive forms of respiratory support for newborn infants and a desire to keep babies in their hospital of birth. Further research is needed before HFNC therapy for newborn infants can be safely recommended, and HFNC use in NTCs should perhaps be restricted to participation in a clinical trial at this time. Such a trial would need to include extensive medical and nursing education prior to implementation, and strict inclusion and failure criteria so that retrieval and transfer to a tertiary centre are expedited in unstable infants. The selection of NTCs to be involved in a HFNC trial should maximise recruitment based on the patient population and birth rate to ensure timely completion, and aim to answer the question of whether HFNC use in NTCs reduces the need for transfer of infants to a tertiary care centre.

Appendix

Appendix I

List of survey questions and possible responses, as sent to Australian non-tertiary centres

Demographics

This page asks for some information about your unit:

  • 1Which state or territory is your unit located in? (only one response possible)
    • Victoria

    • New South Wales

    • Queensland

    • Tasmania

    • Western Australia

    • South Australia

    • Northern Territory

    • Australian Capital Territory

  • 2Please enter the name of your hospital/unit below: (free text)
  • 3Please enter the name of the town/city your unit is located in: (free text)
  • 4Is your unit predominantly public or private? (only one response possible)
  • 5What is the maximum bed capacity of your unit? (only one response possible)
    • 1–5

    • 6–10

    • 11–15

    • 16–20

    • >20

  • 6What is the lowest CORRECTED age of infants admitted to your unit for ongoing care? (only one response possible)
    • No lower limit

    • 30 weeks

    • 32 weeks

    • 34 weeks

    • 36 weeks

    • Other (please specify) (free text)

  • 7What is the lowest weight of infants admitted to your unit for ongoing care? (only one response possible)
    • No lower limit

    • 1.5 kg

    • 2 kg

    • 2.5 kg

    • Other (please specify) (free text)

Survey questions
  • 1Nasal continuous positive airway pressure (nCPAP) is defined as the use of nasal prongs or mask to deliver a set pressure via a closed ventilator CPAP circuit or a ‘bubble’ circuit. Does your unit use nCPAP to treat newborn babies or infants? (only one response possible)
    • YES

    • NO

  • 2Low-flow nasal cannulae (LFNC) are defined as a flow rate < 1 L/min of blended or unblended air/oxygen delivered via nasal cannulae which may be heated and/or humidified. Does your unit use LFNC to treat newborn babies or infants? (only one response possible)
    • YES

    • NO

  • 3At what flow rate (mL/min) do you routinely humidify gas being delivered to newborn babies or infants? (only one response possible)
    • We do not humidify at all

    • >100 mL/min

    • >200 mL/min

    • >300 mL/min

    • >500 mL/min

    • >1000 mL/min

    • We always humidify

    • Other (please specify) (free text)

  • 4High-flow nasal cannulae (HFNC) are defined as a gas (air/oxygen) flow rate of ≥1 L/min, delivered via nasal prongs, which may or may not be heated and humidified. Do you use HFNC to treat newborn babies or infants on your unit? (only one response possible)
    • YES (If YES, please answer all questions)

    • NO (If NO, please skip to Question 16)

  • 5Which brand of circuit/system do you use to deliver HFNC? (Check all that apply) (only one response possible)
    • Fisher & Paykel

    • Vapotherm

    • Other (please specify) (free text)

  • 6How long has your unit been using HFNC to treat newborn babies or infants? (only one response possible)
    • Less than 1 year

    • 1–2 years

    • 2–3 years

    • 3–4 years

    • >4 years

  • 7Why did your unit start using HFNC to treat newborn babies and infants? (free text)
  • 8For which disease processes/situations is HFNC used in the treatment of newborn babies or infants on your unit? (Check all that apply) (multiple responses possible)
    • Respiratory distress from birth

    • Apnoea

    • As a ‘step-down’ therapy from nCPAP

    • As post-extubation respiratory support

    • Other (please specify) (free text)

  • 9What is the HIGHEST flow rate you use with HFNC in newborn babies or infants? (only one response possible)
    • 4 L/min

    • 5 L/min

    • 6 L/min

    • 8 L/min

    • Other (please specify) (free text)

  • 10What is the LOWEST flow rate you would use with HFNC before trying the infant in air or on LFNC? (only one response possible)
    • 1 L/min

    • 2 L/min

    • 3 L/min

    • Other (please specify) (free text)

  • 11What is the lowest gestational age (at birth) of infant that you would consider treating with HFNC on your unit? (only one response possible)
    • Any gestation

    • 28 weeks

    • 32 weeks

    • Term

    • Other (please specify) (free text)

  • 12What is the lowest CORRECTED age of infant you would consider treating with HFNC on your unit? (only one response possible)
    • Any corrected age

    • 32 weeks

    • 36 weeks

    • Term

    • Other (please specify) (free text)

  • 13What is the lowest current weight of infant you would consider treating with HFNC? (only one response possible)
    • Any weight

    • 1.5 kg

    • 2 kg

    • 2.5 kg

    • Other (please specify) (free text)

  • 14What problems with HFNC have you encountered on your unit? (If none, leave response blank) (multiple responses possible)
    • Problems with condensation in the circuit

    • Pneumothoraces/air leaks

    • Treatment failure

    • Equipment failure

    • Prong selection

    • Nasal skin/mucosal trauma

    • Infant pain/discomfort

  • 15Do you include infants being treated with HFNC as requiring ‘respiratory support’ for bed status/audit purposes? (only one response possible)
    • YES

    • NO

    • Don't know

    • If YES, what flow rate is considered ‘respiratory support’? (free text)

  • 16In your opinion, what advantages does HFNC provide over nCPAP in the treatment of newborn babies or infants? (If any) (free text response)
  • 17In your opinion, what questions about HFNC use in newborn babies and infants remain unanswered? (free text response)
  • 18Is your unit currently involved in clinical or benchtop research into HFNC use in infants?
    • YES

    • NO

  • 19Would your unit consider joining clinical trials of HFNC use in newborn babies or infants?
    • YES

    • NO

Thank you for taking the time to complete this survey. Your assistance is much appreciated.

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