Comparing Nasal High-Flow Therapy to Nasal Continuous Positive Airway Pressure during Neonatal Transport

Submitted by: Alishia Campbell, BSc. SRT, Conestoga College

Respiratory Therapists are involved in patient care while transferring patients from one hospital to another (Kiss, Bolke & Spieth, 2017). It has become increasingly important to ensure safe and effective transport of patients, as hospitals trend toward offering specialized services and the demand for complex medicine increases (Kiss et al., 2017). In the neonatal population, there is little but growing research exploring non-invasive ventilation (NIV) methods, specifically nasal high-flow therapy (nHFT) (Muniyappa, Honey & Yoder, 2019). Non-invasive ventilation methods are preferable to health care providers while treating neonatal patients as they reduce the risk of lung injury, and in the case of nasal high flow therapy (nHFT), potentially decreases patient discomfort (Muniyappa et al., 2019). During neonatal patient transport, nasal continuous positive airway pressure (nCPAP) has been proven safe and effective, and thus is the most used method of providing ventilatory support of patients (Muniyappa et al., 2019). Select studies aim to determine the efficacy of nHFT during neonatal patient transport, while further studies explore the use of nHFT and prevention of adverse outcomes.

Comparing Nasal High-Flow Therapy to Nasal Continuous Airway Pressure

In the neonatal population, there is concern over injury to the lungs during invasive ventilation methods (Yoder, Stoddart, Li, King, Dirnberger & Abbasi, 2013). In the neonatal intensive care unit (NICU) healthcare providers prefer to use non-invasive respiratory supports to prevent damage to patients’ lungs (Yoder et al., 2013). Invasive methods can result in vascular destruction and may impair the gas exchange in the lungs, as well as lead to inflammatory effects (Behnke, Lemyre, Czernik, Zimmer, Erhardt & Waitz, 2019). Nasal CPAP devices deliver constant positive pressure to the lungs non-invasively using an interface fixated nasally; the positive pressure can better facilitate gas exchange and prevent potential lung collapse (Behnke et al., 2019).  There are challenges associated with using nCPAP, including difficulty with positioning and fixating the device on the patient, skin breakdown and/or nasal trauma, and agitation (Yoder et al., 2013). This has led to the increased use of nHFT as a method of respiratory support (Yoder et al., 2013). Nasal high flow therapy can be defined as high flow nasal cannula therapy that exceeds standard flow rates of 1- 2 L/min for neonatal patients (McQueen, Rojas, Sun, Tero, et al., 2014).  Gases are heated, humidified and administered through a thin tapered cannula that sits at the nasal aperture of the patient (Boyle, Dhar, Chaudhary, Kent, et al., 2016). It is important that the gases being delivered via nHFT are adequately heated and humidified, as studies comparing nHFT that was not heated or humidified to nCPAP found nHFT to be inferior (Yoder et al., 2013).

Why Look for Alternatives?

Respiratory Therapists are presented with a dynamic and changing environment when transporting a patient, as lung mechanics and gas exchange may be affected by acceleration of the vehicle, vibration and temperature variance (Boyle et al., 2016). Emerging studies are aiming to identify successful alternative methods of NIV during neonatal patient transport, to provide the respiratory therapist with more treatment options while reducing patient discomfort that accompanies current NIV methods (Tauzin & Durrmeyer, 2019). As previously mentioned, there are some challenges when using nCPAP including nasal trauma and agitation, resulting in patient discomfort (Muniyappa et al., 2019). It is important to ensure patient comfort, as this allows the patient to better tolerate treatment, and in the case of neonatal patients, to facilitate development (Tauzin & Durrmeyer, 2019). Discomfort can be assessed using visual cues and pain scores.  To quantify the pain score in neonates, studies have used the “EDIN pain score” or the “premature infant pain profile (PIPP)” (Tauzin & Durrmeyer, 2019, p. 2). A study using both EDIN and PIPP found no significant difference using the EDIN score between neonates being treated with nCPAP vs. heated, humidified nHFT; however, using the PIPP score there was a significant difference in favour of nHFT noted (Tauzin & Durrmeyer, 2019).

Success of Neonatal Transport Using Nasal High-Flow Therapy

Despite limited research, there have been a few studies that have found success with transporting neonatal patients using nHFT. A study by Muniyappa and colleagues (2019) reviewing neonatal transport using heated, humidified nHFT, included all participants regardless of gestational age, birthweight, weight during transfer, and diagnosis.  Patients were not included in the study if they had a current apnea, abdominal distension, diaphragmatic hernia or required intubation before transport (Muniyappa et al., 2019). These patients either had no or mild respiratory distress while on a nasal cannula between 1 L/min and 6 L/min, or on nCPAP equal to or less than 6cmH₂O, requiring equal to or less than 30% fraction of inspired oxygen (FiO₂) (Muniyappa et al., 2019). The transport was deemed successful if the neonatal patient remained on nHFT without requiring an increase of 2 L/min or more above their starting flow rate, and if patient delivered FiO₂ did not increase by 0.20 or more (Muniyappa et al., 2019).

Results of the study found that 87% of the patients were successfully transported, with an average transport time of 93 minutes (Muniyappa et al., 2019). For the neonates that required escalation, 75% were able to remain on nHFT while increasing FiO₂ or flow rate (Muniyappa et al., 2019). However, 3% of patients were not able to remain on nHFT; five patients required intubation and one patient transitioned to nCPAP (Muniyappa et al., 2019). Key differences were noted between the patients that were successfully transported on nHFT compared to those who required escalation; the patients requiring intervention had a lower SpO₂/FiO₂ ratio pre-transport, as well as a longer period in hospital before transport (Muniyappa et al., 2019). This indicates that these patients required more stabilization before transport, potentially reflecting more severe and/or sensitive respiratory conditions (Muniyappa et al., 2019). An additional study by Boyle and colleagues determined that it is safe to introduce nHFT to the neonatal transport environment without negative patient outcomes (Boyle, Dhar, Chaudhary, Kent, O’Hare, Dassios & Broster, 2016). A statistically significant increase of FiO₂ was observed in transported patients that was not found to be clinically significant (as it relates to neonatal transport) (Boyle et al., 2016). Research regarding heated, humidified nHFT during neonatal transport is promising but relatively new and limited, and therefore at this time it is not possible to recommend one over the other (Tauzin & Durrmeyer, 2019).

How Does This Impact Respiratory Therapy?

Studies such as those previously discussed represent a promising future for neonatal transport. There is a trend toward better outcomes or minimizing adverse outcomes for patients being treated with nHFT during transfer (McQueen et al., 2014). In this fragile patient population, delivering the best care is important particularly in early stages of life, to encourage neonatal growth and development and prevent adverse outcomes. As an RT, knowing you have various options to provide ventilator support allows you to best tailor your treatment, as not all patients are the same. This was made evident through the studies discussed, where neonates with lower SpO₂/FiO₂ ratios required further intervention whereby nHFT may not be suitable for them. In addition to reduced damage to the respiratory anatomy, NIV methods are preferable to invasive methods due to the decreased risk of developing bronchopulmonary dysplasia (BPD) (Behnke et al., 2019). Overall, the sensitive environment created during neonatal transport requires more research to determine the best outcome for patients. Further research regarding the efficacy of nHFT for patients with more complex respiratory conditions would supplement the current data. Overall, nHFT in addition to nCPAP as transport treatment options allows for more individualized respiratory care and support for neonatal patients, which has potential to improve health outcomes.

References

Behnke, J., Lemyre, B., Czernik, C., Zimmer, K.-P., Ehrhardt, H., & Waitz, M. (2019).
Non-Invasive Ventilation in Neonatology. Deutsches Ärzteblatt International, 116(11), 117–183. https://doi.org/10.3238/arztebl.2019.0177

Boyle, M. A., Dhar, A., Chaudhary, R., Kent, S., O’Hare, S. S., Dassios, T., & Broster, S. (2016).
Introducing high-flow nasal cannula to the neonatal transport environment. Acta Pædiatrica, 106(3), 509–512. https://doi.org/10.1111/apa.13702

Kiss, T., Bolke, A., & Spieth, P. (2017).
Interhospital transfer of critically ill patients. Minerva Anestesiologica, 83(10), 1101–1108. https://doi.org/10.23736/S0375-9393.17.11857-2

McQueen, M., Rojas, J., Sun, S. C., Tero, R., Ives, K., Bednarek, F., … Miller, T. L. (2014).
Safety and Long-Term Outcomes with High Flow Nasal Cannula Therapy in Neonatology: A Large Retrospective Cohort Study. Journal of Pulmonary & Respiratory Medicine, 4(6), 1–5. https://doi.org/10.4172/2161-105X.1000216

Muniyappa, B., Honey, G., & Yoder, B. A. (2019).
Efficacy and Safety of Nasal High-Flow Therapy for Neonatal Transport. Air Medical Journal, 38(4), 298–301. https://doi.org/10.1016/j.amj.2019.04.005

Tauzin, M., & Durrmeyer, X. (2019).
Managing neonatal pain in the era of non-invasive respiratory support. Seminars in Fetal & Neonatal Medicine, 24(4), 1–6. https://doi.org/10.1016/j.siny.2019.04.004

Yoder, B. A., Stoddard, R. A., Li, M., King, J., Dirnberger, D. R., & Abbasi, S. (2013).
Heated, humidified high-flow nasal cannula versus nasal CPAP for respiratory support in neonates. Pediatrics, 131(5), 1482–1490. https://doi.org/10.1542/peds.2012-2742

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