Noise Levels of Neonatal High-Flow Nasal Cannula Devices - An in-vitro Study

Abstract

Background: Excessive ambient noise levels have been identified as a potential risk factor for adverse outcome in very preterm infants. Noise level measurements for continuous positive airway pressure (CPAP) devices demonstrated that these constantly exceed current recommendations. The use of high-flow nasal cannula (HFNC) as an alternative non-invasive ventilation modality has become more popular in recent years in neonatal care. Objective: To study noise levels of two HFNC devices commonly used in newborns. As a comparison, noise levels of a continuous flow CPAP device were also studied. Methods: In-vitro study. The noise levels of two contemporary HFNC devices (Fisher & Paykel NHF™ and Vapotherm Precision Flow®) and one CPAP device (Dräger Babylog® 8000 plus) were measured in the oral cavity of a newborn manikin in an incubator in a quiet environment. HFNC flows of 4-8 l/min and CPAP pressures of 4-8 cm H₂O were applied. The CPAP flow was set at 8 l/min as per unit practice. Results: Vapotherm HFNC generated the highest noise levels, measuring 81.2-91.4 dB(A) with increasing flow. Fisher & Paykel HFNC noise levels were between 78.8 and 81.2 dB(A). The CPAP device generated the lowest noise levels between 73.9 and 77.4 dB(A). Conclusions: Both HFNC devices generated higher noise levels than the CPAP device. All noise levels were far above current recommendations of the American Academy of Pediatrics. In light of the long duration of non-invasive respiratory support of very preterm infants, less noisy devices are required to prevent the potentially adverse effects of continuing excessive noise exposure in the neonatal intensive care unit.

Physiologic Effects of High-Flow Nasal Cannula Oxygen in Critical Care Subjects

“…The short duration of sessions in our study may explain the lack of differences in comfort, as longer durations are needed for the emergence of adverse experiences such as upper airway dryness caused by the high-F IO 2 face mask, 26 intolerance to CPAP, 19 or noise with HFNC. 34 However, contrary to this result, 75% of our subjects found that HFNC was more pleasant than the other oxygen delivery techniques (CPAP and high-F IO 2 , non-rebreathing face mask). In clinical practice, Sztrymf et al 15,16 reported a remarkable tolerance of HFNC over longer use.…”

Results of an Acoustic Incubator Cover among Preterm Infants: Incubators and Modes of Respiratory Therapy

“…Treatment intervention did not reduce HF sound as well in the in vivo as the in vitro study likely to exclusion of respiratory modes in the in vitro study. These findings support the observation that CPAP contributes to HF sound energy in neonatal intensive care units 31 .…”

“…Previous studies [28][29][30][31] supported the need to evaluate differences among modes of respiratory therapy. Surenthiran et al measured sound frequencies outside and within the ears of neonates receiving one of three respiratory therapy modes 28 .…”

Are high flow nasal cannulae noisier than bubble CPAP for preterm infants?

“…Given the findings of the CPAP studies, there is concern that HFNC may expose infants to noise levels greater than from CPAP. A recent in vitro study17 is the first to compare noise production from HFNC with that from CPAP. Noise levels generated by two HFNC devices (Fisher & Paykel ‘Optiflow’ and Vapotherm ‘Precision Flow’) were higher than those produced by continuous-flow CPAP, and again well above recommended levels.…”