Comparative bench study evaluation of different infant interfaces for non-invasive ventilation

Abstract

Background: To compare, in terms of patient-ventilator interaction and performance, a new nasal mask (Respireo, AirLiquide, FR) with the Endotracheal tube (ET) and a commonly used nasal mask (FPM, Fisher and Paykel, NZ) for delivering Pressure Support Ventilation (PSV) in an infant model of Acute Respiratory Failure (ARF).

Methods: An active test lung (ASL 5000) connected to an infant mannequin through 3 different interfaces (Respireo, ET and FPM), was ventilated with a standard ICU ventilator set in PSV. The test lung was set to simulate a 5.5 kg infant with ARF, breathing at 50 and 60 breaths/min). Non-invasive ventilation (NIV) mode was not used and the leaks were nearly zero.

Results: The ET showed the shortest inspiratory trigger delay and pressurization time compared to FPM and Respireo (p < 0.01). At each respiratory rate tested, the FPM showed the shortest Expiratory trigger delay compared to ET and Respireo (p < 0.01). The Respireo presented a lower value of Inspiratory pressure-time product and trigger pressure drop than ET (p < 0.01), while no significant difference was found in terms of pressure-time product at 300 and 500 ms. During all tests, compared with the FPM, ET showed a significantly higher tidal volume (V_T) delivered (p < 0.01), while Respireo showed a trend toward an increase of tidal volume delivered compared with FPM.

Conclusions: The ET showed a better patient-ventilator interaction and performance compared to both the nasal masks. Despite the higher internal volume, Respireo showed a trend toward an increase of the delivered tidal volume; globally, its efficiency in terms of patient-ventilator interaction was comparable to the FPM, which is the infant NIV mask characterized by the smaller internal volume among the (few) models on the market.

Keywords: Acute respiratory failure; Bench test; Infant mask; Mechanical ventilation; Non invasive ventilation; Patient-ventilator interaction.

Fig. 1

Schematic representation of a bench study setting with the new infant nasal mask (Respireo) or the endotracheal tube (ET)

Fig. 2

Example from a real patient tracing (from our database) of patient-ventilator interaction measurements during NIV. From the top to the bottom: Flow (V′), Airway pressure (Paw) and Esophageal pressure (Pes). Delay_trinsp: between the first dotted line and the first black line is the delay between the onset of patient inspiration and the start of the mechanical assistance. Delay_trexp: between the second dotted line and the second black line is the delay between the end of patient inspiration and the end of the mechanical insufflation. Time_sync: between the first black line and the second dotted line is the time during which the patient and the ventilator are in phase

Fig. 3

Mechanical Tidal Volume (V_T) with the endotracheal tube (ET) (black column), the Fisher and Paykel infant nasal mask (FPM) (gray column) and the new infant nasal mask (Respireo) (white column) at two different Respiratory Rates (RR 50 and 60 breath/min). The V_T can be expressed also in ml per kg as follows: ET 9.1 ml/kg, FPM 6 ml/kg, Respireo 7.1 ml/kg (at RR 50); ET 8.2 ml/kg, FPM 5.8 ml/kg, Respireo 6.9 ml/kg (at RR 60)

Fig. 4

Inspiratory trigger delay (Delay_trinsp), Pressurization Time (Time_press) and Expiratory Trigger delay (Dealy_trexp) with the endotracheal tube (ET) (black column), the Fisher and Paykel infant nasal mask (FPM) (gray column) and the new infant nasal mask (Respireo) (white column) at two different Respiratory Rates (RR 50 and 60 breath/min)

Fig. 5

Time of synchrony with the endotracheal tube (ET) (black column), the Fisher and Paykel infant nasal mask (FPM) (gray column) and the new infant nasal mask (Respireo) (white column) at two different Respiratory Rates (RR 50 and 60 breath/min)