Aerosol delivery through high flow nasal cannula compared to biphasic positive airway pressure, at two different pressure: an in-vitro study

Marina E Boules,Nabila Ibrahim Laz,Raghda R S Hussein,Mohamed E A Abdelrahim,Ahmed A Elberry

doi:10.1186/s43088-021-00169-w

Marina E Boules, Nabila Ibrahim Laz + Show 3 more

Open Access

https://doi.org/10.1186/s43088-021-00169-w

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Abstract

BackgroundBoth non-invasive ventilation and high flow oxygen therapy are preferred over low flow oxygen therapy in many conditions. Nebulizers, for aerosol delivery, can be used within them without interrupting the circuit. The present study aimed to compare the efficiency of drug delivery within high flow nasal cannula (HFNC) and biphasic positive airway pressure (BiPAP) ventilation mode using two different inspiratory positive airway pressures. The aerosol delivery was examined in HFNC system at low flow, 5 L min−1, and BiPAP non-invasive ventilation under 2 different pressures [high pressure; inspiratory positive airway pressure/expiratory positive airway pressure (IPAP/EPAP) of 20/5 cm water, and low pressure; IPAP/EPAP of 10/5 cm water]. The total inhalable dose (TID) was measured by inserting an Aerogen Solo nebulizer installed with 1 mL salbutamol respiratory solution (5000 μg mL−1) within the circuit, and the salbutamol was collected on an inhalation filter placed in a filter holder connected to a breathing simulator. The breathing simulator was adjusted at a tidal volume of 500 mL, respiratory rate of 15 breaths min−1, and inhalation to exhalation (I:E) ratio of 1:1 for the adult setting. In each technique of the three (HFNC, and low, and high-pressures BiPAP), TID was determined 5 times (n = 5). For particle size characterization, cooled Anderson Cascade Impactor (ACI) was inserted instead of the inhalation filter and the breathing simulator with the same scheme. In each technique of the three, particle size characterization was determined 3 times (n = 3).ResultsThe BiPAP mode at low inspiratory pressure had the highest TID, followed by HFNC at flow 5 L min−1, then BiPAP mode at high inspiratory pressure. There was a significant difference only between low and high inspiratory pressure modes of BiPAP mode. Low-inspiratory pressure BiPAP delivered the highest mean ± SD fine particle dose (FPD). It was significantly higher than that delivered in high inspiratory pressure BiPAP, and HFNC. Also, FPD in HFNC was significantly higher than that in high inspiratory pressure BiPAP. HFNC system had the smallest mass median aerodynamic diameter (MMAD) and the highest FPF followed by low then high inspiratory pressure BiPAP.ConclusionsIncreasing the inspiratory positive airway pressure in BiPAP, from 10 to 20 cm water, decreased the total inhalable dose and FPF nearly by half. Low inspiratory pressure BiPAP delivered the highest TID and FPD. The HFNC system at low oxygen flow resulted in the least MMAD, and the highest FPF. Using HFNC delivered a TID that was non-significant from that delivered by low inspiratory pressure BiPAP.Graphical

Highlights

Both non-invasive ventilation and high flow oxygen therapy are preferred over low flow oxygen therapy in many conditions
The amount of salbutamol that was lost in the tubes was greatest in the case of low-inspiratory pressure biphasic positive airway pressure (BiPAP) mode followed by high flow nasal cannula (HFNC) high inspiratory pressure BiPAP, as shown in Table 1 with a significant difference between high inspiratory pressure BiPAP mode and both HFNC (p = 0.046) and low inspiratory pressure BiPAP mode (p = 0.039)
The HFNC system was operated in the present study at a low flow rate of 5 L min−1, as it was found that increasing the high flow therapy flow rate significantly decreased the respirable mass [13, 23]

Summary

Introduction

Both non-invasive ventilation and high flow oxygen therapy are preferred over low flow oxygen therapy in many conditions. The present study aimed to compare the efficiency of drug delivery within high flow nasal cannula (HFNC) and biphasic positive airway pressure (BiPAP) ventilation mode using two different inspiratory positive airway pressures. The aerosol delivery was examined in HFNC system at low flow, 5 L min−1, and BiPAP non-invasive ventilation under 2 different pressures [high pressure; inspiratory positive airway pressure/expiratory positive airway pressure (IPAP/EPAP) of 20/5 cm water, and low pressure; IPAP/EPAP of 10/5 cm water]. In each technique of the three (HFNC, and low, and high-pressures BiPAP), TID was determined 5 times (n = 5). Results: The BiPAP mode at low inspiratory pressure had the highest TID, followed by HFNC at flow 5 L m in−1, BiPAP mode at high inspiratory pressure. Low-inspiratory pressure BiPAP delivered the highest mean ± SD fine particle dose (FPD). Its implementation is difficult, certain resources are required, and patient discomfort is common [11]

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