Assessment of Aerosol Delivery during Simulated Invasive Ventilation, Non-invasive Ventilation and High Flow Nasal Therapy

Gavin Bennett¹, Mary Joyce¹, Louise Sweeney¹ & Ronan MacLoughlin¹

¹Aerogen, IDA Business Park, Dangan, Galway, Ireland

Summary

Patients receiving mechanical ventilation are often prescribed nebulised therapy. Non-invasive ventilation and high flow nasal therapy are increasingly used for ventilatory support in patients with acute respiratory failure. Some patients receiving these therapies may also benefit from inhaled drug delivery. The objective of this study was to evaluate aerosol delivery during simulated adult mechanical ventilation, non-invasive ventilation and high flow nasal therapy using a vibrating mesh nebuliser.

Simulated adult mechanical ventilation assessed the filter dose beyond the endotracheal tube across four potential nebuliser placement positions within the circuit. Simulated non-invasive ventilation assessed the filter dose when the nebuliser (Aerogen Solo, Aerogen, Ireland) was positioned between the facemask (Pneumocare Health, India) and the patient circuit with continuous positive airway pressure (10cmH₂0 and 15cmH₂0). Simulated high flow nasal therapy assessed the filter dose downstream of the model oropharyngeal region at two clinically relevant gas flow rates, in line with the Fisher & Paykel Airvo 2. For each ventilation type, a 2 mL dose of albuterol sulphate (2 mg/mL) was nebulised using a vibrating mesh nebuliser (Aerogen Solo, Aerogen, Ireland) of similar droplet size (4.5µm). The drug captured on a filter was eluted using a 10 mL buffer solution of 0.1M HCI. The mass of drug eluted was determined using UV spectroscopy at 276nm.

The greatest aerosol delivery was observed during simulated non-invasive ventilation (26.79%), in comparison with invasive ventilation (22.81%) and high flow nasal therapy (21.00%). A one way analysis of variance resulted in a p-value of 0.0012, indicating that there was a statistically significance difference in aerosol delivery between each type of ventilatory support.

This study suggests that continuity of high efficiency aerosol delivery is possible across both invasive and non-invasive patient interventions using a vibrating mesh nebuliser.