Usability and inspiratory flow profiles of patients with pulmonary hypertension inhaling with a novel Soft Mist Inhaler (SMI)

Authors: B. Müllinger, N. Buchmann, R. Huedepohl, G. Prins

Event: ISAM Congress, 26 – 30th August 2023, Saarbrücken, Germany

Abstract: Good inhaler technique is key for an effective inhalation treatment and reduction of critical inhaler errors.

Recent publications show that treatment effects can be improved if inhalers are easy to use and support patients with pulmonary hypertension in their inhaler technique. The aims of this study were the usability assessment of the soft mist inhaler (PFSI, Resyca®, Netherlands), evaluation of inhalation flow profiles with the resistance of the inhaler, and observation of ability to safely use the inhaler.

A formative human factors study was conducted in 15 patients with pulmonary hypertension, functional class II, III, or IV, thereof 3 patients with handling difficulties like scleroderma. User device interaction, inhaler flow profiles and use tasks were assessed for all patients.

Patient satisfaction and user needs were assessed in qualitative interviews. Results from this human factors study show that patients with PAH of functional class 2 to 4 comfortably inhaled slow and deep with the high resistance soft mist inhaler.

All patients were able to inhale with an inhalation duration of 3.6 seconds. Median inhalation duration was 6.8 seconds, median inhaled volume was 1.3 L and median flow rate was 13.5 L/min.

The intuitive device design supported patients of different functional classes including patients with comorbid tissue disorder in applying steps to good inhalation technique, while informing further design improvements.