Exhalation immediately before inhalation optimizes dry powder inhaler use

Area of Science:

• Respiratory medicine
• Pharmacology
• Biomedical engineering

Background:

• Exhalation immediately prior to inhalation (EPI) is a commonly advised maneuver for dry powder inhaler (DPI) use.
• The specific benefits of EPI on inhaled flow dynamics from DPIs have not been previously investigated.

Purpose of the Study:

• To evaluate the impact of EPI on inhaled flow parameters when using DPIs.
• To determine if EPI enhances peak inhaled flow rate (PIFR) and inhaled volume.

Main Methods:

• Twenty-five volunteers unfamiliar with DPIs participated in the study.
• Peak inhaled flow rate (PIFR) and inhaled gas volume were measured using a flow meter.
• Participants inhaled deeply with and without EPI, both before and after connecting Turbuhaler or Diskus devices.

Main Results:

• EPI significantly increased median PIFR across all conditions: without DPIs, with Diskus, and with Turbuhaler.
• The proportion of subjects achieving a PIFR > 60 L/min increased with EPI when using Diskus (76% vs. 64%) and Turbuhaler (24% vs. 4%).
• EPI also significantly increased median inhaled volume and improved early inhalation flow parameters (F0.2 and AC30) in all tested conditions.

Conclusions:

• EPI demonstrably increases PIFR and inhaled volume from DPIs.
• The enhanced airflow facilitated by EPI may improve drug dispersion and fine particle generation.
• This finding supports the clinical relevance of EPI for optimizing DPI performance.