Spirometry to predict dry powder inhaler performance: Insights from in-check DIAL

Area of Science:

• Pulmonary Medicine
• Respiratory Diagnostics

Background:

• Chronic obstructive pulmonary disease (COPD) management relies on inhaler-based pharmacologic therapy.
• Selecting the correct inhaler is crucial but can be challenging for clinicians.
• The In-Check Dial G16® assesses inspiratory capacity but is time-consuming.

Purpose of the Study:

• To explore spirometry as a predictive tool for assessing inspiratory flow requirements for dry powder inhaler (DPI) use in COPD patients.
• To determine if spirometry can offer a more efficient alternative to the In-Check Dial G16®.

Main Methods:

• Ninety-one COPD patients using inhalers for at least one month were enrolled.
• Spirometry and In-Check DIAL G16® assessments were performed on the same day.
• DPI usability was defined by achieving >30 L/min flow at R3 resistance on the In-Check DIAL G16®.

Main Results:

• Peak inspiratory flow (PIF) was the best spirometry predictor of DPI use (cut-off 3.10 L/s; 69.2% sensitivity, 76.9% specificity).
• Forced inspiratory flow at 50% of FVC (FIF50) was the second-best predictor (cut-off 2.91 L/s; 63.7% sensitivity, 69.2% specificity).
• Most patients used metered-dose inhalers/soft mist inhalers and low-to-medium resistance inhalers.

Conclusions:

• Spirometry, particularly PIF and FIF50, is important for COPD evaluations and predicting inhalation capacity.
• Identified spirometry cut-off values aid clinicians in selecting appropriate inhalers for COPD patients.
• Spirometry presents a more accessible and time-efficient alternative to the In-Check Dial G16® for inhaler assessment.