Which spirometry pattern differentiates obstructive from restrictive lung disease, and how should you educate a patient about inhaler use accordingly?

• A. Obstructive: normal FEV1/FVC; Restrictive: reduced FVC.
• B. Obstructive: increased FEV1/FVC; Restrictive: reduced FVC with reduced FEV1.
• C. Obstructive: reduced FEV1/FVC ratio; Restrictive: proportional reduction of FVC with normal or increased FEV1/FVC; educate on correct inhaler technique, spacer use, and adherence.
• D. Obstructive: increased FEV1; Restrictive: increased FVC.

Answer: (C)

Spirometry relies on the FEV1 and FVC values to separate obstructive from restrictive patterns. In obstructive disease, airways narrowing makes the amount of air you can forcefully exhale (FEV1) fall more than the total expired volume (FVC), so the FEV1/FVC ratio decreases. In restrictive disease, lung volumes are reduced overall, but FEV1 and FVC decline in parallel, so the ratio remains normal or even higher. This is why the pattern described as Obstructive: reduced FEV1/FVC ratio; Restrictive: proportional reduction of FVC with normal or increased FEV1/FVC best differentiates the two.

For patient education on inhaler use, emphasize correct technique, the use of a spacer when coordination is an issue, and adherence to the prescribed regimen. Proper technique ensures the medication reaches the lungs; a spacer can improve delivery and reduce oropharyngeal deposition, especially for those with coordination challenges or using inhaled corticosteroids. Reiterate consistency with daily controller or rescue meds as prescribed to achieve better symptom control and fewer flares.