Which spirometry pattern is typically observed in patients with interstitial lung disease (ILD)?

In patients with interstitial lung disease (ILD), the spirometry pattern that is typically observed is a restrictive pattern. This occurs because ILD is characterized by inflammation and scarring of the lung tissue, which leads to decreased lung compliance. As a result, patients have difficulty fully expanding their lungs, resulting in reduced total lung capacity (TLC) and vital capacity (VC) on spirometry.

In a restrictive pattern, the forced expiratory volume in one second (FEV1) is usually decreased, but the ratio of FEV1 to forced vital capacity (FVC) remains normal or may even be increased. This differs significantly from an obstructive pattern, where there is a decreased FEV1 and a reduced FEV1/FVC ratio, common in conditions like asthma or chronic obstructive pulmonary disease (COPD).

The normal pattern would indicate that lung function is unaffected, which is not characteristic of ILD. A mixed pattern could suggest a combination of obstructive and restrictive features, which is not the primary characteristic of ILD.

Recognizing this spirometry result is crucial for diagnosing and managing ILD, as it directs further evaluation and treatment strategies aimed at preserving lung function and addressing factors contributing to the disease.