For a restrictive patient, what is the predicted FVC usually less than?

In patients with restrictive lung disease, the forced vital capacity (FVC) is typically reduced due to limitations in lung expansion and overall lung volume. The predicted FVC is usually less than 80% of the expected value for a healthy individual. This threshold of 80% is significant because it marks the distinction between normal pulmonary function and the early stages of restrictive disease; values below this level indicate an impairment in lung capacity and efficiency.

Restrictive lung conditions limit the lungs' ability to expand fully, often due to conditions affecting the lung tissue itself or the pleura, or because of neuromuscular issues that impair respiratory mechanics. Hence, a patient demonstrating a predicted FVC of less than 80% provides a clear indication of restrictive pathology that requires further analysis and treatment options.

Values less than 70%, 60%, or any lower percentage relate to more severe restrictions and may not serve to characterize patients in the earlier stages of restrictive disorders, where intervention may still be viable. Therefore, stating that the predicted FVC is usually less than 80% effectively helps clinicians recognize and manage these patients promptly and appropriately.