Studies in Emphysema

II. Bedside Versus Laboratory Estimations of Timed and Total Vital Capacity and Diaphragmatic Height and Movement

¹ The Veterans Administration Center., Area Consultant in Allergy.
² The Veterans Administration Center.
³ The Veterans Administration Center., Assistant Director, Professional Service, for Research.

These studies demonstrate that for clinical purposes bedside tests for timed and total vital capacity are as valuable as the more time-consuming pulmonary function laboratory tests. The bedside method has the additional advantage that the clinician in charge of the patient observes the test, can watch the movement of the dial and can determine the degree of cooperation of the patient.

The wide variations between paired tests in patients with emphysema make judgment of the effects of therapy difficult. These patients respond subjectively to attention and frequently report improvement which cannot be demonstrated objectively. Objective evidence of improvement requires differences of at least 20 per cent in timed or total vital capacity. One cannot use the standard error figures for normals for the evaluation of therapy in patients with emphysema.

Our studies additionally demonstrate that the height and movement of the diaphragms can be measured at the bedside with sufficient accuracy for clinical purposes and that recourse to elaborate x-ray examinations yields no more significant information.