THE PHYSICAL PROPERTIES OF THE LUNG IN CHRONIC OBSTRUCTIVE PULMONARY EMPHYSEMA 1

Journal/Book: Reprinted from THE JOURNAL OF CLINICAL INVESTIGATION VOI. XXXV No. 4 pp. 394-404 April 1956. 1955/1956;

Abstract: (From the Departments of Environmental Medicine and of Medicine The Johns Hopkins University and Hospital Baltimore Md.) (Submitted for publication September 12 1955; accepted December 14 1955) 1 This study was aided by a contract between the Office of Naval Research Department of the Navy and The Johns Hopkins University (NR 112-101) and was also supported by funds provided under Contract AF 18 (600)-435 with the USAF School of Aviation Medicine Randolph Field Texas. 2 Postdoctoral Fellow of The Life Insurance Medical Research Fund. 3 Present address : Faculty of Medicine The University of Manitoba Winnipeg Canada. SUMMARY AND CONCLUSIONS The physical properties of the lungs were measured in 7 normal subjects and 18 patients with chronic obstructive emphysema 6 of whom had developed right heart failure. In patients with pulmonary emphysema the compliance of the lungs varied with the respiratory rate the functional compliance during spontaneous breathing being lower than the normal. In the normals functional and static compliance were approximately the same. These findings in the abnormal subjects are most readily explained by the effects of a non-uniformly distributed viscous resistance. Measurements of static compliance indicated a loss of rigidity of the lungs in pulmonary emphysema and increased rigidity in cases with associated right heart failure. Since the compliance varied with the rate of air flow in emphysema the viscous resistance and particularly that resulting from turbulence may be overestimated. At the resting rate of respiration both elastic and viscous resistances were high in emphysema particularly after the development of right heart failure. Any increase in respiratory rate increased the amount of work required for respiration. A single dose of nebulized bronchodilator diminished both viscous and elastic resistance to respiration in patients with pulmonary emphysema. schö

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