Biomaterial Database

Pseudophysiologic emphysema resulting from severe small-airways disease. 1998

A F Gelb, and N Zamel, and J C Hogg, and N L Müller, and M J Schein

Departments of Medicine and Radiology, Lakewood Regional Medical Center, University of California Los Angeles, School of Medicine, Los Angeles, California, USA. afgelb@msn.com

Loss of lung elastic recoil causing hyperinflation with increased TLC and decreased diffusing capacity and expiratory airflow are physiologic hallmarks of emphysema. We studied lung mechanics in 10 patients (seven men and three women) aged 69 +/- 9 yr (mean +/- SD) who had fixed, severe expiratory airflow limitation with a mean FEV1 = 0.73 +/- 0.1 L (mean +/- SD) (32 +/- 7% predicted) and lung computed tomographic picture grade score <= 20, indicating no or trivial emphysema. Three patients died, in whom whole-lung emphysema scores were 15 each and small airways were abnormal. Marked hyperinflation was present in all 10 patients studied, with TLC 7.3 +/- 1.1 L (140 +/- 12% predicted); FRC 5.6 +/- 0.8 L (177 +/- 30% predicted); and RV 5.2 +/- 0.8 L (242 +/- 28% predicted). Diffusing capacity of carbon monoxide (DLCO was reduced, at 12 +/- 6 ml/min/mm Hg (61 +/- 29% predicted). The pressure-volume curves of the lung were markedly abnormal. Pst(L) at TLC was 11.6 +/- 1.4 cm H2O. Transdiaphragmatic pressure (Pdi) in five patients was 66 +/- 13 cm H2O. These results indicate that severe small-airways disease with no or trivial emphysema may cause a spurious reduction in diffusing capacity as well as severe loss of lung elastic recoil resulting in marked hyperinflation, increased TLC, and decreased Pdi and expiratory airflow.

UI	MeSH Term	Description	Entries
D008170	Lung Compliance	The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)	Compliance, Lung,Compliances, Lung,Lung Compliances
D008297	Male		Males
D008449	Maximal Expiratory Flow-Volume Curves	Curves depicting MAXIMAL EXPIRATORY FLOW RATE, in liters/second, versus lung inflation, in liters or percentage of lung capacity, during a FORCED VITAL CAPACITY determination. Common abbreviation is MEFV.	Maximal Expiratory Flow Volume Curves
D010366	Peak Expiratory Flow Rate	Measurement of the maximum rate of airflow attained during a FORCED VITAL CAPACITY determination. Common abbreviations are PEFR and PFR.	Expiratory Peak Flow Rate,Flow Rate, Peak Expiratory,PEFR
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
D011653	Pulmonary Diffusing Capacity	The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.	Capacity, Pulmonary Diffusing,Diffusing Capacity, Pulmonary
D011656	Pulmonary Emphysema	Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.	Emphysema, Pulmonary,Centriacinar Emphysema,Centrilobular Emphysema,Emphysemas, Pulmonary,Focal Emphysema,Panacinar Emphysema,Panlobular Emphysema,Pulmonary Emphysemas,Centriacinar Emphysemas,Centrilobular Emphysemas,Emphysema, Centriacinar,Emphysema, Centrilobular,Emphysema, Focal,Emphysema, Panacinar,Emphysema, Panlobular,Emphysemas, Centriacinar,Emphysemas, Centrilobular,Emphysemas, Focal,Emphysemas, Panacinar,Emphysemas, Panlobular,Focal Emphysemas,Panacinar Emphysemas,Panlobular Emphysemas
D012120	Respiration Disorders	Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.	Disorder, Respiration,Disorders, Respiration,Respiration Disorder
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D001982	Bronchial Diseases	Diseases involving the BRONCHI.	Bronchial Disease,Disease, Bronchial,Diseases, Bronchial