Restrictive Lung Diseases
Definition - What does Restrictive Lung Diseases mean?
Restrictive lung diseases are classified as pulmonary conditions that impair full expansion and contraction of lung tissue, reducing volume of air to complete normal respiratory rate cycles. Etiological implications that result in lung tissue scarring and/or weakened chest wall musculature include constant dust exposure, certain drug treatments, and numerous cardiopulmonary conditions. Functional reserve capacity (FRC) represents the elasticity of the lungs in proportion to surrounding chest wall muscles and their interdependent function to perform sustainable breaths.
WorkplaceTesting explains Restrictive Lung Diseases
Restrictive lung diseases are divided into two primary subgroups classified as extrinsic and intrinsic lung diseases. Extrinsic pathologies affect the chest wall and connective muscle tissue including the pleura, a protective membrane encasing the lungs, inhibiting respiratory ventilation. Intrinsic pathologies affect the structural integrity of lung tissue through the development of fibrosis, or scarring on alveoli (small air sacs) responsible for absorbing oxygen and removing carbon dioxide. Development of restrictive lung diseases minimizes total lung capacity (TLC), causing loss of elasticity in the lungs and/or chest wall muscles.
For this reason, the respiratory system underperforms during biomechanical activities such as exercise. In the workplace, overexposure to airborne pollutants such as dust particles and chemical solution by-products contribute to detrimental restrictive lung diseases. Epidemiological factors such as age, gender, prevalence, and smoking habits can increase the morbidity rate.
Common extrinsic conditions that lead to restrictive lung diseases include kyphosis (outward curvature of spine), muscular dystrophy, and obesity. Conversely, intrinsic lung disorders encompass chemical worker’s lung, farmer’s lung, rheumatoid arthritis combined with pharmacological causes from drug therapy treatment.
Early pulmonary testing procedures is imperative to determine the onset of a restrictive lung disease. Spirometry is a basic, common method applied to examine lung tissue composition and elasticity by measuring forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). The ratio of FEV1/FVC serves as a benchmark criteria in diagnosing a restrictive lung disease in patients.