Obstructive and restrictive lung disease

Late pulmonary complications cover a wide spectrum of disorders and include both obstructive and restrictive lung diseases. Included in these disorders are bronchiolitis obliterans with or without organizing pneumonia, diffuse alveolar damage, and lymphocytic interstitial pneumonia. 9,80 xjjgj- py consists of steroids, which are... 

In recent years, many new tests have been developed to assess pulmonary function in man. Here are presented the general principles, methodology, and clinical significance of the major lung function tests used in the diagnosis of obstructive and restrictive lung diseases. Obstructive diseases of the lung... 

CHRONIC HEALTH RISKS produces talcosis due to talc, silica and asbestos (talc pneumoconiosis) productive cough dyspnea rales diminished breath sounds limited chest expansion interstitial fibrosis granulomas chronic talc inhalation may increase the risk of bronchogenic carcinoma pneumoconiosis associated with obstructive and restrictive lung disease has been reported. 

Spirometry Measurement of inhaled and exhaled volumes and flow rates of gas from the lungs. Pulmonary function tests obtained from spirometry are used to aid in the diagnosis of obstructive and restrictive airway diseases. 

Spirometry is the most widely available and useful PFT. It takes only 15 to 20 minutes, carries no risks, and provides information about obstructive and restrictive disease. Spirometry allows for the measurement of aU lung volumes and capacities except RV, FRC, and TLC and allows assessment of FEVi and FEF25%-7s%. Spirometry measurements can be reported in two different formats—standard spirometry (Eig. 25-2) and the flow-volume loop (Fig. 25-3). In standard spirometry, the volumes are recorded on the vertical (y) axis and the time on the horizontal (x) axis. In flow-volume loops, volume is plotted on the horizontal (x) axis, and flow (derived from volume/time) is plotted on the vertical (y) axis. The shape of the flow-volume loop can be helpful in differentiating obstructive and restrictive defects and in the diagnosis of upper airway obstruction (Fig. 25 ). This curve gives a visual representation of obstruction because the expiratory descent becomes more concave with worsening obstruction. 

Q8 The majority of the test results support a diagnosis of obstructive pulmonary disease. Chandra s FEVi is greatly decreased and the ratio FEVi/FVC is <0.7, a significant value in determining whether the condition is restrictive or obstructive. A larger residual volume and total lung capacity than normal is typical of obstructive lung disease. 

Fig. 9. Primary lung volumes and capacities and how they vary in obstructive or restrictive diseases.

Asbestos is still a major menace to health in India, whilst it is restricted as a building material in many countries. The National Institute of Occupational Health studies reveal that the prevalence of lung diseases, including asbestosis, has remained >20% among asbestos factories and mine workers. The average male life span is about 40 years in Multanpur, MP., where the major industry is of slate pencils. Mortality is due to chronic lung obstructive disease [S]. 

Lower respiratory disorders are conditions that obstruct or restrict tracheobronchial tubes and prevent the exchange of gas within the lungs. These conditions are referred to as chronic obstructive pulmonaiy disease (COPD) and include chronic bronchitis, bronchiectasis, emphysema, and asthma. 

Pulmonary function tests reveal a restrictive pattern in early disease. In the acute phase, a reduction in lung volume, carbon monoxide diffusing capacity, and static lung compliance are common. Some patients also show evidence of small airway obstruction. 

Lung volumes are changed differently by restrictive and obstructive disease. In restrictive disease most volumes and capacities are decreased to the same extent and the ratio of FEV1/FVC is within the normal range (> 0.8). In obstructive disease FEVi is greatly reduced and the FEVi/FVC ratio is... 

---