Infections of any portion of the pulmonary system may occur. Infections of the lower portions usually follow an upper respiratory infection. In many instances more than one portion of the system is simultaneously infected. Inflammation of the trachea is called tracheitis, and that of the bronchial tubes, bronchitis. Infection of the lung is labeled pneumonitis or pneumonia. Various combinations may occur, such as tracheo-bronchitis. Pneumonitis may involve one small area, an entire lobe, an entire lung, or parts or all of both lungs. Inflammation of the pleura is called pleuritis or pleurisy.
In pneumonia there is usually one specific type of germ which causes the infection. Most often it is acute and not long-lasting with today’s methods of treatment. Treatment is usually by medical measures, but surgery may be indicated for some of the complications, such as abscesses or empyema. Acute pneumonia may also be a complication of anesthesia or operation.
Chronic lung infections are most serious diseases requiring prolonged treatment. The most common chronic infection is tuberculosis; histoplasmosis and coccidioides are rare chronic infections. Surgical treatment methods of pulmonary tuberculosis have been mentioned previously in this chapter in the section entitled Surgery of the Chest Wall. Also employed to halt this chronic disease process is removal of a lobe, or part of a lobe, when the disease is confined to one area.
Tumors of the lungs are not uncommon. They may be benign or malignant, the latter unfortunately predominating. Spread from malignancies (metastasis) in other parts commonly travels to the lungs. Lung neoplasms are most often discovered by x-ray picture. Benign tumors require removal to assure their nature and to prevent their enlarging to crowd adjacent structures. Malignant growths demand early removal before there has been extensive invasion of the organs and before parts of the tumor have spread to other areas of the body through the blood and lymph streams. Often it is necessary to remove an entire lobe or an entire lung for malignant disease.
In recent years much attention has been focused upon the relationship between lung cancer and tobacco. To date, statistics show no specific correlation.
Pulmonary fibrosis is scarring within the lungs. This develops as a result of chronic inflammation such as a chronic bronchitis, asthma, or from continued exposure to dusts and fumes. Breathing is impaired as the air passages become narrowed and as the lung loses its elasticity. Emphysema may result.
Emphysema is the swelling or inflation of the alveoli, the small sac-like structures at the end of the smallest air tubes. These primary respiratory units become overdistended with air as the expiratory phase of respiration does not seem complete. The lung is over-aerated and the gas exchanges in the lungs are not efficient. Breathing must be more rapid and deeper. In advanced stages of emphysema the chest actually enlarges as the millions of alveoli become distended, the so-called barrel-chest.
Pulmonary scarring may result from continued exposure to irritating dusts. The general term for the disease is pneumoconiosis and several types occur. For examples, anthracosis develops from coal dust inhalation, as seen in miners; silicosis may be seen in quarry workers from continued stone dust inhalation. Several other forms exist.
Bronchiectasis is an enlargement of the bronchial tubes. It develops usually from a chronic infection around the tubes. Great quantities of sputum may be produced and cough is prominent. It most often involves the lower portions of the lungs. In advanced cases, surgical removal of a lobe or segment may be necessary.
Blebs and Bullae
Blebs and bullae are large air-containing sacs within the lungs. Their cause is poorly understood; some may be congenital, others the result of advanced emphysema. They may vary in size from V\ inch to several inches in diameter. Most lie dormant and cause no symptoms. Occasionally these blebs may rupture, to cause a sudden spontaneous pneumothorax. Others may leak slowly, causing a chronic spontaneous pneumothorax. Treatment of pneumothorax has been mentioned. In chronic or repeated incidences of rupture, the blebs may have to be removed surgically, or the lung pleura removed so that the lung becomes adherent to the chest wall and pneumothorax cannot ensue.
In all chest conditions, especially those given above, the value of chest x-ray pictures cannot be overestimated. Diseases are diagnosed and confirmed by this invaluable tool and the progress of treatment evaluated.