Category Archives: Respiratory disease

Disorders of the diaphragm

Diaphragmatic fatigue The diaphragm can become fatigued if the force of contraction during inspiration exceeds 40% of the force it can develop in a maximal static effort. When this occurs acutely in patients with exacerbations of chronic airflow limitation or CF or in quadriplegics, positive-pressure ventilation is required followed by attempts to increase the strength and endurance of the diaphragm by breat

Disorders of the chest wall and pleura

Trauma Trauma to the thoracic wall can be due to penetrating wounds and can lead to pneumothoraces or haemothoraces. RIB FRACTURES Rib fractures can be caused by trauma or coughing (particularly in the elderly), and can occur in patients with osteoporosis. Pathological rib fractures may be due to metastatic spread from carcinoma of the bronchus, breast, kidney, prostate and thyroid. Ribs can also become invol

Tumours of the respiratory tract

Bronchial carcinoma accounts for 95% of all primary tumours of the lung. Alveolar cell carcinoma accounts for 2% of lung tumours and other less malignant or benign tumours account for the remaining 3%. BENIGN TUMOURS Pulmonary hamartoma This is the most common benign tumour of the lung and is usually seen as a very well-defined round lesion 1-2 em in diameter in the periphery of the lung. Growth is extremely

Lung cysts

These may be congenital, bronchogenic cysts or may result from a sequestrated pulmonary segment. Hydatid disease causes fluid-filled cysts. Thin-walled cysts are due to lung abscesses, which are particularly found in staphylococcal pneumonia, tuberculous cavities, septic pulmonary infarction, primary bronchogenic carcinoma, cavitating metastatic neoplasm, or paragonimiasis caused by the lung fluke Paragonimu

Occupational lung disease

Exposure to dusts, gases, vapours and fumes at work can lead to the development of the following types of lung disease: • Acute bronchitis and even pulmonary oedema from irritants such as sulphur dioxide, chlorine, ammonia or the oxides of nitrogen • Pulmonary fibrosis due to mineral dust • Occupational asthma • Extrinsic allergic bronchiolar alveolitis • Bronchial carcinoma due to industrial agents (


POLYMORPHONUCLEAR LEUCOCYTE COUNT is raised in acute cases. PRECIPITATING ANTIBODIES are present in the serum. One-quarter of pigeon fanciers have precipitating antibody against pigeon protein and droppings in their serum but only a small proportion have lung disease. Precipitating antibodies are evidence of exposure, not disease. LUNG FUNCTION TESTS show a restrictive ventilatory defect with a decrease in g

Simple and prolonged pulmonary eosinophilia

Simple pulmonary eosinophilia is a relatively mild illness with a slight fever and cough and usually lasting for less than 2 weeks. It is probably due to a transient allergic reaction in the alveolus. Many allergens have been implicated, including Ascaris lumbricoides, Ankylostoma braziliense and Trichuris trichiura as well as drugs such as paminosalicylic acid, aspirin, penicillin, nitrofurantoin and sulpho

Histiocytosis X

CLINICAL FEATURES There are three variants of this disease, all characterized by the presence of granulomas consisting predominantly of characteristic histiocytes intermingled with eosinophilic and neutrophilic granulocytes, giant cells and lymphocytes. Electron microscopic studies have shown that the histiocytes contain granules characteristic of Langerhan cells. Fibrosis may occur early, with the developmen

Other mycobacteria

M. kansasii occurs in water and milk, though not in soil. Disease caused by this mycobacterium has mainly been described in Europe and the USA. It rarely causes a relatively benign type of human pulmonary disease, usually in middle-aged males. Men working in dusty jobs (e.g. miners) apear to be especially at risk, as are those who have underlying chronic bronchitis and emphysema. M.avium intracellulare is an i


Tuberculosis is on the increase particularly where immunosuppressive drugs have altered the host defence mechanisms, or in AIDS. In developing countries, it still remains a problem partly because of inadequately supervised treatment. EPIDEMIOLOGY For the last 20 years tuberculosis was thought to be under control, but it is now the world’s leading cause of death from a single infectious disease due to: