Various conditions affecting the LUNGS are dealt with under the following headings: ASTHMA; BRONCHIECTASIS; CHEST, DEFORMITIES OF; CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD); COLD, COMMON; EMPHYSEMA; EXPECTORATION; HAEMOPTYSIS; HAEMORRHAGE; OCCUPATIONAL HEALTH, MEDICINE AND DISEASES; PLEURISY; PNEUMONIA; PULMONARY EMBOLISM; TUBERCULOSIS.
In?ammation of the lungs is generally known as PNEUMONIA, when it is due to infection; as ALVEOLITIS when the in?ammation is immunological; and as PNEUMONITIS when it is due to physical or chemical agents.
Abscess of the lung consists of a collection of PUS within the lung tissue. Causes include inadequate treatment of pneumonia, inhalation of vomit, obstruction of the bronchial tubes by tumours and foreign bodies, pulmonary emboli (see EMBOLISM) and septic emboli. The patient becomes generally unwell with cough and fever. BRONCHOSCOPY is frequently performed to detect any obstruction to the bronchi. Treatment is with a prolonged course of antibiotics. Rarely, surgery is necessary.
Pulmonary oedema is the accumulation of ?uid in the pulmonary tissues and air spaces. This may be caused by cardiac disease (heart failure or disease of heart valves – see below, and HEART, DISEASES OF) or by an increase in the permeability of the pulmonary capillaries allowing leakage of ?uid into the lung tissue (see ACUTE RESPIRATORY DISTRESS SYNDROME (ARDS)).
Heart failure (left ventricular failure) can be caused by a weakness in the pumping action of the HEART leading to an increase in back pressure which forces ?uid out of the blood vessels into the lung tissue. Causes include heart attacks and HYPERTENSION (high blood pressure). Narrowed or leaking heart valves hinder the ?ow of blood through the heart; again, this produces an increase in back pressure which raises the capillary pressure in the pulmonary vessels and causes ?ooding of ?uid into the interstitial spaces and alveoli. Accumulation of ?uid in lung tissue produces breathlessness. Treatments include DIURETICS and other drugs to aid the pumping action of the heart. Surgical valve replacement may help when heart failure is due to valvular heart disease.
Acute respiratory distress syndrome Formerly known as adult respiratory distress syndrome (ARDS), this produces pulmonary congestion because of leakage of ?uid through pulmonary capillaries. It complicates a variety of illnesses such as sepsis, trauma, aspiration of gastric contents and di?use pneumonia. Treatment involves treating the cause and supporting the patient by providing oxygen.
Collapse of the lung may occur due to blockage of a bronchial tube by tumour, foreign body or a plug of mucus which may occur in bronchitis or pneumonia. Air beyond the blockage is absorbed into the circulation, causing the affected area of lung to collapse. Collapse may also occur when air is allowed into the pleural space – the space between the lining of the lung and the lining of the inside of the chest wall. This is called a pneumothorax and may occur following trauma, or spontaneously
– for example, when there is a rupture of a subpleural air pocket (such as a cyst) allowing a communication between the airways and the pleural space. Lung collapse by compression may occur when ?uid collects in the pleural space (pleural e?usion): when this ?uid is blood, it is known as a haemothorax; if it is due to pus it is known as an empyema. Collections of air, blood, pus or other ?uid can be removed from the pleural space by insertion of a chest drain, thus allowing the lung to re-expand.
Tumours of the lung are the most common cause of cancer in men and, along with breast cancer, are a major cause of cancer in women. Several types of lung cancer occur, the most common being squamous cell carcinoma, small- (or oat-) cell carcinoma, adenocarcinoma, and large-cell carcinoma. All but the adenocarcinoma have a strong link with smoking. Each type has a di?erent pattern of growth and responds di?erently to treatment. More than 30,000 men and women die of cancer of the trachea, bronchus and lung annually in England and Wales.
The most common presenting symptom is cough; others include haemoptisis (coughing up blood), breathlessness, chest pain, wheezing and weight loss. As well as spreading locally in the lung – the rate of spread varies – lung cancer commonly spawns secondary growths in the liver, bones or brain. Diagnosis is con?rmed by X-rays and bronchoscopy with biopsy.
Treatment Treatment for the two main categories of lung cancer – small-cell and nonsmall-cell cancer – is di?erent. Surgery is the only curative treatment for the latter and should be considered in all cases, even though fewer than half undergoing surgery will survive ?ve years. In those patients unsuitable for surgery, radical RADIOTHERAPY should be considered. For other patients the aim should be the control of symptoms and the maintenance of quality of life, with palliative radiotherapy one of the options.
Small-cell lung cancer progresses rapidly, and untreated patients survive for only a few months. Because the disease is often widespread by the time of diagnosis, surgery is rarely an option. All patients should be considered for CHEMOTHERAPY which improves symptoms and prolongs survival.
Wounds of the lung may cause damage to the lung and, by admitting air into the pleural cavity, cause the lung to collapse with air in the pleural space (pneumothorax). This may require the insertion of a chest drain to remove the air from the pleural space and allow the lung to re-expand. The lung may be wounded by the end of a fractured rib or by some sharp object such as a knife pushed between the ribs.... lungs, diseases of
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