Pneumothorax Health Dictionary

Pneumothorax: From 3 Different Sources


A condition in which air enters the pleural cavity (the space between the layers of the pleura).

Symptoms are chest pain or shortness of breath.

If air continues to leak, the pneumothorax may grow to produce a tension pneumothorax.

This may be life-threatening.

Diagnosis is confirmed by chest X-ray.

A small pneumothorax may disappear in a few days without treatment.

If not, treatment involves removing the air through a tube with a one-way valve.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
A collection of air in the pleural cavity, into which it has gained entrance by a defect in the lung or a wound in the chest wall. When air enters the chest, the lung immediately collapses towards the centre of the chest; but, air being absorbed from the pleural cavity, the lung expands again within a short time. (See LUNGS, DISEASES OF.)

Tension pneumothorax is a life-threatening condition in which the air in the hemithorax is under such pressure that it forces the heart to the other side and compresses the still-in?ated lung on the other side. It must be promptly relieved by inserting a hollow tube into the pleural cavity – a chest drain.

Arti?cial pneumothorax was an operation often performed in the pre-antibiotic days to treat pulmonary tuberculosis. Air was run into the pleural cavity to cause collapse of one lung, which rested it and allowed cavities in it to heal.

Health Source: Medical Dictionary
Author: Health Dictionary
n. air in the *pleural cavity. Any breach of the lung surface or chest wall allows air to enter the pleural cavity, causing the lung to collapse. The leak can occur without apparent cause, in otherwise healthy people (spontaneous pneumothorax), or result from injuries to the chest (traumatic pneumothorax). In tension pneumothorax a breach in the lung surface acts as a valve, admitting air into the pleural cavity when the patient breathes in but preventing its escape when he breathes out. This air must be let out by surgical incision.

A former treatment for pulmonary tuberculosis – artificial pneumothorax – was the deliberate injection of air into the pleural cavity to collapse the lung and allow the tuberculous areas to heal.

Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Breath Sounds

The transmitted sounds of breathing, heard when a stethoscope is applied to the chest. Normal breath sounds are described as vesicular. Abnormal sounds may be heard when there is increased ?uid in the lungs or ?brosis (crepitation or crackles), when there is bronchospasm (rhonchi or wheezes), or when the lung is airless (consolidated – bronchial breathing). Breath sounds are absent in people with pleural e?usion, pneumothorax, or after pneumonectomy.... breath sounds

Cough

A natural re?ex reaction to irritation of the AIR PASSAGES and LUNGS. Air is drawn into the air passages with the GLOTTIS wide open. The inhaled air is blown out against the closed glottis, which, as the pressure builds up, suddenly opens, expelling the air – at an estimated speed of 960 kilometres (600 miles) an hour. This explosive exhalation expels harmful substances from the respiratory tract. Causes of coughing include infection – for example, BRONCHITIS or PNEUMONIA; in?ammation of the respiratory tract associated with ASTHMA; and exposure to irritant agents such as chemical fumes or smoke (see also CROUP).

The explosive nature of coughing results in a spray of droplets into the surrounding air and, if these are infective, hastens the spread of colds (see COLD, COMMON) and INFLUENZA. Coughing is, however, a useful reaction, helping the body to rid itself of excess phlegm (mucus) and other irritants. The physical e?ort of persistent coughing, however, can itself increase irritation of the air passages and cause distress to the patient. Severe and protracted coughing may, rarely, fracture a rib or cause PNEUMOTHORAX. Coughs can be classi?ed as productive – when phlegm is present – and dry, when little or no mucus is produced.

Most coughs are the result of common-cold infections but a persistent cough with yellow or green sputum is indicative of infection, usually bronchitis, and sufferers should seek medical advice as medication and postural drainage (see PHYSIOTHERAPY) may be needed. PLEURISY, pneumonia and lung CANCER are all likely to cause persistent coughing, sometimes associated with chest pain, so it is clearly important for people with a persistent cough, usually accompanied by malaise or PYREXIA, to seek medical advice.

Treatment Treatment of coughs requires treatment of the underlying cause. In the case of colds, symptomatic treatment with simple remedies such as inhalation of steam is usually as e?ective as any medicines, though ANALGESICS or ANTIPYRETICS may be helpful if pain or a raised temperature are among the symptoms. Many over-the-counter preparations are available and can help people cope with the symptoms. Preparations may contain an analgesic, antipyretic, decongestant or antihistamine in varying combinations. Cough medicines are generally regarded by doctors as ine?ective unless used in doses so large they are likely to cause sedation as they act on the part of the brain that controls the cough re?ex.

Cough suppressants may contain CODEINE, DEXTROMETHORPHAN, PHOLCODINE and sedating ANTIHISTAMINE DRUGS. Expectorant preparations usually contain subemetic doses of substances such as ammonium chloride, IPECACUANHA, and SQUILL (none of which have proven worth), while demulcent preparations contain soothing, harmless agents such as syrup or glycerol.

A list of systemic cough and decongestant preparations on sale to the public, together with their key ingredients, appears in the British National Formulary.... cough

Indirect Insult

Septic, haemorrhagic and cardiogenic SHOCK

METABOLIC DISORDERS such as URAEMIA and pancreatitis (see PANCREAS, DISORDERS OF)

Bowel infarction

Drug ingestion

Massive blood transfusion, transfusion reaction (see TRANSFUSION OF BLOOD), CARDIOPULMONARY BYPASS, disseminated intravascular coagulation

Treatment The principles of management are supportive, with treatment of the underlying condition if that is possible. Oxygenation is improved by increasing the concentration of oxygen breathed in by the patient, usually with mechanical ventilation of the lungs, often using continuous positive airways pressure (CPAP). Attempts are made to reduce the formation of pulmonary oedema by careful management of how much ?uid is given to the patient (?uid balance). Infection is treated if it arises, as are the possible complications of prolonged ventilation with low lung compliance (e.g. PNEUMOTHORAX). There is some evidence that giving surfactant through a nebuliser or aerosol may help to improve lung e?ectiveness and reduce oedema. Some experimental evidence supports the use of free-radical scavengers and ANTIOXIDANTS, but these are not commonly used. Other techniques include the inhalation of NITRIC OXIDE (NO) to moderate vascular tone, and prone positioning to improve breathing. In severe cases, extracorporeal gas exchange has been advocated as a supportive measure until the lungs have healed enough for adequate gas exchange. (See also RESPIRATORY DISTRESS SYNDROME; HYALINE MEMBRANE DISEASE; SARS.)... indirect insult

Pneumoperitoneum

A collection of air in the peritoneal cavity (see PERITONEUM). Air introduced into the peritoneal cavity collects under the diaphragm which is thus raised and collapses the lungs. This procedure was sometimes carried out in the treatment of pulmonary tuberculosis in the pre-antibiotic days as an alternative to arti?cial PNEUMOTHORAX.... pneumoperitoneum

Bulla

n. (pl. bullae) 1. a large blister, containing serous fluid. 2. (in anatomy) a rounded bony prominence. 3. a thin-walled air-filled space within the lung, arising congenitally or in *emphysema. It may cause trouble by rupturing into the pleural space (see pneumothorax), by adding to the air that does not contribute to gas exchange, and/or by compressing the surrounding lung and making it inefficient. —bullous adj.... bulla

Drain

1. n. a device, usually a tube or wick, used to draw fluid from an internal body cavity to the surface. A drain is sometimes inserted during an operation to ensure that any fluid formed immediately passes to the surface, so preventing an accumulation that may become infected or cause pressure in the operation site. Negative pressure (suction) can be applied through a tube drain to increase its effectiveness. Chest drains can be used in the treatment of chest trauma to drain blood (haemothorax) or air (pneumothorax) that accumulates in the pleural space. 2. vb. see drainage.... drain

Flail Chest

fracture of two or more ribs in two or more places, resulting from trauma. It produces an unstable ‘flail’ segment and is often associated with underlying lung trauma or pneumothorax. It leads to asphyxia unless corrected promptly.... flail chest

Chronic Obstructive Pulmonary Disease (copd)

This is a term encompassing chronic BRONCHITIS, EMPHYSEMA, and chronic ASTHMA where the air?ow into the lungs is obstructed.

Chronic bronchitis is typi?ed by chronic productive cough for at least three months in two successive years (provided other causes such as TUBERCULOSIS, lung cancer and chronic heart failure have been excluded). The characteristics of emphysema are abnormal and permanent enlargement of the airspaces (alveoli) at the furthermost parts of the lung tissue. Rupture of alveoli occurs, resulting in the creation of air spaces with a gradual breakdown in the lung’s ability to oxygenate the blood and remove carbon dioxide from it (see LUNGS). Asthma results in in?ammation of the airways with the lining of the BRONCHIOLES becoming hypersensitive, causing them to constrict. The obstruction may spontaneously improve or do so in response to bronchodilator drugs. If an asthmatic patient’s airway-obstruction is characterised by incomplete reversibility, he or she is deemed to have a form of COPD called asthmatic bronchitis; sufferers from this disorder cannot always be readily distinguished from those people who have chronic bronchitis and/ or emphysema. Symptoms and signs of emphysema, chronic bronchitis and asthmatic bronchitis overlap, making it di?cult sometimes to make a precise diagnosis. Patients with completely reversible air?ow obstruction without the features of chronic bronchitis or emphysema, however, are considered to be suffering from asthma but not from COPD.

The incidence of COPD has been increasing, as has the death rate. In the UK around 30,000 people with COPD die annually and the disorder makes up 10 per cent of all admissions to hospital medical wards, making it a serious cause of illness and disability. The prevalence, incidence and mortality rates increase with age, and more men than women have the disorder, which is also more common in those who are socially disadvantaged.

Causes The most important cause of COPD is cigarette smoking, though only 15 per cent of smokers are likely to develop clinically signi?cant symptoms of the disorder. Smoking is believed to cause persistent airway in?ammation and upset the normal metabolic activity in the lung. Exposure to chemical impurities and dust in the atmosphere may also cause COPD.

Signs and symptoms Most patients develop in?ammation of the airways, excessive growth of mucus-secreting glands in the airways, and changes to other cells in the airways. The result is that mucus is transported less e?ectively along the airways to eventual evacuation as sputum. Small airways become obstructed and the alveoli lose their elasticity. COPD usually starts with repeated attacks of productive cough, commonly following winter colds; these attacks progressively worsen and eventually the patient develops a permanent cough. Recurrent respiratory infections, breathlessness on exertion, wheezing and tightness of the chest follow. Bloodstained and/or infected sputum are also indicative of established disease. Among the symptoms and signs of patients with advanced obstruction of air?ow in the lungs are:

RHONCHI (abnormal musical sounds heard through a STETHOSCOPE when the patient breathes out).

marked indrawing of the muscles between the ribs and development of a barrel-shaped chest.

loss of weight.

CYANOSIS in which the skin develops a blue tinge because of reduced oxygenation of blood in the blood vessels in the skin.

bounding pulse with changes in heart rhythm.

OEDEMA of the legs and arms.

decreasing mobility.

Some patients with COPD have increased ventilation of the alveoli in their lungs, but the levels of oxygen and carbon dioxide are normal so their skin colour is normal. They are, however, breathless so are dubbed ‘pink pu?ers’. Other patients have reduced alveolar ventilation which lowers their oxygen levels causing cyanosis; they also develop COR PULMONALE, a form of heart failure, and become oedematous, so are called ‘blue bloaters’.

Investigations include various tests of lung function, including the patient’s response to bronchodilator drugs. Exercise tests may help, but radiological assessment is not usually of great diagnostic value in the early stages of the disorder.

Treatment depends on how far COPD has progressed. Smoking must be stopped – also an essential preventive step in healthy individuals. Early stages are treated with bronchodilator drugs to relieve breathing symptoms. The next stage is to introduce steroids (given by inhalation). If symptoms worsen, physiotherapy – breathing exercises and postural drainage – is valuable and annual vaccination against INFLUENZA is strongly advised. If the patient develops breathlessness on mild exertion, has cyanosis, wheezing and permanent cough and tends to HYPERVENTILATION, then oxygen therapy should be considered. Antibiotic treatment is necessary if overt infection of the lungs develops.

Complications Sometimes rupture of the pulmonary bullae (thin-walled airspaces produced by the breakdown of the walls of the alveoli) may cause PNEUMOTHORAX and also exert pressure on functioning lung tissue. Respiratory failure and failure of the right side of the heart (which controls blood supply to the lungs), known as cor pulmonale, are late complications in patients whose primary problem is emphysema.

Prognosis This is related to age and to the extent of the patient’s response to bronchodilator drugs. Patients with COPD who develop raised pressure in the heart/lung circulation and subsequent heart failure (cor pulmonale) have a bad prognosis.... chronic obstructive pulmonary disease (copd)

Hydropneumothorax

n. the presence of air and fluid in the pleural cavity. If the patient is shaken the fluid makes a splashing sound (called a succussion splash). An *effusion of serous fluid commonly complicates a *pneumothorax, and must be drained.... hydropneumothorax

Pleurectomy

n. surgical removal of part of the *pleura, which is sometimes done to prevent further recurrences of spontaneous *pneumothorax or to remove diseased areas of pleura.... pleurectomy

Pneumomediastinum

n. air in the mediastinum visible on chest X-ray. It can be a complication of surgical *emphysema due to pneumothorax, but the air can originate from the upper airways or the upper gastrointestinal tract. A rare cause is gas-forming organisms. See Hamman’s sign.... pneumomediastinum

Pulseless Electrical Activity

(electromechanical dissociation) the appearance of normal-looking complexes on the electrocardiogram that are, however, associated with a state of *cardiac arrest. It is usually caused by large pulmonary emboli (see pulmonary embolism), *cardiac tamponade, tension *pneumothorax, severe disturbance of body salt levels, severe haemorrhage, or hypothermia causing severe lack of oxygen to the heart muscle.... pulseless electrical activity

Intermittent Positive Pressure (ipp)

The simplest form of intermittent positive-pressure ventilation is mouth-to-mouth resuscitation (see APPENDIX 1: BASIC FIRST AID) where an individual blows his or her own expired gases into the lungs of a non-breathing person via the mouth or nose. Similarly gas may be blown into the lungs via a face mask (or down an endotracheal tube) and a self-in?ating bag or an anaesthetic circuit containing a bag which is in?ated by the ?ow of fresh gas from an anaesthetic machine, gas cylinder, or piped supply. In all these examples expiration is passive.

For more prolonged arti?cial ventilation it is usual to use a specially designed machine or ventilator to perform the task. The ventilators used in operating theatres when patients are anaesthetised and paralysed are relatively simple devices.They often consist of bellows which ?ll with fresh gas and which are then mechanically emptied (by means of a weight, piston, or compressed gas) via a circuit or tubes attached to an endotracheal tube into the patient’s lungs. Adjustments can be made to the volume of fresh gas given with each breath and to the length of inspiration and expiration. Expiration is usually passive back to the atmosphere of the room via a scavenging system to avoid pollution.

In intensive-care units, where patients are not usually paralysed, the ventilators are more complex. They have electronic controls which allow the user to programme a variety of pressure waveforms for inspiration and expiration. There are also programmes that allow the patient to breathe between ventilated breaths or to trigger ventilated breaths, or inhibit ventilation when the patient is breathing.

Indications for arti?cial ventilation are when patients are unable to achieve adequate respiratory function even if they can still breathe on their own. This may be due to injury or disease of the central nervous, cardiovascular, or respiratory systems, or to drug overdose. Arti?cial ventilation is performed to allow time for healing and recovery. Sometimes the patient is able to breathe but it is considered advisable to control ventilation – for example, in severe head injury. Some operations require the patient to be paralysed for better or safer surgical access and this may require ventilation. With lung operations or very unwell patients, ventilation is also indicated.

Arti?cial ventilation usually bypasses the physiological mechanisms for humidi?cation of inspired air, so care must be taken to humidify inspired gases. It is important to monitor the e?cacy of ventilation – for example, by using blood gas measurement, pulse oximetry, and tidal carbon dioxide, and airways pressures.

Arti?cial ventilation is not without its hazards. The use of positive pressure raises the mean intrathoracic pressure. This can decrease venous return to the heart and cause a fall in CARDIAC OUTPUT and blood pressure. Positive-pressure ventilation may also cause PNEUMOTHORAX, but this is rare. While patients are ventilated, they are unable to breathe and so accidental disconnection from the ventilator may cause HYPOXIA and death.

Negative-pressure ventilation is seldom used nowadays. The chest or whole body, apart from the head, is placed inside an airtight box. A vacuum lowers the pressure within the box, causing the chest to expand. Air is drawn into the lungs through the mouth and nose. At the end of inspiration the vacuum is stopped, the pressure in the box returns to atmospheric, and the patient exhales passively. This is the principle of the ‘iron lung’ which saved many lives during the polio epidemics of the 1950s. These machines are cumbersome and make access to the patient di?cult. In addition, complex manipulation of ventilation is impossible.

Jet ventilation is a relatively modern form of ventilation which utilises very small tidal volumes (see LUNGS) from a high-pressure source at high frequencies (20–200/min). First developed by physiologists to produce low stable intrathoracic pressures whilst studying CAROTID BODY re?exes, it is sometimes now used in intensive-therapy units for patients who do not achieve adequate gas exchange with conventional ventilation. Its advantages are lower intrathoracic pressures (and therefore less risk of pneumothorax and impaired venous return) and better gas mixing within the lungs.... intermittent positive pressure (ipp)

Breathing

The process by which air passes into and out of the lungs to allow the blood to take up oxygen and dispose of carbon dioxide. Breathing is controlled by the respiratory centre in the brainstem. When air is inhaled, the diaphragm contracts and flattens. The intercostal muscles (muscles between the ribs) contract and pull the ribcage upwards and outwards. The resulting increase in chest volume causes the lungs to expand, and the reduced pressure draws air into the lungs. When air is exhaled, the chest muscles and diaphragm relax, causing the ribcage to sink and the lungs to contract, squeezing air out.

In normal, quiet breathing, only about a 10th of the air in the lungs passes out to be replaced by the same amount of fresh air (tidal volume). This new air mixes with the stale air (residual volume) already held in the lungs. The normal breathing rate for an adult at rest is 13–17 breaths per minute. (See also respiration.)breathing difficulty Laboured or distressed breathing that includes a change in the rate and depth of breathing or a feeling of breathlessness. Some degree of breathlessness is normal after exercise, particularly in unfit or overweight people. Breathlessness at rest is always abnormal and is usually due to disorders that affect the airways (see asthma), lungs (see pulmonary disease, chronic obstructive), or cardiovascular system (see heart failure). Severe anxiety can result in breathlessness, even when the lungs are normal (see hyperventilation). Damage to the breathing centre in the brainstem due to a stroke or head injury can affect breathing. This may also happen as a side effect of certain drugs. Ventilator assistance is sometimes needed.

At high altitudes, the lungs have to work harder in order to provide the body with sufficient oxygen (see mountain sickness). Breathlessness may occur in severe anaemia because abnormal or low levels of the oxygen-carrying pigment haemoglobin means that the lungs need to work harder to supply the body with oxygen. Breathing difficulty that intensifies on exertion may be caused by reduced circulation of blood through the lungs. This may be due to heart failure, pulmonary embolism, or pulmonary hypertension. Breathing difficulty due to air-flow obstruction may be caused by chronic bronchitis, asthma, an allergic reaction, or lung cancer. Breathing difficulty may also be due to inefficient transfer of oxygen from the lungs into the bloodstream. Temporary damage to lung tissue may be due to pneumonia, pneumothorax, pulmonary oedema, or pleural effusion. Permanent lung damage may be due to emphysema. Chest pain (for example, due to a broken rib) that is made worse by chest or lung movement can make normal breathing difficult and painful, as can pleurisy, which is associated with pain in the lower chest and often in the shoulder tip of the affected side.

Abnormalities of the skeletal structure of the thorax (chest), such as severe scoliosis or kyphosis, may cause difficulty in breathing by impairing normal movements of the ribcage.... breathing

Lungs, Diseases Of

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

Ribavirin

n. an antiviral drug effective against a range of DNA and RNA viruses, including the herpes group, *respiratory syncytial virus, and *hepatitis C. Possible side-effects include breathing difficulty, bacterial pneumonia, and *pneumothorax (when inhaled) and haemolytic anaemia (with oral treatment); it also antagonizes the action of *zidovudine against HIV.... ribavirin

Lung

One of the 2 main organs of the respiratory system. The lungs supply the body with the oxygen needed for aerobic metabolism and eliminate the waste product carbon dioxide. Air is delivered to the lungs via the trachea (windpipe); this branches into 2 main bronchi (air passages), with 1 bronchus supplying each lung. The main bronchi divide again into smaller bronchi and then into bronchioles, which lead to air passages that open out into grape-like air sacs called alveoli (see alveolus, pulmonary). Oxygen and carbon dioxide diffuse into or out of the blood through the thin walls of the alveoli. Each lung is enclosed in a double membrane called the pleura; thetwo layers of the pleura secrete a lubricating fluid that enables the lungs to move freely as they expand and contract during breathing. (See also respiration.) lung cancer The most common form of cancer in the. Tobacco-smoking is the main cause. Passive smoking (the inhalation of tobacco smoke by nonsmokers) and environmental pollution (for example, with radioactive minerals or asbestos) are also risk factors.

The first and most common symptom is a cough. Other symptoms include coughing up blood, shortness of breath, and chest pain. Lung cancer can spread to other parts of the body, especially the liver, brain, and bones. In most cases, the cancer is revealed in a chest X-ray. To confirm the diagnosis, tissue must be examined microscopically for the presence of cancerous cells (see cytology). If lung cancer is diagnosed at an early stage, pneumonectomy (removal of the lung) or lobectomy (removal of part of the lung) may be possible. Anticancer drugs and radiotherapy may also be used. lung, collapse of See atelectasis; pneumothorax.... lung

Lung, Disorders Of

The most common lung disorders are infections. These diseases include pneumonia, tracheitis, and croup. Bronchitis and bronchiolitis, which are inflammatory disorders affecting the airways within the lungs, can be complications of colds or influenza. The disorder bronchiectasis may occur as a complication of severe bacterial pneumonia o.

cystic fibrosis. The lungs can also be affected by allergic disorders. The most important of these is asthma. Another such disorder is allergic alveolitis, which is usually a reaction to dust of plant or animal origin. Irritation of the airways, usually by tobacco-smoking, can cause diseases characterized by damage to lung tissue and narrowing of the airways (see pulmonary disease, chronic obstructive). The lungs can also be affected by cancerous tumours; lung cancer is one of the most common cancers. Noncancerous lung tumours are uncommon.

Injury to a lung, usually resulting from penetration of the chest wall, can cause the lung to collapse (see pneumothorax; haemothorax). Damage to the interior of the lungs can be caused by inhalation of toxic substances (see asbestosis; silicosis). Blood supply to the lungs may be reduced by pulmonary embolism.

Lung disorders can be investigated in various ways, such as chest X-ray, bronchoscopy, and pulmonary function tests.... lung, disorders of

Pertussis

A highly contagious infectious disease, also called whooping cough, which mainly affects infants and young children. The main features of the illness are bouts of coughing, often ending in a characteristic “whoop”. The main cause is infection with BORDETELLA PERTUSSIS bacteria, which are spread in airborne droplets.

After an incubation period of 7–10 days, the illness starts with a mild cough, sneezing, nasal discharge, fever, and sore eyes. After a few days, the cough becomes more persistent and severe, especially at night. Whooping occurs in most cases. Sometimes the cough can

cause vomiting. In infants, there is a risk of temporary apnoea following a coughing spasm. The illness may last for a few weeks. The possible complications include nosebleeds, dehydration, pneumonia, pneumothorax, bronchiectasis (permanent widening of the airways), and convulsions. Untreated, pertussis may prove fatal.

Pertussis is usually diagnosed from the symptoms. In the early stages, erythromycin is often given to reduce the child’s infectivity. Treatment consists of keeping the child warm, giving small, frequent meals and plenty to drink, and protecting him or her from stimuli, such as smoke, that can provoke coughing. If the child becomes blue or persistently vomits after coughing, hospital admission is needed.

In developed countries, most infants are vaccinated against pertussis in the 1st year of life. It is usually given as part of the DPT vaccination at 2, 3, and 4 months of age. Possible complications include a mild fever and fretfulness. Very rarely, an infant may have a severe reaction, with high-pitched screaming or seizures.... pertussis

Tuberculosis

An infectious disease, commonly called , caused in humans by the bacterium MYCOBACTERIUM TUBERCULOSIS. is usually transmitted in airborne droplets expelled when an infected person coughs or sneezes. An inhaled droplet enters the lungs and the bacteria begin multiplying. The immune system usually seals off the infection at this point, but in about 5 per cent of cases the infection spreads to the lymph nodes. It may also spread to other organs through the bloodstream, which may lead to miliary tuberculosis, a potentially fatal form of the disease.

In about another 5 per cent of cases, bacteria held in a dormant state by the immune system become reactivated months, or even years, later. The infection may then progressively damage the lungs, forming cavities.

The primary infection is usually without symptoms. Progressive infection in the lungs causes coughing (sometimes bringing up blood), chest pain, shortness of breath, fever and sweating, poor appetite, and weight loss. Pleural effusion or pneumothorax may develop. The lung damage may be fatal.

A diagnosis is made from the symptoms and signs, from a chest X-ray, and from tests on the sputum. Alternatively, a bronchoscopy may also be carried out to obtain samples for culture.

Treatment is usually with a course of 3 or 4 drugs, taken daily for 2 months, followed by daily doses of isoniazid and rifampicin for 4–6 months. However, bacteria are increasingly resistant to the drugs used in treatment, and others may have to be used and treatment carried out for a longer period. If the full course of drugs is taken, most patients recover.

can be prevented by BCG vaccination, which is offered routinely at birth or age 10–14.

Any contacts of an infected person are traced and examined, and, if infected, are treated early to reduce the risk of the infection spreading.... tuberculosis




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