Page 131 - Medicine and Surgery

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Chapter 3: Respiratory failure, heart disease and embolism 127

Table 3.16 Causes of a pneumothorax Tension pneumothorax (a large pneumothorax caus-
ing mediastinal shift) is a medical emergency and re-
Type Aetiology
quires aspiration immediately.
Spontaneous
Primary Most commonly thin, tall young men
Rupture of congenital subpleural bleb Pleurisy
Secondary Rupture of emphysematous bulla,
congenital cyst Definition
Asthma, COPD Acute inflammation of the pleura.
Pleural malignancy
Cystic fibrosis
Pneumonia Aetiology
Sarcoidosis The most common cause of pleurisy is infection, related
Traumatic Penetrating chest wounds to an underlying bacterial or viral pneumonia. Pleurisy
Rib fractures canalsobeafeatureofpulmonaryembolism,pulmonary
Oesophageal rupture
Iatrogenic Subclavian cannulation infarction, malignancy and connective tissue diseases
Positive pressure ventilation such as rheumatoid arthritis.
Pleural aspiration
Oesophageal perforation during endoscopy Clinical features
Lung biopsy
Sharp, well-localised pain, worse on inspiration or
coughing,andapleuralrubheardonauscultation.There
may be an associated pleural effusion.
Investigations
Chest X-ray shows the visceral pleura as a thin line with
Macroscopy
absent lung markings beyond.
Fibrinous exudate is seen over the pleural surfaces and
there is variable exudation of fluid.
Management
Observation if the pneumothorax is small. The air is
Investigations and treatment
Aimed at identification and treatment of the underlying
reabsorbed gradually over days to weeks.
cause.Nonsteroidalanti-inflammatorydrugsandparac-
If the pneumothorax is >20%, particularly if the pa-

etamol are used for analgesia.
tient has underlying lung disease or is significantly
dyspnoeic, then simple aspiration is indicated.
If this fails, i.e. the lung does not re-inflate sufficiently

or if the pneumothorax recurs, an intercostal drain Respiratory failure, heart
with underwater seal is required. If after a few days disease and embolism
the drain continues to bubble and the pneumothorax
persists this indicates a bronchopleural fistula, i.e. a Respiratory failure
continuedleakofairfromthelungtothepleuralspace.
This may require surgical treatment. Definition
Pleurectomy is indicated in recurrent pneumotho-
Respiratory failure is defined as a fall in the arterial oxy-
racesor for bronchopleural fistulae that fail to close gen tension below 8 kPa. Carbon dioxide tension defines
with conservative management. This is performed respiratory failure into type I (normal or low pCO 2 ) and
by stripping the pleura from the inside of the chest type II (pCO 2 above 6 kPa).
through a limited thoracotomy. Any blebs or bul-
lae are stapled or tied off and the lung re-inflated. Aetiology/pathophysiology
The opposition of lung to the raw area on the chest Type I failure, sometimes called ‘acute hypoxaemic
wall causes the surfaces to adhere to one another. respiratoryfailure’,isusuallyduetomismatchbetween
Talc or another irritant is often used to improve this ventilation and perfusion or right to left shunts. It
adherence. can occur in any respiratory disease most commonly