1 Alverti A, Quaranta M, Chakrabarti B, et al. Paradoxical movement of the lower rib cage at rest and during exercise in COPD patients. Eur Respir J 2009; 33: 49–60. 2 Douglas G, Nicol F, Robertson C. Macleod’s Clinical Examination. London: Churchill Livingstone Elsevier, 2009. 3 Morice AH, McGarvey L, Pavord I, British Thoracic Society Guideline Group. Recommendations for the management of cough in adults. Thorax 2006; 61 (Suppl. 1): 1–24. 4 Spiteri M, Cook D, Clarke S. Reliability of eliciting physical signs in examination of the chest. Lancet 1988; 1: 873–5. 5 Vyshedsky A, Alhashem RM, Paciej R, et al. Mechanism of inspiratory and expiratory crackles. Chest 2009; 135: 156–64.
Multiple choice questions
1 2.1 A 72‐year‐old man presents with breathlessness, clubbing and prominent fine bibasal crackles on auscultation of his chest. These findings are most consistent with:pulmonary oedemaidiopathic pulmonary fibrosisbronchiectasisemphysemalung cancer
2 2.2 A 76‐year‐old man presents with breathlessness. On examination, there is diminished expansion of the left hemithorax, breath sounds are louder on the right than the left. These features suggest: bronchiectsis on the rightconsolidation on the leftlobar collapse on the leftlobar collapse on the rightpneumothorax on the right
3 2.3 A 45‐year‐old woman is admitted to hospital with a 3‐day history of cough, breathlessness and right pleuritic pain. She has smoked 20 cigarettes/day for 25 years. On examination, chest expansion is diminished on the right. There is dullness over the right lung base with bronchial breathing and crackles. These features suggest: emphysemapneumonic consolidationpneumothorax on the leftpleural effusionpulmonary embolism
4 2.4 A 25‐year‐old woman presents with a sudden onset of chest pain while playing football. The pain ‘catches’ when she breathes in. She has smoked 10 cigarettes/day for 8 years. On examination, there are decreased breath sounds over the right hemithorax with hyperresonance on percussion. The trachea is central, jugular venous pressure is normal, heart sounds are normal and there is no tenderness on palpation of the chest. These features suggest: a pulmonary embolismpleurisy with a pleural effusiona traumatic rib fracturepneumonic consolidation with pleurisya pneumothorax
5 2.5 A 68‐year‐old man presents with worsening breathlessness over the past 5 years. He stopped smoking 10 years ago, having previously smoked 20 cigarettes/day for 50 years. He had worked with asbestos though that was as an apprentice at the age of 17. On examination, he is not clubbed. He is cyanosed. His chest is ‘barrel shaped’ with decreased cricosternal distance. The lower costal margin moves inwards during inspiration. There are diminished breath sounds but no crackles or wheeze. These features suggest a diagnosis of: chronic obstructive pulmonary diseaseasthmaasbestosispneumothoraxpulmonary oedema
6 2.6 A bovine cough is characteristic of: pharyngitisbovine TBfarmer’s lungcancer in the left lunginducible laryngeal obstruction
7 2.7 Which of the following is not a sign of airway obstruction? tracheal tugdull percussion notelower costal margin paradoxprolonged expiratory phase to respirationpursed lip breathing
8 2.8 Causes of clubbing include which of the following? lung cancerCOPDpneumoniaatrial septal defectliver cirrhosis
9 2.9 Diminished chest expansion on the left can be caused by which of the following? consolidation on the leftlobar collapse on the leftpleural effusion on the rightpneumothorax on the rightpneumonectomy on the left
10 2.10 A tension pneumothorax on the LEFT would cause which of the following? trachea deviated to the rightdull percussion note on the leftbreath sounds to be louder on the right than leftdiminished expansion on the left (compared to the right)diminished vocal resonance on the left
Multiple choice answers
1 2.1 BBilateral crackles and clubbing are characteristic features of pulmonary fibrosis. Pulmonary oedema may exhibit fine crackles but is not associated with clubbing.
2 2.2 CThe abnormal side always moves less so the abnormality must be on the left. Consolidation increases breath sounds, collapse diminishes conduction of breath sounds.
3 2.3 BPneumonic consolidation is characterised by dullness to percussion, bronchial breathing and crackles. Pneumonia is sometimes associated with inflammation of the overlying pleura, causing pleuritic pain.
4 2.4 EPneumothorax typically causes acute pleuritic pain and is characterised by reduced breath sounds and hyperresonance on the side of the pneumothorax. Pulmonary embolism and rib fracture would not be associated with hyperresonance. There would be tenderness associated with a rib fracture.
5 2.5 AHe has been a smoker and shows features of airways obstruction with paradoxical inward movement of the costal margins on inspiration (in a normal person they move outwards), with a hyperinflated chest (reduced cricosternal distance and increased A–P diameter ‘barrel shaped’). The reduced breath sounds and absence of wheeze are more characteristic of COPD than asthma. The presence of cyanosis indicates hypoxia and respiratory failure.
6 2.6 DSuggesting involvement of the recurrent laryngeal nerve.
7 2.7 BAirway obstruction leads to hyperinflation which (if severe enough) might be associated with a hyperresonant percussion note.
8 2.8 A, E
9 2.9 A, B, EWhatever the abnormality, the abnormal side moves less.
10 2.10 A, C, D, E
3 Pulmonary function tests
Despite the bewildering array of sophisticated tests and investigations now available, a few, fairly basic tests of lung function remain central to clinical practice. Together with a good history, clinical examination and a chest X‐ray, these tests provide most of the information needed for diagnosis, quantification of severity and monitoring of disease.
This chapter covers all you will probably ever need to know about lung function. The tests are not difficult to understand, yet despite their simplicity, they are all too often misinterpreted or even misunderstood. Master the next few pages and you may find you acquire the status of ‘expert’ in whatever medical circle you move in.
Normal values
Ventilatory performance varies greatly with patient height, age and sex. Tables and prediction equations are available to help determine a patient’s ‘predicted normal value’. The patient’s test result may be compared with the mean reference value and the standard deviation of results obtained in the healthy population or (more commonly, though less usefully) may be expressed as a percentage of the population’s mean reference value. For example, a man with a vital capacity of 3.95 litres (predicted value 4.70 litres). His result could be expressed as 84% of the predicted mean and an injudicious interpretation of this might lead to the mistaken assumption that there is a 16% ‘disability’. The deficit may be due to lung disease but the standard deviation for vital capacity is about 500 mL. His value is only 1.5 standard deviations from the mean, and many normal individuals (of the same age and size) with no apparent lung disease will have values lower than this.
Pulmonary function tests should not be interpreted in isolation and should be considered in the context of all additional information concerning the patient.
In this chapter, we will look at:
simple tests of ventilatory function
tests of gas transfer
arterial blood gases.
Simple tests of ventilatory function
Ventilation