Lung Examination: Clubbing, Trachea and Expansion – Lung Disease

00:02 Moving onto the hands, I mentioned clubbing is a very important respiratory sign. It’s actually relatively rare but if somebody’s clubbed you need to find the reason for that.

00:11 And the respiratory causes for that will be lung cancer, bronchiectasis – especially the severe end in cystic fibrosis – pulmonary fibrosis and then occasionally, although this is less common now we have routine antibiotic use for infections, prolonged lung abscess and prolonged empyema.

00:28 What we mean by clubbing is that the normal angle of the nail bed has been lost. And the reason why it’s been lost is it’s been filled in by this spongy tissue. So there’s two things when you examine a patient for clubbing: one is that the nail curves over and the second is that, when you squeeze that nail bed, it feel spongy. It bounces a little bit.

00:52 Now there are non-respiratory causes to clubbing as well and these need to be considered if you identify clubbing in somebody presenting with respiratory problems. An example: it’s not uncommon to come across somebody with liver cirrhosis that is causing clubbing and they have a respiratory disease which is pretty independent of that.

01:10 So the non-respiratory causes: liver cirrhosis, bacterial endocarditis, congenital cyanotic heart disease and inflammatory-bowel disease. And occasionally you get patients with idiopathic clubbing. In fact, this x-ray is an example of idiopathic clubbing. It’s clear. The patient’s clubbed but there was no reason. And they’re a relatively young patient with no active problem that might explain why they’re clubbed.

01:35 Moving on to the – examining the mediastinum: mediastinal shift is a very important sign is respiratory disease. And a shift of the mediastinum occurs if one lung has been made smaller or if that hemithorax has increased in volume. So if you have a disease that makes the lung smaller, that will pull the mediastinum across and you can feel that when you’re examining the trachea, as the trachea’s being shifted to the affected side. And the apex beat will also move with that. So that, for a left-sided lesion, the apex beat will move round the chest wall. For a right-sided lesion causing a shift to the mediastinum to the right, it will pull the apex beat across towards the right. An increased volume on a hemithorax will do the opposite. So it’s a sign of a unilateral lung disease problem.

02:31 So the diseases that shift towards the abnormal side is when you get collapse. A bronchus has been obstructed and all the air distal to that bronchus has been resorbed and that lobe or that lung, if the main bronchus has been obstructed, will collapse down and form a smaller volume. And that will pull the trachea towards it.

02:53 The same thing happens with a pneumonectomy. Of course, the patient with a pneumonectomy or lobectomy will have a surgical scar as well. And occasionally, you get the same thing happening after severe destructive lung infections – tuberculosis being the best example. Chronic empyema can also cause something similar, as can mesothelioma which, in the end stages, cause a very restricted lung with pleural thickening around the outside, getting smaller and smaller compared to the other side.

03:19 The opposite – when you get mediastinal shift away from the abnormal side largely occurs with pleural problems. Either very big pleural effusions or pneumothoraxes. And there are the occasional very large pleural lung tumours that can push the mediastinum across. But they’re unusual.

03:36 Lung expansion: now this is different to hyperexpansion. Hyperexpansion means that the chest is, as you look at it, visibly bigger than it should be. Expansion is the movement that occurs on inspiration of the chest wall. So that should be equal and about 2 or 3 cm in total.

03:55 But clearly, it depends to a certain extent on the patient’s size. A small person will have less expansion during inspiration than a large person.

04:05 Expansion can only go down with pathology. So the question with expansion is: is it normal – equal expansion on both sides – or is it reduced? And if it’s reduced then the question is whether it is unilaterally reduced, on one side, suggesting the right side’s been affected, or both sides, suggesting a bilateral disease. The trouble about bilateral expansion being reduced is that it’s quite difficult to detect, unless it’s very obvious.

04:35 Causes of unilateral reduction in expansion: well, any disease that occurs on one side of the chest is going to affect expansion of that chest if it’s extensive enough.

04:43 A large pneumothorax, and even a small pneumothorax probably would be detectable by careful clinical examination. A severe pneumonia, a pleural effusion, lung collapse, a previous surgery to remove lobes or the whole lung itself and again, destructive lesions of the lung, mesothelioma and pleural thickening. They will all reduce expansion on the affected side.

05:04 Bilateral diseases: well, by definition, you’re talking about diseases that affect both lungs equally. And that will be airways diseases such as COPD and asthma, interstitial lung diseases and bronchiectasis, depending on the cause. Some causes of bronchiectasis are unilateral, most are bilateral.