Читать книгу Respiratory Medicine - Stephen J. Bourke - Страница 57

A voluntarily produced cough is an extremely useful but much neglected sign in respiratory examination. It is probably wise to start with it, lest it be missed. The clues it provides to later examination findings are so useful it can almost feel like cheating.

From the explanation of cough given earlier, it can be seen that when the vocal cords are not opposed, cough will no longer have its normal distinct, crisp start. Such a cough is known as bovine cough (cows don’t have vocal cords). It is a sign not to be missed, as it may result from tumour in the left side of the chest, causing recurrent laryngeal nerve palsy. The hoarse voice that accompanies this abnormality may be missed, particularly if the doctor and patient are meeting for the first time.

If airway obstruction is present, the cough will have a wheezy quality (listen out for it). As described already, the expiratory flow rate during a cough is greater than that generated in a normal forced expiration. Therefore, if airway obstruction is mild, it may be that wheeze is only heard during a cough.

When reporting a cough, a patient is usually asked if they produce sputum. The answer ‘no’ normally results in the doctor documenting that the cough is ‘dry’. Beware: an inability to ‘bring up’ sputum doesn’t imply it isn’t there. Consciously listening to the quality of a cough will avoid such a mistake.

Knowing whether a cough is wet or dry can be invaluable when it comes to determining the nature of the crackles heard later in the examination. Whilst in theory the ‘coarse’ crackles of bronchiectasis are different from the ‘fine’ crackles of fibrosis, in practice – on sound quality alone – it can be a difficult call. If you’ve already listened to the quality of the cough by the time of auscultation, your ability to distinguish fine from coarse will be uncannily good.

A loud, booming cough heard from one end of the ward to the other is unlikely to be as serious as it sounds.

Next, start with the hands and look for signs en route to the chest.