Past Medical and Social History – Lung Disease

00:00 The past medical history is important, because respiratory disease can be a consequence or related to previous medical problems. And there are numerous examples, but the common important ones are asthma, which childhood asthma often returns in an older adult and, therefore, could explain somebody who's presenting with cough or breathlessness at that point. Previous tuberculosis for two reasons: One is that actually TB often causes chronic lung damage, which can cause the presentation that you're reviewing the patient for there—hemoptysis, for example—due to underlying bronchiectasis caused by previous tuberculosis or a mycetoma. And also, previous tuberculosis means the patient could have—well, has latent tuberculosis and therefore is at risk of reactivated tuberculosis disease, which might explain their presentation. Hay fever and eczema (atopy) we've already discussed as a risk for asthma. Cardiac problems are important really as a differential diagnosis for respiratory patients who are presenting with dyspnea or edema. So if somebody's got a past history of hypertension, diabetes, ischemic heart disease, all these are predisposed to left ventricular failure, which would be a cause of breathlessness as a differential diagnosis of somebody presenting to a respiratory clinic.

01:15 Previous cancer is important, because the patient may be presenting with metastases from the cancer now affecting the respiratory system such as, for example, pleural metastases and pleural effusion. Or because the treatment that they receive for their cancer—and the classic example for that would be radiotherapy for breast cancer—can cause damage to the underlying lung, and that might explain why the patient has respiratory symptoms at that time. And chemotherapy, for example, can cause both widespread lung damage in the form of interstitial lung disease but also makes patients more likely to get various types of infection, and that might be why they're presenting with lung disease.

01:50 Patients with bronchiectasis: One of the major causes is previous severe childhood infections, and so those would need to be discussed if somebody might have bronchiectasis. And connective tissue diseases such as rheumatoid arthritis, systemic lupus erythematosus, dermatomyositis, systemic sclerosis: They are all associated with various types of lung disease, specifically lung interstitial infiltrations, which could be a differential diagnosis in somebody presenting with fibrosis. And a very important point is that premature birth and poor lung development in very early life actually, by reducing your overall lung volumes, makes you more likely to develop diseases such as COPD in the future. And if somebody's presenting with relatively early onset of breathlessness, it would be worth working out whether they had a premature birth that might have predisposed them to an earlier problem than they otherwise would have developed. With lung disease, because the lungs are exposed to the environment, what you do in that environment has a very big effect on the potential diseases you might have. And the most obvious example for that is that if you smoke. But there are other substances which are relevant—for example, if you smoke cannabis or if you inject drugs. In addition, the jobs that you do can expose you to various dusts and things which may be relevant for lung disease—the classic example being asbestos exposure and the risk of asbestos pleural disease, the other main example being pneumoconiosis, which are associated with mining and factory work. But asthma can be made worse by antigens which are present in your work environment, and that's so-called occupational asthma. And hypersensitivity pneumonitis is a problem where you get lung interstitial… so you get interstitial lung disease due to inhalation of an antigen to which you're allergic, and that is often due to exposure to birds or, if you're a farmer, due to fungi which grow in the hay, etc. So it's very important with respiratory disease—and specifically for interstitial lung diseases, asthma, and patients presenting with infiltrates in the lung—to identify their occupational history and social factors that might be relevant for their presentation.

04:27 Lastly, if you have a lung disease and you are more breathless than you should be, then there is the issue about who's going to be looking after you. If you're… have MRC Grade 4, for example, and you're breathless on moving around the house, who will do the housework for you? Who will go and get the shopping for you? And these issues are important and a part of the social history and need to be discussed with the patient, so you get a full feel for the effects of whatever respiratory disease they may have on their actual function in life. So to go into substance use, misuse, and abuse in a bit more detail: Cigarette smoking is associated with COPD but also… and lung cancer; everyone knows that. But it also massively increases your chance of pneumonia. It makes asthma very difficult to control. It increases your chance of pneumothorax. And it is associated with interstitial lung disease as well. Alcohol is not a major problem for lung disease, apart from the fact that it makes you more likely to get infections such as pneumonia or tuberculosis, and it makes you likely to get aspiration. So it's a classic presentation is that somebody has been out for a drink in one night and the next day presents having aspirated, with a pneumonitis affecting one lung. Also, alcohol is a sedative, and that does cause problems for patients with sleep apnea and other problems of ventilation of the lung, where sedatives make the ventilation… the underventilation that's occurring even worse.

05:52 And patients with alcoholic liver disease will present with pleural effusions. Recreational drugs other than smoking and alcohol—cocaine, intravenous heroin, crack—they are all relevant for lung disease. COPD, emphysema, asthma, HIV infection, pneumothorax, lung infections, tuberculosis, bullae... They're all related to recreational drug use, and as many patients that I see who have used to use recreational IV drugs in their early life are now presenting with emphysema or bullae in their later life, age 40 to 50s.

06:31 So smoking history: This is described in pack years. This is a vital part of the respiratory history. You need to know whether the patient has smoked in the past, is smoking now, or has never smoked. So often when we ask a patient, "Are you a smoker?" they say no. But that could be because they gave up smoking three weeks ago. So you just need to define whether it's ex-smoker or never smoked. And we describe the cigarette exposure in pack years. And that is one pack smoked each day for a year is one pack year. So for example if you have somebody who smoked 10 cigarettes a day for 20 years, that's equivalent to 10 pack years.

07:13 If you have somebody who smoked for 30 years, 30 cigarettes a day, then that's 45 pack years.

07:18 In general, COPD and lung cancer, you normally have to smoke around 20 pack years to get the increased risk for developing both those disease. That's a rule of thumb; there are exceptions to that. And certainly, it doesn't mean you will get lung cancer or COPD if you smoke 20 pack years; it just means your chance of developing those diseases is much, much higher. Treatment history and allergies: Well, you have to know the patient's allergies if you're going to give them… especially antibiotics.

07:49 Because penicillin allergy is not uncommon, and you give somebody with a penicillin allergy an antibiotic which is penicillin-based, then that is incredibly dangerous and potentially fatal error. So allergies: vital. You must know… must ask specifically about allergies.

08:04 But also, drug diseases cause respiratory problems. The commonest example, perhaps, may be ACE inhibitors, which are used for hypertension, and they are a common cause of chronic, intractable cough. And unless you take a good treatment history and ask the patient directly, you may not get the fact that they're on an ACE inhibitor volunteered.

08:24 The treatment history also gives you the chance to double-check their past medical history, because many patients won't mention the fact that they have hypertension, but then when you ask them about what drugs they're on, it turns out they're on antihypertensives.

08:36 That's a very common example of how patients think about their diseases.

08:42 Family history for respiratory disease is important in certain circumstances. There are diseases that run in families—-asthma, for example—and there are inherited genetic diseases, such as cystic fibrosis. And in addition, prior tuberculosis exposure makes you… through your family members makes you likely to have latent tuberculosis, and that might reflect what's happening with your presentation in a future life.

09:11 So just to summarize the main learning points for the clinical assessment, the history side of the clinical assessment: 1. A good history is essential and will help you identify what the medical problem is in a very high proportion of patients who are presenting. It will at least identify the clinical question that needs to be answered by targeted investigation. And this requires a systematic approach to the history to ensure every aspect is covered that might be important. 2. The demography, the social history, of the patient is important, because that does identify whether they are at risk of certain diseases. And you need to learn about what those associations are so you can ask the relevant questions for people presenting with specific problems.

09:58 3. You do need to know what causes the symptoms. So you have to know what the common causes of cough are, what the common causes of breathlessness are. Now fairly obvious, most of this, but if you don't know the important causes of symptoms, then you will not be able to exclude or include those causes in a differential diagnosis when discussing a problem with a patient. And that does include the rarer causes as well, because part of the art of medicine is to make sure that you don't always make the common diagnosis. So if a patient's presenting with cough, say it's asthma. But in fact, actually, it may not always be asthma. There are the occasional patients with rarer conditions which may be coming, which you would miss unless you knew that might be a presentation for… a cause of cough.

10:50 4. One aspect that often is underdone by students is the detail of the history of the presenting complaint. So I've discussed earlier when talking about breathlessness: You need to find out how long the patient's been breathless; the periodicity—whether it's up and down, whether it's constant, whether it's progressive. And actually ask very specific questions to get a full feel for how fast if it's progressive it's deteriorating or how severe the breathlessness is; what it stops them doing. And that needs to be done for all the sort of symptoms that… all the symptoms that the patient's presenting with. Obviously, this requires a bit of practice, and taking a good history which is fast, efficient, and targeted to get the information you require will require a detailed underlying knowledge about respiratory disease as well as constant practice of actually the art of taking the history from a patient.

11:50 Thank you.