Co-morbid cardio-respiratory disease: diagnostic dilemmas

Part one: Cardiac and respiratory symptoms are often non-specific and the skill of the clinician in assembling the clues gained from careful history taking and assessment is paramount. Nurses working in advanced roles may be faced with patients whose history, signs and symptoms can be related to new or pre-existing pathology. They need to develop and hone their diagnostic skills.

Recent changes in the NHS means that GP clinical commissioning groups (CCG) are having to think more creatively about how and where to spend, and save, money. The Department of Health's Quality, Innovation, Productivity and Prevention (QIPP) programme is developing projects to support the NHS to commission care more effectively. This includes reviewing the way in which the NHS cares for people with long-term conditions. The QIPP programme has a responsibility for 'supporting the NHS to improve staff productivity, non-clinical procurement, the use and procurement of medicines, and workforce'.¹ It has the potential to review how we run, staff and supply our organisations, all of which is highly relevant for nurses working at the 'coalface'.

One of the biggest areas of expenditure in the NHS is in the extensive range of long-term conditions, including diabetes, chronic lung disease and dementia. Most of the costs associated with long-term conditions, however, are linked to unplanned admissions and/or the complications of these conditions. For example, more money is spent on treating the complications of diabetes than on treating the condition itself.² It goes without saying that prompt recognition of symptoms and early diagnosis is vital in reducing both admissions and complications. However, co-morbidities are common in those with a long term condition.³ It can therefore be more difficult to determine the cause of an acute episode of ill health and this may result in delays in instigating appropriate treatment - with obvious implications for both patients and the NHS.

The presentation of respiratory and cardiac disease is often similar. Symptoms such as dyspnoea, tight chest and cough are common, but may have different underlying causes. Careful assessment and diagnosis is therefore particularly important in order that an accurate diagnosis is reached. This article, the first of a two part series, will use a case study approach to explore how patients with comorbidities can present and how the history, assessment and objective tests can help to improve the diagnostic process and increase the likelihood of effective and timely management. The second article will cover the management of such patients in more detail.

COMPETENCE

A general practice nurse (GPN) working at a more advanced level, seeing patients either within a long-term conditions clinic or with acute undifferentiated illness, may well see the type of patient illustrated by the following case study. It not only explains the importance of careful assessment and diagnosis, but also demonstrates the medico-legal importance of working within your competence level.

The Working in Partnership Programme (WIPP) developed The General Practice Nurse Toolkit to enable nurses to understand how to identify the competencies needed in their role and to allow them to measure their own competence levels.

INTRODUCING JED

Jed is a 67 year-old, with an extensive past medical history, which includes:

• COPD
• Type 2 diabetes
• Hypertension
• A myocardial infarction (MI) seven years ago.

Jed attends for review of his COPD and, in the course of this review, the COPD Assessment Test (CAT)⁴ is implemented, a tool which can be used to assess the impact of COPD on the patient's life. The CAT identifies that Jed has been suffering from a productive cough and has been feeling more short of breath lately. He has used his own supply of steroids and antibiotics, as stated in his COPD management plan, but is no better. He did not attend sooner as he 'did not want to bother anyone'.

Jed's case study can be used to illustrate the importance of careful history taking. There are several potential causes for his symptoms, both relating to his known diagnoses but also to possible new conditions, which may - or may not - be related to the pre-existing ones. It would therefore be useful to think about what else might be helpful to know at this stage.

HISTORY TAKING

Open questions should be used, such as:

'Tell me how this all started.'

'What else have you noticed apart from the cough and breathlessness?'

This type of question allows Jed to introduce his own concerns and priorities into the consultation at the start. It gives you the opportunity to address his agenda and, if necessary, delve further.

A systematic and logical approach to history taking will ensure that all necessary areas are covered and the temptation to jump to conclusions avoided. This initial history-taking session should include:

• The history of the presenting complaint (plus aggravating and relieving factors)
• Past medical history
• Weight
• Sleep patterns
• Lifestyle (diet, activity levels, smoking, alcohol intake)
• Psychosocial status
• Drug history (including prescription, over-the-counter and recreational drug use), and compliance with prescribed drug regimens
• An overview of other systems (gastro-intestinal, genito-urinary, neurological etc.).

The order in which these areas are explored can be varied, but it is important that they are all covered.

JED'S HISTORY

Psychosocial

Jed is a retired plumber who was widowed 8 years ago. He lives alone in his own home with his dog. His daughter, who visits once a week, also shops and cleans for him. He manages his own laundry and personal care. He has no financial concerns and is generally 'happy with his lot'.

Lifestyle

He is an ex-smoker, having quit 4 years ago, with a 40-pack year history. He drinks 2 bottles of beer a night, equivalent to 5 units a day, and also has two large whiskies twice a week. He tries to include fruit and vegetables with his meals but finds ready meals easier to prepare for one and relies on these at least once a day, most days. He also eats at his local pub two or three times a week. He normally walks his dog twice a day for 20 minutes.

Symptom review

Apart from the current health concerns, described above, he had no other new symptoms.

Drug history

Drug history revealed that he took metformin 2g and pioglitazone 45mg daily for his diabetes. He also took amlodipine 10mg for his blood pressure along with atenolol 50mg, ramipril 10mg, simvastatin 40mg and aspirin 75mg as part of his post MI treatment. For his COPD he took a licensed combination inhaler⁵ and a short acting beta2 agonist inhaler for symptom relief.

Current presentation

When taking a history, it is useful to concentrate initially on the acute presentation before considering other elements of the history.⁶

Jed explains that as well as the cough and breathlessness he has felt more tired and run down lately. He has felt less able to walk his dog and has reduced his walks from twice daily to just once. As a result of the relative reduction in his activity levels he feels he has gained weight, and is feeling increasingly bloated around the middle. He has also noticed some ankle swelling.

All of these symptoms offer potential cause for concern. People may often construct a diagnosis from their symptoms, based on experience of other people's illness, Internet self-diagnosis websites or even a need to deny the possibility of more serious underlying problems. Although it is important to address these health beliefs it is also vital that the final diagnosis is based on objective assessment. Jed may have his own interpretation of what his symptoms mean, but you will need to think carefully about his presentation, keeping an open mind to all possibilities, and avoid allowing yourself to be overly influenced by his self-diagnosis.

Jed has self-treated as an exacerbation of COPD, but has had no respite from his symptoms. Although his presenting symptoms could be due to an exacerbation of his COPD, he is currently experiencing some of the cardinal symptoms of heart failure, i.e. fatigue, dyspnoea and oedema⁷ and the fact that he has not responded to treatment is worth noting. He could also be suffering from chronic kidney disease or anaemia. Further assessment is therefore required.

The nurse asks for more information about his cough. Is it worse in the day or at night? Night cough is rare in COPD⁵ but may be seen in heart failure due to a combination of fluid in the lungs and gravity when lying flat. A useful question to ask is the number of pillows an individual needs at night. More than two should raise suspicion. Jed is high risk for heart failure due to his previous history of MI and the fact that he has a history of COPD.⁷ Even if heart failure seems likely, it is still important to discover which type of heart failure it is, (left ventricular systolic dysfunction, heart failure with preserved ejection fraction or cor pulmonale) in order that the best and most appropriate treatment can be offered. Jed confirms that the cough has been worse at night and that he is only really comfortable sitting upright to sleep. He has been sleeping in his chair, which is why he thinks he is so tired. He describes his sputum as being 'like spit'.

Once again, Jed's symptoms are a useful indicator of the possible cause of his ill health. Breathlessness on lying flat (orthopnoea) could be another sign of fluid on the lungs. Sputum colour and type can give important clues to the cause of a cough. Jed describes his sputum as being 'like spit' which could mean that his sputum is frothy, indicating pulmonary oedema. If he was suffering from an infective exacerbation of COPD, his phlegm would be more likely to be green. Blood-stained sputum could be due to coughing but more sinister causes such as lung cancer or tuberculosis should be borne in mind.

PHYSICAL ASSESSMENT

At this point, the nurse decides that a physical assessment should be carried out. If this is carried out by a nurse it must always be done within her own competency level, so some or all of the physical assessment may be carried out by the nurse or the GP, depending on the individual clinician.

In Jed's case the nurse's initial history taking has led her to suspect that heart failure is a possible diagnosis. Physical assessment should therefore include some specific tests for this condition. However, it is still important to keep an open mind to other co-existing problems.

Jed is apyrexial - temperature 36.7 - suggesting that infection is less likely. However, his pulse rate is raised - 109 - and irregular. This has not been noted previously. His blood pressure, normally around 132/87 on treatment, is also slightly raised at 159/96. His waist measurement has increased by 5cm, from 111cm, and his weight has increased by 6kg since his last diabetes check three months previously. His oxygen saturations, usually 98%, have dropped to 94%.

On examination of his chest, crackles are heard in the bases of both lungs on auscultation. His jugular venous pressure is raised and bilateral pitting ankle oedema is noted.

DIFFERENTIAL DIAGNOSIS

Based on the history and findings, there are several potential differential diagnoses, including:

• Heart failure
• Cardiovascular event
• Partially treated exacerbation of COPD
• Carcinoma of the lung.

As previously mentioned, other possibilities, such as renal or biochemical disease also exist. However, Jed's history, along with symptoms such as weight gain, as opposed to weight loss, orthopnoea, possible central and pulmonary as well as peripheral oedema all point towards heart failure - but the irregular pulse needs investigating and further tests should be requested.

FURTHER INVESTIGATION

Electrocardiogram (ECG)

Anyone with a newly identified irregular pulse rate should be urgently referred for ECG to identify the presence and type of arrhythmia.⁸ The most common arrhythmia is atrial fibrillation (AF) and this poses a significant risk factor for stroke.⁸ If AF is confirmed risk assessment for stroke should be immediately carried out and the appropriate antithrombotic therapy instigated.

Echocardiogram

NICE advise that any patient with symptoms suggestive of heart failure who has had a previous MI should have an echocardiogram within two weeks of presentation.⁸ This will help identify structural and functional abnormalities within the heart and will allow the correct, evidence-based treatment pathway to be followed. NICE also recommends 2-week referral for patients with very high B-type natriuretic peptide (BNP) levels (>400).⁹

Spirometry

Spirometry is a suggested part of the assessment of a patient suspected of having heart failure.⁹ This recommendation is mainly to exclude COPD and may therefore be less relevant in this particular case. However, up-to-date spirometry might be useful to identify any worsening of Jed's lung function and any new features - such as a combined restrictive and obstructive pattern, where all spirometry parameters (FVC, FEV1 and FEV1/FVC ratio) are reduced. This is often seen in the presence of pulmonary oedema.

It should also be remembered that spirometry should NOT be undertaken when patients are acutely unwell, or have possible unstable cardiovascular status.¹⁰ In Jed's case a judgment will need to be made about his fitness to perform the test against the possible benefits of obtaining current spirometry results.

Bloods

A full blood count, renal and liver screen, thyroid function test and glucose reading will help to identify whether new pathology is present and whether any current disease is being managed effectively.

As well as these routine blood tests, BNP testing may be considered to identify the presence of heart failure. This test may give false positive (and false negative) results but can be a useful 'rule out' test for heart failure.^11,12 However, as Jed requires an echocardiogram within two weeks this test may be superfluous to requirements.

Chest X-ray

In Jed's case a chest X-ray may be useful for identifying pulmonary oedema and cardiomegaly and could support a diagnosis of heart failure. It might also be indicated to identify new signs of lung disease, such as pneumonia and carcinoma. Not all patients with pneumonia have a fever and physical signs can be missed. Most, but not all carcinomas will be visible on chest X-ray by the time they are causing symptoms.

The logistics of when these investigations are carried out and in what order needs to be considered in light of how unwell the patient is, what is the most likely diagnosis, and with reference to local guidelines. For example, ECG is available in most general practice settings and many areas have open access to chest X-ray. However, not all areas have direct access to echocardiogram and BNP testing has not been made available in all areas. In these situations, it is important to know how to ensure that the patient is seen as quickly and efficiently as possible. In Jed's case a 2-week referral for echocardiogram is warranted.

JED'S RESULTS

In Jed's case, the echocardiogram revealed an ejection fraction of 34%, suggesting significant left ventricular systolic dysfunction (LVSD). The ECG confirmed atrial fibrillation and the bloods revealed an HbA1c of 64 and an eGFR of 56. The remaining bloods were all within normal limits. The chest X-ray identified an increased cardiac-thoracic ratio suggesting cardiomegaly. Spirometry revealed a combined pattern with an FEV1/FVC ratio of 55%, an FEV1 of 39% predicted and a low FVC.

Clearly, Jed required immediate management of his newly diagnosed LVSD and AF along with a careful review of his existing co-morbidities. The next article will discuss how Jed's new diagnosis affects his current conditions and how a review of both his medication and lifestyle will be addressed.

REFERENCES

1. Department of Health. Quality, Innovation, Productivity, Prevention. DH. 2011 http://www.dh.gov.uk/en/Healthcare/Qualityandproductivity/QIPP/index.htm

2. Gugliucci A. Diabetes and diabetic complications. 2007 www2.warwick.ac.uk/fac/med/research/csri/proteindamage/physiology/diabetes/

3. Department of Health. National Service Framework for Long Term Conditions. London. DH. 2005 http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_4105361

4. Jones PW, Jenkins C, Bauerle O, on behalf of the CAT Development Steering Group. COPD Assessment Test Healthcare Professional User Guide: Expert Guidance on frequently asked questions. 2009 http://www.catestonline.org/images/UserGuides/CATHCPUser%20guideEn.pdf

5. National Institute for Health and Clinical Excellence. Chronic obstructive pulmonary disease: management of chronic obstructive pulmonary disease in adults in primary and secondary care. London: National Clinical Guideline Centre. 2010 http://guidance.nice.org.uk/CG101/Guidance/pdf/English

6. Bickley LS. Guide to Physical Examination and History Taking. Lippincott Williams & Wilkins. 2008

7. National Institute for Health and Clinical Excellence. Heart Failure quick reference guide. NICE. 2010 http://guidance.nice.org.uk/CG108/QuickRefGuide/pdf/English

8. National Institute for Health and Clinical Excellence. Atrial Fibrillation: The management of atrial fibrillation. NICE CG36. 2006 http://www.nice.org.uk/nicemedia/live/10982/30052/30052.pdf

9. National Institute for Health and Clinical Excellence. Chronic heart failure: management of chronic heart failure in adults in primary and secondary care. NICE. CG108. 2010. http://guidance.nice.org.uk/CG108

10. Levy ML, Quanjer PH, Booker R et al. Diagnostic Spirometry in Primary Care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations. PCRJ 2009: 18(3);130-47 http://www.thepcrj.org/journ/view_article.php?article_id=653

11. Maisel AS, Koon J, Krishnaswamy P, et al. Utility of B-natriuretic peptide as a rapid, point-of-care test for screening patients undergoing echocardiography to determine left ventricular dysfunction. Am Heart J. 2001;141(3):367-374.

12. Schneider HG, Lam L, Lokuge A, et al. B-type natriuretic peptide testing, clinical outcomes, and health services use in emergency department patients with dyspnea: A randomized trial. Ann Intern Med. 2009;150(6):365-371.