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The effective assessment of acute breathlessness in a patient.

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VOL: 100, ISSUE: 24, PAGE NO: 61

Rachel Booker, RGN, DN(Cert), HV, is head of student support, The National Respiratory Training Centre, Warwick

Breathing is a fundamental life process that usually occurs without conscious thought and, for the healthy person, is taken for granted. It involves:

Breathing is a fundamental life process that usually occurs without conscious thought and, for the healthy person, is taken for granted. It involves:

- The coordinated action of inspiratory and expiratory muscles;

- The unimpeded passage of air from the atmosphere through the upper to the lower respiratory tract;

- The exchange of oxygen (O2) and carbon dioxide (CO2) across the alveolar membrane.

Anything that disrupts this process can lead to abnormal awareness or difficulty with breathing. Breathlessness is described using a variety of different terms (Table 1).

Breathlessness can be an entirely normal physiological response to increased O2 demand during activity. O2 levels become depleted during exercise and the body responds by increasing the depth and rate of breathing to replenish the O2 levels and eliminate the CO2 produced as a waste product of tissue respiration.

Abnormal breathlessness

This can be the result of:

- Respiratory disease;

- Cardiac disease;

- Systemic disease, such as hyperthyroidism or diabetic ketoacidosis;

- Psychological distress;

- Dysfunctional breathing; 

- Adverse lifestyle factors, such as obesity and smoking.

It may present as an acute problem or as a long-term chronic symptom that a patient has to cope with.

A patient who has chronic breathlessness may also experience acute episodes on top of her or his chronic symptoms: acute on chronic breathlessness. These symptoms need to be accurately assessed and a cause diagnosed, so that appropriate management is offered.

Initial assessment: is it an emergency?

Typically, acute breathlessness has a sudden onset and symptoms may be severe. It can develop over a period of hours, a few days, or weeks. It can also be the presenting symptom of a serious and life-threatening event, so it is important that diagnosis and treatment are not delayed.

The first step is to conduct a rapid assessment of the patient’s condition and vital signs (blood pressure, pulse, temperature, and respiratory rate). Immediate resuscitation will be required if the patient:

- Is too breathless to speak;

- Is tachycardic (pulse rate >110/minute). In life-threatening situations the patient may have bradycardia (a pulse rate below 50 beats per minute) or an irregular pulse, and may be hypotensive (low blood pressure);

- Is tachypnoeic with a respiratory rate that is >25 breaths /minute. In life-threatening situations respiratory effort may be feeble;

- Is cyanosed (has a bluish discolouration of the skin) or has an O2 saturation of less than 90 per cent; 

- Is confused, drowsy, exhausted, or close to collapse;

- Has crushing central chest pain - particularly with radiation to the left arm or left side of the neck or jaw with associated nausea;

- Is hypotensive.

Brief clinical history - This should include questions on:

- Existing medical conditions, for example, pre-existing asthma, chronic obstructive pulmonary disease (COPD), ischaemic heart disease (IHD), or diabetes;

- Associated pain, such as crushing central chest pain, particularly if it radiates down the left arm or up the left side of the neck, which suggests acute myocardial ischaemia or infarction. Sudden, stabbing, pleuritic pain may indicate a pneumothorax or pulmonary embolism. Dull, generalised pain can point to a diagnosis of pneumonia. About 1 in 1,000 people need admission to hospital every year with pneumonia (Bourke and Brewis, 1998). Pleuritic pain may suggest pleurisy or a pleural effusion. Central chest pain may also be present in supraventricular tachycardia;

- Any recent viral symptoms in the upper respiratory tract such as runny nose, cough, and fever. This may point to pneumonia or acute bronchitis as a cause of the acute breathlessness;

- Recent injury or inhalation of a foreign body that may indicate pneumothorax or airway obstruction;

- Recent surgery, long-distance travel or a period of immobility that may predispose to pulmonary embolism. About 60,000 hospital patients develop pulmonary embolism every year and about a third of patients will die (Bourke and Brewis, 1998).

Emergency treatment - This will be required for patients who have signs and symptoms of:

- Acute severe or life-threatening asthma (Table 2);

- Severe exacerbation of COPD (Table 3);

- Airway obstruction;

- Myocardial infarction;

- Pneumothorax;

- Acute pulmonary embolus;

- Lobar pneumonia;

- Diabetic ketoacidosis.

Full clinical history

Once it has been established that the patient is not in immediate danger, a more comprehensive clinical history will assist in determining the cause of the breathlessness. Establishing the diagnosis is often a process of elimination.

Some causes may be obvious - a chest wall injury for example - but most are more obscure and will entail the elimination of unlikely causes.

Patients’ perception of their symptoms

A good starting point is to ask patients to describe their breathlessness in their own words. You may need to prompt them to tell you if it developed over minutes, hours, days, or weeks.

The onset of the symptoms can be an important indicator of the cause. Breathlessness that develops very rapidly could indicate a serious, life-threatening condition. However, it could also indicate acute hyperventilation or a panic attack.

Asking about any precipitating factors, or the circumstances surrounding the onset of the attack, can be helpful. Breathlessness that develops suddenly at night could be due to acute left ventricular failure but could also be a sign of acute asthma.

Onset of symptoms

Pneumonia, exacerbations of asthma and COPD or diabetic ketoacidosis typically develop over several days. Some people do experience sudden attacks of asthma with no warning but there are usually some indications of worsening asthma control before the acute attack develops, such as increasing symptoms, nocturnal disturbance, and a decreased tolerance of exercise.

Associated symptoms

Accompanying symptoms such as cough, wheeze, sputum, haemoptysis, and pain could indicate the cause of breathlessness:

- A dry cough that is worse at night, triggered by exercise and/or cold air and accompanied by wheeze is highly suggestive of asthma;

- Purulent sputum may indicate respiratory infection, such as pneumonia or acute bronchitis. It is also a feature of exacerbations of COPD. Sputum can be present during episodes of acute asthma, when it is often thick and difficult to clear. Copious, frothy sputum may indicate acute left ventricular failure;

- Haemoptysis (blood present in sputum) is a common presenting symptom of lung cancer and must always be thoroughly investigated. Haemoptysis can also occur as a consequence of pneumonia and pulmonary embolism, and may be a feature of bronchiectasis (widening of the bronchi or their branches);

- Chest pain is a feature of both respiratory and cardiac disease. Chest pain with associated nausea and vomiting is characteristic of myocardial infarction. Pleuritic pain - a localised, sharp pain, worsened by breathing in - is typical of a pneumothorax, pleurisy associated with pneumonia or acute, minor pulmonary embolism. Dull chest pain is often present in pneumonia.

It is also helpful to ask if there is anything that aggravates or relieves the pain. Angina may be brought on by exercise and relieved by rest. Coughing makes pleuritic pain much worse.

Circumstances surrounding the attack

When acute onset breathlessness is triggered by a stressful situation it could be suggestive of acute hyperventilation, particularly if it is accompanied by tingling of the hands and lips and light-headedness. However, it is important not to make a diagnosis of acute hyperventilation until other causes of the symptoms have been excluded.

Hyperventilation commonly occurs alongside other conditions such as acute asthma. The hyperventilation often resolves once the underlying condition is treated.

Exposure to a known allergen may precipitate an acute attack of asthma. Accidental exposure to high concentrations of chemical fumes may result in acute pneumonitis (inflammation of the lungs).

Social history and lifestyle It is important to ask about current and previous smoking habits. Smoking is a major risk factor for IHD and COPD, both of which can present as acute breathlessness.

There are several risk factors for IHD (Gray et al, 2002) and these include sedentary lifestyle, excessive weight, and being male.

Excessive alcohol intake can cause cardiomyopathy and heart failure. There are also some social circumstances that can predispose to the development of pneumonia:

- Smoking;

- History of a high alcohol intake;

- Intravenous drug abuse;

- Malnutrition.

Medication history

It is important to ask about prescribed and over-the-counter medicines. The use of cardiac medications such as beta blockers, angiotensin-converting enzyme (ACE) inhibitors, and calcium channel blockers may raise suspicion of a cardiac cause for the symptoms. Beta blockers can also precipitate asthma and will make COPD worse.

Non-steroidal anti-inflammatory drugs, such as ibuprofen and aspirin, can precipitate acute asthma in a small number of susceptible individuals.

Family history

A family history of asthma may raise suspicions that asthma is the cause of the symptoms. Similarly, a strong family history of IHD will make heart disease more likely. COPD can also occur in family clusters.

Examination and investigation

Many nurses who work with people with cardiac and respiratory problems have taken on an extended role. Nurse practitioners and clinical nurse specialists may be expected to examine a patient and interpret their findings.

This requires extensive training, a great deal of practice and experience, as well as supervision and support from medical and nursing colleagues.

It is beyond the scope of this article to describe the clinical findings for every cause of acute breathlessness, but the clinical examination, particularly of the respiratory and cardiovascular systems, is a vital part of the assessment of the breathless patient.

The history and the findings on clinical examination will usually suggest a likely diagnosis. This hypothesis will then need to be confirmed by investigation.

Respiratory investigations

Pulse oximetry

This is a useful, non-invasive method of assessing oxygenation. The percentage of haemoglobin saturated with O2 passing through the capillaries is measured. Saturations of 95 per cent or above are normal. When the saturation drops to 92 per cent or less the patient is likely to be significantly hypoxic and assessment of arterial blood gases (ABG) is indicated. ABG tests allow a full assessment of O2 and CO2 concentrations, and are used to diagnose and monitor patients in respiratory failure.

Peak expiratory flow (PEF)

This is a simple, quick test that is easy for a patient with acute breathlessness to perform. It is particularly helpful in cases of acute asthma and should always be carried out before and after a patient is given a nebulised bronchodilator. It forms the basis of assessment of the severity of the attack and is an objective measurement of treatment response (Table 2).


This measures both lung volumes and flow rates and gives far more information than PEF. It forms an essential part of the diagnostic process for COPD and is essential for the differentiation of diseases that cause airflow obstruction (such as asthma and COPD) from those that cause restriction of lung volumes (such as interstitial lung disease).

However, a patient with acute breathlessness would find spirometry difficult to perform. More reliable results are likely to be obtained when the patient is in a stable condition.

Pulmonary function tests (PFTs)

These are used to examine the functioning of the respiratory system and include spirometry. PFTs can be used to accurately assess lung volumes (including the residual volume), airflow through the lungs, and the efficiency of gas exchange. They are a vital part of the assessment and diagnosis of respiratory disease.

The use of chest X-ray (CXR) and computerised axial tomography (CAT) A CXR is indicated for any adult patient presenting with acute breathlessness - particularly smokers. Cardiac enlargement, pleural effusion, pneumothorax, pulmonary oedema, pneumonia, and most (but not all) cases of lung cancer will be visible on the CXR. Hyperinflated lung fields suggest obstructive lung disease, such as asthma or COPD.

CAT scan and magnetic resonance imaging (MRI) can give a clear picture of the position and extent of any lung or heart lesions, and spiral CT is used to diagnose the extent of emphysema.

Cardiovascular investigations

Electrocardiography (ECG) and echocardiography

These are non-invasive tests and give information about the functioning of the heart. An ECG can be used to detect ischaemia and myocardial infarction. The cardiac rhythm and any rhythm abnormalities can also be seen (Table 4).

An echocardiogram will give detailed information about how well the heart is functioning as a pump and whether the heart valves are working normally. Coronary angiography is used to ascertain the extent of coronary artery disease.

A suspicion of myocardial infarction can be confirmed by serial cardiac enzyme blood tests (Table 5). Ventilation perfusion scans and spiral computerised tomography (CT) are used to diagnose pulmonary embolism. Embolism blocks the blood supply to the affected area of the lung and presents as a perfusion defect.


Nurses are the first point of contact for patients in an increasing number of settings. Breathlessness is a common cause of acute and emergency presentations.

As we face a shortage of both nurses and doctors we need to continue to increase the skills of nurses if we are to continue to deliver high-quality care. The traditional professional boundaries between nurses and doctors will need to be at least partially broken down.

A quality service depends on good, multidisciplinary working, where all team members appreciate the skills and contribution that others bring to improve care.


- The National Respiratory Training Centre (NRTC) offers one-day short courses in the assessment of acute breathlessness and in the assessment and holistic management of chronic breathlessness.

- The NRTC also offers a six-month distance learning course in the assessment and management of breathlessness. This course is accredited through the Open University at 30 CATS points at degree level 3.

- The NRTC has produced a pocket book called ‘Simply Breathlessness’.

Details of publications and courses, together with future course dates, are available on the website

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