Emergency admission is most commonly required when a new acute problem (such as a respiratory tract infection, pulmonary embolism, or sudden-onset arrhythmia) exacerbates breathlessness caused by a chronic condition (such as chronic obstructive pulmonary disease or chronic heart failure).

• Determine the need for emergency admission by assessing the person's blood pressure, pulse, temperature, level of consciousness, peak expiratory flow rate (PEFR), oxygen saturation, and (if possible) electrocardiogram (ECG).
• Arrange emergency admission for people with:
• Respiratory rate of more than 30 breaths per minute.
• Tachycardia greater than 130 beats per minute.
• Systolic blood pressure less than 90 mmHg, or diastolic blood pressure less than 60 mmHg (unless this is normal for them).
• Oxygen saturation less than 92%, or central cyanosis (if the person has no history of chronic hypoxia).
• Peak expiratory flow rate (PEFR) less than 33% of predicted.
• Altered level of consciousness.
• A large respiratory effort (particularly if the person is becoming exhausted).
• Stridor.
• Clinical features of a pulmonary embolus or pneumothorax.
• ECG suggesting a cardiac arrhythmia or myocardial infarction.
• Consider arranging emergency admission, depending on the severity and number of risk factors present, if the person has breathlessness associated with any of the following:
• Elevated respiratory rate (but if it is more than 30 breaths per minute, arrange emergency admission).
• Tachycardia (but if it is more than 130 beats per minute, arrange emergency admission).
• Hypotension (but if blood pressure is less than 90 mmHg systolic or 60 mmHg diastolic, arrange emergency admission).
• A high temperature (particularly if it is higher than 38.5°C).
• PEFR less than 50% of predicted (but if it is less than 33%, arrange emergency admission).
• Older than 65 years of age.

• Sit the person up.
• If the person has an oxygen saturation of less than 92%, give oxygen and continuously monitor their oxygen saturation levels while waiting for transfer to hospital.
• ONLY USE A 28% VENTURI MASK AT 4 L/MIN FOR PEOPLE WITH SUSPECTED CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), morbid obesity, a chest wall deformity, or a neuromuscular disorder. This is because they are at risk of hypercapnic respiratory failure.
• For other people who are acutely ill, use a simple face mask. Adjust the flow rate to 5–10 L/min to achieve a target oxygen saturation of 94–98%.

If the person does not have an indication for emergency admission:

• Look for clinical features of:
• Chronic heart failure, especially if the person has a history of ischaemic or valvular heart disease, hypertension, or the onset of chronic cardiac arrhythmias (such as atrial fibrillation).
• Asthma, especially in people with wheeze or cough that is worse at night, or upon exercise or exposure to allergens.
• Chronic obstructive pulmonary disease (COPD), especially in people older than 35 years of age who smoke (or who have smoked), particularly if they have wheeze and a new or worsening cough.
• Bronchiectasis, especially in non-smokers with chronic progressive breathlessness that is associated with either a chronic productive cough or recurrent chest infections.
• Interstitial lung disease, especially in people with a history of exposure to asbestos, dust (such as coal dust), birds, hay, or mushrooms.
• Pleural effusion, especially in people with: heart, liver, or renal failure; cancer; tuberculosis; or pleural infection.
• Abdominal splinting secondary to obesity or ascites.
• Anaemia.
• Arrange investigations to confirm the cause of breathlessness.
• Manage the underlying cause of chronic breathlessness. For people with:
• Chronic heart failure — see the CKS topic on Heart failure - chronic.
• Asthma — see the CKS topic on Asthma.
• COPD — see the CKS topic on Chronic obstructive pulmonary disease.
• Bronchiectasis — see the CKS topic on Bronchiectasis.
• Restrictive lung disease — refer the person to a respiratory specialist for assessment and management of the cause.
• Pleural effusion — refer (or admit) the person, for drainage and investigations of the underlying cause of the effusion.
• Anaemia — see the CKS topics on:
• Anaemia - B12 and folate deficiency.
• Anaemia - iron deficiency.
• Diaphragmatic splinting that is secondary to:
• Obesity — see the CKS topic on Obesity.
• Ascites — refer the person to an appropriate specialist for management of the underlying cause.
• For people with chronic breathlessness that remains of uncertain cause, reassess for risk factors and clinical features of pulmonary embolism:
• If pulmonary embolism is suspected, arrange urgent referral.
• If pulmonary embolism seems unlikely, arrange routine referral.

• If the person does not have an indication for emergency admission, arrange investigations to identify or confirm the underlying cause of breathlessness.
• Where the diagnosis cannot confidently be established by clinical features alone:
• Initial investigations should include:
• Chest radiography — to look for signs of heart failure and pulmonary pathology (including pleural effusion).
• Electrocardiography (ECG) — to look for signs of heart failure, arrhythmia, and pulmonary embolism.
• Spirometry — to look for signs of obstructive airway disease or a restrictive pattern associated with interstitial lung disease (such as idiopathic pulmonary fibrosis, sarcoidosis, pneumoconiosis, or extrinsic allergic alveolitis).
• Full blood count — to check for anaemia.
• Urea and electrolytes, and random blood glucose level — to test for renal failure and diabetes as causes of metabolic acidosis and breathlessness.
• Thyroid function tests — to detect thyroid disease as a cause of breathlessness.
• If initial investigations do not identify the cause of breathlessness:
• Arrange echocardiography and test for B-type natriuretic peptide (BNP), depending on local guidelines, to assess for heart failure.
• Reassess for risk factors and clinical features of pulmonary embolism. If this is suspected, arrange urgent referral for further investigations.
• Suspected asthma or COPD
• Assess airways obstruction by spirometry. Airway obstruction is confirmed by a forced expiratory volume in 1 second (FEV₁) less than 80% of the predicted value and FEV₁/forced vital capacity (FVC) ratio less than 70%.
• Distinguish asthma from COPD, based on:
• Smoking history — almost always present in people with COPD.
• Age — usually older than 35 years of age for COPD.
• Chronic productive cough — common with COPD, uncommon with asthma.
• Breathlessness — progressive with COPD, variable with asthma.
• Variability of symptoms — common with asthma, uncommon with COPD.
• If asthma and COPD can not be distinguished based on clinical features:
• Arrange measurements of peak expiratory flow rate (PEFR) — morning and night-time measurements, and during symptoms (to assess variability).
• If doubt still remains, a large response (more than 400 mL) to bronchodilators or prednisolone (30 mg orally per day, for 14 days) is characteristic of asthma; but not COPD.
• If doubt still remains, refer the person for a specialist's opinion.
• For people with COPD, arrange chest radiography (to exclude other serious lung pathology, such as lung cancer) and full blood count (to identify polycythaemia/erythrocytosis secondary to chronic hypoxia).
• Suspected bronchiectasis. Arrange chest radiography to exclude other causes for the symptoms, and refer the person to a respiratory specialist for confirmation of the diagnosis (by high resolution computed tomography scanning).
• Suspected pleural effusion. Arrange chest radiography to confirm the diagnosis.
• Suspected abdominal splinting secondary to ascites. Arrange an abdominal ultrasound scan to confirm the presence of ascites and to exclude or confirm liver cirrhosis and peritoneal cancer. Arrange other investigations guided by clinical findings (for example liver function tests or erythrocyte sedimentation rate; for signs of cancer).