Acute Shortness of Breath
This is a terrifying symptom for the patient, and the subjective feeling of shortness of breath is not predictably related to the type or degree of pathology. This, combined with the fact that the cause is often organic, means that a careful and urgent assessment is mandatory.
- Acute LVF
- Acute Exacerbation of COPD
- Pulmonary Embolism
- Pleural Effusion
- Diabetic Ketoacidosis (DKA)
- Lobar Collapse (Tumour)
- Aspiration Pneumonitis
- Guillain–Barré Syndrome
- Hypovolaemic Shock
- Shock Lung (Adult Respiratory Distress Syndrome)
- Laryngeal Obstruction
Key distinguishing features of the most common diagnoses
|Asthma||Pneumonia||LVF||Exacerbation of COPD||Hyperventilation|
|Bilateral Fine Crackles||No||No||Yes||Possible||No|
|Focal Reduced Air Entry||No||Yes||No||No||No|
- The GP is highly unlikely to initiate any investigations at all. If the patient with acute shortness of breath is ill enough – or the diagnosis obscure enough – to warrant investigation, then the patient probably requires admission. The following therefore refers to those few cases in which the patient is reasonably well, the diagnosis unclear and the scenario not so urgent that immediate referral is required.
- Urinalysis: Glucose and ketones in DKA. Confirm with a glucometer reading.
- Sputum culture: Very occasionally helpful in infective processes not settling with first-line empirical treatment.
- FBC: WCC raised in infection. Anaemia may be significant incidental finding.
- Pulse oximetry: Hypoxia suggests a significant problem.
- CXR an essential part of assessment but usually done after admission/referral.
- Other investigations such as blood gases and investigations for pulmonary embolus might be required to clinch a diagnosis but would be arranged by the admitting team.
- If the diagnosis is likely to be hyperventilation, instruct the patient to rebreathe from a paper bag while waiting for you. This action may curtail the attack by the time you arrive.
- Spacer devices can be as effective as nebulisers when managing acute exacerbations of asthma, and are more practical to use when on call.
- Sudden onset of breathlessness in an elderly patient in the middle of the night is likely to be LVF. Remember that it may be have been precipitated by an infarct.
- Cyanosis is an ominous sign meriting a ‘blue light’ ambulance and oxygen as soon as possible.
- The presence of intercostal recession and use of accessory muscles of respiration indicate severe respiratory distress whatever the aetiology. Admit.
- If a foreign body has been inhaled, astute telephone assessment and clear, calm advice may be lifesaving.
- Acute confusion with breathlessness indicates severe hypoxaemia, metabolic disturbance or sepsis. Admit urgently.
- Don’t forget that pneumothorax is commoner in asthmatics and patients with COPD – consider this diagnosis if the patient suddenly becomes more short of breath especially if there is no other obvious explanation, such as a supervening chest infection.