Dyspnoea, acute and chronic Flashcards
Dyspnoea is
the subjective sensation of breathlessness that is excessive for any given level of physical activity.
Probability diagnosis
Bronchial asthma
Bronchiolitis (children)
COPD
Ageing, lack of fitness
Left heart failure/CCF
Obesity
Functional hyperventilation
Serious disorders not to be missed
Cardiovascular:
- acute heart failure (e.g. AMI)
- acute coronary syndromes
- arrhythmia
- pulmonary embolism
- fat embolism
- pulmonary hypertension
- dissecting aneurysm
- cardiomyopathy
- pericardial tamponade
- anaphylaxis
Neoplasia:
- bronchial carcinoma, other malignancy
Infection:
- SARS
- avian influenza
- pneumonia
- acute epiglottitis (children)
Respiratory disorders:
- inhaled foreign body
- upper airways obstruction
- pneumothorax
- atelectasis
- pleural effusion
- tuberculosis
- acute respiratory distress syndrome (ARDS)
Neuromuscular disease:
- infective polyneuritis (Guillain-Barré)
- poliomyelitis
Pitfalls (often missed)
Interstitial lung diseases:
- idiopathic pulmonary fibrosis
- extrinsic allergic alveolitis
- sarcoidosis
- drug-induced interstitial lung disease (e.g. cytotoxics, sulfasalazine, amiodarone)
Chemical pneumonitis
Metabolic acidosis
Radiotherapy
Kidney failure (uraemia)
Hypersensitive pneumonitis
Multiple small pulmonary emboli
Masquerades checklist
Depression
Diabetes—Ketoacidosis
Drugs (see list)
Anaemia
Thyroid disorder (thyrotoxicosis)
Is the patient trying to tell me something?
Consider functional hyperventilation (anxiety and panic attacks).
Key history
Aim to differentiate between pulmonary causes such as COPD and asthma and cardiac failure.
Assess the rate of development of dyspnoea.
Key examination
Careful inspection is mandatory.
With pt stripped to waist observe for factors such as;
- cyanosis
- clubbing
- mental alertness
- dyspnoea at rest
- use of accessory muscles and rib retraction
Use auscultation to differentiate between crackles and wheezes
Key investigations
The two most important are;
- CXR
- pulmonary function test including pulse oximetry.
Others include:
- FBE/ESR
- Arterial blood gases
- Cardiology e.g.
- ECG
- echocardiography
- enzymes
- other medical imaging
Diagnostic tips
All heart diseases have dyspnoea on exertion as a common early symptom.
If a pt develops a relapse of dyspnoea while on digoxin therapy, consider digoxin toxicity and/or electrolyte abnormalities leading to left HF.
Several drugs can produce a wide variety of respiratory disorders especially pulm fibrosis and pulm eosinophilia;
- amiodarone and cytotoxic drugs.
Causes of hyperventilation include:
- asthma
- thyrotoxicosis
- panic attacks/anxiety.
- Toxic agents;
- salicylate
- methyl alcohol
- theophylline
- ethylene glycol.
Practice tips for dyspnoea
Abrupt onset of severe dyspnoea suggests pneumothorax or PE
Remember to order a CXR and PFT in all doubtful cases of dyspnoea.
Dyspnoea in the presence of lung cancer may be caused by:
- pleural effusion
- lobar collapse
- upper airway obstruction
- lymphangitis carcinomatosis.
Recurrent attacks of sudden dyspnoea, esp. waking pt at night, are suggestive of asthma or left heart failure
Comparison of distinguishing features between dyspnoea due to heart disease and to lung disease
Lung disease / Heart disease
Hx of respiratory disease / Hx of HTN, cardiac ischaemia or valvular heart disease
Slow development / Rapid development
Present at rest / Mainly on exertion
Productive cough common / Cough uncommon, and then ‘dry’
Aggravated by resp infection/Usually unaffected by resp infection
