What is the initial approach to a patient presenting with breathlessness on exertion?

Initial Approach to Breathlessness on Exertion

When evaluating a patient presenting with breathlessness on exertion, immediately obtain vital signs including pulse rate, respiratory rate, blood pressure, and oxygen saturation, followed by a focused history targeting smoking status, age, exercise tolerance, cough pattern, sputum production, and cardiac symptoms to differentiate between COPD, cardiac disease, and other causes. 1

Critical Historical Elements

Respiratory Disease Indicators

• Smoking history and age >50 years with chronic breathlessness on minor exertion (such as walking on level ground) strongly suggests COPD until proven otherwise 2
• Morning cough, recurrent respiratory infections, or breathlessness with vigorous exertion/manual labor indicate possible early COPD 2
• Document specific exercise tolerance (e.g., distance walked, stairs climbed) to establish baseline and monitor progression 2
• Cough with discolored sputum production suggests moderate COPD with infectious exacerbations 2

Cardiac vs. Pulmonary Differentiation

• Breathlessness associated with effort-related palpitations, chest discomfort, or peripheral edema points toward cardiac causes including heart failure or pulmonary hypertension 2
• Orthopnea and paroxysmal nocturnal dyspnea suggest cardiac dysfunction rather than primary lung disease 2
• Syncope, dizziness, or accentuated pulmonary component of second heart sound may indicate pulmonary hypertension 2

Red Flags Requiring Alternative Diagnosis

• Childhood wheeze, atopy, or pertussis history suggests asthma rather than COPD 2
• Past pneumonia or tuberculosis may indicate restrictive lung disease or bronchiectasis 2
• Weight loss warrants evaluation for occult malignancy 2
• Symptoms occurring only during/after exercise in younger patients (<50 years) without smoking history suggest exercise-induced bronchoconstriction 2

Physical Examination Priorities

Signs of Severity

• Assess for respiratory distress markers: audible wheeze, tachypnea, accessory muscle use, peripheral edema, cyanosis, or confusion 1
• Central cyanosis indicates significant hypoxemia but its absence does not exclude it 2
• Signs of chronic overinflation (loss of cardiac dullness, decreased cricosternal distance, increased AP chest diameter) suggest advanced COPD 2

Cardiac Assessment

• Elevated jugular venous pressure, peripheral edema, and hepatomegaly indicate right heart failure 2
• Flapping tremor, bounding pulse, or drowsiness during acute presentations suggest hypercapnia 2

Immediate Investigations

Essential First-Line Tests

• Measure arterial blood gas tensions noting the inspired oxygen concentration (FiO₂) within 60 minutes of presentation 1
• Obtain chest radiograph to exclude pneumonia, pulmonary edema, or pneumothorax 1
• Perform ECG to assess for cardiac ischemia, arrhythmias, or right heart strain 1
• Complete blood count and basic metabolic panel within 24 hours 1

Pulmonary Function Assessment

• Spirometry is mandatory when patient is stable enough to perform it—degree of airways obstruction cannot be predicted from symptoms or signs alone 2
• Record initial FEV₁ and/or peak flow when feasible 1
• In mild COPD, spirometry may show FEV₁ 60-79% predicted; moderate COPD shows 40-59% predicted; severe COPD shows <40% predicted 2

Oxygen Therapy Considerations

For patients >50 years who are long-term smokers with chronic breathlessness, initially limit oxygen to 28% via Venturi mask or 2 L/min via nasal cannulae until blood gas results are available to prevent hypercapnic respiratory failure 2, 1. Target oxygen saturation of 88-92% in suspected COPD rather than normal saturation 2, 1.

Critical Pitfall

Excessive oxygen administration (>35% or PaO₂ >10 kPa/75 mmHg) in COPD patients causes CO₂ retention and respiratory acidosis 2. If acidosis develops from excessive oxygen, step down to 28% Venturi mask rather than discontinuing oxygen abruptly, as oxygen levels fall faster than CO₂ corrects 2.

Special Populations Requiring Modified Approach

Exercise-Induced Symptoms in Younger Patients

• Breathlessness occurring specifically during or shortly after exercise in patients without chronic symptoms requires exercise challenge testing rather than resting spirometry alone 2
• Self-reported symptoms without objective testing are insufficient for diagnosis 2
• Exercise challenge should achieve heart rate ≥85% of maximum (95% in children) for 6 minutes 2

Patients at Risk for Hypercapnic Failure

Beyond COPD, consider these high-risk groups requiring controlled oxygen therapy 2:

• Patients already on long-term oxygen therapy
• Bronchiectasis with fixed airflow obstruction
• Severe kyphoscoliosis or ankylosing spondylitis
• Morbid obesity (BMI >40 kg/m²)
• Neuromuscular disorders with wheelchair dependence
• Home mechanical ventilation users

Monitoring and Reassessment

• Repeat arterial blood gas if clinical situation deteriorates 1
• Continuous pulse oximetry monitoring 1
• Reassess within 3-4 months if treatment initiated to determine adequate response, defined as WHO functional class I or II with marked hemodynamic improvement 2