Acute Dyspnea: A Practical Guide for Junior Doctors

Acute dyspnea, or sudden onset shortness of breath, is a common and potentially life-threatening presentation in the emergency department (ED). For junior doctors, recognizing the underlying causes, efficiently gathering information, and initiating appropriate management is crucial. This blog post provides a structured approach to history-taking, examination, investigations, and management of acute dyspnea.

History Taking: Key Questions

A thorough and focused history is critical. Start by understanding the nature of the dyspnea and its potential causes:

·       Symptom Onset and Duration

• When did the breathlessness start? (sudden vs gradual onset)

• Was there any specific trigger? (e.g., exertion, allergen exposure, trauma)

• Is the dyspnea constant, intermittent, or worsening?

·       Associated Symptoms

• Chest pain: Consider myocardial infarction, pulmonary embolism (PE), or pneumothorax.

• Cough: Is it productive or dry? Look for infection or asthma.

• Wheezing: Suggests asthma or COPD exacerbation.

• Fever or chills: Indicative of infection (e.g., pneumonia, COVID-19).

• Hemoptysis: Points towards PE, infection, or malignancy.

• Leg swelling: Raises suspicion for DVT with secondary PE.

·       Past Medical History

• Respiratory conditions: Asthma, COPD, interstitial lung disease.

• Cardiac conditions: Heart failure, ischemic heart disease.

• Risk factors for PE: Recent surgery, immobility, pregnancy, malignancy.

·       Medication and Allergies

• Current medications: Beta-blockers (can exacerbate asthma), diuretics (fluid status), or anticoagulants.

• Recent drug changes: New medications that might cause an allergic reaction.

·       Social History

• Smoking: Increases risk of COPD and lung cancer.

• Occupational exposure: Asbestos, dust, or chemicals.

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Examination Findings: What to Look For

Physical examination can provide vital clues to the underlying cause of dyspnea:

·       General Appearance

• Assess the work of breathing: Use of accessory muscles, nasal flaring.

• Look for cyanosis or pallor (hypoxia, anemia).

• Measure oxygen saturation and consider supplemental oxygen if <92% (or <88% in COPD).

·       Vital Signs

• Heart rate: Tachycardia may indicate PE, sepsis, or heart failure.

• Respiratory rate: Tachypnea is a common sign of respiratory distress.

• Blood pressure: Hypotension suggests sepsis or tension pneumothorax.

• Temperature: Fever raises suspicion of infection.

·       Cardiovascular Examination

• Check for jugular venous distension (JVD): Suggestive of right heart strain or heart failure.

• Auscultate for murmurs or gallop rhythm.

·       Respiratory Examination

• Inspect for asymmetry (e.g., pneumothorax).

• Percuss the chest: Dullness (effusion) vs hyper-resonance (pneumothorax).

• Auscultate for:

  • Wheezing: Asthma or COPD.

  • Crackles: Heart failure, pneumonia, or interstitial lung disease.

  • Absent breath sounds: Pneumothorax or large effusion.

·       Peripheral Signs

• Swollen legs: DVT and PE.

• Clubbing or cyanosis: Chronic lung disease.

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Investigations: A Stepwise Approach

·       Bedside Tests

• Pulse oximetry: Assess oxygen saturation.

• ECG: Rule out myocardial infarction or right heart strain (PE).

• Arterial blood gas (ABG): Look for hypoxia, hypercapnia, or metabolic acidosis.

·       Laboratory Tests

• Full blood count (FBC): Anemia or infection.

• D-dimer: Elevated in PE (only if low Wells’ score).

• Troponin: Rule out myocardial infarction.

• BNP: Elevated in heart failure.

·       Imaging

• Chest X-ray (CXR): Pneumonia, pneumothorax, pleural effusion, or heart failure.

• CT pulmonary angiogram (CTPA): Gold standard for diagnosing PE.

• Echocardiography: Evaluate cardiac function or rule out tamponade.

·       Special Tests

• Peak expiratory flow rate (PEFR): Asthma or COPD exacerbations.

• Spirometry: Chronic lung diseases if stable.

  
  

Management Plan: Treat the Underlying Cause

Management depends on the suspected or confirmed diagnosis:

·       Immediate Resuscitation

• Airway: Ensure patency. Intubate if necessary.

• Breathing: Administer oxygen therapy or non-invasive ventilation (e.g., CPAP for pulmonary edema).

• Circulation: IV fluids for hypotension, vasopressors if needed.

·       Specific Treatments

• Asthma or COPD exacerbation:

  • Nebulized bronchodilators (salbutamol, ipratropium).

  • Corticosteroids (oral or IV).

  • Consider antibiotics if infection suspected.

• Heart failure:

  • Diuretics (furosemide).

  • Nitrates (if hypertensive).

• Pneumonia: Antibiotics per local guidelines.

• Pneumothorax: Needle decompression followed by chest drain.

• PE: Anticoagulation (e.g., heparin) or thrombolysis if massive.

• Anaphylaxis: Adrenaline (IM), antihistamines, steroids.

Red Flags

Recognize and act immediately if any of the following are present:

• SpO₂ <90% despite oxygen therapy.

• Hypotension with signs of shock.

• Severe respiratory distress or exhaustion.

• Reduced consciousness.

  
  

Summary

Acute dyspnea requires a systematic approach:

·       Obtain a detailed history focused on potential life-threatening causes.

·       Conduct a targeted examination to identify red flags and guide investigations.

·       Use appropriate investigations to confirm the diagnosis.

·       Initiate management promptly, prioritizing airway, breathing, and circulation.

As a junior doctor, remember: Always escalate concerns to senior colleagues early for unstable patients. Every second counts in acute dyspnea!