Step 1 - Rapid triage and red flags (first 60 seconds)

• Confirm airway and breathing. If not maintained, secure the airway and provide oxygen immediately.
• Assess perfusion. Systolic blood pressure below 90 mmHg or signs of shock require immediate resuscitation.
• Watch for red flags: severe hypoxia, severe respiratory distress, silent chest, new cyanosis, sudden collapse, massive hemoptysis.

If any red flag is present call senior help and the resuscitation team without delay.

Step 2 - Rapid bedside assessment (first 5 minutes)

1. Look - work of breathing, respiratory rate, accessory muscle use, chest wall symmetry and cyanosis.
2. Listen - breath sounds on both sides, wheeze, crackles or absent sounds.
3. Hands on - pulse oximetry, blood pressure, capillary refill, temperature and capillary glucose where relevant.
4. Quick tests - 12 lead ECG, portable chest X-ray and point of care lung ultrasound if available.
5. Point measurements - ABG or VBG plus lactate when severely unwell. Use the ABG flowchart to interpret results quickly.

Step 3 - Use the five category checklist

Think of causes using these categories to avoid missing uncommon but important problems.

• Airway obstruction - foreign body or severe allergic reaction.
• Breathing problems - asthma, COPD exacerbation, pneumothorax, pneumonia.
• Circulation problems - acute heart failure, myocardial infarction, massive pulmonary embolism. See ESC guidance on pulmonary embolism for testing and risk stratification.
• Disability or metabolic causes - severe anemia, acidosis, sepsis.
• Drugs and toxins - opioid overdose and other poisonings.

Step 4 - Focused investigations and interpretation

• Pulse oximetry and arterial blood gas for oxygenation and ventilation status. Use your ABG flowchart for quick interpretation.
• 12 lead ECG to detect ischaemia, arrhythmia or right heart strain that may suggest pulmonary embolism.
• Portable chest X-ray for consolidation, effusion, pneumothorax and device checks.
• Point of care ultrasound for pneumothorax, pleural effusion and interstitial patterns, and focused echo for left ventricular function and right ventricular strain.
• D-dimer with clinical probability using Wells or Geneva scores, then CT pulmonary angiogram if indicated. Many societies recommend age adjusted D-dimer cutoffs for patients older than 50 to improve specificity.
• Blood cultures and microbiology when infection is suspected. Early appropriate antibiotics improve outcomes in sepsis.

Step 5 - Immediate management pathways

Treat the most life threatening cause first. Below are common scenarios and immediate actions to consider.

Acute heart failure with pulmonary edema

• Sit the patient upright, give oxygen to target saturations, start IV loop diuretics and consider vasodilators if hypertensive and not hypotensive.
• Consider CPAP for severe respiratory distress and arrange urgent cardiology review.

Pneumonia with hypoxia

• Give oxygen to target saturations, obtain blood cultures where possible, and start empiric antibiotics guided by local antibiogram and severity.

Suspected pulmonary embolism

• Use a validated clinical probability score and age adjusted D-dimer to decide on imaging. Consider thrombolysis only for massive PE with haemodynamic compromise.

Severe asthma or COPD exacerbation

• Give bronchodilators, follow oxygen targets appropriate for COPD, use short courses of systemic steroids and consider nebulised therapy as needed.

Respiratory failure due to sepsis or ARDS

• Activate the sepsis bundle, support airway and oxygenation and consider high flow nasal oxygen or early intubation if work of breathing or gas exchange deteriorates. Use lung protective ventilation in ARDS.

Practical checklists to keep on the trolley

• Rapid ABC checklist for the breathless patient.
• ABG quick interpretation flowchart for acid-base and ventilation checks.
• ECG checklist for right heart strain and ischaemia.
• Emergency drugs cheat sheet for immediate pharmacologic actions.

All pocket PDFs for these checks are linked in the sidebar and at the top of the post.

When to escalate

• Increasing oxygen requirement despite non-invasive support.
• Progressive hypercapnia or falling level of consciousness.
• Haemodynamic instability not responding to initial resuscitation.
• Massive pulmonary embolism, refractory sepsis or severe ARDS.

Learning plan for students and juniors

1. Practice 5 minute focused assessments on ward patients and run simulated acute breathlessness scenarios.
2. Memorise the ABG steps and ECG signs of right heart strain.
3. Keep the one-page PDFs on your phone and print one copy for the resus trolley.
4. Review guideline pages linked below weekly for updates to thresholds and management steps.

References and further reading

• NICE Clinical Knowledge Summary - Breathlessness. (Use for initial assessment and primary care pointers.)
• European Society of Cardiology - Acute Pulmonary Embolism guideline. (Risk stratification and imaging pathways.)
• Surviving Sepsis Campaign - adult guidelines. (Sepsis bundles and timing of antimicrobials.)
• British Thoracic Society - Asthma guidance. (Diagnosis and acute care pathways.)
• Age adjusted D-dimer strategies and evidence summaries are available in reviews and guideline pages linked above.