What are the next steps for a patient with shortness of breath (SOB) on oxygen support and moderate to high back rest, possibly with a history of Chronic Obstructive Pulmonary Disease (COPD) or asthma?

Management of Shortness of Breath in a Patient on Oxygen Support and Elevated Back Rest

Continue oxygen therapy targeting SpO2 88-92% (if COPD/at risk of hypercapnia) or 94-98% (if not at risk), obtain arterial blood gases within 30-60 minutes, administer nebulized bronchodilators (salbutamol 2.5-5 mg and ipratropium 0.25-0.5 mg), and initiate systemic corticosteroids (prednisone 30-40 mg daily) immediately. 1, 2

Immediate Assessment and Positioning

• Maintain the upright position as fully conscious hypoxaemic patients should be allowed to maintain the most upright posture possible, since oxygenation is reduced in the supine position 3
• Check that oxygen delivery equipment is functioning correctly: verify the oximeter placement, confirm oxygen flow rate matches prescription, ensure oxygen cylinder is not empty, and verify it is actually an oxygen cylinder 3
• Measure vital signs including respiratory rate, pulse rate, blood pressure, temperature, and oxygen saturation 3

Oxygen Therapy Optimization

For Patients at Risk of Hypercapnic Respiratory Failure (COPD, severe obesity, chest wall disease, neuromuscular disease):

• Target SpO2 88-92% using controlled oxygen delivery 1, 2
• Use 24% Venturi mask at 2-3 L/min OR 28% Venturi mask at 4 L/min OR nasal cannulae at 1-2 L/min 1, 3
• Obtain arterial blood gases within 30-60 minutes of starting or adjusting oxygen 1, 2
• Recheck blood gases after 30-60 minutes or if clinical deterioration occurs 1, 2
• Avoid high-flow oxygen (>4 L/min or FiO2 >0.28) as this significantly increases mortality risk in COPD exacerbations 2

For Patients NOT at Risk of Hypercapnia:

• Target SpO2 94-98% 3, 4
• Increase oxygen concentration if SpO2 remains below target and patient is clinically stable 3
• Continue monitoring with pulse oximetry and repeat blood gases if deterioration occurs 3

Pharmacological Management

Bronchodilators (Immediate Priority):

• Administer nebulized short-acting beta-2 agonist (salbutamol 2.5-5 mg) AND anticholinergic (ipratropium 0.25-0.5 mg) 1, 5, 6
• Use air-driven nebulizers for patients at risk of hypercapnia, or oxygen at maximum 6 L/min to avoid excessive oxygen delivery 2
• If patient is at risk of hypercapnia, continue oxygen via nasal prongs at 1-2 L/min during nebulization to prevent desaturation 3
• Repeat nebulizers every 4-6 hours, or more frequently if needed 3
• Peak bronchodilation occurs within 1-2 hours and persists for 4-5 hours in most patients 5

Systemic Corticosteroids (High Priority):

• Initiate prednisone 30-40 mg orally daily for 5-10 days (or equivalent IV dose if oral route not possible) 1, 2
• This improves lung function, oxygenation, and shortens recovery time 1, 2
• Consider inhaled corticosteroids via MDI or nebulizer as adjunct 3

Antibiotics (If Indicated):

• Prescribe antibiotics if patient has increased sputum purulence PLUS either increased dyspnea OR increased sputum volume 1, 2
• First-line options: amoxicillin, tetracycline, or amoxicillin/clavulanate for 5-7 days 1
• Consider respiratory fluoroquinolones (levofloxacin, moxifloxacin) for more severe cases 3, 1

Monitoring and Escalation Criteria

Continuous Monitoring:

• Monitor SpO2 continuously with pulse oximetry 2
• Reassess arterial blood gases 30-60 minutes after any oxygen adjustment 1, 2
• Use physiological track-and-trigger system (e.g., NEWS score) 3

Consider Non-Invasive Ventilation (NIV) if:

• Respiratory acidosis (pH <7.35) persists >30 minutes after standard medical management 1, 2
• Patient remains hypoxemic despite optimal oxygen therapy 2
• Severe dyspnea persists despite bronchodilators and corticosteroids 2
• NIV reduces mortality and intubation rates with 80-85% success rate in COPD exacerbations 2

Intubation Indicated if:

• NIV failure with worsening blood gases/pH 2
• Severe acidosis (pH <7.26 predicts poor outcome) 3
• Life-threatening hypoxemia 2
• Respiratory arrest 2

Common Pitfalls to Avoid

• Never give FiO2 >28% or >2 L/min via nasal cannulae to patients with known COPD until arterial blood gases are obtained 3
• Do not discontinue oxygen to obtain room air oximetry in patients who clearly require oxygen therapy 3
• Do not use oxygen-driven nebulizers in patients with elevated PaCO2 or respiratory acidosis; use air-driven nebulizers instead 3
• Do not delay blood gas measurement beyond 60 minutes of initiating or changing oxygen therapy 3, 1
• Prevention of tissue hypoxia supersedes CO2 retention concerns, but monitor for acidemia if CO2 retention occurs 3

Weaning Considerations (Once Stable)

• Begin weaning when patient is clinically stable and SpO2 has been in upper zone of target range for 4-8 hours 3
• For patients at risk of hypercapnia: step down to 1 L/min via nasal cannulae or 24% Venturi mask before discontinuation 3, 7
• For other patients: step down to 2 L/min via nasal cannulae before discontinuation 3, 7
• Monitor SpO2 for 5 minutes after stopping oxygen, then recheck at 1 hour 3, 7