Can oxygen supplementation be decreased in a patient with COVID-19 and Influenza who is stable on Optiflow (high-flow nasal oxygen therapy) with oxygen saturations of 94-95%?

Oxygen Supplementation Can Be Decreased in This Stable Patient

Oxygen supplementation can and should be decreased in this elderly woman with COVID-19 and Influenza who has been stable on high-flow nasal oxygen for over 24 hours with saturations of 94-95%. There is no requirement to maintain oxygen therapy until saturations reach 98-99%, and doing so may expose the patient to unnecessary hyperoxia risks.

Target Oxygen Saturation Range

• The recommended target oxygen saturation for COVID-19 patients is 92-96%, not 98-99% 1
• The European Respiratory Society specifically recommends maintaining SpO2 between 90-96% without exceeding 96% to avoid hyperoxia 1
• The British Thoracic Society recommends starting oxygen only when SpO2 falls below 92%, with strong recommendation for oxygen when SpO2 <90% 2
• Current saturations of 94-95% fall within the optimal target range of 94-98% for patients without risk factors for hypercapnic respiratory failure 2

Rationale for Weaning High-Flow Oxygen

• After 24+ hours of stability, this patient has demonstrated sustained improvement and can tolerate a trial of lower oxygen support 1
• High-flow nasal cannula (HFNC) is classified as an aerosol-generating procedure requiring full PPE and secure environments, making it resource-intensive 3, 1
• The goal is to use the minimum oxygen flow necessary to maintain adequate arterial oxygen saturation, preferably <5 L/min when possible to reduce aerosolization risk 1

Weaning Algorithm

Step 1: Assess Stability Criteria

• Respiratory rate <30 breaths/min 2
• Heart rate <100 bpm 4
• Stable mental status 4
• No increasing oxygen requirements over the past 24 hours 4

Step 2: Trial of Reduced Support

• Transition from high-flow nasal oxygen to standard nasal cannula at 2-6 L/min 2
• Target SpO2 of 94-98% (or 92-96% per European guidelines) 2, 1
• Monitor continuously for the first 30-60 minutes after transition 2

Step 3: Monitoring Parameters During Weaning

• Measure respiratory rate immediately—a rate >30 breaths/min requires urgent escalation even with adequate SpO2 2
• Check oxygen saturation every 1-2 hours initially, then at least twice daily once stable 2
• Monitor vital signs including heart rate, blood pressure, and mental status at least twice daily 2

Critical Warning Signs Requiring Re-escalation

• SpO2 dropping below 92% mandates reinitiation or increase of supplemental oxygen 2, 1
• Respiratory rate >30 breaths/min indicates respiratory distress requiring immediate intervention 2
• SpO2 <85% requires high-flow oxygen at 15 L/min via reservoir mask 2
• Worsening mental status, inability to speak in full sentences, or signs of respiratory exhaustion warrant urgent medical evaluation 2

Common Pitfalls to Avoid

• Do not target oxygen saturations of 98-99%—this represents unnecessary hyperoxia and has no evidence-based benefit 1, 5
• Do not delay weaning in stable patients due to fear of deterioration—prolonged unnecessary high-flow oxygen increases infection transmission risk and resource utilization 3, 1
• Do not rely solely on SpO2—respiratory rate and work of breathing are crucial parameters that may indicate deterioration before oxygen saturation falls 2
• Do not wean too rapidly—gradual stepwise reduction with close monitoring is safer than abrupt discontinuation 2

Evidence Regarding Conservative vs. Liberal Oxygen Strategies

• While one observational study suggested an association between conservative oxygen strategies (starting oxygen at SpO2 ≤91%) and higher national mortality rates 6, this conflicts with established guidelines recommending against hyperoxia 1
• The ongoing HOT-COVID trial is investigating optimal oxygenation targets (PaO2 of 8 kPa vs 12 kPa) in ICU patients, but results are not yet available 7
• Current best evidence supports avoiding both hypoxemia (SpO2 <90%) and hyperoxia (SpO2 >96%) 1, 5

Practical Implementation

• Position the patient upright to optimize ventilation and reduce work of breathing 2
• Provide a hand-held fan directed at the face for symptomatic breathlessness relief 2
• Continue current corticosteroid therapy (prednisone 20 mg daily is appropriate for post-COVID management) 2
• Consider nebulized bronchodilators (salbutamol 2.5-5 mg or ipratropium 0.25-0.5 mg) if dyspnea persists despite adequate oxygenation 2