What are the guidelines for initiating and managing oxygen therapy in patients?

From the Guidelines

Oxygen therapy should be initiated in patients with hypoxemia, aiming for a target oxygen saturation of 94-98% for most patients, but 88-92% in those with COPD or risk of hypercapnic respiratory failure, as recommended by the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.

Key Considerations for Oxygen Therapy

• Oxygen is a treatment for hypoxaemia, not breathlessness, and should be prescribed according to a target saturation range 1.
• The initial oxygen therapy should be nasal cannulae at 2–6 L/min or simple face mask at 5–10 L/min, unless the patient has a saturation below 85%, in which case a reservoir mask at 15 L/min should be used 1.
• For patients with COPD or other risk factors for hypercapnic respiratory failure, the target oxygen saturation range should be 88-92% pending blood gas results, and adjusted to 94-98% if the PCO2 is normal 1.
• Oxygen therapy should be continuously monitored, and flow rates titrated accordingly to maintain the target saturation range and prevent hyperoxia-related complications 1.
• Weaning and discontinuation of oxygen therapy should be done gradually, with patients stepped down to 2 L/min via nasal cannulae prior to cessation of oxygen therapy, and oxygen saturation monitored for 5 minutes after stopping oxygen therapy 1.

Monitoring and Adjusting Oxygen Therapy

• Continuously monitor oxygen saturation, respiratory rate, and work of breathing, and titrate oxygen flow rates accordingly to maintain the target saturation range.
• Assess the need for oxygen therapy regularly and wean patients gradually when clinical improvement occurs.
• Humidify oxygen when flow rates exceed 4 L/min or for prolonged therapy to prevent mucosal drying.
• Document the indication for oxygen, delivery device, flow rate, and patient response.

Special Considerations

• Patients with COPD or other risk factors for hypercapnic respiratory failure require careful monitoring and adjustment of oxygen therapy to prevent hypercapnic respiratory failure.
• Patients with severe anaemia or other underlying conditions may require individualized oxygen therapy targets and monitoring.
• Oxygen therapy should be used with caution in patients with a history of previous hypercapnic respiratory failure requiring NIV or IMV.

From the Research

Guidelines for Initiating and Managing Oxygen Therapy

• The guidelines for initiating and managing oxygen therapy in patients vary depending on the underlying condition and severity of respiratory failure 2, 3, 4, 5, 6.
• For patients with acute respiratory failure, high-flow nasal cannula oxygen therapy (HFOT) may be considered as an alternative to noninvasive ventilation (NIV) and standard oxygen therapy 4, 5.
• In patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure, noninvasive positive pressure ventilation (NPPV) has been shown to reduce the need for endotracheal intubation, inhospital mortality, and length of hospital stay compared to usual medical care alone 6.
• The use of NPPV has also been shown to be effective in weaning COPD patients from invasive mechanical ventilation (IMV), with significant reductions in mortality, nosocomial pneumonia, and weaning failure 6.

Key Considerations for Oxygen Therapy

• The initial arterial oxygen saturation on oxygen should be maximized whenever possible by increasing the inspiratory oxygen fraction 3.
• The choice of oxygen therapy device, such as Venturi masks or nasal prongs, should be based on the patient's individual needs and the severity of their respiratory failure 3.
• High-flow nasal cannula oxygen therapy may be more efficient than bag-valve mask in preventing severe adverse events in mild hypoxemic patients 5.
• The ROX index (ratio of SpO2/FiO2 to respiratory rate) may be used to predict the success of high-flow nasal oxygen therapy in patients with de novo respiratory failure 5.

Areas for Further Research

• Additional studies are needed to confirm the superiority of high-flow nasal oxygen to standard oxygen in de novo respiratory failure and other causes of acute respiratory failure 2, 5.
• Further research is also needed to define the appropriate indications for NPPV and HFOT in patients with acute respiratory failure 4, 5.