From the Guidelines
Your patient's high flow oxygen therapy at 15L/min should be titrated to maintain an oxygen saturation target range of 94-98% unless they have coexisting COPD or other risk factors for hypercapnic respiratory failure, in which case the target range should be 88-92% pending blood gas results 1. This level of oxygen therapy indicates your patient likely has severe hypoxemia requiring substantial respiratory support. You should closely monitor their oxygen saturation levels, respiratory rate, work of breathing, and overall clinical status. Consider arterial blood gas analysis to assess oxygenation and ventilation status. If the patient remains hypoxemic despite this high flow oxygen, they may need escalation to non-invasive ventilation (like CPAP or BiPAP) or possibly intubation and mechanical ventilation. The underlying cause of their respiratory failure should be investigated and treated - common causes include pneumonia, pulmonary edema, COPD exacerbation, or acute respiratory distress syndrome. Some key points to consider in the management of your patient's oxygen therapy include:
- Ensuring adequate humidification to prevent drying of the airways
- Monitoring for signs of respiratory depression or absorption atelectasis, particularly in patients with chronic CO2 retention
- Regularly documenting oxygen requirements and developing a plan for weaning when clinically appropriate
- Adjusting the oxygen saturation target range based on the patient's underlying condition and blood gas results, as recommended in the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.
From the Research
High Flow Oxygen Therapy
- High flow oxygen therapy is being used in intensive care and emergency medicine to maintain aerobic metabolism 2.
- The optimal targets for oxygenation need to be further defined, but harm has been shown for mild hyperoxia in ventilated critically ill patients 2.
- High flow nasal cannulae can be used for selected patients with acute hypoxaemic respiratory failure 3.
Benefits and Risks of High Flow Oxygen Therapy
- High flow oxygen therapy may improve oxygenation and decrease pneumonia rate without affecting the length of ICU stay, intubation or reintubation rate, mortality, and SpO₂ at the end of oxygen therapy 4.
- Hyperoxia may increase morbidity and mortality, presumably due to the formation of reactive-oxygen species 2.
- Hyperoxia may lead to an increase of hypercarbia in patients with acute exacerbation of chronic obstructive lung disease 2.
Guidelines for Oxygen Therapy
- Aim for an SpO₂ range of 94-98% for most hospitalized patients, and 88-92% for those with COPD 5.
- Consider early initiation of high-flow oxygen therapy, and consider humidification for supplemental oxygen when flows > 4 L/min are used 5.
- High flow oxygen therapy may be used to avoid escalation to noninvasive ventilation, and to avoid re-intubation immediately postextubation 5.