From the Guidelines
The patient's blood gas values indicate hypoxemia with a partial pressure of oxygen (PO2) of 55 mmHg and an oxygen saturation (O2 sat) of 90%, requiring supplemental oxygen therapy immediately to achieve a target oxygen saturation of 94-98%. According to the British Thoracic Society guideline for oxygen use in adults in healthcare and emergency settings 1, a desirable target saturation range is 94-98%, which mirrors the normal range for UK adults with a wide margin of safety above the 90% threshold.
Key Considerations
- The patient's current oxygen saturation of 90% is below the recommended target range, indicating the need for supplemental oxygen therapy.
- The guideline suggests that most experts emphasize the importance of keeping the SaO2 above 90% for the majority of acutely ill patients 1.
- Sudden exposure to low SaO2 levels (below about 80%) can cause impaired mental functioning even in healthy participants, and the brain is the most sensitive organ to the adverse effects of hypoxia 1.
Recommendations
- Start with 2-4 liters per minute of oxygen via nasal cannula and titrate as needed to achieve the target oxygen saturation.
- Implement continuous pulse oximetry monitoring to track response to therapy.
- Investigate the underlying cause of hypoxemia promptly through clinical assessment, chest imaging, and additional laboratory tests as appropriate.
- Consider escalating to high-flow nasal cannula, non-invasive ventilation, or intubation based on clinical status and trajectory if the patient shows signs of respiratory distress despite supplemental oxygen.
From the Research
Oxygen Saturation Levels
- The given oxygen saturation (O2 sat) level is 90%, which is considered low according to the study 2.
- A SpO2 level of less than 90% is considered a clinical emergency, and if the SpO2 level is below 94%, the patient is assumed to be hypoxic until proven otherwise 2.
PO2 Levels
- The given PO2 level is 55, which indicates hypoxemia.
- Hypoxemia is a common presentation in critically ill patients and requires appropriate management to prevent severe harm 3.
Management of Hypoxemia
- The management of hypoxemia involves ascertaining the severity of hypoxemia, the underlying diagnosis, and implementing the most appropriate treatment 3.
- Oxygen therapy can be delivered by variable or fixed rate devices, and non-invasive ventilation; if patients deteriorate, they may require tracheal intubation and mechanical ventilation 3.
- The target oxygen saturation range for most hospitalized patients is 94-98%, and 88-92% for patients with COPD 4.
Supplemental Oxygen Administration
- Supplemental oxygen administration during mechanical ventilation can reduce diaphragm blood flow and oxygen delivery 5.
- The use of high-flow oxygen therapy may be beneficial in certain patients, but it is important to consider the potential risks and benefits 4.
- The management of postoperative hypoxemia involves the use of conventional oxygen therapy, high-flow nasal cannula oxygen therapy, CPAP, and noninvasive ventilation, and the recommendations are based on the currently available evidence 6.