From the Guidelines
The approach to hypoxia involves immediate oxygen supplementation while identifying and treating the underlying cause, with the goal of maintaining oxygen saturation above 90% (or 88-92% in COPD patients) as recommended by the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.
Key Considerations
- Start with high-flow oxygen via nasal cannula, face mask, or non-rebreather mask depending on severity, as suggested by the 2019 ESC guidelines for the diagnosis and management of acute pulmonary embolism 1.
- Position the patient upright if possible to optimize ventilation, as recommended for patients with stroke and cardiorespiratory comorbidities 1.
- Assess airway, breathing, and circulation, and be prepared for potential intubation in severe cases, considering the use of non-invasive ventilation in patients with dyspnea and/or persistent hypoxemia despite oxygen therapy 1.
Diagnostic Approach
- Obtain arterial blood gases to determine the severity and type of hypoxemia (PaO2 < 60 mmHg or SpO2 < 90%), as part of the diagnostic workup for hypoxia.
- Monitor oxygen saturation, vital signs, and mental status continuously, with oxygen saturation targets based on individual patient needs, such as 94-98% for most acutely ill patients 1.
Therapeutic Approach
- Administer bronchodilators like albuterol 2.5-5 mg via nebulizer for bronchospasm, diuretics like furosemide 40 mg IV for pulmonary edema, or antibiotics for pneumonia based on clinical presentation, as part of the treatment for underlying causes of hypoxia.
- Consider long-term oxygen therapy for chronic hypoxemia, with the goal of improving quality of life and reducing morbidity and mortality, as supported by the BTS guideline for oxygen use in adults in healthcare and emergency settings 1.
From the Research
Approach to Hypoxia
- The approach to hypoxia involves the use of supplemental oxygen, with the goal of maintaining a peripheral oxygen saturation (SpO2) of 92% or above 2.
- Pulse oximetry should be continuous and initiated as early as possible, and oxygen should be available to all trauma and medical patients in the forward operating environment 2.
- If SpO2 is less than 92%, supplemental oxygen should be titrated to achieve an SpO2 of greater than 92%, and if flow rates of greater than 5 L/min are required, then urgent evacuation and critical care support should be requested 2.
- Non-invasive ventilation (NIV) and high-flow nasal oxygen therapy are also used to manage acute hypoxemic respiratory failure, with NIV appearing to be safe and effective in mild-to-moderate hypoxemia (PaO2/FiO2 > 150 mmHg) 3.
- However, in moderate-to-severe hypoxemia (PaO2/FiO2 ≤ 150 mmHg), NIV may yield delayed intubation with increased mortality, and high-flow nasal oxygen and helmet NIV represent the most promising techniques for first-line treatment of severe patients 3.
Non-Invasive Ventilation
- NIV has gained an increasingly pivotal role in the treatment of acute hypoxemic and/or hypercapnic respiratory failure, offering multiple advantages over invasive mechanical ventilation, including the preservation of airway defense mechanisms and a reduced need for sedation 4.
- However, NIV has some contraindications, including severe encephalopathy, and its use in patients with an altered level of consciousness requires careful consideration and monitoring 4.
- The role of NIV has expanded in recent years, and it is now considered first-line therapy in some conditions, such as chronic obstructive pulmonary disease, pulmonary oedema, and mild-to-moderate hypoxaemic respiratory failure in immunocompromised patients 5.
Comparison of Oxygen Therapies
- A comparison of NIV and high-flow nasal oxygen therapy found no difference between the two in terms of preventing severe hypoxia during intubation, although NIV was associated with higher pulse oximetry values during preoxygenation 6.
- The choice of oxygen therapy depends on the individual patient's needs and circumstances, and should be guided by careful assessment and monitoring 2, 6, 3.