Which assessments guide oxygen therapy initiation and the selection of the delivery system?

• A. Respiratory rate, oxygen saturation, work of breathing
• B. Blood pressure and heart rate
• C. Glasgow Coma Scale
• D. Pain level

Answer: (A)

The main idea is that decisions about starting oxygen and choosing how to deliver it are made from real-time checks of how well the lungs and blood are meeting the body's oxygen needs. Respiratory rate shows how hard the person is working to breathe; a rising rate or marked tachypnea suggests increased oxygen demand or distress. Oxygen saturation (SpO2) tells you how much oxygen is actually being carried in the blood; a low SpO2 indicates under-oxygenation and the need for supplemental oxygen. Work of breathing reflects how much effort the person must exert to breathe (nasal flaring, use of accessory muscles, retractions); if this is elevated, it signals that current breathing isn’t adequate and oxygen support is likely needed.

Together, these three measurements guide not only whether to start oxygen but also which delivery method to use. Begin with the least invasive option that can achieve adequate oxygenation—for mild cases with stable work of breathing, a nasal cannula may be enough; for more significant hypoxemia or increased work of breathing, more supportive devices like a simple face mask or non-rebreather may be necessary, with ongoing monitoring of SpO2 and clinical status.

Other measurements like blood pressure and heart rate, or neurological status and pain level, don’t directly determine the need for oxygen therapy. They’re important for overall assessment but don’t specify oxygen requirements.