NREMT Emergency Medical Technician (EMT) Cognitive ExamAirway, Respiration & VentilationMedium
A 45-year-old male with a history of chronic bronchitis is experiencing an acute exacerbation. He is alert but struggling to breathe, with a respiratory rate of 28 breaths per minute, SpO2 88% on room air, and diffuse wheezing. What is the most appropriate oxygen delivery device for this patient?
- AVenturi mask at 24% oxygen.
- BNasal cannula at 4 L/min.
- CBag-valve mask with supplemental oxygen.
- DNon-rebreather mask at 15 L/min.
Show answer & explanationAnswer & explanation
Correct answer: D. Non-rebreather mask at 15 L/min.
The patient has significant respiratory distress with an SpO2 of 88% and wheezing, indicating hypoxemia. A non-rebreather mask at 15 L/min provides the highest concentration of supplemental oxygen to rapidly improve oxygenation. While a Venturi mask can provide precise concentrations, the immediate need for high oxygen saturation outweighs the need for precision in this acute setting.
Why the other options are wrong
- A. A Venturi mask provides precise oxygen concentrations, but 24% is a very low concentration. While useful for COPD patients who retain CO2, the immediate priority is to improve the SpO2 from 88%. If the patient were in less distress and had a history of CO2 retention, this might be considered, but 88% is too low.
- B. Nasal cannula at 4 L/min provides a low concentration of oxygen and would be insufficient for a patient with an SpO2 of 88% and respiratory distress.
- C. The patient is alert and breathing adequately (though struggling), so positive pressure ventilation with a BVM is not yet indicated. He needs high-flow supplemental oxygen.
Oxygen Delivery Devices
Various devices are used to deliver supplemental oxygen, each providing different flow rates and oxygen concentrations, tailored to the patient's respiratory status.
- Nasal cannula: 1-6 L/min, 24-44% O2.
- Simple face mask: 6-10 L/min, 35-60% O2.
- Non-rebreather mask: 10-15 L/min, up to 90-100% O2.
- Venturi mask: Fixed concentrations (e.g., 24%, 28%, 35%, 40%, 50%) at specific flow rates.
Memory trick: Low flow for mild, high flow for severe, Venturi for precise, BVM for fear.