Equipment, Oxygen Delivery, and Airway Management
Core concepts
This area tests whether you can select and troubleshoot respiratory equipment. Know the oxygen delivery devices and their approximate FiO2 ranges: nasal cannula 1-6 L/min (about 24-44%), simple mask 5-10 L/min (about 35-50%), air-entrainment (Venturi) masks for precise FiO2, partial and nonrebreather masks, and high-flow nasal cannula. Understand humidification needs at higher flows. For airway management, know indications for intubation, how to confirm tube placement (auscultation over the epigastrium and bilateral chest, chest rise, and especially waveform capnography), and how to secure and monitor the tube. Familiarize yourself with suctioning, bag-valve-mask technique, and the difference between invasive and noninvasive ventilation.
Traps
The most common trap is choosing a device by habit rather than by the patient's need. A nonrebreather on a patient who needs controlled, precise FiO2 is wrong; an air-entrainment mask is right. Another trap is forgetting that a patient with a high oxygen demand may need a device that guarantees FiO2 regardless of inspiratory effort. Items also test troubleshooting: sudden desaturation after intubation should prompt you to verify tube position and patency before anything else.
Rule of thumb
Match device to goal: if the goal is precise FiO2, use an air-entrainment mask; if the goal is high FiO2, use a nonrebreather or high-flow system; if the goal is low-flow comfort oxygen, use a cannula. Worked example: a patient needs a stable 28% FiO2 for COPD management. A nasal cannula cannot guarantee 28%, but a 28% Venturi mask can, so the Venturi mask is the correct answer.