Clinical meaning
Oxygen delivery devices are classified as low-flow (nasal cannula, simple mask, non-rebreather) or high-flow (Venturi mask, high-flow nasal cannula) systems. Low-flow systems deliver supplemental O2 that mixes with room air during inspiration, so the actual FiO2 varies with the patient's respiratory pattern. High-flow systems provide all or most of the patient's inspiratory flow, delivering a more consistent FiO2. Proper setup and maintenance of equipment ensures safe and effective oxygen delivery.
Exam relevance
Risk factors: - COPD patients at risk for CO2 retention with high-flow oxygen: chronic CO2 retainers rely on hypoxic drive; excessive O2 can suppress respiratory drive - Nasal and facial skin breakdown from prolonged device contact especially at the ears, bridge of nose, and nares - Fire hazard from oxygen use near open flames, smoking, or petroleum-based products - Oxygen toxicity from prolonged exposure to high FiO2 (above 60% for more than 24-48 hours) causing alveolar damage - Drying of nasal and oral mucosa from non-humidified oxygen at flow rates above 4 L/min - Tripping hazard from oxygen tubing on the floor or connected to a portable tank during ambulation