REBEL Core Cast 135.0: A Simple Approach to Hypoxemia (vs. Hypoxia)

Managing critically ill patients requires a systematic bedside approach to differentiate between the five primary causes of hypoxemia: hypopnea or apnea, high altitude, diffusion defects, shunt, and dead space. While apnea and chronic lung-related diffusion defects are often identifiable through patient history or physical observation, acute hypoxemia frequently necessitates distinguishing between shunt and dead space physiology. Shunt physiology, characterized by fluid, pus, or alveolar collapse, presents as refractory hypoxemia that fails to improve with supplemental oxygen, mandating the use of positive pressure ventilation. Conversely, dead space disease, often involving perfusion blockages like pulmonary embolisms, typically responds to supplemental oxygen. This clinical framework prioritizes immediate, actionable interventions at the bedside, moving beyond reliance on invasive diagnostic testing to ensure timely and effective patient stabilization.