Hypoxemia Differential Diagnosis Algorithm by A-a Gradient Normal A-a Gradient: • ↓ Atmospheric pressure • Hypoventilation: CNS depression, neuromuscular disease, ↓ chest wall compliance ↑ A-a Gradient: • Right-to-Left Shunt: Cardiac, Vascular, Alveolar • V/Q Mismatch: ↓Ventilation (↑Shunting), ↓Perfusion (↑Dead space) • ↓Diffusion Capacity Matthew Ho, MD PhD @MatthewHoMD #Hypoxemia #Hypoxia #Differential #Diagnosis #Algorithm #pulmonary #Aa #Gradient
