The Curious Clinicians 106 - Pulse Check: Methemoglobin
Mar 13, 2025
Dive into the fascinating world of methemoglobinemia, where patients sport fixed oxygen saturations at 85%. Discover the complexities of diagnosing severe hypoxemia and the challenges healthcare providers face. The podcast also highlights the critical role of pulse oximeters in measuring blood oxygen levels, especially for individuals with darker skin tones. Learn about the biochemical effects of methemoglobin on oxygen delivery and the impact of treatment strategies on patient outcomes.
AI Snips
Chapters
Transcript
Episode notes
Case Presentation
- A patient with cavitary lung lesions from lung cancer experienced refractory hypoxemia.
- Their oxygen saturation remained at 85% despite 100% FiO2.
Fixed Oxygen Saturation
- An oxygen saturation fixed at 85% is unusual.
- Supplemental oxygen should improve saturation unless a shunt, hemoglobinopathy, PE, or low cardiac output exists.
Methemoglobinemia Diagnosis
- The patient's ABG showed a high PO2 of 284 despite an 85% oxygen saturation.
- This dissociation, along with chocolate-brown blood, suggested methemoglobinemia.