Count to 10 - Anaesthetic Primary Podcast EP15 - Pulse Oximetry | MiniPod | CT10
12 snips
Jul 18, 2023 Discover the fascinating world of pulse oximetry and how these devices measure oxygen saturation through light absorbance. Learn about common errors that can impact readings, as well as the importance of R values for accurate interpretation. Dive into past exam questions and uncover the types of tricky inquiries you might face. This episode demystifies a core clinical topic while preparing you for success in your assessments.
AI Snips
Chapters
Transcript
Episode notes
Core Principles Of Pulse Oximetry
- Pulse oximeters measure oxygen bound to hemoglobin using light absorbance and the Beer-Lambert principles.
- Oxyhemoglobin and deoxyhemoglobin absorb red (660nm) and infrared (940nm) differently, enabling SpO2 estimation.
Beer–Lambert Laws Explained Simply
- Beer and Lambert laws explain how concentration and path length affect light absorbance through tissue.
- Combining both laws yields an exponential decrease in transmitted light with greater concentration or distance.
Memorize Key Wavelengths And R Concept
- Remember the diode wavelengths: red 660nm and infrared 940nm; these are exam 'must knows'.
- Know the R-value concept: compute ratios of AC/DC for red and infrared to derive SpO2 via calibration curves.