Pulse oximetry is almost ubiquitous in the acute medicine setting. It can be very useful but has its limitations. Some factors affecting it include:
- Carbon Monoxide (binds up oxygen at higher affinity)
- Cyanide (disrupts electron transport chain)
- Methemoglobin (form of hemoglobin that does not carry oxygen)
- Anemia (hemoglobin deficiency)
- Cold extremities (hypothermia)
- Fingernail polish/ extensive nail pigmentation
- Intravenous Dyes (i.e methylene blue)
REFERENCES
- http://www.hopkinsmedicine.org