Categories: Respirology/ ICU

Factors affecting Pulse Oximetry

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

  1. http://www.hopkinsmedicine.org
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Dr. C Humphreys

Internal Medicine

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