Pulse Oximetry

Question 1

What is pulse oximetry?

Answer 1

Non-invasive method of measuring oxygenation of patients’ blood

Question 2

How does pulse oximetry work?

Answer 2

IR light shone through body tissues and detects colour difference between oxygenated and de-oxygenated blood. Absorption degree depends on blood O2 amount. Often gives pulse rate reading too.

Question 3

When may pulse oximetry be used?

Answer 3

Respiratory difficulties e.g. asthma attack, worsening COPD or during MI

Question 4

What is pulse oximetry accuracy affected by?

Answer 4

Thickness of skin

Temperature of skin

Question 5

Where is the best place for pulse oximetry?

Answer 5

Thin skin areas e.g. ear lobe/ fingertip

Question 6

What is the process for pulse oximetry?

Answer 6

1) Ensure patient comfortable and warm
2) Select suitable site e.g. fingertip (not calloused, no dirty etc.)
3) Place probe according to instructions
4) Make sure sensor also detecting pulse
5) Note O2 level and remove probe
6) Clean and store
7) Document reading and report abnormalities

Question 7

What is the normal level for blood O2 saturation?

Answer 7

96 - 100%

Question 8

What is the life threatening point of blood O2 saturation?