Pulse Oximetry

Question 1

What does pulse oximetry measure?

Answer 1

Peripheral blood oxygenation and pulse rate.
- Transmissive pulse oximetry (most common type)
- Reflective pulse oximetry

Question 2

How do you use a pulse oximeter?

Answer 2

7Cs
Ensure device clean, use alcohol-based wipes, NOT zappitizer
Ensure patient’s hands are warm
Identify an appropriate finger (not thumb)
Place pulse oximeter on finger, and politely ask patient to keep their hand still.
Allow pulse oximeter to stabilise until you see two numbers that remain fairly static.

Question 3

What are the results from the pulse oximeter?

Answer 3

Peripheral oxygen saturation (SpO2)
Pulse rate (beats per minute)

Question 4

What are the normal and abnormal values?

Answer 4

Normal - SpnO2 95% or more
Patients on oxygen therapy: target value of 94-98%
Patients with type 2 respiratory failure: 88-92%

Question 5

What are factors that affect interpretation?

Answer 5

Arrhythmias
Nail varnish/false nails
Cold hands
Patients with darker skin