1. Pulse oximetry Pulse oximeter measures
The oxygen saturation of haemoglobin in arterial blood – which is a measure of the average amount of oxygen bound to each haemoglobin molecule.
Average reading %
Can be placed on finger or ear lobe
The pulse rate – in beats per minute , averaged over 5-20 seconds

3. Indications Monitoring effectiveness of oxygen therapy
Sedation or anesthesia
Haemodynamic instability – AMI, CCf
Respiratory illness
Monitoring during administration of respiratory depressant drugs

4. Inaccurate readings May be caused by
A reduction in peripheral pulsatile blood flow produced by peripheral vasoconstriction (hypovolaemia).
Severe hypotension
Cold shivering
CCF
Some cardiac arrhythmias
PVD
Nail varnish (may cause low readings)
Bright fluorescent lighting