Pulse oximetry is a simple non-invasive method of monitoring the percentage of hemoglobin (Hb) which is saturated with oxygen. The pulse oximeter consists of a probe attached to the patient's finger or ear lobe which is linked to a comprised unit. The unit displays the percentage of Hb saturated with oxygen together with an audible single for each pulse beat, a calculated heart rate and in same models, a graphical display of the blood flow past the probe. Audible alarms witch can be programmed by the user are provided. An oximeter detects hypoxia before the patient becomes clinically cyanosed.
Pulse oximeters may be used in a variety of situations but are particular value for monitoring oxygenation and pulse rates throughout anesthesia. They are also widely used during the recovery phase.
When patients are sedated for procedures such as endoscopy, oximetry has been shown to increase safety by altering the staff to unexpected hypoxia.