BLOOD TECHNOLOGIES

There are two main technologies, which are used to measure the level of gas within the blood. These technologies are Pulse Oximetry and Arterial Blood Gas analysis. Both these technologies allow doctors to examine and determine gas levels within the blood, in order to ensure safety of a patient when treating them.

Pulse Oximetry:
Pulse Oximetry is commonly used in hospitals to measure and monitor oxygen levels, and carbon dioxide levels in blood of patients. They are most commonly used to monitor a patient’s blood during a surgery, whilst they are under anaesthesia. Pulse Oximetry is also used on patients who: * Have breathing disorders (asthma) * Have reactions to certain medications * Are recently out of surgery * Are on a ventilator * Are undergoing sleep tests (sleep talking, sleep walking etc.)
Pulse Oximetry is non-invasive and thus considered an accurate and more comfortable way to analysis oxygen and carbon dioxide saturation & levels within a patient’s blood. This analysis indicates breathing & circulation within a patient is normal.
A Pulse Oximeter is attached to the patient’s finger, and emits a red light signal. This signal measures the amount of light absorbed through finger tissue and into the blood, which gives indications of oxygen saturation, depending on the blood colour. Pulse Oximeter readings are given as a percentage, for example 94%, which is a normal healthy reading (the percentage being the amount of oxygen saturation).

Arterial Blood Gas analysis:
Arterial Blood Gas (ABG) analysis is much less common, and is only really used if abnormal readings are found through the use of a Pulse Oximeter, or severe breathing abnormalities displayed by a patient.
Arterial Blood Gas analysis is much more invasive, as a sample of blood is taken from an artery (usually from the arm). This form of blood analysis monitors the rate of diffusion of oxygen & carbon dioxide through an artificial membrane and results are monitored. Oxygen diffusing through an artificial membrane creates an electrical current, and diffusion of carbon dioxide changes the pH of the blood. Arterial Blood Gas analysis gives more information and detail on the blood, however is much more invasive and therefore is