Hypoxia and Medicine

Why is it important to monitor oxygen saturation of the blood during surgery?

Why is an oximeter important? Can it be measured without a pulse oximeter (as in, a different type of oximeter, if one exists) and how?

Public Comments

1. During surgery the patient is intubated and a machine is breathing for the patient. A pulse oximeter is vital to monitoring the patient to make sure they are receiving adequate amounts of oxygen. If the sat drops there may be a disconnect between the patient and the machine or there may be a problem with the patient's lung in which case the anesthesiologist would have to fix the issue. Pulse ox is the most common method for monitoring oxygen saturation.
2. Oxygen has to get to all the body parts (especially the brain and heart) and oxygen saturation is the best way to know that the blood is carrying enough of it. Anesthetics decrease respiratory drive and blood pressure, both of which can decrease the delivery of oxygen. We like to make sure that the blood is holding all the oxygen it can. We don't intubate and ventilate everybody, as another answerer suggested, but we do that to a lot of people. Oxygen saturation decreases can be a clue that the tube has gone down a mainstem bronchus, that there is a problem with oxygen delivery, that the patient is having bronchospasm, or a million other things. It's not the only thing we use to look for problems, but it is one of the most important and sensitive monitors we have. Another way to check the hemoglobin saturation is by arterial blood gas analysis, but that involves getting blood out of an artery and running lab tests on it. Pulse oximetry is real time and non-invasive. You can also look at the color of the blood in the surgical wound, but if it's dark enough to look bad, your patient is in real trouble.