CMS pulse oximeters are medical gadgets that help medical professionals determine, somewhat indirectly, if a patient is getting enough oxygen. The devices clip onto the finger, the earlobes or, in infants, a foot. What they actually measure is the amount of hemoglobin that is fully loaded up with oxygen. In most people, this figure should be at least 95% or more.
The physical principles of how a pulse oximeter works are beyond the scope of this article. It is based on the absorbance of light. By shining light of two different wavelengths into the skin, the instrument can calculate the light absorbance, and hence the concentration of O2 in blood that is circulating in the arteries.
While this is an excellent way of screening sick people from really sick people, a more accurate measurement is obtained by measuring oxygen directly from arterial blood. This is important in places like intensive care units or when a patient is under anesthesia having an operation.
This is a painful and invasive procedure and there needs to be a good reason for collecting this information. Patients who have their arterial blood sampled while they are awake describe the sensation as akin to having a needle stuck directly into their bone. Unfortunately, because one of the circumstances in which this information is important is while a patient is under an anesthetic, so the poor patient has to have the needle inserted while they are still awake.
A pulse oximeter may also be used for research purposes, for example, during sleeping studies. These investigations are performed when a patient is suspected to have a condition called sleep apnea. People with this type of disorder are unable to breathe, sometimes for dangerously long periods, while they are sleeping. This can result in stroke, heart attack or even death. At best, it can leave people foggy headed and tired the next day.
There are two categories of sleep apnea, neurological and obstructive. Obstructive sleep apnea (OSA) is more common than neurological sleep apnea, but no less dangerous. Treatments may include a device that is prescribed by a dentist to keep the mouth partially open at night, continuous positive airway pressure (CPAP) or, in extreme cases, surgery to correct an anatomic deformity that makes the airway unable to open.
The other form of sleep apnea, central, is less common and potentially more serious than OSA. This is because the center of the brain that regulates physiological processes like heart rate and breathing, malfunctions to the point where the body won't try to breathe. Either type of apnea may occur on its own or in conjunction with the other form.
The biggest risk factors for sleep apnea are being overweight, male gender or being over the age of 40. However, sleep apnea can happen to anybody. Some small babies can stop breathing for as long as 20 seconds, which is very disturbing for already anxious new parents. If a baby is discovered to be at risk for this condition, the parents can obtain an alarm that will alert them if and when this happens. CMS pulse oximeters are also available for use at home.
The physical principles of how a pulse oximeter works are beyond the scope of this article. It is based on the absorbance of light. By shining light of two different wavelengths into the skin, the instrument can calculate the light absorbance, and hence the concentration of O2 in blood that is circulating in the arteries.
While this is an excellent way of screening sick people from really sick people, a more accurate measurement is obtained by measuring oxygen directly from arterial blood. This is important in places like intensive care units or when a patient is under anesthesia having an operation.
This is a painful and invasive procedure and there needs to be a good reason for collecting this information. Patients who have their arterial blood sampled while they are awake describe the sensation as akin to having a needle stuck directly into their bone. Unfortunately, because one of the circumstances in which this information is important is while a patient is under an anesthetic, so the poor patient has to have the needle inserted while they are still awake.
A pulse oximeter may also be used for research purposes, for example, during sleeping studies. These investigations are performed when a patient is suspected to have a condition called sleep apnea. People with this type of disorder are unable to breathe, sometimes for dangerously long periods, while they are sleeping. This can result in stroke, heart attack or even death. At best, it can leave people foggy headed and tired the next day.
There are two categories of sleep apnea, neurological and obstructive. Obstructive sleep apnea (OSA) is more common than neurological sleep apnea, but no less dangerous. Treatments may include a device that is prescribed by a dentist to keep the mouth partially open at night, continuous positive airway pressure (CPAP) or, in extreme cases, surgery to correct an anatomic deformity that makes the airway unable to open.
The other form of sleep apnea, central, is less common and potentially more serious than OSA. This is because the center of the brain that regulates physiological processes like heart rate and breathing, malfunctions to the point where the body won't try to breathe. Either type of apnea may occur on its own or in conjunction with the other form.
The biggest risk factors for sleep apnea are being overweight, male gender or being over the age of 40. However, sleep apnea can happen to anybody. Some small babies can stop breathing for as long as 20 seconds, which is very disturbing for already anxious new parents. If a baby is discovered to be at risk for this condition, the parents can obtain an alarm that will alert them if and when this happens. CMS pulse oximeters are also available for use at home.