If you’ve ever been admitted to a hospital, chances are you’ve had a nurse slip a little device onto your fingertip for a short time to take a diagnostic reading. This device is called a pulse oximeter, a device that uses a small light and sensor to detect your pulse (how many times your heart beats in one minute) and the level of oxygen present in your blood (otherwise known as oxygen saturation). If you have COPD or are concerned about persistent shortness of breath, it is worth considering purchasing a pulse oximeter of your own to use at home.
While pulse oximetry does not directly indicate your lung capacity nor evalu¬ate your specific level of breathlessness, it does provide insight into the quality of the functioning of your respiratory system. A low oximetry reading indicates that a low amount of oxygen has been transferred from your lungs into your bloodstream.
Most consumer-friendly pulse oximeters are fingertip devices. To use the device, you place the device directly over your fingertip. After a few seconds, the oximeter will display the saturation percent¬age of oxygen in your blood (on a scale of 0% to 100%) and your heart’s pulse rate. Just like a heart rate or blood pressure monitor, a pulse oximeter’s readings change from moment to moment depending on your activity level, so it often makes sense to take your readings at various points of the day (both at rest and during various physical activities including during exer¬cise sessions) to get a good sense of your typical blood oxygen saturation and pulse rate. It should be noted that those with circulatory problems may find fingertip devices do not produce accurate readings. In this case, a forehead, wrist or earlobe probe is typically recommended by respiratory care professionals.
At rest, a pulse oximeter reading of 94 to 98 percent is considered normal. During exercise, oxygen levels typically fall as you stress your respiratory system to keep up with the higher level of activity. Healthy adults generally should not see their oxygen level dip below 92 percent while exercising. Below this level, there is not enough oxygen in your lungs to enter red blood cells (which are the vehicles for transporting oxygen to the rest of your body). Therefore, you are in effect starving your body’s need for oxygen to operate your organs and muscles.
In COPD patients, oxygen levels typically fluctuate between 88 and 92 percent, whether at rest or during exercise. If you fall in this range and are experiencing breathlessness, this is a definite warning sign. If you use a pulse oximeter and receive multiple read¬ings below 90 percent, you should see your doctor immediately to determine whether your device is faulty or whether you need medical assistance. In more serious cases (typically when blood oxygen saturation levels fall below 88 percent), doctors will recommend oxygen therapy.
Aerobic exercise improves physical endurance and this is often noticeable in the reduction of your resting heart rate. Likewise, the better your aerobic conditioning, the more likely your blood oxygen levels over time will increase both during exercise and at rest. Further, the pursed lip breathing technique can also increase blood oxygen levels for COPD patients. For step by step instructions of the pursed lip breathing technique taken from our Breathe Better for Life CD-ROM, click here.
A number of things can affect a pulse oximetry reading. If you are smoking while taking an oximetry reading, the chemicals in cigarettes that find their way into your blood system can generate inaccurate readings. Additionally, if you wear heavy, dark fingernail pol¬ish, the fingernail polish can inhibit the transmission of the light signals used in pulse oximetry and generate inaccurate readings. Extremely cold fingertips can also generate inaccu¬rate readings due to reduction of blood flow to the fingertip.
Most pulse oximeters are only available by prescription. If you are interested in using one at home, ask your doctor to prescribe one for you. The only pulse oximeter we are aware of that is available with or without a pre¬scription is the Nonin GO2 Achieve Pulse Oximeter (people use pulse oximeters for other purposes that don’t require prescriptions, such as mountain climbers and other adventure enthusiasts who often use pulse oximeters to gauge the effects of high elevations on their oxygen levels). The GO2 Achieve is a relatively inexpensive device to use at home to help track your oxygen levels – it costs about the same as a good blood pressure monitor or heart rate monitor. If you are interested in learning more about the GO2 Achieve, click here.