The Pros and Cons of Pulse Oximetry

Using a Pulse Oximeter to Monitor COPD

Hand with pulse oximeter
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If you have COPD and are using supplemental oxygen, pulse oximetry is an oxygen measurement technique you should know about. Learn about the benefits and drawbacks of pulse oximetry, and how to properly use a pulse oximeter at home.

What is Pulse Oximetry?

Pulse oximetry is a non-invasive means of measuring oxygen saturation, or the percentage of hemoglobin saturated with oxygen in arterial blood. Measuring oxygen saturation can be a useful tool in the management of COPD, especially when supplemental oxygen is in use.

Normal oxygen saturation levels range between 95 percent and 100 percent, but typically run lower in patients with COPD or other chronic lung diseases. Pulse oximetry should not replace, but rather complement, the use of spirometry in the diagnosis and management of chronic respiratory illnesses like COPD.

Choosing a Pulse Oximeter

The device used for pulse oximetry is called a pulse oximeter. To date, there are a number of finger pulse oximeter monitors available for purchase that patients can use in the comfort of their own homes. Many are approved as medical devices by the Food and Drug Administration (FDA). Compact and easy to use, a home pulse oximeter is an affordable option for many COPD patients who want to get a better handle on their oxygenation status while using oxygen therapy at home.

It should be noted, however, that pulse oximetry monitors, no matter how well-made, are not perfect.

Like any medical device, they are not always accurate under certain conditions. Before you buy, take a look at some of the pros and cons associated with using home pulse oximetry and decide for yourself if a home oximeter is right for you.

The Benefits of Pulse Oximetry

Pulse oximeters are widely used in hospitals, clinics, doctor's offices and homes.

They are generally accurate and provide spot-on readings of oxygen saturation levels. This can be a valuable tool, especially in emergency situations. The benefits of a pulse oximeter, when used correctly, include:

  • Easy to use and affordable
  • Beneficial for monitoring a wide variety of chronic illnesses, including COPD, asthma and other chronic health conditions
  • Non-invasive, pain-free and convenient
  • Can be used continuously, which is beneficial for monitoring patients who desaturate at night, during sleep
  • Allows for the accurate use of oxygen.
  • Provides the user, or their caregiver, with early warning of impending or existing hypoxemia (low blood oxygen)
  • Provides oxygen saturation trends during physical activity allowing patients, under the advice of their doctors, to easily titrate oxygen to meet their individual needs

Drawbacks of Pulse Oximetry

Like any medical device, pulse oximeters have their downsides. Patients are cautioned to use common sense when using a pulse oximeter at home and not to rely, solely, on an oxygen saturation reading as an indicator that something is medically wrong.

Before purchasing a home pulse oximeter, you should understand the following:

  • They may provide a false reading. For example, a COPD patient can be severely short of breath, but their oxygen saturation reading may be normal. (Read: Why Am I Short of Breath When My Oxygen Saturation Level is Normal?)
  • They may be ineffective in the presence of certain conditions, including cardiac or respiratory arrest, cardiac arrhythmias, shock, carbon monoxide poisoning, conditions that cause poor circulation or poor perfusion to the tissues, arteriovenous fistulas, cold extremities, edema, tremors, shivering, rigor or muscle twitching. Even wearing black, green or blue nail polish can affect the readings.
  • They may lag behind a patient's condition. For example, the blood oxygen level (PaO2) could potentially decrease to a critical level before the decreased SpO2 (oxygen saturation reading) is displayed on the monitor.

Although widely accepted in clinical and home settings, pulse oximetry should never replace blood gas analysis and/or sound medical advice from your doctor. It should only be used as a screening tool when low blood oxygen levels are suspected.

Tips for Home Use

Keep in mind the following tips before you start to use a pulse oximeter at home:

  • Monitor and keep a log of your oxygen saturation levels at various times during the day and during specific activities. Share them with your doctor so he or she can get a better understanding as to how rest and activity affect your oxygen saturation levels.
  • Work carefully with your doctor to develop a target oxygen saturation level. Under the instruction of your doctor, adjust your oxygen flow rate to maintain your target oxygen saturation level.
  • Never titrate oxygen without specific instruction from your health care provider.
  • Never rely on a pulse oximeter to determine how you should be feeling. If your oxygen saturation level is normal but you are severely short of breath and/or are experiencing other troubling symptoms, seek emergency medical attention and notify your health care provider as soon as possible.
  • A sudden drop in oxygen saturation can be a sign of trouble. Call your doctor as soon as possible if your normal oxygen flow rate fails to maintain your target oxygen saturation level.

Once you purchase a home pulse oximeter, take it with you to your doctor's office for further operating instructions. With your doctor's approval, you can work together to learn how to adjust your oxygen flow based on your fluctuating oxygen saturation levels.

Sources:

Susan DeMeulenaere. Pulse Oximetry: Uses and Limitations. The Journal for Nurse Practitioners. Volume 3, Issue 5 , Pages 312-317, May 2007.

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