taking someone's pulse

Pulse Oximeter Alert: Poor Probe Placement Can Lead to Inaccurate Results

Pulse oximeters are used both at home and in clinical settings to measure blood oxygen levels. However, recently experts have been warning people that poor probe placement could lead to highly inaccurate results. This may put a patient’s health in danger.

In fact, a patient safety alert has been issued by regulators in the UK warning of the risk of inappropriate placement of pulse oximeter probes. NHS Improvement says readings may be highly inaccurate if probes meant for the finger and ear are mixed up, or when devices were used to measure the wrong patient group.

What Happens if a Pulse Oximeter Probe is Inappropriately Placed?

Pulse oximeter probes are designed to be attached to either a finger or an ear. However, they are not interchangeable. Furthermore, probes also need to be selected according to the patient’s weight when babies and children are being monitored.

If a finger probe is attached to the ear or vice versa, the results may be up to 50% lower or 30% higher than the actual value.

If a reading is 30% higher, you may falsely assume that your blood oxygen levels are normal. In reality, your condition may actually be deteriorating.

If your reading is lower, you may seek out unnecessary care when your condition is actually stable or improving.

Training is Key in Clinical Settings

Part of the problem in clinical settings, experts say, is that staff are unaware that finger probes can give misleading results if placed on the ear.

A quarter of the staff surveyed by NHS Improvement said they did not have access to ear probes. Ear probes will need to be used on at least some patients – no matter the clinical setting.

Another problem is product design. Once probes are removed from packaging, there are no visible reminders of where to place the probe.

The patient alert is calling on NHS organizations to ensure that staff have access to all of the equipment they need and to educate on the dangers of inappropriately placed pulse oximeter probes. NHS Improvement is also calling on manufacturers to change their product labels to clearly indicate where to attach the probe.

How to Properly Attach a Pulse Oximeter Probe

It’s important to understand how to properly attach a pulse oximeter probe to the finger or ear. Whether you’re using an at-home device or getting tested at the doctor’s office.

If you understand how to use a pulse oximeter, you can determine whether the nurse is attaching the probe properly.

How to Attach an Ear Oximeter Probe

  • Gently clean the earlobe with an alcohol pad for 10-20 seconds.
  • Attach the probe to the earlobe or another visible part of the ear, such as the pinna.
  • Make sure the LED side of the probe is facing toward the head on the lower, fleshy area of the ear. There needs to be sufficient blood flow in order to get an accurate, solid reading. Avoid areas with cartilage, and do not press on the clip as this will restrict blood flow.
  • The LED light detector should be fully covered by the ear and not exposed to any light in the room.
  • You can use an adhesive disk to better secure the probe.
  • Leave the probe on for about three minutes until you have a stable reading.

How to Attach a Finger Oximeter Probe

  • Turn on the pulse oximeter.
  • Place the sensor on any finger (with the exception of the thumb). The sensor screen should be above the fingernail.
  • Wait for the pulse oximeter to acquire a signal. This can take 10 seconds or more.
  • Limit your movement while trying to acquire a signal, as this can affect the accuracy of the results.
  • The oxygen saturation results are typically indicated as “SpO2.”

Many finger oximeter probes can be left on the finger for continuous monitoring (common in a hospital setting). If you’re going to leave the probe on, you may want to move the sensor every 2-4 hours to prevent discomfort.

Pulse oximeter devices are relatively easy to use, but the results are only accurate if the appropriate probe is placed in the appropriate area. In a clinical setting, it’s crucial for staff to understand that ear and finger probes cannot be interchanged. Educating yourself on how to properly use an oximeter probe can help protect your health, whether you monitor at home or at the doctor’s office.

Which Pulse Oximeter Should I Use?

There are a lot of fingertip pulse oximeters on the market today. It can be quite overwhelming to choose the right one. I have put together a post that reviews my favorite pulse oximeters for use in your home or on the go. You can find that post here.

About the author

Tim Brewer

Tim is a professional caregiver who has helped hundreds of seniors gain back their freedom and independence. He has been actively helping the senior community for 20+ years.

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