Factors That Could Affect the Readings of an Oximeter

Pulse oximetry is a commonly used, non-invasive device for observing and reading the oxygen saturation in the blood. It was first introduced by the Nihon Kohden Corporation in 1970’s. At first, its uses were limited to the operating room but steadily it became more commonplace in other parts of health care as well. Today it is a standard part of every healthcare facility as well as emergency health transportation services.

The oxygen level in blood not only helps with monitoring the condition of lungs in a person but increasing and decreasing readings also serves as an indication of a condition most dangerous in nature. A large number of times, readings with an oximeter even serve as lifesaving signals.

For this reason and many others, it is imperative that the readings taken during the testing must be accurate. The test itself should be conducted by an expert who is well aware of the workings of the device. It is also important for the patient and the device conductor to be conscious of all those factors that can affect the readings of an oximeter.

Allow us to enlighten you with them:

Insufficient Blood Flow:
The sensors in the probes, reach across to the blood to detect the saturation of oxygen. But in cases of poor perfusion where the blood flow is inadequate, readings will be affected greatly. It is a must for the blood pressure to be above 80. The low pressure of the blood can be caused by any of the following:

  • cold, nerve blocker medications and fear
  • Wrong placement of probes and compression
  • Because of cardiac arrest
  • Vascular impingement
  • Tight clothing, pressure cuffs or restraints

Increased Movement:
Patients with conditions that can lead to increased and rapid movement or shivering can have an inaccurate reading. There are some devices however that can overcome this shortcoming.

Fake Fingernails:
Fake fingernails might affect the readings in addition to nail polish colors as they are pigmentations and act as a hindrance for the probes and sensors.

Interference of Light:
Lights can also affect the readings of a pulse oximeter if it is too harsh. It can be tested by covering the light source and taking the readings again. The presence of any sort of radiated lights like infrared or ultraviolet can definitely have an impact on the reading.

Health Conditions:
There are certain health conditions of the patient themselves that can lead to inaccurate readings; for instance, patients with unreliable carboxyhemoglobin readings, methemoglobinemia, sickle cell anemia, thalassemias and anemia will always have wrong readings.

There are certain pigmentations and dyes on skin that can also affect the readings of pulse oximeter. Before the test patients and practitioners both should make sure that external conditions of the room are suitable for the testing.