During measurement, ensure that the application site:
For fully conscious maternal patients, who have a normal function of perfusion and sensory
perception at the measurement site:
For all other patients:
Injected dyes such as methylene blue, or intravascular dyshemoglobins such as methemoglobin
and carboxyhemoglobin may lead to inaccurate measurements.
Inaccurate measurements may result when the application site for the sensor is deeply pigmented
or deeply colored, for example, with nail polish, artificial nails, dye or pigmented cream.
Interference can be caused by:
has a pulsatile flow, ideally with a signal quality indicator of at least medium.
has not changed in its thickness (for example, due to edema), causing an improper fit of the
To ensure skin quality and correct optical alignment of the sensor, inspect the application site
when the measurement results are suspicious, or when the patient complains about pressure at
the application site, but at least every 24 hours. Correct the sensor alignment if necessary.
Move the sensor to another site, if the skin quality changes.
Inspect the application site every two to three hours to ensure skin quality and correct optical
alignment. Correct the sensor alignment if necessary. If the skin quality changes, move the
sensor to another site. Change the application site at least every four hours.
High levels of ambient light (including IR warmers), or strobe lights or flashing lights (such as
fire alarm lamps). (Hint: cover application site with opaque material).
sensor in close proximity (e.g. when more than one SpO
performed on the same patient). Always cover both sensors with opaque material to reduce
Electromagnetic interference, especially when the signal quality indicator is below medium.
Excessive patient movement and vibration.
20 Monitoring SpO2