User's Manual

Optimizing SpO
2
Measurement Performance
SpO
2
Monitoring 8-21
Arterial Blood Flow
The measurement depends on the pulsatile nature of blood flow in the arteries
and arterioles; with the following conditions arterial blood flow can be reduced
to a level at which accurate measurements cannot be made:
•shock
• hypothermia
• use of vasoconstrictive drugs
• anemia
Wavelength Absorption
The measurement also depends on the absorption of particular light wavelengths
by the oxyhemoglobin and reduced hemoglobin. If other substances are present
which absorb the same wavelengths, they will cause a falsely high, or falsely
low SpO
2
value to be measured. For example:
• carboxyhemoglobin
• methemoglobin
• methylene blue
• indocyanine green*
• indiocarmine*
*These chemicals are used in dye dilution cardiac output calculations.
Ambient Light
Very high levels of ambient light can also affect the measurement; an "SpO
2
Interference" message will appear on the display. The measurement quality can
be improved by covering the sensor with suitable opaque material.
Care and Cleaning
For care and cleaning instructions, see the instructions accompanying the
sensors.
Sensor Wear
Normal wear and tear associated with patient movement and regular sensor
cleaning typically mean that the sensor will have a limited lifetime. However,
provided you handle the sensor and its cable with care, you can expect useful
service from it for up to two years. Harsh treatment will drastically reduce the
lifetime of the sensor. Moreover, Philips Medical Systems’ warranty agreement
shall not apply to defects arising from improper use.
To get the best results from your SpO
2
reusable sensor: