Use Instructions

Vital Signs Monitor User Manual Monitoring SpO
2
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 incorrect sensor application
 high levels of ambient light sources, such as surgical lights (especially those with a xenon
light source), bilirubin lamps, fluorescent lights, infrared heating lamps, and direct sunlight
 failure to cover the sensor with opaque material in high levels of ambient light conditions
 dysfunctional hemoglobins
 low peripheral perfusion
 excessive or violent patient movement
 venous pulsations
 intravascular dyes, such as indocyanine green or methylene blue
 externally applied coloring agents (nail polish, dye, pigmented cream)
 defibrillation
 placement of the sensor on an extremity with a blood pressure cuff, arterial catheter, or
intravascular line
 electromagnetic interference
Loss of pulse signal can occur for the following reasons:
 the sensor is applied too tightly
 a blood pressure cuff is inflated on the same extremity as the one with the sensor attached
 there is arterial occlusion proximal to the sensor
 low peripheral perfusion
NOTE:
1 To prevent interference from ambient light, ensure that the sensor is properly applied,
and cover the sensor site with opaque material.
2 Adjacent SpO
2
sensors may interfere with each other (eg, multiple SpO
2
measurements in the same patient). Be sure to cover the sensor with opaque
material to reduce cross-interference.
3 Move the sensor to a less active site, and keep the patient still, if possible.
12.5 Assessing the Validity of a SpO
2
Reading
You can check the quality of the pleth wave and the stability of the SpO
2
values to assess whether
the sensor functions properly and whether the SpO
2
readings are valid. Always use these two
indications simultaneously to assess the validity of a SpO
2
reading.
Generally, the quality of the SpO
2
pleth wave reflects the quality of the light signals obtained by
the sensor. A wave of poor quality manifests a decline of the signal validity. On the other hand,
the stability of the SpO
2
values also reflects the signal quality. Different from varying SpO
2
readings caused by physiological factors, unstable SpO
2
readings are resulted from the sensor‘s
receiving signals with interference. The problems mentioned above may be caused by patient
movement, wrong sensor placement or sensor malfunction. To obtain valid SpO
2
readings, try to