24
by measurement and will allow finding the hypoxemia patient earlier,
thereby preventing or reducing accidental death caused by hypoxia
effectively.
Factors affecting SpO
2
measuring accuracy
(interference reason)
- Intravascular dyes such as indocyanine green or methylene blue.
- Exposure to excessive illumination, such as surgical lamps, bilirubin
lamps, fluorescent lights, infrared heating lamps, or direct sunlight.
- Vascular dyes or external used color-up product such as nail enamel
or color skin care.
- Excessive patient movement.
- Placement of a sensor on an extremity with a blood pressure cuff,
arterial catheter, or intravascular line.
- Exposure to the chamber with High pressure oxygen.
- There is an arterial occlusion proximal to the sensor.
- Blood vessel contraction caused by peripheral vessel hyperkinesias
or body temperature decreasing.
Factors causing low SpO
2
Measuring value (pathology reason)
- Hypoxemia disease, functional lack of HbO
2
.
- Pigmentation or abnormal oxyhemoglobin level.
- Abnormal oxyhemoglobin variation.
- Methemoglobin disease.
- Sulfhemoglobinemia or arterial occlusion exists near sensor.
- Obvious venous pulsations.
- Peripheral arterial pulsation becomes weak.
- Peripheral blood supply is not enough.
2.4 Caution
A. The finger should be placed properly (see the figure 3 of this manual),
or else it may cause inaccurate measurement.
B. The SpO
2
sensor and photoelectric receiving tube should be ar-
ranged in a way with the subject’s arteriole in a position there be-
tween.
C. The SpO
2
sensor should not be used at a location or limb tied with
ENGLISH
