Spo Monitoring; Measuring Principle; Sources Of Interference For Spo Measurement; Pathological Reasons For Low Spo - Gima VITAL PRO-SNET Manual Del Usuario

when the oscillating method is used. As a matter of fact, the so-called "big discreteness" must be a term in the
sense of statistical significance of mass data. Abnormal data may be observed in some individual cases. It is
normal in the scientific experiments. It may be caused by an apparent reason, or by an unknown factor in
some cases. Such individual doubtful experimental data may be identified and eliminated using the special
statistical technique. It is not a part of this manual. The practitioner may eliminate the apparently
unreasonable data according to the experience.
8.3 SpO Monitoring
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8.3.1 Measuring Principle

Based on Lamber-Beer law, the light absorbance of a given substance is directly proportional with its density or
concentration. When the light with certain wavelength emits on human tissue, the measured intensity of light after
absorption, reflecting and attenuation in tissue can reflect the structure character of the tissue by which the light passes.
Due to that oxygenated hemoglobin (HbO
the spectrum range from red to infrared light (600nm~1000nm wavelength), by using these characteristics, SpO
determined. SpO measured by this monitor is the functional oxygen saturation -- a percentage of the hemoglobin that
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can transport oxygen. In contrast, hemoximeters report fractional oxygen saturation – a percentage of all measured
hemoglobin, including dysfunctional hemoglobin, such as carboxyhemoglobin or metahemoglobin.
8.3.2 Sources of interference for SpO
² Intravascular dyes such as indocyanine green or methylene blue
² Exposure to excessive illumination, such as surgical lamps, bilirubin lamps, fluorescent lights, infrared
heating lamps, or direct sunlight.
²
Vascular dyes or external used colouring producta such as nail polish or tinted skin care
² Excessive patient movement
² Placement of a sensor on an extremity with a blood pressure cuff, arterial catheter, or intravascular line
² Exposure to a high pressure oxygen chamber
² Arterial occlusion proximal to the sensor
² Blood vessel contraction caused by peripheral vessel hyperkinesias or decreasing body temperature

8.3.3 Pathological reasons for low SpO

² Hypoxemia, functional lack of HbO
² Pigmentation or abnormal oxyhemoglobin level
²
Abnormal oxyhemoglobin variation
²
Methemoglobin disease
² Sulfhemoglobinemia or arterial occlusion exists near sensor
² Obvious venous pulsations
² Peripheral arterial pulsation becoming weak
² Insufficient peripheral blood supply

8.3.4 Clinical Limitations

² As the measurement is taken on the basis of arteriole pulse, a substantial pulsating blood stream is required.
For a patient with weak pulse, perhaps due to shock, low ambient/body temperature, major bleeding, or use of
) and deoxygenated hemoglobin (Hb) have different absorption character in
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Measurement
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measurements

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2
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can be
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