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Reliability of SpO2 sensor signal readings

Статья

Автор: Munir Karjaghli, Elmar Paetzold

Дата: 02.08.2019

A missing signal or incorrect measurement of the SpO2 values may affect the proper functioning of the PEEP and Oxygen controllers in INTELLiVENT®-ASV®.

Reliability of SpO2 sensor signal readings

Signal of poor quality or not available

1. Causes of intermittent dropouts or an inability to read SpO2 values:

  • Dislocation of the SpO2 probe
  • Poor perfusion due to a number of causes, such as hypovolemia, vasoconstriction, etc.
  • Excessive patient movement

False values

2. Causes of false normal or elevated SpO2 values:

  • Carbon monoxide poisoning
  • Sickle cell anemia vaso-occlusive crises (overestimation of FO2Hb and underestimation of SaO2)

3. Causes of false low SpO2 values:

  • Dislocation of the SpO2 probe
  • Skin pigmentation
  • Venous pulsations
  • Poor perfusion due to a number of causes, such as hypovolemia, vasoconstriction, etc.
  • Excessive patient movement
  • Intravenous pigment dyes
  • Inherited forms of abnormal hemoglobin
  • Nailpolish
  • Severe anemia (with concomitant hypoxemia)
  • Interference from a second SpO2 probe in the same vicinity

4. Further possible causes of either false low or high values:

  • Methemoglobinemia
  • Sulfhemogobinemia
  • Poor probe positioning
  • Sepsis and septic shock

For more information, see  the review about pulse oximetry by Jubran (Jubran A. Pulse oximetry. Crit Care. 2015;19(1):272. Published 2015 Jul 16. doi:10.1186/s13054-015-0984-81​).

Relevant devices: HAMILTON-G5/S1; HAMILTON-C6; HAMILTON-C3; HAMILTON-C1/T1
Relevant software: HAMILTON-G5/S1 SW v2.81; HAMILTON-C6 SW v1.1.4; HAMILTON-C3 SW v2.0.5; HAMILTON-C1/T1 SW v3.0.x

Image showing pulse oximeter waveforms for different signals
Figure 1: Source Jubran
Image showing pulse oximeter waveforms for different signals
Figure 1: Source Jubran
Workflow for corrective action
Figure 2: Corrective action
Workflow for corrective action
Figure 2: Corrective action

Pulse oximetry.

Jubran A. Pulse oximetry. Crit Care. 2015;19(1):272. Published 2015 Jul 16. doi:10.1186/s13054-015-0984-8

Pulse oximetry is universally used for monitoring patients in the critical care setting. This article updates the review on pulse oximetry that was published in 1999 in Critical Care. A summary of the recently developed multiwavelength pulse oximeters and their ability in detecting dyshemoglobins is provided. The impact of the latest signal processing techniques and reflectance technology on improving the performance of pulse oximeters during motion artifact and low perfusion conditions is critically examined. Finally, data regarding the effect of pulse oximetry on patient outcome are discussed.