Abstract
Objective.For determining the adequacy of ventilation, conventional pulse oximetry should be amended by PaCO2 (= arterial carbon dioxide partial pressure). This study investigates the precision of carbon dioxide measurements of the first digitalear-clip sensor providing continuous non-invasive monitoring of PaCO2, SpO2 (= functional arterial oxygen saturation as estimated with a pulse oximeter) and pulse rate and compares it to two conventional analog oximeters. Methods.30 hypoxemia episodes in 6 adult volunteers were investigated in a standardized protocol. Equipment: Masimo™ analog finger sensor, Nellcor™ analog ear sensor, SenTec™ digital ear sensor. Results.The difference between PCO2 data (= PaCO2 estimated from the measured PcCO2 based on an algorithm by Severinghaus) (PcCO2 = cutaneous carbon dioxide pressure) and the PaCO2 is clinically unimportant. Therefore, we suggest, the two methods of estimating patient's carbon dioxide status can be used interchangeably. Conclusions.Combined digital SpO2/PcCO2 ear sensors are very promising to allow for a fast and reliable monitoring of patient's oxygenation, hyper-/hypocapnia and ventilation with one single non-invasive probe. Optimal primary signal processing – amplification and digitalisation within the probe – allow for fast and reliable downstream signal processing algorithms. The resulting short SpO2 response times give the medical staff more time to take appropriate actions.
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Kocher, S., Rohling, R. & Tschupp, A. Performance of a Digital PCO2/SpO2 Ear Sensor. J Clin Monit Comput 18, 75–79 (2004). https://doi.org/10.1023/B:JOCM.0000032693.78829.42
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DOI: https://doi.org/10.1023/B:JOCM.0000032693.78829.42