J Dent Anesth Pain Med.  2020 Apr;20(2):73-81. 10.17245/jdapm.2020.20.2.73.

Quantitative analysis of the effect of fraction ofinspired oxygen on peripheral oxygen saturation inhealthy volunteers

• Kang BJ
• Kim M
• Bang JY
• Lee EK
• Choi BM
• Noh GJ

• KMID: 2500090
• DOI: http://doi.org/10.17245/jdapm.2020.20.2.73

Abstract

Background
The international organization for standardization (ISO) 80601-2-61 dictates that the accuracy of a pulse oximeter should be assessed by a controlled desaturation study. We aimed to characterize the relationship between the fraction of inspired oxygen (FiO2) and peripheral oxygen saturation (SpO2) using a turnover model by retrospectively analyzing the data obtained from previous controlled desaturation studies.
Materials and Methods
Each volunteer was placed in a semi-Fowler’s position and connected to a breathing circuit to administer the hypoxic gas mixture containing medical air, oxygen, nitrogen, and carbon dioxide. Volunteers were exposed to various levels of induced hypoxia over 70-100% arterial oxygen saturation (SaO2). The study period consisted of two rounds of hypoxia and the volunteers were maintained in room air between each round. FiO2 and SpO2 were recorded continuously during the study period. A population pharmacodynamic analysis was performed with the NONMEM VII level 4 (ICON Development Solutions, Ellicott City, MD, USA).
Results
In total, 2899 SpO2 data points obtained from 20 volunteers were used to determine the pharmacodynamic characteristics. The pharmacodynamic parameters were as follows: kout = 0.942 1/min, Imax = 0.802, IC50 = 85.3%, γ = 27.3.
Conclusion
The changes in SpO2 due to decreases in FiO2 well explained by the turnover model with inhibitory function as a sigmoidal model.

Keyword

Mathematical Computing; Oximetry; Pharmacology