Detection effects of 4 near-infrared cerebral oximeters: a comparative study in simulated high altitude (4 500 m)

Abstract

Objective To evaluate the detection effects of 4 brands of near-infrared cerebral oximeters (NICOs), INVOS 5100C (Medtronic), EGOS-600 (Aegean), MNIR-P100 (Mingxi) and BRS-1 (Casibrain Technology) in high-altitude environment. Methods From March 3, 2021 to March 16, 2021, a total of 174 healthy male volunteers (18~22 years old, 172.8±5.1 cm, BMI 22.5±2.2 kg/m2) were subjected from Army Medical University, and then randomly divided into 6 groups (n=29). Their regional cerebral oxygen saturation (rcSO2), instrument response time, blood pressure (BP), heart rate (HR), and pulse oxygen saturation (SPO2) were recorded and compared in the plain (300 m) and the 4 500-m altitude environment. The correlations among the above indicators were evaluated by Pearson correlation analysis. The difference and consistency of above indicators by the 4 devices were investigated. Results ① The effective detection rates of all 4 NICOs were 100% in 4 500 m environment. In the plain environment, the response time was 2.13±0.34, 6.60±1.23, 2.87±0.48 and 2.65±0.47 s for INVOS 5100C, EGOS-600, MNIR-P100 and BRS-1, respectively, while the time was 2.22±0.41, 6.83±1.25, 2.86±0.49 and 2.67±0.49 s respectively in the 4 500-m altitude environment. EGOS-600 had the longest response time, with more than 3 s longer than the other 3 NICOs (P 0.05). But the response time of INVOS 5100C and EGOS-600 was increased by 0.1 and 0.2 s respectively in the 4 500 m altitude environment than the plain (P < 0.05). ②In the plain environment, INVOS 5100C and BRS-1 showed better consistency in rcSO2 detection than EGOS-600 and MNIR-P100. While in the 4 500 m altitude environment, EGOS-600 and INVOS 5100C performed better consistency than BRS-1 and MNIR-P100. When the subjects entered from the plain to 4 500 m altitude environment, the decline range showed better consistency in BRS-1 and INVOS 5100C than EGOS-600 and MNIR-P100. ③When taking the decline range of rcSO2 reaching 20% as the intervention value of cerebral hypoxia, 78%, 94% and 76% of the subjects respectively detected by EGOS-600, MNIR-P100 and BRS-1 were under the threshold. When taking the decline range of rcSO2 reaching 50% as the intervention value of cerebral hypoxia, 52.9%, 54.6% and 54.3% of the subjects respectively detected by EGOS-600, MNIR-P100 and BRS-1 were under the threshold. ④The correlation coefficients of SpO2 and rcSO2 detected by INVOS 5100C, EGOS-600, MNIR-P100 and BRS-1 were 0.876 4 (P < 0.000 1), 0.641 7 (P < 0.000 1), 0.761 8 (P < 0.000 1) and 0.6525 (P < 0.0001), respectively. Conclusion In terms of rcSO2, INVOS 5100C shows great consistency with the 3 domestic NICOs, and the 3 domestic instruments also show great specificity but less good sensitivity.

Keywords

• near-infrared spectroscopy
• cerebral oxygen saturation
• cerebral oximeter