Four-wavelength near-infrared peripheral oximetry in cardiac surgery patients: a comparison between EQUANOX and O3

Abstract

Near-infrared spectroscopy (NIRS) is a continuous and noninvasive technology that measures regional tissue oxygen saturation (rSO). A new 4-wavelength generation of NIRS monitors is now available. We aimed to compare peripheral somatic rSO values given by the 4-wavelength EQUANOX™ 7600 device (Nonin Medical Inc., Plymouth, Mn) and O3™ device (Masimo Corporation, Irvine, CA). Twenty adult patients scheduled for conventional elective cardiac surgery with cardiopulmonary bypass over a 4-month period were included after local Ethics Committee approval. For each patient, 2 NIRS sensors (EQUANOX and O3) were placed over the medial part of the forearm. Thirteen couples of measurements were performed at predefined intraoperative time points. We compared 260 couples of absolute intraoperative rSO values. No significant difference was found between both monitors: EQUANOX median rSO 60% (95% CI 57-62) versus O3 median rSO 62% (95% CI 61-64), P = 0.103. Bias was 4.0% and limits of agreement were ±26.3%. Significant correlations were evidenced between EQUANOX and O3 rSO absolute values: rho = 0.758 (95% CI 0.701-0.806), P < 0.0001, and rSO percent maximum difference versus baseline: rho = 0.582 (95% CI 0.188-0.815), P = 0.007. While absolute values of rSO given by both devices were equivalent and well correlated, the clinical agreement is probably not acceptable, meaning that EQUANOX and O3 are not interchangeable in routine practice.

Journal of Clinical Monitoring and Computing 2017/2018 end of year summary: monitoring—and provocation—of the microcirculation and tissue oxygenation

“…baseline StO 2 , before initiation a VOT), all observed dynamic characteristics (both the down- and upslope part of the VOT) turned out to be different. Similarly, the study of Ferraris et al [4] discussed above found significant differences from individual baseline StO 2 values during a VOT between the two devices studied (Masimo O3 and Nonin EQUANOX, respectively). These clear observations indicate that differences in NIRS techniques itself (e.g.…”

“…Another method comparison study on NIRS devices was published by Ferraris et al [4] in the same issue. Although such devices are primarily developed for cerebral oximetry, the authors compared peripheral (somatic) StO 2 values obtained on the forearm with two different last generation four-wavelength NIRS devices in 20 adult patients undergoing elective cardiac surgery at several predefined time points.…”

Evaluation of Different Near-Infrared Spectroscopy Devices for Assessing Tissue Oxygenation with a Vascular Occlusion Test in Healthy Volunteers

“…Theoretically, NIRS devices that use more wavelengths would be more accurate and have enhanced tissue recognition [21]. However, no published studies have examined the superiority of 4-wavelength NIRS systems over others, DOI: 10.1159/000510072 and since no reference value exists for measuring peripheral tissue oxygen saturation, it is difficult to say whether 1 NIRS device is more accurate than another [16]. Second, despite the technological similarities, the optical technology and computational algorithms that are used to derive actual oxygen saturation values may differ between devices, and these values are derived from various assumptions that may not be error free [21].…”

“…INVOS ® (Somanetics Corp., Troy, MI, USA) was developed for measuring regional brain oxygen saturation through the use of 2 light-emitting diodes [13], and IN-VOS ® has also been widely used to obtain tissue oxygen saturation in areas other than the brain and peripheral microcircular reactivity measurements using VOT [1,2,14]. O3 TM (Massimo Corp., Irvine, CA, USA) is a recently developed NIRS method that uses 4 wavelengths, and only a few studies have used this device to measure cerebral oxygen saturation [15] or StO 2 [16]. For NIRS devices, oximetry values are calculated using an assumed cerebral or tissue arterial:venous ratio (A/V ratio).…”

Suspension syndrome: a potentially fatal vagally mediated circulatory collapse—an experimental randomized crossover trial

“…However, measurement of the orthostatic blood volume accumulation in the small vessels is more challenging. To track intravascular orthostatic volume changes within the small blood vessels of the lower leg, a new four-wavelength generation NIRS monitor has been used (Ferraris et al 2018). NIRS tissue oxygen saturation measurement is made on a mixture of both venous and arterial blood with a mean ratio of this mixture estimated to be 70% venous–30% arterial (Benni et al 2018).…”