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Near-infrared spectroscopy (NIRS) is a continuous and noninvasive technology that measures regional tissue oxygen saturation (rSO 2 ). A new 4-wavelength generation of NIRS monitors is now available. We aimed to compare peripheral somatic rSO 2 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 2 values. No significant difference was found between both monitors: EQUANOX median rSO 2 60% (95% CI 57-62) versus O3 median rSO 2 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 2 absolute values: rho = 0.758 (95% CI 0.701-0.806), P < 0.0001, and rSO 2 percent maximum difference versus baseline: rho = 0.582 (95% CI 0.188-0.815), P = 0.007. While absolute values of rSO 2 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.

The feasibility and clinical utility of the endotracheal cardiac output monitor (ECOM) to optimize intraoperative hemodynamics and improve short-term outcome in off-pump coronary artery bypass grafting (OPCAB) is unknown. We aimed to compare ECOM with a standard of care in that specific surgical setting. Twenty consecutive adult ECOM-monitored patients undergoing OPCAB were prospectively included (ECOM group) and retrospectively compared to 42 patients scheduled for similar surgery without ECOM monitoring (Control group). The primary endpoint was the global rate of postoperative admission to the intensive care unit (ICU). Secondary endpoints were the time to extubation, the length of stay in ICU and in hospital, the postoperative levels of lactate and troponin and the feasibility of ECOM. The rate of postoperative admission to the ICU was 38/42 (90%) in the Control group versus 11/20 (55%) in the ECOM group, P = 0.008. None unexpected admission for hemodynamic instability was observed in the ECOM group. The time to extubation, the length of stay in ICU, and both troponin level at admission and lactate level at H6 were all significantly decreased in the ECOM group. On a scale ranging from 0 to 5, convenience and satisfaction regarding ECOM were 4.30 ± 1.17 and 3.45 ± 0.68, respectively. The systematic use of ECOM is associated with a significant reduction in the rate of admission to the ICU and an improvement in immediate outcome in OPCAB.

Smokers are exposed to early endothelial dysfunction. This microcirculatory damage can be demonstrated by near-infrared spectroscopy (NIRS). The aim of this study was to compare microvascular reactivity by NIRS during a dynamic vascular occlusion test in healthy smokers and nonsmokers volunteers. Twenty healthy volunteers (10 men, 10 women), aged from 22 to 38 years old, were included after approval of the local Ethics Committee and divided into two groups: smokers (n = 10) and nonsmokers (n = 10). Tissue oxygen saturation (StO2) was measured at the level of each individual's calves during an ischemia and reperfusion test. In addition, during the ischemia phase, the slope of decline in StO2 was determined. Therefore, for each group, we were able to deduce the speed of desaturation (ΔStO2/ischemia time). The same was applied for resaturation rates during the reperfusion phase (ΔStO2/reperfusion time). StO2 values were comparable at all experimental steps between smokers and nonsmokers. During the vascular occlusion test, rates of desaturation were the same between smokers and nonsmokers [respectively 3.7%·min(-1) (range 2.5-12.6) and 3.7%·min(-1) (range 1.8-15.1); p = 0.50]. It was the same for the rate of resaturation [smokers 30.4%·min(-1) (range 14.2-51.6) and nonsmokers 30.5%·min(-1) (range 18.6-44.5); p = 0.82]. NIRS study of microvascular reactivity during a dynamic vascular occlusion test did not reveal any difference between smokers and nonsmokers. Therefore, NIRS could not be sensitive enough to highlight endothelial dysfunction in healthy subjects exposed to tobacco smoke.

The objective was to compare the impact of an early goal-directed hemodynamic therapy based on cardiac output monitoring (Endotracheal Cardiac Output Monitor, ECOM) with a standard of care on postoperative outcome following coronary surgery. This prospective, controlled, parallel-arm trial randomized 100 elective primary coronary artery bypass grafting patients to a study group (ECOM; n = 50) or a control group (control; n = 50). In the ECOM group, hemodynamic therapy was guided by respiratory stroke volume variation and cardiac index given by the ECOM system. A standard of care was used in the control. Goal-directed therapy was started immediately after induction of anesthesia and continued until arrival in the intensive care unit (ICU). The primary endpoint was the time when patients fulfilled discharge criteria from hospital (possible hospital discharge). Secondary endpoints were the hospital discharge, the time to reach extubation, the length of stay in ICU, the number of major adverse cardiac events, and in-hospital mortality. Patients in the ECOM group received more often fluid loading and dobutamine. The time to reach extubation was reduced in the ECOM group: 510 min [360-1,110] versus 570 min [320-1,520], P = 0.005. No significant differences were found between both groups for possible hospital discharge [Hazard Ratio = 0.96 (95 % CI 0.64-1.45)] and hospital discharge [Hazard Ratio = 1.20 (95 % CI 0.79-1.81)]. A mini-invasive early goal-directed hemodynamic therapy based on ECOM can reduce the time to reach extubation but fails to significantly reduce the length of stay in hospital and the rate of major cardiac morbidity.