Factors Affecting the Performance of 5 Cerebral Oximeters During Hypoxia in Healthy Volunteers
Factors Affecting the Performance of 5 Cerebral Oximeters During Hypoxia in Healthy Volunteers
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DOI：
10.1213/ane.0b013e318297d763
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发表时间：
2013-10-01
影响因子：
5.7
通讯作者：
Rollins, Mark D.
中科院分区：
文献类型：
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作者：
Bickler, Philip E.;Feiner, John R.;Rollins, Mark D.
背景：脑血氧饱和度是一种无创的光学技术，用于测量额叶皮质血红蛋白-氧饱和度。尚未对市售脑血氧计进行独立评价。与脉搏血氧仪不同，目前没有食品和药物管理局的性能或准确性标准。我们测试了脑血氧仪准确测量脑混合静脉和动脉血中氧饱和度的固定比率的假设。方法：我们评估了5种市售脑血氧仪的性能：EQUAN 0X（R）7600在3-和4-波长版本中（Nonin Medical，Plymouth，MN）、FORE-SIGHT（R）（Casmed，Branford，CT）、INVOS（R）5100C（Covidien，Boulder，CO）和NIRO-200NX（R）（Hamamatsu Photonics，Hamamatsu City，Japan）。23名健康成年人（14名男性，9名女性）的前额两侧放置了传感器。然后改变受试者的吸入氧（Fio（2）），以产生100%至70%之间的6个稳态动脉血氧饱和度（Sao（2））水平，同时潮气末CO2保持恒定。在每个平台期，使用血氧计（OSM-3，Radiometer Medical A/S，Copenhagen，丹麦）同时分析颈静脉球和桡动脉的血样。每个脑血氧仪的偏差计算为仪器的阅读（脑饱和度，Sco（2））与静脉和动脉血的加权饱和度（Sa/vo（2）），如各制造商所规定（INVOS：25%动脉/75%静脉; FORE-SIGHT、EQUANOX和NIRO：30%动脉/70%静脉）。分析了配对血液样本和血氧计读数之间的542个比较。合并的均方根误差为8.06%，高于脉搏血氧仪的值，根据食品和药物管理局的标准，脉搏血氧仪的均方根误差为+/- 3%。平均偏倚%+/- SD（精密度）和均方根误差分别为：FORE-SIGHT 1.76 +/- 3.92和4.28; INVOS 0.05 +/- 9.72和9.69; NIRO-200 NX-1.13 +/- 9.64和9.68; EQUNOX-3 lambda 2.48 +/- 8.12和8.47; EQUANOX-4 λ 2.84 +/- 6.27和6.86。FORE-SIGHT、NIRO-200 NX和EQUANOX-3 lambda在较低Sao时具有显著更大的正偏倚（2）。当根据血氧计阅读与动脉和混合静脉饱和度差之间的差异而不是血液饱和度的加权平均值计算偏倚时，缺氧期间的偏倚量减少，表明动脉和静脉血容量之间的比值差异导致了低饱和度下的一些正偏倚。深色皮肤色素倾向于在所有仪器中产生更多的负偏差，但仅FORE-SIGHT血氧计的偏差显著大于零。偏差是显着更负的妇女INVOS和EQUANOX设备，但不是为FORE-SIGHT device.CONCLUSIONS：虽然对去饱和反应，脑血氧饱和度仪表现出很大的变化，受试者之间的阅读错误，平均偏差可能与在大脑的采样区域的动脉和静脉血的比例的变化。这个比例可能不是固定的，如制造商所假设的，而是随着缺氧而动态变化。更好地了解这些因素可以提高脑血氧仪的性能，并帮助建立大脑健康的饱和度或血流阈值。
BACKGROUND: Cerebral oximetry is a noninvasive optical technology that measures frontal cortex blood hemoglobin-oxygen saturation. Commercially available cerebral oximeters have not been evaluated independently. Unlike pulse oximeters, there are currently no Food and Drug Administration standards for performance or accuracy. We tested the hypothesis that cerebral oximeters accurately measure a fixed ratio of the oxygen saturation in cerebral mixed venous and arterial blood.METHODS: We evaluated the performance of 5 commercially available cerebral oximeters: the EQUANOX (R) 7600 in 3- and 4-wavelength versions (Nonin Medical, Plymouth, MN), FORE-SIGHT (R) (Casmed, Branford, CT), INVOS (R) 5100C (Covidien, Boulder, CO), and the NIRO-200NX (R) (Hamamatsu Photonics, Hamamatsu City, Japan) during stable isocapnic hypoxia in volunteers. Twenty-three healthy adults (14 men, 9 women) had sensors placed on each side of the forehead. The subject's inspired oxygen (Fio(2)) was then changed to produce 6 steady-state arterial oxygen saturation (Sao(2)) levels between 100% and 70%, while end-tidal CO2 was maintained constant. At each plateau, simultaneous blood samples from the jugular bulb and radial artery were analyzed with a hemoximeter (OSM-3, Radiometer Medical A/S, Copenhagen, Denmark). Each cerebral oximeter's bias was calculated as the difference between the instrument's reading (cerebral saturation, Sco(2)) with the weighted saturation of venous and arterial blood (Sa/vo(2)), as specified by each manufacturer (INVOS: 25% arterial/75% venous; FORE-SIGHT, EQUANOX, and NIRO: 30% arterial/70% venous).RESULTS: Five hundred forty-two comparisons between paired blood samples and oximeter readings were analyzed. The pooled root mean square error was 8.06%, a value higher than for pulse oximeters, which is +/- 3% by Food and Drug Administration standards. The mean % bias +/- SD (precision) and root mean square errors were: FORE-SIGHT 1.76 +/- 3.92 and 4.28; INVOS 0.05 +/- 9.72 and 9.69; NIRO-200NX -1.13 +/- 9.64 and 9.68; EQUANOX-3 lambda 2.48 +/- 8.12 and 8.47; EQUANOX-4 lambda 2.84 +/- 6.27 and 6.86. The FORE-SIGHT, NIRO-200NX, and EQUANOX-3 lambda had significantly more positive bias at lower Sao(2). The amount of bias during hypoxia was reduced when the bias was calculated on the basis of difference between oximeter reading and the arterial and mixed venous saturation difference rather than the weighted average of blood saturation, indicating that differences in the ratio between arterial and venous blood volumes account for some of the positive bias at low saturation. Dark skin pigment tended to produce more negative bias in all instruments but bias was significantly larger than zero only for the FORE-SIGHT oximeter. Bias was significantly more negative in women for INVOS and EQUANOX devices but not for the FORE-SIGHT device.CONCLUSIONS: While responsive to desaturation, cerebral oximeters exhibited large variation in reading errors between subjects, with mean bias possibly related to variations in the ratio of arterial and venous blood in the sampling area of the brain. This ratio is probably not fixed, as assumed by the manufacturers, but dynamically changes with hypoxia. Better understanding these factors could improve the performance of cerebral oximeters and help establish saturation or blood flow thresholds for brain well-being.