Department of Anesthesia and Critical Care Medicine, Johns Hopkins School of Medicine, 600 N. Wolfe St., Meyer 8-134, Baltimore, MD 21287, USA.
Anesth Analg. 2011 Dec;113(6):1396-402. doi: 10.1213/ANE.0b013e318230b425. Epub 2011 Sep 29.
Monitoring hemoglobin levels in the operating room currently requires repeated blood draws, several steps, and a variable time delay to receive results. Consequently, blood transfusion management decisions may be delayed or made before hemoglobin results become available. The ability to measure hemoglobin continuously and noninvasively may enable a more rapid assessment of a patient's condition and more appropriate blood management. A new technology, Pulse CO-Oximetry, provides a continuous, noninvasive estimate of hemoglobin concentration (SpHb) from a sensor placed on the finger. We evaluated the accuracy of SpHb compared with laboratory CO-Oximetry measurements of total hemoglobin (tHb) during complex spine procedures in patients at high risk for blood loss.
Patients eligible for the study were undergoing complex spine surgery with planned invasive arterial or central venous monitoring and hourly blood draws for hemoglobin measurement. During each surgery, blood samples were obtained hourly (or more often if clinically indicated) and analyzed by the central laboratory with CO-Oximetry, a standard method of hemoglobin measurement in many hospitals. The tHb measurements were compared with SpHb obtained at the time of the blood draw.
Twenty-nine patients were included in the study. The tHb values ranged from 6.9 to 13.9 g/dL, and the SpHb values ranged from 6.9 to 13.4 g/dL. A total of 186 data pairs (tHb/SpHb) were analyzed; after removal of SpHb readings with low signal quality, the bias (defined as the difference between SpHb and tHb) and precision (defined as 1 SD of the bias) were -0.1 g/dL ± 1.0 g/dL for the remaining 130 data pairs. Bland-Altman analysis showed good agreement of SpHb to tHb values over the range of values; limits of agreement were -2.0 to 1.8 g/dL. The absolute bias and precision were 0.8 ± 0.6 g/dL.
Continuous, noninvasive hemoglobin measurement via Pulse CO-Oximetry demonstrated clinically acceptable accuracy of hemoglobin measurement within 1.5 g/dL compared with a standard laboratory reference device when used during complex spine surgery. This technology may provide more timely information on hemoglobin status than intermittent blood sample analysis and thus has the potential to improve blood management during surgery.
目前，手术室中监测血红蛋白水平需要多次采血、多个步骤，并需要一定的时间延迟才能得到结果。因此，输血管理决策可能会延迟或在血红蛋白结果可用之前做出。能够连续、无创地测量血红蛋白可能使患者病情的评估更加迅速，并进行更恰当的血液管理。一种新的技术，脉搏 CO-血氧仪，通过放置在手指上的传感器提供血红蛋白浓度（SpHb）的连续、无创估计。我们评估了 SpHb 与实验室 CO-血氧仪测量总血红蛋白（tHb）的准确性，在高失血风险的患者中进行复杂脊柱手术时。
符合研究条件的患者接受复杂脊柱手术，计划进行有创动脉或中心静脉监测，并每小时抽取血液测量血红蛋白。在每次手术中，每小时（或根据临床需要更频繁地）采集血样，并由中心实验室用 CO-血氧仪进行分析，这是许多医院血红蛋白测量的标准方法。将 tHb 测量值与采血时获得的 SpHb 进行比较。
共有 29 名患者纳入研究。tHb 值范围为 6.9 至 13.9 g/dL，SpHb 值范围为 6.9 至 13.4 g/dL。共分析了 186 对数据（tHb/SpHb）；去除 SpHb 读数信号质量低后，其余 130 对数据的偏差（定义为 SpHb 与 tHb 之间的差异）和精度（定义为偏差的 1 SD）分别为-0.1 g/dL ± 1.0 g/dL。Bland-Altman 分析显示，在整个数值范围内，SpHb 与 tHb 值具有良好的一致性；一致性界限为-2.0 至 1.8 g/dL。绝对偏差和精度分别为 0.8 ± 0.6 g/dL。
在复杂脊柱手术中使用脉搏 CO-血氧仪进行连续、无创的血红蛋白测量，与标准实验室参考设备相比，血红蛋白测量的临床可接受准确性在 1.5 g/dL 以内。与间歇性血液样本分析相比，该技术可能提供更及时的血红蛋白状态信息，从而有可能改善手术期间的血液管理。
