Department of Anesthesia and Perioperative Care, University of California, San Francisco, 521 Parnassus Avenue, Box 0648, San Francisco, CA 94143, USA.
Anesth Analg. 2011 Apr;112(4):858-63. doi: 10.1213/ANE.0b013e31820eecd1. Epub 2011 Mar 8.
Hemoglobin values (Hb) can facilitate decisions regarding perioperative transfusion management. Currently, Hb can be determined invasively by analyzing blood via laboratory Co-Oximetry (tHb) or by point-of-care HemoCue (HCue). Recently, a new noninvasive, continuous spectrophotometric sensor (Masimo SpHb) was introduced into clinical practice. We compared the accuracy of the SpHb and HCue with tHb.
Twenty patients, ages 40 to 80 years, were studied. They received general anesthesia and underwent spine surgery in the prone position. All blood samples were obtained from a radial artery catheter. SpHb, tHb, and HCue were determined immediately after induction of anesthesia, but before the start of surgery and approximately every hour thereafter. Primary outcomes were defined on the basis of the following differences between measures: SpHb - tHb or HCue - tHb. All patients had 3 to 5 observations taken on each measure. Differences and absolute differences were analyzed by several techniques to assess accuracy. We also investigated the relationship between observed differences and the following variables: tHb level, duration of surgery, age, weight, and perfusion index.
Data consisted of 78 measurements of SpHb, tHb, and HCue made on the 20 patients. Absolute differences between SpHb and tHb were <1.5 g/dL for 61% of observations, between 1.6 to 2.0 g/dL for 16% and >2.0 g/dL for 22% of the observations. Observed differences displayed significant decreases with time and higher perfusion index values. No systematic relationships were observed with age or weight. Except for 1 value, all of the HCue values were <1.0 g/dL of tHb.
Although HCue was consistently accurate, our data confirm that SpHb often correlated well with tHb values. Yet our study indicates that SpHb may not be as accurate as clinically necessary in some patients. Improved refinement of continuous, noninvasive technology, such as SpHb, could address important clinical requirements.
血红蛋白值（Hb）可有助于确定围手术期输血管理决策。目前，可通过实验室比色法（tHb）分析血液来对 Hb 进行有创测定，或通过即时检验（POC）HemoCue（HCue）进行测定。最近，一种新的非侵入性、连续分光光度传感器（Masimo SpHb）已引入临床实践。我们比较了 SpHb 和 HCue 与 tHb 的准确性。
研究纳入 20 名年龄在 40 岁至 80 岁之间的患者。他们接受全身麻醉并在俯卧位下接受脊柱手术。所有血样均取自桡动脉导管。SpHb、tHb 和 HCue 在麻醉诱导后、手术开始前以及此后每小时测定一次。主要结局基于以下测定值之间的差异来定义：SpHb-tHb 或 HCue-tHb。所有患者每种方法均有 3 至 5 次测量。采用多种技术分析差异和绝对差异，以评估准确性。我们还研究了观察到的差异与以下变量之间的关系：tHb 水平、手术持续时间、年龄、体重和灌注指数。
数据包括 20 名患者的 78 次 SpHb、tHb 和 HCue 测量值。SpHb 与 tHb 之间的绝对差异有 61%的观察值<1.5g/dL，16%的观察值为 1.6 至 2.0g/dL，22%的观察值>2.0g/dL。观察到的差异随时间呈显著下降趋势，且与较高的灌注指数值相关。未观察到与年龄或体重有系统关系。除 1 个值外，所有 HCue 值均<tHb 的 1.0g/dL。
尽管 HCue 始终准确，但我们的数据证实，SpHb 通常与 tHb 值密切相关。然而，我们的研究表明，在某些患者中，SpHb 可能不如临床需要的那样准确。连续、非侵入性技术（如 SpHb）的改进可能会满足重要的临床需求。
