Department of Anaesthesiology, University Medical Centre of Johannes Gutenberg University, Mainz, Germany.
Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Centre of Johannes Gutenberg University, Mainz, Germany.
Anaesthesia. 2021 May;76(5):647-654. doi: 10.1111/anae.15312. Epub 2020 Nov 23.
Non-invasive haemoglobin measurement using absolute values lacks the precision to be the sole basis for the treatment of pre-operative anaemia. However, it can possibly serve as a screening test, indexing 'anaemia' with high sensitivity when values remain under prespecified cut-off values. Based on previous data, non-invasive haemoglobin cut-off values (146 g.l for women and 152 g.l for men) detect true anaemia with 99% sensitivity. An index test with these prespecified cut-off values was verified by prospective measurement of non-invasive and invasive haemoglobin pre-operatively in elective surgical patients. In 809 patients, this showed an estimated sensitivity (95%CI) of 98.9% (94.1-99.9%) in women and 96.4% (91.0-99.0%) in men. This saved invasive blood tests in 9% of female and 28% of male patients. In female patients, a lower non-invasive haemoglobin cut-off value (138 g.l ) would save 28% of invasive blood tests with a sensitivity of 95%. The target 99% sensitivity would be reached by non-invasive haemoglobin cut-off values of 152 g.l in female and 162 g.l in male patients, saving 3% and 9% of invasive blood tests, respectively. Bias and limits of agreement between non-invasive and laboratory haemoglobin levels were 2 and - 25 to 28 g.l , respectively. Patient and measurement characteristics did not influence the agreement between non-invasive and laboratory haemoglobin levels. Although sensitivity was very high, the index test using prespecified cut-off values just failed to reach the target sensitivity to detect true anaemia. Nevertheless, with respect to blood-sparing effects, the use of the index test in men may be clinically useful, while an index test with a lower cut-off (132 g.l ) could be more clinically appropriate in women.
使用绝对值进行非侵入性血红蛋白测量缺乏准确性，无法成为治疗术前贫血的唯一依据。然而，它可能可以作为一种筛选测试，当数值低于预设截止值时，以高灵敏度索引“贫血”。根据先前的数据，非侵入性血红蛋白截止值（女性 146g/L，男性 152g/L）以 99%的灵敏度检测真正的贫血。在择期手术患者中，通过前瞻性测量术前非侵入性和侵入性血红蛋白，对具有这些预设截止值的指数测试进行了验证。在 809 名患者中，这表明女性的估计灵敏度（95%CI）为 98.9%（94.1-99.9%），男性为 96.4%（91.0-99.0%）。这使得 9%的女性和 28%的男性患者免于进行侵入性血液检查。在女性患者中，较低的非侵入性血红蛋白截止值（138g/L）将以 95%的灵敏度节省 28%的侵入性血液检查。通过女性患者的非侵入性血红蛋白截止值为 152g/L 和男性患者的 162g/L，可分别达到 99%的灵敏度目标，分别节省 3%和 9%的侵入性血液检查。非侵入性和实验室血红蛋白水平之间的偏倚和一致性界限分别为 2 和-25 至 28g/L。患者和测量特征并未影响非侵入性和实验室血红蛋白水平之间的一致性。尽管灵敏度非常高，但使用预设截止值的指数测试仅未能达到检测真正贫血的目标灵敏度。然而，就节省血液效果而言，该指数测试在男性中的应用可能具有临床意义，而使用较低截止值（132g/L）的指数测试在女性中可能更具临床意义。
