Department of Anaesthesia, Stanford University School of Medicine, Stanford CA 94305, USA.
Br J Anaesth. 2012 Feb;108(2):271-7. doi: 10.1093/bja/aer373. Epub 2011 Nov 23.
The ability to measure haemoglobin (Hb) real-time and non-invasively offers important clinical value in the assessment of acute changes in maternal Hb during the peripartum period. This study evaluates the Masimo Rainbow SET(®) Radical-7 Pulse CO-Oximeter in a pregnant population undergoing Caesarean section (CS).
Fifty patients undergoing elective CS were enrolled in this prospective, controlled study and followed for 48 h after surgery. Non-invasive Masimo Hb (SpHb) values were compared with laboratory Hb values from venous blood samples drawn at baseline, immediately post-CS, and 24 h post-CS using the Bland-Altman plots. Longitudinal analysis of SpHb changes over time was performed using mixed-effects regression modelling.
For the comparison between SpHb and laboratory Hb, SpHb displayed a significant positive bias at baseline {1.22 g dl(-1) [95% confidence interval (CI): 0.89-1.54]} and at 24 h post-CS [1.36 g dl(-1) (95% CI: 1.04-1.68)]. The bias immediately post-CS was 0.14 g dl(-1) (95% CI: -0.18 to 0.46). The limits of agreement at baseline, immediately post-CS, and at 24 h post-CS were: -0.9 and 3.33, -2.35 and 2.56, and -0.55 and 3.27 g dl(-1), respectively. The mean decrease in SpHb from baseline to 48 h post-CS was ∼1 g dl(-1).
The variability in bias and limits of agreements of the Rainbow SET(®) Radical-7 Pulse CO-Oximeter SpHb may limit its clinical utility for assessing Hb concentration in patients undergoing elective CS. Modifications are needed in the calibration of the device to improve accuracy and precision in an obstetric setting. The study was registered at clinicaltrials.gov (NCT01108471) before participant enrolment: URL=http://clinicaltrials.gov/ct2/show/NCT01108471?term=butwick&rank=1.
实时、非侵入性地测量血红蛋白 (Hb) 在评估围产期母体 Hb 的急性变化方面具有重要的临床价值。本研究评估了 Masimo Rainbow SET(®) Radical-7 脉搏 CO- 血氧仪在接受剖宫产术 (CS) 的孕妇人群中的应用。
本前瞻性对照研究纳入了 50 例行择期 CS 的患者，并在手术后随访 48 小时。使用 Bland-Altman 图比较基线、CS 即刻和 CS 后 24 小时时从静脉血样中提取的非侵入性 Masimo Hb (SpHb) 值与实验室 Hb 值。使用混合效应回归模型对 SpHb 随时间的纵向变化进行分析。
对于 SpHb 与实验室 Hb 的比较，SpHb 在基线时显示出显著的正偏倚{1.22 g dl(-1) [95%置信区间 (CI)：0.89-1.54]}，在 CS 后 24 小时时显示出 1.36 g dl(-1) (95% CI：1.04-1.68)]。CS 即刻的偏倚为 0.14 g dl(-1) (95% CI：-0.18 至 0.46)]。基线、CS 即刻和 CS 后 24 小时时的一致性界限分别为：-0.9 和 3.33、-2.35 和 2.56、-0.55 和 3.27 g dl(-1)。从基线到 CS 后 48 小时时 SpHb 的平均下降量约为 1 g dl(-1)。
Rainbow SET(®) Radical-7 脉搏 CO- 血氧仪 SpHb 的偏倚和一致性界限的变异性可能限制了其在评估择期 CS 患者 Hb 浓度方面的临床应用。需要对设备进行校准修改，以提高在产科环境中的准确性和精密度。研究在参与者入组前在 clinicaltrials.gov 上进行了注册（NCT01108471）：URL=http://clinicaltrials.gov/ct2/show/NCT01108471?term=butwick&rank=1。
