Jia Z S, Xie H X, Yang J, Liu X M, Sun Z Q, Li J, Wang Z, Hou X T
Department of Extracorporeal Circulation, Beijing An Zhen Hospital, Capital Medical University, An Ding Men Wai An Zhen Li, Chao Yang District, Beijing, PR China.
J Cardiovasc Surg (Torino). 2013 Jun;54(3):423-30. Epub 2013 Mar 13.
Current cardiopulmonary bypass (CPB) procedures use non-hematic fluids to prime bypass circuits, often resulting in marked hemodilution. Patients' total blood volume (TBV) is estimated prior to hemodilution. We aimed to evaluate differences between calculation of TBV by Nadler's formula, a classic reference book method, and an established formula calculated by the authors.
A total of 285 patients of Asian origin received primary cardiac surgery between September 2010 and October 2011 in our institution. Patients' total blood volume was estimated by: 1) standard Nadler formula: TBV (men) =0.417H3+0.045TBM-0.030L TBM (total body mass, Kg); TBV (women) =0.414H3+0.0328 TBM-0.030L; 2) classic reference book method: patient's weight in kilograms times 7% (women) or 7.5% (men); and 3) our practical calculation: TBV=HCT2*(CPB prime volume + intravenous fluids before CPB - urine volume before CPB)/(HCT1- HCT2).
Bland-Altman plotting revealed no mean differences between Nadler formula and reference book TBV measurements (Figure 1A). Differences in means (95% limit of agreement) for reference book/Nadler formulas was 0.52 (-0.21, 1.24, N.=285). Comparing authors' results with those of reference book/Nadler, TBV yielded divergent results. TBV correlated positively to patient's height (P=0.001) and body surface area (P<0.01), and correlated positively to height after controlling for age and gender (β=87.3, SE=42.9, P=0.043).
Total blood volume of Asian patients calculated by the authors differs markedly from that estimated by Nadler and classic reference book formulas, which suggests that more accurate calculation of TBV is needed for Asian cardiac patients requiring CPB, especially patients with valvular disease.
当前的体外循环（CPB）程序使用非血液性液体预充体外循环回路，常常导致明显的血液稀释。在血液稀释前估算患者的总血容量（TBV）。我们旨在评估通过经典参考书方法Nadler公式计算TBV与作者建立的公式之间的差异。
2010年9月至2011年10月期间，共有285名亚洲裔患者在我们机构接受了初次心脏手术。通过以下方法估算患者的总血容量：1）标准Nadler公式：TBV（男性）=0.417H³+0.045TBM-0.030L，TBM（总体重，千克）；TBV（女性）=0.414H³+0.0328TBM-0.030L；2）经典参考书方法：患者体重（千克）乘以7%（女性）或7.5%（男性）；3）我们的实际计算方法：TBV = HCT2×(CPB预充量+CPB前静脉输液量-CPB前尿量)/(HCT1 - HCT2)。
Bland-Altman绘图显示Nadler公式与参考书TBV测量值之间无均值差异（图1A）。参考书/Nadler公式的均值差异（95%一致性界限）为0.52（-0.21，1.24，N = 285）。将作者的结果与参考书/Nadler的结果进行比较，TBV得出了不同的结果。TBV与患者身高呈正相关（P = 0.001），与体表面积呈正相关（P < 0.01），在控制年龄和性别后与身高呈正相关（β = 87.3，SE = 42.9，P = 0.043）。
作者计算的亚洲患者总血容量与Nadler公式和经典参考书公式估算的结果明显不同，这表明对于需要CPB的亚洲心脏患者，尤其是瓣膜病患者，需要更准确地计算TBV。
