Despotis G J, Levine V, Goodnough L T
Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Crit Care Med. 1997 Aug;25(8):1338-46. doi: 10.1097/00003246-199708000-00021.
To evaluate the relationship between leukocyte counts and risk for excessive blood loss after cardiac surgery when including numerous demographic, operative, and laboratory factors in the comparison.
A prospective, clinical evaluation.
A point-of-care laboratory and the cardiac surgical unit of a university-affiliated tertiary center.
Patient-related and hematologic variables were measured, using blood specimens obtained from 89 hospitalized patients who underwent cardiac surgery involving cardiopulmonary bypass.
None.
Demographic, operative, and transfusion-related data were recorded for each patient. Routinely obtained measurements of laboratory-based prothrombin time, partial thromboplastin time, complete blood count, and bleeding time were recorded. Hemoglobin concentration, platelet count, and red and white blood cell counts were measured with an on-site instrument before initiation (pre-cardiopulmonary bypass) and before discontinuation (end-cardiopulmonary bypass) of cardiopulmonary bypass. Hematocrit was calculated using recorded variables, and white blood cell percent change values were calculated using white blood cell counts from both periods, using the following formula: [(end-cardiopulmonary bypass - pre-cardiopulmonary bypass)/pre-cardiopulmonary bypass] x 100. When we excluded four patients who had a surgical source of post-cardiopulmonary bypass bleeding, significant (p < .0001) relationships were observed between white blood cell count (r2 = .46) and white blood cell percent change values (r2 = .71) and cumulative mediastinal chest tube drainage in the first 4 postoperative hours in 85 patients. Bayes theorem was used to evaluate the predictive ability of hematologic measurements in identifying patients with excessive bleeding (n = 24), defined as >1000 mL of cumulative chest tube drainage in the first 24 postoperative hours, when compared with patients without excessive bleeding (n = 61). Demographic and operative variables were similar between these patients except that patients with excessive bleeding required more red blood cell, platelet, and plasma transfusions during the postoperative interval. Significantly (p < .0001) greater white blood cell percent change values were obtained in the excessive bleeding cohort (119 +/- 93 percent change) when compared with patients without excessive bleeding (28 +/- 36 percent change).
On-site measurements of white blood cell count, as an index of the inflammatory response to extracorporeal circulation, may be useful in identifying patients at increased risk for excessive bleeding. Further studies are needed to examine whether white blood cell counts during multiple cardiopulmonary bypass periods may identify patients with an exaggerated inflammatory response to extracorporeal circulation. By using this information, physicians may be able to intervene with anti-inflammatory medications and blood preservation techniques.
在比较中纳入众多人口统计学、手术和实验室因素，评估心脏手术后白细胞计数与失血过多风险之间的关系。
一项前瞻性临床评估。
大学附属三级中心的即时检验实验室和心脏外科病房。
对89例接受涉及体外循环的心脏手术的住院患者采集血标本，测量与患者相关的和血液学变量。
无。
记录每位患者的人口统计学、手术和输血相关数据。记录基于实验室的凝血酶原时间、活化部分凝血活酶时间、全血细胞计数和出血时间的常规测量值。在体外循环开始前（体外循环前）和体外循环停止前（体外循环结束时），使用现场仪器测量血红蛋白浓度、血小板计数以及红细胞和白细胞计数。使用记录的变量计算血细胞比容，并使用两个时期的白细胞计数计算白细胞百分比变化值，公式如下：[（体外循环结束时 - 体外循环前）/体外循环前]×100。当我们排除4例有体外循环后手术源性出血的患者后，在85例患者中观察到白细胞计数（r2 = 0.46）和白细胞百分比变化值（r2 = 0.71）与术后4小时内纵隔胸腔引流管累计引流量之间存在显著（p < 0.0001）关系。使用贝叶斯定理评估血液学测量在识别术后24小时内累计胸腔引流管引流量>1000 mL的出血过多患者（n = 24）与无出血过多患者（n = 61）时的预测能力。这些患者之间的人口统计学和手术变量相似，但出血过多的患者在术后期间需要更多的红细胞、血小板和血浆输注。与无出血过多的患者（28±36%变化）相比，出血过多组（119±93%变化）的白细胞百分比变化值显著更高（p < 0.0001）。
作为体外循环炎症反应指标的现场白细胞计数测量，可能有助于识别出血过多风险增加的患者。需要进一步研究以检查多个体外循环期间的白细胞计数是否可识别对体外循环炎症反应过度的患者。利用这些信息，医生或许能够采用抗炎药物和血液保存技术进行干预。
