Department of Cardiothoracic and Vascular Anesthesia and Intensive Care Unit, IRCCS Policlinico S. Donato, Milan, Italy.
Ann Thorac Surg. 2010 Jan;89(1):11-7. doi: 10.1016/j.athoracsur.2009.07.078.
Preoperative anemia and the lowest registered hematocrit value on cardiopulmonary bypass are recognized risk factors for morbidity and mortality after coronary operations. A low hematocrit often results in blood transfusions with all of the associated possible complications. The relative contribution of these three factors to long-term outcome is still not well established. This study aimed to identify the role of preoperative anemia and hemodilution during cardiopulmonary bypass as determinants of morbidity and mortality after coronary operations.
A consecutive series of 3,003 patients was analyzed. They had all undergone isolated coronary operations without receiving blood transfusions during their hospital stay. The preoperative hematocrit and the lowest hematocrit on cardiopulmonary bypass were analyzed in a multivariable model as predictors of major morbidity and operative mortality.
After adjustment for the other explanatory variables, both the preoperative hematocrit and the lowest hematocrit on cardiopulmonary bypass were found to be independent risk factors for major morbidity, but not for operative mortality. However, low values of preoperative hematocrit were not associated with an increased morbidity, provided that the lowest hematocrit on cardiopulmonary bypass was maintained above 28%. Median values of the lowest hematocrit on cardiopulmonary bypass below 25% were associated with an increased major morbidity rate.
Excessive hemodilution during cardiopulmonary bypass is a risk factor for major morbidity even in the absence of blood transfusions. Techniques that aim to reduce the fall in hematocrit during cardiopulmonary bypass, including blood cardioplegia, may be useful, especially in patients with a low preoperative hematocrit.
术前贫血和体外循环时的最低红细胞压积值被认为是冠状动脉手术后发病率和死亡率的危险因素。低红细胞压积通常会导致输血，以及所有可能的相关并发症。这三个因素对长期结果的相对贡献仍未得到很好的确立。本研究旨在确定术前贫血和体外循环期间血液稀释作为冠状动脉手术后发病率和死亡率的决定因素。
分析了连续的 3003 例患者。他们均接受了单纯的冠状动脉手术，住院期间未接受输血。在多变量模型中分析了术前红细胞压积和体外循环时的最低红细胞压积作为主要发病率和手术死亡率的预测因素。
在调整了其他解释变量后，术前红细胞压积和体外循环时的最低红细胞压积均被发现是主要发病率的独立危险因素，但不是手术死亡率的危险因素。然而，只要体外循环时的最低红细胞压积保持在 28%以上，低术前红细胞压积值与增加的发病率无关。体外循环时最低红细胞压积中位数低于 25%与主要发病率增加有关。
即使没有输血，体外循环期间过度血液稀释也是主要发病率的危险因素。旨在减少体外循环期间红细胞压积下降的技术，包括血液心脏停搏，可能是有用的，特别是在术前红细胞压积较低的患者中。
