Division of Cardiac Surgery, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
Ann Thorac Surg. 2012 Sep;94(3):703-9. doi: 10.1016/j.athoracsur.2012.03.038. Epub 2012 May 19.
Recent literature suggests that a restrictive approach to red blood cell transfusions is associated with improved outcomes in cardiac surgery patients. Even in the absence of bleeding, intravascular fluid shifts cause hemoglobin levels to drift postoperatively, possibly confounding the decision to transfuse. The purpose of this study was to define the natural progression of hemoglobin levels in postoperative cardiac surgery patients.
All cardiac surgery patients from October 2010 through March 2011 who did not receive a postoperative transfusion were included. Primary stratification was by intraoperative transfusion status. Change in hemoglobin was evaluated relative to the initial postoperative hemoglobin. Maximal drift was defined as the maximum minus the minimum hemoglobin for a given hospitalization. Final drift was defined as the difference between initial and discharge hemoglobin.
The final cohort included 199 patients: 71 (36%) received an intraoperative transfusion, whereas 128 (64%) did not. The average initial and final hemoglobin levels for all patients were 11.0±1.4 g/dL and 9.9±1.3 g/dL, respectively, giving a final drift of 1.1±1.4 g/dL. The maximal drift was 1.8±1.1 g/dL and was similar regardless of intraoperative transfusion status (p=0.9). Although all patients' hemoglobin initially dropped, 79% of patients reached a nadir and experienced a mean recovery of 0.7±0.7 g/dL by discharge. On multivariable analysis, increasing cardiopulmonary bypass time was significantly associated with total hemoglobin drift (coefficient/hour, 0.3 [0.1-0.5] g/dL; p=0.02).
In this report of hemoglobin drift after cardiac surgery, although all postoperative patients experienced downward hemoglobin drift, 79% of patients exhibited hemoglobin recovery before discharge. Physicians should consider the eventual upward hemoglobin drift before administering red blood cell transfusions.
近期文献表明，在心脏外科手术患者中，采用限制输血策略与改善预后相关。即使没有出血，血管内液体转移也会导致血红蛋白水平在术后漂移，可能会影响输血决策。本研究旨在明确心脏外科手术后患者血红蛋白水平的自然变化过程。
纳入 2010 年 10 月至 2011 年 3 月期间未接受术后输血的所有心脏外科手术患者。主要分层依据术中输血状态。血红蛋白变化相对于术后初始血红蛋白进行评估。最大漂移定义为特定住院期间的最大血红蛋白减去最小血红蛋白。最终漂移定义为初始血红蛋白与出院血红蛋白之间的差值。
最终纳入了 199 例患者：71 例（36%）术中接受了输血，而 128 例（64%）未输血。所有患者的平均初始和最终血红蛋白水平分别为 11.0±1.4 g/dL 和 9.9±1.3 g/dL，最终漂移为 1.1±1.4 g/dL。最大漂移为 1.8±1.1 g/dL，与术中输血状态无关（p=0.9）。尽管所有患者的血红蛋白最初均下降，但 79%的患者达到最低点，并在出院时平均恢复了 0.7±0.7 g/dL。多变量分析显示，体外循环时间的增加与总血红蛋白漂移显著相关（每小时系数，0.3 [0.1-0.5] g/dL；p=0.02）。
在本报告中，心脏手术后血红蛋白漂移的患者虽然所有患者的血红蛋白均呈下降趋势，但 79%的患者在出院前出现血红蛋白恢复。在给予红细胞输血之前，医生应考虑最终的血红蛋白向上漂移。
