Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA.
Divisions of Cardiothoracic Anesthesiology and Critical Care Medicine, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA.
Can J Anaesth. 2018 Jan;65(1):46-59. doi: 10.1007/s12630-017-0991-0. Epub 2017 Nov 2.
Preoperative and postoperative anemia have been identified individually as potential risk factors for postoperative complications after coronary artery bypass grafting (CABG) surgery. Their interrelationship with acute kidney injury (AKI) and long-term mortality, however, has not been clearly defined and was the purpose of this study.
We retrospectively evaluated 6,130 adult patients undergoing CABG surgery performed at a single large academic medical center. Preoperative and postoperative hemoglobin concentrations were used as continuous predictors of postoperative AKI and mortality. Additionally, sex-specific preoperative (< 13 g·dL in men and < 12 g·dL in women) and postoperative anemia (the median of the lowest in-hospital values) were used as categorical predictors. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guidelines, when serum creatinine rose ≥ 50% during the period between day of surgery and postoperative day ten, or when a 0.3 mg·dL (26.5 μmol·L) increase was detected in a rolling 48-hr window from the day of surgery to the tenth postoperative day. The association of preoperative and postoperative hemoglobin levels and anemia patterns with postoperative AKI and mortality were assessed via univariable and multivariable Cox proportional hazard analyses with time-varying effects for postoperative serum hemoglobin concentrations.
The median preoperative and median minimum postoperative serum hemoglobin concentrations were 13.1 g·dL and 8.8 g·dL, respectively. The incidence of AKI was 58%. Overall, 1,880 (30.7%) patients died an average of 6.8 yr after surgery. After adjusting for differences in baseline and clinical characteristics, on any given day, patients with preoperative anemia (multivariable hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.13 to 1.33; P < 0.001) and those with a combination of preoperative and postoperative anemia (multivariable HR, 1.24; 95% CI, 1.09 to 1.40; P < 0.0008) were at an elevated risk for developing postoperative AKI and mortality (preoperative anemia: multivariable HR, 1.29; 95% CI, 1.15 to 1.44; P < 0.001; preoperative and postoperative anemia: multivariable HR, 1.50; 95% CI, 1.25 to 1.79; P < 0.001).
Our findings suggest that preoperative anemia alone and preoperative anemia combined with postoperative anemia are associated with AKI and mortality after CABG surgery.
术前和术后贫血已被分别确定为冠状动脉旁路移植术（CABG）后术后并发症的潜在危险因素。然而，它们与急性肾损伤（AKI）和长期死亡率之间的相互关系尚未明确，这也是本研究的目的。
我们回顾性评估了在一家大型学术医疗中心接受 CABG 手术的 6130 名成年患者。术前和术后的血红蛋白浓度被用作术后 AKI 和死亡率的连续预测因子。此外，还使用了性别特异性术前（男性<13g·dL，女性<12g·dL）和术后贫血（住院期间最低值的中位数）作为分类预测因子。AKI 根据肾脏疾病：改善全球结局（KDIGO）临床实践指南定义，当血清肌酐在手术期间至术后第 10 天期间升高≥50%，或在手术日至术后第 10 天的 48 小时滚动窗口中检测到 0.3mg·dL（26.5μmol·L）的增加时。通过单变量和多变量 Cox 比例风险分析评估术前和术后血红蛋白水平及贫血模式与术后 AKI 和死亡率之间的关系，术后血清血红蛋白浓度具有时变效应。
术前中位数和术后中位数最低血清血红蛋白浓度分别为 13.1g·dL 和 8.8g·dL，AKI 的发生率为 58%。总体而言，1880 名（30.7%）患者在手术后平均 6.8 年死亡。在调整了基线和临床特征差异后，在任何给定的日子里，术前贫血的患者（多变量风险比[HR]，1.23；95%置信区间[CI]，1.13 至 1.33；P<0.001）和术前和术后合并贫血的患者（多变量 HR，1.24；95% CI，1.09 至 1.40；P<0.0008）发生术后 AKI 和死亡率的风险增加（术前贫血：多变量 HR，1.29；95% CI，1.15 至 1.44；P<0.001；术前和术后贫血：多变量 HR，1.50；95% CI，1.25 至 1.79；P<0.001）。
我们的研究结果表明，术前贫血和术前贫血合并术后贫血与 CABG 术后 AKI 和死亡率相关。
