Cardiac Surgery Department, University of Rome La Sapienza, Policlinico S. Andrea, Rome, Italy.
J Thorac Cardiovasc Surg. 2010 Aug;140(2):464-70. doi: 10.1016/j.jtcvs.2010.03.028. Epub 2010 Apr 22.
In clinical situations in which rhabdomyolysis is common, renal dysfunction association with myoglobinemia is well described. After coronary artery bypass grafting, a rapid increase in serum myoglobin concentration is generally seen, but whether it might independently increase the risk of acute kidney injury remains to be determined.
The study population consisted of 731 consecutive patients undergoing coronary artery bypass grafting. Creatine kinase, myoglobin, and creatinine concentrations were assessed in each patient preoperatively and postoperatively. Acute kidney injury was defined as an absolute increase in serum creatinine concentration of 0.3 mg/dL or greater.
Overall, 295 (40.3%) of 731 patients had acute kidney injury. Patients' risk profiles were significantly worse in those with acute kidney injury, and 31 (4.2%) of 731 patients required dialysis. Acute kidney injury was associated with a higher increase in serum myoglobin concentration after 1 hour from aortic declamping (534 microg/mL [interquantile range, 354-733 microg/mL] vs 377 microg/mL [interquantile range, 278-528 microg/mL], P < .0001), which persisted at 24 and at 48 hours. After adjusting for confounding factors, myoglobin concentration was found to independently predict postoperative acute kidney injury (odds ratio, 1.0011 [1 microg/mL increase]; 95% confidence interval, 1.0003-1.0019; P = .005), and this result persisted when patients with perioperative myocardial infarction were excluded from the analysis (odds ratio, 1.0007; 95% confidence interval, 1.0002-1.0009; P = .01). Myoglobin concentration had a better accuracy to discriminate patients having acute kidney injury than creatine kinase concentration at any time.
An increase in laboratory findings of muscle injury postoperatively, especially serum myoglobin concentration, predicts the incidence of acute kidney injury and renal replacement therapy requirement, as reported in other surgical settings. Perioperative myocardial injury cannot totally explain the occurrence of increased myoglobinemia. These results suggest an important role of skeletal muscle breakdown and necrosis in determining an increased myoglobinemia concentration after coronary artery bypass grafting.
在横纹肌溶解症常见的临床情况下，肾功能障碍与肌红蛋白尿相关已有明确描述。在冠状动脉旁路移植术后，通常会看到血清肌红蛋白浓度的快速升高，但它是否会独立增加急性肾损伤的风险仍有待确定。
研究人群包括 731 例连续接受冠状动脉旁路移植术的患者。每位患者术前和术后均评估肌酸激酶、肌红蛋白和肌酐浓度。急性肾损伤定义为血清肌酐浓度绝对增加 0.3mg/dL 或以上。
总体而言，731 例患者中有 295 例（40.3%）发生急性肾损伤。急性肾损伤患者的风险状况明显更差，731 例患者中有 31 例（4.2%）需要透析。与急性肾损伤相关的是，从主动脉阻断后 1 小时血清肌红蛋白浓度的升高幅度更大（534μg/mL [四分位距，354-733μg/mL] 比 377μg/mL [四分位距，278-528μg/mL]，P<0.0001），这一现象在术后 24 小时和 48 小时仍存在。在调整混杂因素后，发现肌红蛋白浓度可独立预测术后急性肾损伤（比值比，1.0011[每增加 1μg/mL]；95%置信区间，1.0003-1.0019；P=0.005），当排除围术期心肌梗死患者进行分析时，该结果仍成立（比值比，1.0007；95%置信区间，1.0002-1.0009；P=0.01）。肌红蛋白浓度在任何时间的准确性都优于肌酸激酶浓度，可用于区分发生急性肾损伤的患者。
术后实验室检查发现肌肉损伤增加，尤其是血清肌红蛋白浓度增加，可预测急性肾损伤和肾脏替代治疗的发生，这在其他外科手术环境中已有报道。围术期心肌损伤不能完全解释肌红蛋白尿的发生。这些结果表明，在冠状动脉旁路移植术后，骨骼肌分解和坏死在确定肌红蛋白浓度升高方面起着重要作用。
