Background Systemic inflammation contributes to cardiac surgery–associated acute kidney injury (AKI). Cardiomyocytes and other organs experience hypothermia and hypoxia during cardiopulmonary bypass (CPB), which induces the secretion of cold-inducible RNA-binding protein (CIRP). Extracellular CIRP may induce a proinflammatory response.

Materials and Methods The serum CIRP levels in 76 patients before and after cardiac surgery were determined to analyze the correlation between CIRP levels and CPB time. The risk factors for AKI after cardiac surgery and the in-hospital outcomes were also analyzed.

Results The difference in the levels of CIRP (ΔCIRP) after and before surgery in patients who experienced cardioplegic arrest (CA) was 26-fold higher than those who did not, and 2.7-fold of those who experienced CPB without CA. The ΔCIRP levels were positively correlated with CPB time (r = 0.574, p < 0.001) and cross-clamp time (r = 0.54, p < 0.001). Multivariable analysis indicated that ΔCIRP (odds ratio: 1.003; 95% confidence interval: 1.000–1.006; p = 0.027) was an independent risk factor for postoperative AKI. Patients who underwent aortic dissection surgery had higher levels of CIRP and higher incidence of AKI than other patients. The incidence of AKI and duration of mechanical ventilation in patients whose serum CIRP levels more than 405 pg/mL were significantly higher than those less than 405 pg/mL (65.8 vs. 42.1%, p = 0.038; 23.1 ± 18.2 vs. 13.8 ± 9.2 hours, p = 0.007).

Conclusion A large amount of CIRP was released during cardiac surgery. The secreted CIRP was associated with the increased risk of AKI after cardiac surgery.

背景 全身性炎症会导致心脏手术相关的急性肾损伤 (AKI)。心肌细胞和其他器官在体外循环 (CPB) 期间经历低温和缺氧，这会诱导冷诱导 RNA 结合蛋白 (CIRP) 的分泌。细胞外 CIRP 可诱导促炎反应。

材料与方法 测定76例心脏手术前后血清CIRP水平，分析CIRP水平与CPB时间的相关性。还分析了心脏手术后 AKI 的危险因素和住院结果。

结果 心脏停搏（CA）患者手术前后CIRP（ΔCIRP）水平的差异是未经历心脏停搏（CA）患者的26倍，是未经历CA的CPB患者的2.7倍。ΔCIRP 水平与 CPB 时间 ( r  = 0.574, p  < 0.001) 和交叉钳夹时间 ( r  = 0.54, p  < 0.001)呈正相关。多变量分析表明 ΔCIRP（优势比：1.003；95% 置信区间：1.000–1.006；p = 0.027) 是术后 AKI 的独立危险因素。接受主动脉夹层手术的患者比其他患者具有更高的 CIRP 水平和更高的 AKI 发生率。血清 CIRP 水平超过 405 pg/mL 的患者的 AKI 发生率和机械通气持续时间显着高于低于 405 pg/mL 的患者（65.8 vs. 42.1%，p  = 0.038；23.1 ± 18.2 vs. 13.8 ± 9.2 小时，p  = 0.007）。

结论 心脏手术过程中会释放大量CIRP。分泌的 CIRP 与心脏手术后 AKI 风险增加有关。