Kanji Hussein D, Schulze Costas J, Hervas-Malo Marilou, Wang Peter, Ross David B, Zibdawi Mohamad, Bagshaw Sean M
Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada.
J Cardiothorac Surg. 2010 Sep 8;5:71. doi: 10.1186/1749-8090-5-71.
Cardiac surgery-associated acute kidney injury (CSA-AKI) contributes to increased morbidity and mortality. However, its pathophysiology remains incompletely understood. We hypothesized that intra-operative mean arterial pressure (MAP) relative to pre-operative MAP would be an important predisposing factor for CSA-AKI.
We performed a prospective observational study of 157 consecutive high-risk patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). The primary exposure was delta MAP, defined as the pre-operative MAP minus average MAP during CPB. Secondary exposure was CPB flow. The primary outcome was early CSA-AKI, defined by a minimum RIFLE class - RISK. Univariate and multivariate logistic regression were performed to explore for association between delta MAP and CSA-AKI.
Mean (± SD) age was 65.9 ± 14.7 years, 70.1% were male, 47.8% had isolated coronary bypass graft (CABG) surgery, 24.2% had isolated valve surgery and 16.6% had combined procedures. Mean (± SD) pre-operative, intra-operative and delta MAP were 86.6 ± 13.2, 57.4 ± 5.0 and 29.4 ± 13.5 mmHg, respectively. Sixty-five patients (41%) developed CSA-AKI within in the first 24 hours post surgery. By multivariate logistic regression, a delta MAP≥26 mmHg (odds ratio [OR], 2.8; 95%CI, 1.3-6.1, p = 0.009) and CPB flow rate ≥54 mL/kg/min (OR, 0.2, 0.1-0.5, p < 0.001) were independently associated with CSA-AKI. Additional variables associated with CSA-AKI included use of a side-biting aortic clamp (OR, 3.0; 1.3-7.1, p = 0.012), and body mass index ≥25 (OR, 4.2; 1.6-11.2, p = 0.004).
A large delta MAP and lower CPB flow during cardiac surgery are independently associated with early post-operative CSA-AKI in high-risk patients. Delta MAP represents a potentially modifiable intra-operative factor for development of CSA-AKI that necessitates further inquiry.
心脏手术相关的急性肾损伤（CSA-AKI）会导致发病率和死亡率增加。然而，其病理生理学仍未完全明确。我们推测术中平均动脉压（MAP）相对于术前MAP会是CSA-AKI的一个重要诱发因素。
我们对157例连续接受体外循环（CPB）心脏手术的高危患者进行了一项前瞻性观察研究。主要暴露因素是MAP差值，定义为术前MAP减去CPB期间的平均MAP。次要暴露因素是CPB流量。主要结局是早期CSA-AKI，定义为最低RIFLE分级 - 风险级。进行单因素和多因素逻辑回归以探讨MAP差值与CSA-AKI之间的关联。
平均（±标准差）年龄为65.9±14.7岁，70.1%为男性，47.8%接受单纯冠状动脉旁路移植术（CABG），24.2%接受单纯瓣膜手术，16.6%接受联合手术。术前、术中及MAP差值的平均（±标准差）分别为86.6±13.2、57.4±5.0和29.4±13.5 mmHg。65例患者（41%）在术后24小时内发生CSA-AKI。通过多因素逻辑回归分析，MAP差值≥26 mmHg（比值比[OR]，2.8；95%置信区间，1.3 - 6.1，p = 0.009）和CPB流量≥54 mL/kg/min（OR，0.2，0.1 - 0.5，p < 0.001）与CSA-AKI独立相关。与CSA-AKI相关的其他变量包括使用侧咬式主动脉钳（OR，3.0；1.3 - 7.1，p = 0.012），以及体重指数≥25（OR，4.2；1.6 - 11.2，p = 0.004）。
心脏手术期间较大的MAP差值和较低的CPB流量与高危患者术后早期CSA-AKI独立相关。MAP差值代表了CSA-AKI发生过程中一个潜在可改变的术中因素，有必要进一步探究。
