Cardiovascular Disease Program, Department of Physiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.
Department of Surgery, School of Clinical Sciences at Monash Health, Monash University, Melbourne, Victoria, Australia.
Clin Exp Pharmacol Physiol. 2023 Nov;50(11):878-892. doi: 10.1111/1440-1681.13812. Epub 2023 Aug 7.
Targeting greater pump flow and mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) could potentially alleviate renal hypoxia and reduce the risk of postoperative acute kidney injury (AKI). Therefore, in an observational study of 93 patients undergoing on-pump cardiac surgery, we tested whether intraoperative hemodynamic management differed between patients who did and did not develop AKI. Then, in 20 patients, we assessed the feasibility of a larger-scale trial in which patients would be randomized to greater than normal target pump flow and MAP, or usual care, during CPB. In the observational cohort, MAP during hypothermic CPB averaged 68.8 ± 8.0 mmHg (mean ± SD) in the 36 patients who developed AKI and 68.9 ± 6.3 mmHg in the 57 patients who did not (p = 0.98). Pump flow averaged 2.4 ± 0.2 L/min/m in both groups. In the feasibility clinical trial, compared with usual care, those randomized to increased target pump flow and MAP had greater mean pump flow (2.70 ± 0.23 vs. 2.42 ± 0.09 L/min/m during the period before rewarming) and systemic oxygen delivery (363 ± 60 vs. 281 ± 45 mL/min/m ). Target MAP ≥80 mmHg was achieved in 66.6% of patients in the intervention group but in only 27.3% of patients in the usual care group. Nevertheless, MAP during CPB did not differ significantly between the two groups. We conclude that little insight was gained from our observational study regarding the impact of variations in pump flow and MAP on the risk of AKI. However, a clinical trial to assess the effects of greater target pump flow and MAP on the risk of AKI appears feasible.
目标是在体外循环 (CPB) 期间增加泵流量和平均动脉压 (MAP)，以减轻肾脏缺氧并降低术后急性肾损伤 (AKI) 的风险。因此，在一项对 93 名接受体外循环心脏手术的患者进行的观察性研究中，我们测试了在发生 AKI 和未发生 AKI 的患者之间，术中血流动力学管理是否存在差异。然后，在 20 名患者中，我们评估了一项更大规模试验的可行性，在该试验中，患者将被随机分配到 CPB 期间泵流量和 MAP 高于正常目标或常规治疗。在观察队列中，在发生 AKI 的 36 名患者中，低温 CPB 期间的 MAP 平均为 68.8 ± 8.0 mmHg（平均值 ± 标准差），在未发生 AKI 的 57 名患者中为 68.9 ± 6.3 mmHg（p = 0.98）。两组患者的泵流量平均为 2.4 ± 0.2 L/min/m。在可行性临床试验中，与常规治疗相比，那些随机接受增加目标泵流量和 MAP 的患者具有更高的平均泵流量（复温前期间分别为 2.70 ± 0.23 和 2.42 ± 0.09 L/min/m）和全身氧输送（363 ± 60 和 281 ± 45 mL/min/m）。干预组 66.6%的患者达到了目标 MAP≥80mmHg，而常规治疗组只有 27.3%的患者达到了目标 MAP≥80mmHg。然而，两组患者的 CPB 期间 MAP 没有显著差异。我们得出结论，我们的观察性研究几乎没有获得有关泵流量和 MAP 变化对 AKI 风险影响的见解。然而，评估更大目标泵流量和 MAP 对 AKI 风险影响的临床试验似乎是可行的。
