Department of Cardiovascular Surgery, Yokosuka General Hospital Uwamachi, Yokosuka, Kanagawa, Japan.
Department of Anesthesiology and Critical Care Medicine, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
J Card Surg. 2022 Aug;37(8):2338-2347. doi: 10.1111/jocs.16590. Epub 2022 May 12.
Although hemodilution during hypothermic cardiopulmonary bypass (CPB) had been thought to improve microcirculation and reduce blood viscosity, there has been no report investigating the effect of low nadir hematocrit (Hct) values caused by severe hemodilution on the surgical outcomes of patients with acute type A aortic dissection (ATAAD).
We retrospectively reviewed 112 consecutive patients who emergently underwent emergency surgical repair of ATAAD at our institution. The patients were classified into the high Hct (nadir Hct ≥ 21% during CPB; n = 51) and low Hct (nadir Hct < 21% during CPB; n = 61) groups. After propensity score matching of preoperative characteristics, surgical outcomes were compared between the groups.
Although there was no difference in the surgical procedure, longer CPB time and more blood transfusion during surgery were needed in the low Hct group than in the high Hct group. After surgery, estimated glomerular filtration rate was significantly lower (p = .015), lactaic acid was higher (p = .045), and intubation time was longer (p = .018) in the low Hct group than in the high Hct group, although there was no difference in hospital mortality between the groups. The AUC of the nadir Hct during CPB as a prognostic indicator of prolonged postoperative ventilator support was 0.8, with the highest accuracy at 16.7% (sensitivity 88%, specificity 76.9%). In all cohorts, female sex was an independent risk factor for a lower nadir Hct value of <21% during CPB.
A lower nadir Hct value of <21% during CPB may be associated with postoperative renal dysfunction and prolonged ventilator support in patients with ATAAD.
尽管低温体外循环（CPB）期间的血液稀释被认为可以改善微循环并降低血液粘度，但目前尚无报道研究由严重血液稀释引起的低血球压积（Hct）低值对急性 A 型主动脉夹层（ATAAD）患者手术结果的影响。
我们回顾性分析了在我院紧急接受 ATAAD 外科修复的 112 例连续患者。患者分为高 Hct（CPB 期间最低 Hct≥21%；n=51）和低 Hct（CPB 期间最低 Hct<21%；n=61）组。在对术前特征进行倾向评分匹配后，比较两组的手术结果。
尽管手术程序没有差异，但低 Hct 组的 CPB 时间和术中输血量均多于高 Hct 组。手术后，低 Hct 组的估算肾小球滤过率明显降低（p=0.015），乳酸水平升高（p=0.045），拔管时间延长（p=0.018），但两组之间的住院死亡率无差异。CPB 期间最低 Hct 作为术后呼吸机支持时间延长的预后指标的 AUC 为 0.8，准确性最高为 16.7%（灵敏度 88%，特异性 76.9%）。在所有队列中，女性是 CPB 期间最低 Hct 值<21%的独立危险因素。
CPB 期间最低 Hct 值<21%可能与 ATAAD 患者术后肾功能障碍和呼吸机支持时间延长有关。
