Background: Aortic dissection is a life-threatening condition where emergent surgical repair is the standard of care. However, despite operative intervention, mortality is 10-15% in all patients. Objective markers to distinguish when surgical repair is more beneficial versus being futile are warranted. Currently, no such known measures are widely agreed upon. Since most complications from aortic dissection stem from malperfusion, serum lactate is thought to be a surrogate marker for malperfusion. This scoping review aims to examine the preoperative predictive value of lactate or lactate dehydrogenase (LDH) in assessing postoperative mortality in patients undergoing surgical repair for acute Stanford Type A aortic dissection (ATAAD). Methods: PubMed was searched for the following search terms: "Dissection, Ascending Aorta", "Dissection, Thoracic Aorta", or "Aortic Dissection". Prospective and retrospective randomized controlled trials, case reports, and cohort studies were included in the initial search. Studies were first screened for inclusion of preoperative lactate or LDH level with a search of "lac" or "LDH". Included studies consisted of patients aged 18 or older diagnosed with Stanford Type A/Debakey Type I and II aortic dissection with reported preoperative lactate or LDH levels and postoperative mortality treated within 14 days of symptom onset. Preoperative laboratory values were measured from samples collected prior to patient transfer to the operating room or before utilization of ECMO intraoperatively. Results: A comprehensive database search identified a total of 4722 articles. After a rigid screening process, 46 studies fit the inclusion criteria. These papers reported a combined 4696 participants with either preoperative lactate or LDH levels and postoperative mortality. The mean preoperative lactate level was 2.4 mmol/L, whereas the LDH level was 424.9 U/L. Postoperative mortality was 16.51%. Average creatinine, BUN, platelets, INR, PT, PTT, and hemoglobin were all within normal lab analysis limits. Conclusions: Neither lactate nor LDH should be used as a solo predictor of postoperative mortality after ATAAD due to lack of consensus on the cut-off values. Accompanying clinical signs, lab abnormalities, and radiographic findings taken together may be better predictors of prognosis.

Keywords: Stanford Type A aortic dissection; aortic dissection; lactate; lactate dehydrogenase; malperfusion; mortality.

背景： 主动脉夹层是一种危及生命的状况，紧急外科修复是标准治疗方法。然而，尽管进行了手术干预，所有患者的死亡率仍为10-15%。客观指标以区分何时进行手术修复更有益于无望的情况是必要的。目前尚无广泛认可的此类措施。由于大多数主动脉夹层并发症源于灌注不良，血清乳酸被认为是灌注不良的一个替代标志物。本综述旨在探讨乳酸或乳酸脱氢酶（LDH）在预测急性Stanford A型主动脉夹层（ATAAD）患者术后死亡率的术前预测价值。方法： 在PubMed中搜索以下关键词：“Dissection, Ascending Aorta”，“Dissection, Thoracic Aorta”或“Aortic Dissection”。初步搜索包括前瞻性、回顾性随机对照试验、病例报告和队列研究。通过搜索"lac"或"LDH"筛选出包含术前乳酸或LDH水平的研究。纳入的研究对象为18岁及以上被诊断为Stanford Type A/Debakey Type I和II主动脉夹层且有术前乳酸或LDH水平报告及术后死亡率的患者，并在症状出现后14天内接受治疗。术前实验室值从样本采集时测定，即在将病人转至手术室之前或在体外膜氧合（ECMO）使用前。结果： 综合数据库搜索共识别出4722篇文章。经过严格的筛选过程后，符合纳入标准的研究有46项。这些研究共报告了4696名参与者，他们术前乳酸或LDH水平和术后死亡率均有记录。平均术前乳酸水平为2.4 mmol/L，而LDH水平为424.9 U/L。术后死亡率为16.51%。平均肌酐、血尿素氮（BUN）、血小板计数、国际标准化比值（INR）、凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）和血红蛋白水平均在正常实验室分析范围内。结论： 由于缺乏对阈值的共识，乳酸或LDH不应单独用作ATAAD术后死亡率的预测指标。结合临床体征、实验室异常和影像学发现可能会更好地预测预后。

关键词： Stanford Type A主动脉夹层；主动脉夹层；乳酸；乳酸脱氢酶；灌注不良；死亡率。