研究目的

通过系统评价和Meta分析，探讨心脏手术术中低血压（Intraoperative Hypotension, IOH）对术后结局的影响，为优化个性化术中血压管理策略提供循证医学依据。

研究方法

系统检索PubMed、Embase、Web of Science、Cochrane Library、中国知网和万方等六大数据库（截至2024年12月），筛选纳入比较心脏手术当中不同术中血压目标的随机对照试验（Randomized Controlled Trial，RCT）。采用Cochrane偏倚风险评估工具评价研究质量，数据分析使用RevMan5.3软件。主要结局为术后6个月死亡率，次要结局包括术后1个月死亡率、器官系统并发症（心脏、神经系统、肾脏并发症及再次手术）、资源利用指标（术后输血、术后机械通气时间、ICU时间及住院时间）和代谢指标（术后乳酸水平）。二分类结局指标以风险比（Risk Ratio, RR）及95%置信区间（Confidence Interval，CI）表示，连续型结局指标采用加权均数差（Weighted Mean Difference, WMD）及95% CI 表示。异质性较低（I² < 50%）时采用固定效应模型进行合并分析，异质性较高（I² > 50%）时则采用随机效应模型。对数据分布严重偏态的研究进行敏感性分析，以评估数据转换对结果的潜在影响。采用随机效应模型对I²提示异质性较低的结局进行敏感性分析，以评估结果的稳健性。P < 0.05 认为差异有统计学意义。

研究结果

检索数据库最终纳入10项RCT研究，共2102例患者。术中高目标平均动脉压（Mean Arterial Pressure，MAP）与低目标MAP相比，主要结局（术后6个月死亡率）无统计学显著差异（RR = 0.77, 95%CI: 0.48, 1.25, P = 0.29; I² = 10%, P = 0.35）。次要结局中，心脏并发症（心肌梗死：RR = 1.09, 95%CI: 0.49, 2.45；房颤：RR = 1.08, 95%CI: 0.79, 1.48）、神经系统并发症（认知障碍：RR = 0.91, 95%CI: 0.65, 1.28；卒中：RR = 1.03, 95%CI: 0.37, 2.86；谵妄：RR = 0.67, 95%CI: 0.24, 1.84）、肾脏并发症（急性肾损伤：RR = 1.10, 95%CI: 0.84, 1.43；术后透析：RR = 0.93, 95%CI: 0.47, 1.86）及术后机械通气时间均未显示组间差异（P均 > 0.05）。高MAP目标组的术后乳酸水平显著低于对照组（WMD = -0.66 mmol/L, 95%CI: -1.00, -0.32, P = 0.0002; I² = 3%, P = 0.31），但住院时间显著延长（WMD = 1.22天, 95%CI: 0.75, 1.69, P < 0.00001; I² = 34%, P = 0.21）。

研究结论

术中低平均动脉压目标虽未显著增加术后不良事件风险，但可能与术后乳酸水平升高及ICU住院时间延长相关。然而，这些关联可能受限于数据转换方法的潜在误差，且现有研究存在较多局限性，使得术中低血压对心脏手术后发病率和死亡率的实际影响仍不明确。需更多高质量研究进一步明确心脏手术患者的最佳术中血压管理策略。

Objective Through a systematic review and meta-analysis, this study aimed to investigate the impact of intraoperative hypotension (IOH) on postoperative outcomes in cardiac surgery, providing evidence-based medical insights for optimizing personalized intraoperative blood pressure management strategies. Methods Six databases (PubMed, Embase, Web of Science, Cochrane Library, CNKI, and Wanfang) were systematically searched up to December 2024 to identify randomized controlled trials (RCTs) comparing different intraoperative blood pressure targets in cardiac surgery. Study quality was assessed using the Cochrane risk-of-bias tool. Data analysis was performed using RevMan5.3. The primary outcome was 6-month mortality, and secondary outcomes included 1-month mortality, organ-specific complications (cardiac, neurological, renal, and reoperation), resource utilization metrics (postoperative transfusion, mechanical ventilation time, ICU stay, and total hospitalization time), and metabolic indicators (postoperative lactate levels). Dichotomous outcomes were expressed as risk ratios (RR) with 95% confidence intervals (CI), and continuous outcomes as weighted mean differences (WMD) with 95% CI. Fixed-effects models were used for low heterogeneity (I² < 50%), and random-effects models for high heterogeneity (I² > 50%). Sensitivity analyses were performed to evaluate the robustness of findings in studies exhibiting skewed data distributions. Specifically, random-effects models were employed for outcomes demonstrating low heterogeneity (as indicated by I² values) to assess the stability and reliability of the results. Statistical significance was set at P < 0.05. Results Ten RCTs involving 2,102 patients were included. No significant difference was observed in the primary outcome of 6-month mortality between high and low MAP targets (RR = 0.77, 95% CI: 0.48, 1.25, P = 0.29; I2 = 10%, P = 0.35). Secondary outcomes, including cardiac complications (myocardial infarction: RR = 1.09, 95% CI: 0.49, 2.45; atrial fibrillation: RR = 1.08, 95% CI: 0.79, 1.48), neurological complications (cognitive impairment: RR = 0.91, 95% CI: 0.65, 1.28; stroke: RR = 1.03, 95% CI: 0.37, 2.86; delirium: RR = 0.67, 95% CI: 0.24, 1.84), renal complications (acute kidney injury: RR = 1.10, 95% CI: 0.84, 1.43; postoperative dialysis: RR = 0.93, 95% CI: 0.47, 1.86), and mechanical ventilation time, also showed no significant differences (P > 0.05). However, the high MAP group exhibited significantly lower postoperative lactate levels (WMD = -0.66 mmol/L, 95% CI: -1.00, -0.32, P = 0.0002; I2 = 3%, P = 0.31) but prolonged hospitalization (WMD = 1.22 days, 95% CI: 0.75, 1.69, P < 0.00001; I2 = 34%, P = 0.21). Conclusions Intraoperative low MAP targets did not significantly increase postoperative adverse events but were associated with elevated lactate levels and prolonged ICU stays. These associations may be influenced by data conversion limitations and methodological heterogeneity. The actual impact of intraoperative hypotension on morbidity and mortality remains unclear. Further high-quality studies are needed to define optimal intraoperative blood pressure management strategies for cardiac surgery patients.