P-T曲线用于精准诊断低血压原因的可行性研究

Intraoperative hypotension may substantially contribute to death and adverse events after surgery. Rapid and accurate determination of the etiology of hypotension is required for making a goal-directed therapeutic strategy, which may eventually improve outcomes. Unfortunately, there is a lack of an accurate and rapid method for differentiated diagnosis of hypotension until now. In our pilot study, we found that a unique blood pressure reaction pattern would be generated under the stimulation of low dosage of vasopressor with regarding to a definite cause-induced hypotension. This unique pattern can be demonstrated as pressure-time (P-T) curves. Therefore, it is possible that the etiology of hypotension could be diagnosed accurately and rapidly by a specific P-T curve. To test this hypothesis, different models of various-causes-induced hypotension would be established. Using a certain dose of vasopressor, P-T curves would be obtained, and diagnostic indicators derived from P-T curves would be screened to determine the cause of hypotension. After that, the feasibility of qualitative and semi-quantitative analysis of P-T curve would be further studied by comparing with the parameters measures by Swan-Ganz catheter. At last, a program would be written, and try to be used to precisely determine the etiology of hypotension automatically..It is very difficult to make a clinical decision based on the parameters from current monitoring devices, if the blood pressure is unstable. In the present proposal, we provide a safe, accurate and simple method to determine the cause of hypotension by a specific P-T curve. Therefore, it would help clinician to make a decision rapidly, and which may result in reducing mortality and improving the outcome for the patient with hypotension.

术中低血压是手术患者术后死亡和严重并发症的常见原因。快速精准诊断低血压原因有利于制定针对性治疗方案。目前临床尚缺乏快速准确的低血压鉴别方法。我们前期研究发现，不同类型低血压在小剂量血管收缩药物刺激下可形成独特的血压反应模式-这种反应模式可使用血压随时间变化的曲线（P-T曲线）来显示。因此通过独特的P-T曲线可能精准判断低血压原因。为此，本研究拟建立不同类型低血压模型，分别给予小剂量血管收缩药物获得独特的P-T曲线，通过对曲线特点的分析，筛选出特征性诊断指标；通过与漂浮导管的指标对比分析，研究使用P-T曲线定性和半定量判断低血压原因的可行性；最后通过编写的诊断低血压软件，研究自动精准判断低血压的可行性。.当血压不稳定时，目前的监测手段难以用于临床决策。本课题提出使用P-T 曲线精准判断低血压原因，方法安全、简单。本研究的顺利实施将会为抢救患者生命赢得宝贵时间，最终将显著降低死亡率，改善预后。

我们的动物实验发现，结扎前将降支产生的心衰，建立体外辅助后，逆行植入左心室引流管。发现左心室引流管压迫主动脉瓣导致中重度偏心主动脉返流。研发一个远端带可收缩的血管支架的左心引流管，在打开血管支架以后，支撑引流管于三个主动脉瓣正中，主动脉返流变为微量正中返流，同时LVEDP明显降低，提示新型引流管能够减少主动脉瓣返流促进左心功能恢复。. 在动物实验基础上，我们利用之前的插管技术，经下腔静脉逆行插管。这项技术可以用于全主动脉弓置换术的患者，因为目前中低温停循环技术无法为下半身重要器官供血。首次提出将选择性脑灌注联合下腔静脉逆行灌注用于全弓置换术。此技术能在主动脉吻合期间为内脏器官和脊髓血供，使患者不再有缺血时间而不再需要深低温；这不仅避免低温对凝血功能的影响，而且大大缩短体外循环降温和复温时间，减轻体外循环对机体的损伤，因此可能有效改善患者预后。本技术的成功研究与推广不仅使全球每年数万人受益，而且将会为制定主动脉弓置换手术的灌注指南提供依据。. 在下腔静脉逆行插管的基础上，我们开展了一项多中心，随机，对照、单盲的临床试验，拟纳入五个心脏中心的全主动脉弓置换的患者，随机分为中低温选择性脑灌注组和联合下腔静脉逆灌组，以包含死亡率和重大器官并发症的复合指标为主要指标。评估联合下腔静脉逆灌是否能够比单纯使用选择性脑灌注更能保护内脏功能，降低死亡率且减少输血需求和其他资源的消耗等。