Intra-aortic Balloon Pump In Canine Model of Septic Shoc

败血症休克是美国内科和外科重症监护病房最常见的死亡原因。在死于败血症的患者中，有30%的患者的心输出量较低。本研究的目的是探讨主动脉内球囊反搏(IABC)在感染性休克治疗中的作用。放置主动脉内球囊反搏(IABP)的目的有两个。它减少了心脏的后负荷，从而允许它做更少的工作，即“辅助收缩”，同时增强其冠脉血流，从而为其提供更多的能量，即“舒张期增强”。 这是首次在具有良好特征的低心输出量脓毒症动物模型中进行IABC的对照、随机生存研究。这项研究分为三个阶段：阶段1(基线)、阶段2(脓毒症)和阶段3(恢复)。在脓毒症阶段，所有动物将接受细菌凝块(18×109CFU？S)、静脉输液(含5%葡萄糖的林格氏液)和抗生素(头孢曲松)。此外，动物将被随机分成四组之一：组1(对照组)、组2(加压药)、组3(IABP)和组4(加压药+IABP)。这项研究设计将使我们能够确定每种治疗干预措施(血管加压药或IABP)与对照相比的益处，并检测干预措施之间的任何相互作用。在这三个阶段中的每一个阶段都将研究相同的动物。 在研究的每个阶段将获得的测量包括：血流动力学(血压、肺动脉压、肺毛细血管楔压、心输出量、射血分数和心率)、静脉和动脉血气、全血计数、血清化学、定量血培养、内毒素水平、肿瘤坏死因子水平、乳酸水平、肌酸激酶水平和肌酸激酶同工酶-CK和CK-MM。在获得研究测量结果后，将从动物身上取出所有导管，并将它们放回笼子里。 IABC的总体作用是在舒张期通过增加冠脉灌注量来增加心肌供氧，在收缩期通过减少后负荷来减少心肌耗氧量。我们认为，IABC可能通过改善冠脉血流量和减少左心做功来减轻脓毒症的心肌抑制，从而降低脓毒症的死亡率。

Septic shock is the most common cause of death in medical and surgical intensive care units in the United States. Thirty percent of patients who die from sepsis are noted to have low cardiac output. The purpose of this study is to examine the role of intra-aortic balloon pump counterpulsation (IABC) in the treatment of septic shock. The goal of placing an intra-aortic balloon pump (IABP) is twofold. It reduces the afterload on the heart, thereby allowing it to do less work, "assisted systole", while enhancing its coronary blood flow, thereby providing it with more energy, "diastolic augmentation." This is the first controlled, randomized survival study of IABC in a well characterized low cardiac output animal model of sepsis. There are three phases in this study: phase 1 (baseline), phase 2 (sepsis), and phase 3 (recovery). During the sepsis phase all animals will receive bacterial clot (18 x 109 cfu?s of E. coli) intravenous fluids (Ringer's solution with 5% dextrose) and antibiotics (Ceftriaxone). In addition, the animals will be randomized to one of four groups: Group 1 (control group), Group2 (vasopressors), Group 3 (IABP) and Group 4 (vasopressors + IABP). This study design will allow us to determine the benefit of each treatment intervention (vasopressors or IABP) compared to control and to detect any interaction between the interventions. The same animals will be studied in each of the three phases. The measurements to be obtained in each phase of the study include: hemodynamics (blood pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, ejection fraction, and heart rate), venous and arterial blood gases, complete blood counts, serum chemistries, quantitative blood cultures, endotoxin levels, tumor necrosis factor levels, lactate levels, creatinine kinase levels, and creatinine kinase isoenzymes-CK and CK-MM. After study measurements have been obtained, all catheters will be removed from the animals and they will be returned to their cages. The overall effect of the IABC is to increase myocardial oxygen supply by increasing coronary perfusion during diastole, and decrease myocardial oxygen demand by decreasing afterload during systole. We believe that the IABC may reduce the myocardial depression of sepsis by improving coronary blood flow and reducing left ventricular work; therefore result in a decrease in mortality during sepsis.