Functional Changes Of Heart And Microcirculation During Septic Shock And Hemodynamic Effects Of β - Blockers

Objective:To research and analysis the sepsis, septic shock, and even to myocardial depression sepsis stage at various stages of patients can benefit from beta blockers treatment. And beta blockers on cardiac systolic and diastolic dysfunction, and arterial, venous return system and waterfalls each blood vessels site effect.Methods:The clinical part:Continuous selection in February2014-March2014at Peking union medical college hospital intensive medicine sepsis, severe sepsis and septic shock and after standard treatment, and with the blood volume is enough, Ramsay sedation score2-4points, but the heart rate still above100times/min, a total of32patients. Give beta blockers pumping treatment, target heart rate drops below the base value by10%to15%. Experiment to maintain all the patients with the rest of the infusion, blood vessels, active drugs, cool, sedation and respiratory support therapy remains the same. The prospective study method, all patients acquired within1h before medication, and after target heart rate2h the transthoracic echocardiography (TTE) and tissue perfusion parameters.Animal experiment part:8mongrel dog, Endotracheal intubation weres dministered after anesthesia satisfaction and with the ventilator to support respiratory. Place the pulmonary artery catheter and the Pulse Indicator Continuous Cardiac Output (PICCO) catheter, and application the transesophageal echocardiography (TEE) to monitoring the change of cardiac systolic and diastolic function. In a sterile state to perform the laparotomy for every dog, and placed ultrasound blood flow meter probe around the left renal artery, real-time monitoring of the left renal artery blood flow (RBF) change, to calculate the critical closing pressure(Pcc) and the mean systemic filling pressure(MSFP) and calculate the height of the waterfall. This experiment for the dog pumping endotoxin (LPS) of total dose5.3ug/Kg, for septic shock model was made. And focus on the study of sepsis myocardial depression stage, when the LVEF below45%to reach the sepsis myocardial depression diagnostic criteria, divided2groups (the control group, beta blockers) for intervention treatment. And compared two groups of whole cycle parameters change, in order to understand the beta blockers can make animals benefit from sepsis myocardial depression period.Results: The clinical part:To sepsis patients after using beta blockers to measure left ventricular outflow velocity time integral (VTI) a rise compared with before using. Ventricular diastolic function assessment shows compliance improved was the foundation of VTI rise. The beta-blockers falling heart rate and reduced the cardiac output (CO) was significant, but the lactic acid level has a significant decline. In addition, our research suggests VTI rise was the result of comprehensively cardiac function improved. Therefore comparison between the rise in VTI and not rise in VTI two groups of echocardiography data before, MAPSElat can predicted the VTI rise, to do ROC curve analysis the cutoff value was1.34. No overload for the preload of cadiac patients were more likely to rise in VTI.Animal experiment part:Along with the occurrence of sepsis, vascular waterfall phenomenon disappeared and tissue perfusion was worsen, which process always accompanied by septic shock the whole process. Septic shock high dynamic state CO didn’t improve tissue perfusion, and high CO did not make a waterfall repetition, but in sepsis myocardial depression stage the lower CO further worsen tissue perfusion. Septic shock system flow high and low related the parts of the circulation stressed volume, and stressed volume related the compliance of the circulation system and the volume of the resuscitation. In sepsis myocardial depression stage, beta blockers treatment group can improve heart compliance, and had no obvious effect on CO. Beta blockers treatment in the sepsis myocardial depression stage could improve tissue perfusion level although with the low CO. Beta blockers treatment could promote vascular waterfall phenomenon. When there was a waterfall phenomenon the height at the waterfall was helpful to improve tissue perfusion.Conclusion:beta blockers treatment to increasing the Pcc, retrieval when septic shock disappeared vascular waterfall was the cause of the beta blockers improve tissue perfusion.