在许多动物实验中,检测心输出量(CO)的突然变化至关重要.这项猪研究比较了在引起血液动力学不稳定的干预期间用Swan-Ganz肺导管与金标准(其是肺动脉周围的运输时间流量探针)测量的CO。
在一个系列中,7头猪暴露于CO的突然变化。在另一个系列中,9头猪经历了更长时间的CO变化。所有猪都将Swan-Ganz导管置于肺动脉中,并在肺动脉周围装有流量探头。使用肾上腺素输注和控制出血来增加和减少CO,分别。比较每次干预前后的CO测量值的相关性,协议,以及每种方法检测至少30%CO变化所需的时间延迟。使用Bland-Altman检验来确定方法之间的相关性和一致性。
在第一个系列中,SwanGanz导管记录30%心输出量变化延迟5-7分钟,与流量探头相比。然而,在第二系列中CO的长期变化期间,两种方法之间有很好的相关性。与CO相比,混合静脉血氧饱和度对变化的反应更快;两者均通过Swan-Ganz导管进行测量。
在许多动物研究中,使用Swan-Ganz导管是合适的;然而,在突然的血流动力学不稳定的实验中,流量探头是测量CO的最有利方法。
In many animal experiments, it is vital to detect sudden changes in cardiac output (CO). This porcine study compared CO that was measured with a Swan-Ganz pulmonary catheter with the gold standard (which was a transit-time flow probe around the pulmonary artery) during interventions that caused hemodynamic instability.
In one series, 7 pigs were exposed to sudden changes in CO. In another series, 9 pigs experienced more prolonged changes in CO. All the pigs had a Swan-Ganz catheter placed into the pulmonary artery and a flow probe around the pulmonary artery. Adrenaline infusion and controlled hemorrhage were used to increase and decrease CO, respectively. The measurements of CO before and after each intervention were compared for correlation, agreement, and the time delay that it took each method to detect at least a 30% change in CO. A Bland-Altman test was used to identify correlations and agreements between the methods.
In the first series, there was a delay of 5-7 min for the Swan Ganz catheter to register a 30% change in cardiac output, compared with the flow probe. However, during prolonged changes in CO in the second series, there was a good correlation between the 2 methods. Mixed venous oxygen saturation reacted faster to changes than did CO; both were measured via the Swan-Ganz catheter.
In many animal studies, the use of Swan-Ganz catheters is suitable; however, in experiments with sudden hemodynamic instability, the flow probe is the most advantageous method for measuring CO.