Gunn Scott R, Kim Hyung Kook, Harrigan Peter W J, Pinsky Michael R
Medical Center, Department of Critical Care Medicine, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA.
Intensive Care Med. 2006 Oct;32(10):1537-46. doi: 10.1007/s00134-006-0284-5. Epub 2006 Jul 28.
Two technologies to acquire beat-to-beat stroke volume values exist, pulse contour analysis and esophageal Doppler monitoring. Pulse contour analysis assumes fixed aortic impedance. Esophageal Doppler assumes a constant proportional descending aortic flow and diameter. These assumptions may not be correct as arterial tone or myocardial contractility vary. We tested these relationships in the setting of rapidly changing stroke volumes and different cardiovascular states over a period of 10-15 cardiac cycles.
In a university research facility we compared beat-to-beat changes in stroke volume as measure by aortic root flow probe or conductance catheter to pulse contour analysis and stroke distance as measured by esophageal Doppler.
Five purpose-bred research hounds.
To obtain a wide range of rapidly changing stroke volumes measurements were made during transient inferior vena cava occlusion. Data were gathered under baseline conditions and during norepinephrine, nitroprusside, and dobutamine infusions.
The pulse contour stroke volumes and esophageal Doppler stroke distance paralleled flow probe stroke volumes under all conditions (R(2)=0.89 for all measures). However, the absolute changes and proportional changes and the absolute values for both surrogate measures differed from absolute stroke volumes. Bland-Altman analysis showed no consistent bias or degree of precision across all animals under any given cardiovascular state.
Both pulse contour stroke volumes and esophageal Doppler derived stroke distance estimates yield significant correlations with aortic root flow probe. However, the absolute values, absolute changes, or proportional changes may not reflect actual stroke volumes as cardiovascular state varies, making their use in estimating absolute changes in stroke volume potentially inaccurate.
存在两种获取逐搏每搏输出量值的技术，即脉搏轮廓分析和食管多普勒监测。脉搏轮廓分析假定主动脉阻抗固定。食管多普勒假定降主动脉血流和直径成恒定比例关系。随着动脉张力或心肌收缩力的变化，这些假设可能并不正确。我们在10 - 15个心动周期内，在每搏输出量快速变化及不同心血管状态的情况下测试了这些关系。
在一所大学研究机构中，我们将通过主动脉根部血流探头或电导导管测量的每搏输出量的逐搏变化与脉搏轮廓分析以及通过食管多普勒测量的行程距离进行了比较。
五只专门培育的研究用猎犬。
为了获得广泛的快速变化的每搏输出量测量值，在短暂性下腔静脉闭塞期间进行了测量。在基线条件下以及去甲肾上腺素、硝普钠和多巴酚丁胺输注期间收集数据。
在所有情况下，脉搏轮廓每搏输出量和食管多普勒行程距离均与血流探头每搏输出量平行（所有测量的R² = 0.89）。然而，两种替代测量方法的绝对变化和比例变化以及绝对值均与绝对每搏输出量不同。布兰德 - 奥特曼分析表明，在任何给定的心血管状态下，所有动物之间均不存在一致的偏差或精密度程度。
脉搏轮廓每搏输出量和食管多普勒得出的行程距离估计值均与主动脉根部血流探头有显著相关性。然而，随着心血管状态的变化，其绝对值、绝对变化或比例变化可能无法反映实际的每搏输出量，这使得它们在估计每搏输出量的绝对变化时可能不准确。
