Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA.
Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA.
Am J Vet Res. 2023 Feb 1;84(3). doi: 10.2460/ajvr.22.11.0198. Print 2023 Mar 1.
To investigate the relationship between invasively measured stroke volume (SV) and (1) esophageal Doppler-derived indices such as stroke distance (StrokeD), flow time corrected (FTc), stroke distance variation (SDV), and peak velocity variation (PVV); and (2) arterial load (AL) variables during evaluation of fluid responsiveness (FR) in anesthetized dogs undergoing sudden hemodynamic shifts in blood volume.
6 healthy male dogs.
Dogs were anesthetized with isoflurane, ventilated mechanically, and instrumented to undergo sequential, nonrandomized experimental stages. The dogs transitioned from normovolemia (NORMO-BL) to hypovolemia (30% blood loss; HYPO-30), followed by autologous blood transfusion, and then to hypervolemia (colloid bolus). During each stage, SV was quantified using pulmonary artery thermodilution and its relationship with StrokeD, FTc, SDV, and PVV; and AL variables such as effective arterial elastance (Ea), dynamic arterial elastance (Eadyn), and total arterial compliance (Ca) were established.
As SV decreased significantly during HYPO-30 compared to NORMO-BL, there was a significant (P < .001) decrease in StrokeD, FTc, and Ca, with simultaneous increases in SDV, PVV, Ea, and Eadyn. Upon restoration of blood volume, these values stabilized closer to NORMO-BL. A significant (P < .001) correlation was observed between SV and StrokeD, FTc, Ea, Eadyn, and Ca.
Minimally invasive StrokeD, FTc, SDV, and PVV act as SV surrogates and help assess FR during different blood volume stages in healthy dogs. During hypovolemia-induced hypotension, Ea, Eadyn, and Ca may be able to guide therapeutic decisions favoring improvement in blood pressure and SV.
探讨在容积急剧变化的犬麻醉模型中，测量得到的每搏量（SV）与（1）食管多普勒衍生指标（如：stroke distance，StrokeD；flow time corrected，FTc；stroke distance variation，SDV；peak velocity variation，PVV）以及（2）动脉负荷（AL）变量之间的关系，以评估其对液体反应性（FR）的预测价值。
6 只健康雄性犬。
犬用异氟烷麻醉，机械通气，并接受序贯、非随机的实验阶段。在每一个阶段，使用肺动脉热稀释法测量 SV，并将其与 StrokeD、FTc、SDV 和 PVV 进行比较；同时测量 AL 变量，如有效动脉弹性（Ea）、动态动脉弹性（Eadyn）和总动脉顺应性（Ca）。
与 NORMO-BL 相比，HYPO-30 期间 SV 显著降低，StrokeD、FTc 和 Ca 显著降低（P <.001），同时 SDV、PVV、Ea 和 Eadyn 显著升高。当恢复血容量时，这些值更接近 NORMO-BL。SV 与 StrokeD、FTc、Ea、Eadyn 和 Ca 之间存在显著（P <.001）的相关性。
微创的 StrokeD、FTc、SDV 和 PVV 可以作为 SV 的替代指标，有助于评估健康犬不同血容量阶段的 FR。在低血容量性低血压期间，Ea、Eadyn 和 Ca 可能能够指导治疗决策，以改善血压和 SV。
