Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, USA.
Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, USA.
Vet Anaesth Analg. 2023 May;50(3):211-219. doi: 10.1016/j.vaa.2023.02.009. Epub 2023 Feb 20.
To demonstrate if modified passive leg raise (PLR) maneuver can be used for volumetric evaluation of fluid responsiveness (FR) by inducing cardiac output (CO) changes during experimental induction and correction of hypovolemia in healthy anesthetized dogs. The effects of PLR on plethysmographic variability index (PVI) and pulse pressure variation (PPV) were also investigated.
Prospective, crossover study.
A total of six healthy anesthetized Beagle dogs.
Dogs were anesthetized with propofol and isoflurane. They were mechanically ventilated under neuromuscular blockade, and normothermia was maintained. After instrumentation, all dogs were subjected to four stages: 1, baseline; 2, removal of 27 mL kg circulating blood volume; 3, after blood re-transfusion; and 4, after 20 mL kg hetastarch infusion over 20 minutes. A 10 minute stabilization period was allowed after induction of each stage and before data collection. At each stage, CO via pulmonary artery thermodilution, PVI, PPV and cardiopulmonary variables were measured before, during and after the PLR maneuver. Stages were sequential, not randomized. Statistical analysis included repeated measures anova and Tukey's post hoc test, considering p < 0.05 as significant.
During stage 2, PLR at a 30° angle significantly increased CO (mean ± standard deviation, 1.0 ± 0.1 to 1.3 ± 0.1 L minute; p < 0.001), with a simultaneous significant reduction in PVI (38 ± 4% to 21 ± 4%; p < 0.001) and PPV (27 ± 2% to 18 ± 2%; p < 0.001). The PLR did not affect CO, PPV and PVI during stages 1, 3 and 4.
In anesthetized dogs, PLR at a 30° angle successfully detected FR during hypovolemia, and identified fluid nonresponsiveness during normovolemia and hypervolemia. Also, in hypovolemic dogs, significant decreases in PVI and PPV occurred in response to PLR maneuver.
通过在实验诱导和纠正健康麻醉犬低血容量期间诱导心输出量 (CO) 变化，证明改良被动抬腿 (PLR) 操作是否可用于评估容量反应性 (FR) 的容积。还研究了 PLR 对容积描记变异指数 (PVI) 和脉搏压变异 (PPV) 的影响。
前瞻性，交叉研究。
总共 6 只健康麻醉的比格犬。
狗用异丙酚和异氟烷麻醉。它们在神经肌肉阻滞下机械通气，并保持体温正常。仪器设备安装后，所有狗都经历了四个阶段：1. 基础期；2. 去除 27 mL/kg 的循环血量；3. 输血后；4. 20 分钟内输注 20 mL/kg 羟乙基淀粉。每个阶段诱导后和数据收集前允许 10 分钟稳定期。在每个阶段，通过肺动脉热稀释法测量 CO、PVI、PPV 和心肺变量，在 PLR 操作前后进行测量。阶段是顺序的，不是随机的。统计分析包括重复测量方差分析和 Tukey 事后检验，认为 p<0.05 为显著。
在第 2 阶段，30°角的 PLR 显著增加了 CO（平均值±标准差，1.0±0.1 至 1.3±0.1 L/min；p<0.001），同时 PVI（38±4%至 21±4%；p<0.001）和 PPV（27±2%至 18±2%；p<0.001）显著降低。PLR 对第 1、3 和 4 阶段的 CO、PPV 和 PVI 没有影响。
在麻醉犬中，30°角的 PLR 在低血容量期间成功检测到 FR，并在正常血容量和高血容量期间确定了液体无反应性。此外，在低血容量犬中，PLR 操作后 PVI 和 PPV 显著降低。
