Objective

To compare pulse pressure variation (PPV) and systolic pressure variation (SPV) measured from a peripheral artery to predict fluid responsiveness in anesthetized healthy dogs.

Study design

Prospective study.

Animals

A total of 39 dogs (13.8–26.8 kg) anesthetized with isoflurane for elective ovariohysterectomy.

Methods

Ventilation was controlled (tidal volume 12 mL kg^–1; 40% inspiratory pause). PPV and SPV were recorded from a dorsal pedal artery catheter using an automated algorithm. A fluid challenge (FC) with lactated Ringer’s solution (20 mL kg^–1 over 15 minutes) was administered once (21 animals) or twice (18 animals) before surgery. Increases in transpulmonary thermodilution stroke volume index > 15% from values recorded before each FC defined responders to volume expansion. Final fluid responsiveness status was based on the response to single FC or second FC. Predictive ability of PPV and SPV was compared by receiver operating characteristic (ROC) curve analysis and by the range of cut-off values associated with uncertain results (gray zone).

Results

All animals after the single FC were responders; all animals administered two FCs were nonresponders after the second FC. The area under the ROC curve (AUROC) of PPV (0.968) did not differ from that of SPV (0.937) (p = 0.45). Best cut-off thresholds to discriminate responders from nonresponders were >11.7% (PPV) and >7.4 mmHg (SPV). The gray zone of PPV and SPV was 8.2–14.6% and 7.0–7.4 mmHg, respectively. The percentage of animals with PPV and SPV values within the gray zone was less for SPV (10.2%) than for PPV (30.8%).

Conclusions and clinical relevance

PPV and SPV obtained from the dorsal pedal artery are useful predictors of fluid responsiveness in dogs. Using an automated algorithm, SPV may more accurately predict fluid responsiveness than PPV, with responders identifiable by PPV > 14.6% and SPV > 7.4 mmHg.

中文翻译：

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从外周动脉测量的脉压变化和收缩压变化之间的比较，以准确预测机械通气犬的液体反应性

客观的

比较从外周动脉测量的脉压变化 (PPV) 和收缩压变化 (SPV)，以预测麻醉健康犬的液体反应性。

学习规划

前瞻性研究。

动物

总共 39 只狗 (13.8-26.8 kg) 用异氟醚麻醉以进行选择性卵巢子宫切除术。

方法

控制通气（潮气量 12 mL kg ^–1；40% 吸气暂停）。使用自动算法从足背动脉导管记录 PPV 和 SPV。手术前一次（21 只动物）或两次（18 只动物）用乳酸林格氏溶液（15 分钟内20 mL kg ^–1）进行液体刺激 (FC) 。经肺热稀​​释每搏输出量指数从每个 FC 定义的对容量扩张的反应者之前记录的值增加 > 15%。最终的液体反应状态基于对单个 FC 或第二个 FC 的反应。PPV 和 SPV 的预测能力通过受试者工作特征 (ROC) 曲线分析和与不确定结果（灰色区域）相关的截止值范围进行比较。

结果

单次FC后的所有动物都是反应者；给予两次 FC 的所有动物在第二次 FC 后均无反应。PPV (0.968) 的 ROC 曲线下面积 (AUROC) 与 SPV (0.937) 的 ROC 曲线下面积 ( p  = 0.45)没有差异。区分反应者和无反应者的最佳截止阈值是 >11.7% (PPV) 和 >7.4 mmHg (SPV)。PPV 和 SPV 的灰色区域分别为 8.2-14.6% 和 7.0-7.4 mmHg。在灰色区域内具有 PPV 和 SPV 值的动物百分比，SPV (10.2%) 低于 PPV (30.8%)。

结论和临床相关性

从足背动脉获得的 PPV 和 SPV 是犬体液反应性的有用预测因子。使用自动化算法，SPV 可以比 PPV 更准确地预测液体反应性，响应者可通过 PPV > 14.6% 和 SPV > 7.4 mmHg 来识别。