Grau-Mercier Laura, Coisy Fabien, Markarian Thibaut, Muller Laurent, Roger Claire, Lefrant Jean-Yves, Claret Pierre-Géraud, Bobbia Xavier
From the Division of Anesthesiology, Critical Care, Pain and Emergency Medicine (L.G.-M., F.C., L.M., C.R., J.-Y.L., P.-G.C.), Nîmes University Hospital, Prévention et prise en charge de la défaillance circulatoire des patients en état de choc (IMAGINE), University of Montpellier, Nîmes; Department of Emergency Medicine (T.M.), Timone University Hospital, Marseille; and Department of Emergency Medicine (X.B.), Montpellier University Hospital Université de Montpellier, Prévention et prise en charge de la défaillance circulatoire des patients en état de choc (IMAGINE), University of Montpellier, Montpellier, France.
J Trauma Acute Care Surg. 2022 May 1;92(5):924-930. doi: 10.1097/TA.0000000000003518. Epub 2022 Jan 4.
Assessment of the volemic loss is a major challenge during the management of hemorrhagic shock. Echocardiography is an increasingly used noninvasive tool for hemodynamic assessment. In mechanically ventilated patients, some studies suggest that respiratory variations of mean subaortic time-velocity integral (∆VTI) would be predictive of fluid filling response. An experimental model of controlled hemorrhagic shock provides a precise approach to study correlation between blood volume and cardiac ultrasonographic parameters.
The main objective was to analyze the ∆VTI changes during hemorrhage in an anesthetized-piglet model of controlled hemorrhagic shock. The secondary objective was to evaluate ∆VTI during the resuscitation process after hemorrhage and other echocardiographic parameters changes during the whole protocol.
Twenty-four anesthetized and ventilated piglets were bled until mean arterial pressure reached 40 mm Hg. Controlled hemorrhage was maintained for 30 minutes before randomizing the piglets to two resuscitation groups: fluid filling group resuscitated with saline solution and noradrenaline group resuscitated with saline solution and noradrenaline. Echocardiography and hemodynamic measures, including pulsed pressure variations (PPV), were performed at different stages of the protocol.
The correlation coefficient between ΔVTI and PPV with the volume of bleeding during the hemorrhagic phase were respectively 0.24 (95% confidence interval, 0.08-0.39; p < 0.01) and 0.57 (95% CI, 0.44-0.67; p < 0.01). Two parameters had a moderate correlation coefficient with hemorrhage volume (over 0.5): mean subaortic time-velocity index (VTI) and mitral annulus diastolic tissular velocity (E').
In this hemorrhagic shock model, ΔVTI had a low correlation with the volume of bleeding, but VTI and E' had a correlation with blood volume comparable to that of PPV.
在失血性休克的治疗过程中，评估血容量丢失情况是一项重大挑战。超声心动图是一种越来越常用的用于血流动力学评估的非侵入性工具。在机械通气患者中，一些研究表明，主动脉下平均时间速度积分（∆VTI）的呼吸变化可预测液体填充反应。可控性失血性休克的实验模型为研究血容量与心脏超声参数之间的相关性提供了一种精确的方法。
主要目的是分析可控性失血性休克麻醉仔猪模型出血期间的∆VTI变化。次要目的是评估出血后复苏过程中的∆VTI以及整个实验过程中其他超声心动图参数的变化。
将24只麻醉并通气的仔猪放血，直至平均动脉压达到40 mmHg。在维持可控性出血30分钟后，将仔猪随机分为两个复苏组：用生理盐水复苏的液体填充组和用生理盐水及去甲肾上腺素复苏的去甲肾上腺素组。在实验的不同阶段进行超声心动图和血流动力学测量，包括脉压变异度（PPV）。
在出血期，∆VTI和PPV与出血量之间的相关系数分别为0.24（95%置信区间，0.08 - 0.39；p < 0.01）和0.57（95%CI，0.44 - 0.67；p < 0.01）。两个参数与出血量的相关系数中等（超过0.5）：主动脉下平均时间速度指数（VTI）和二尖瓣环舒张期组织速度（E'）。
在这个失血性休克模型中，∆VTI与出血量的相关性较低，但VTI和E'与血容量的相关性与PPV相当。
