离体 猪肺力学研究与教学的实验模型
Summary
我们提出了一个 离体 猪肺模型，用于演示肺力学和肺泡复张操作，用于教学目的。肺可以使用超过一天（最多五天），肺力学变量的变化很小。
Abstract
机械通气被广泛使用，需要特定的知识来理解和管理。由于培训和教学方法不足，该领域的卫生专业人员可能会感到不安全和缺乏知识。因此，本文的目的是概述生成离 体 猪肺模型所涉及的步骤，以供将来使用，以研究和教授肺力学。为了生成模型，按照动物研究伦理委员会的指导方针，小心翼翼地从胸部取出五个猪肺，并通过气管插管连接到机械呼吸机。然后对这些肺进行肺泡复张操作。在此过程中记录了呼吸力学参数，并使用摄像机获取肺部视频。这个过程连续重复了五天。不使用时，肺保持冷藏。该模型每天在肺泡复张操作后显示出不同的肺力学;不受日子的影响，只受机动的影响。因此，我们得出结论， 离体 肺模型可以更好地了解肺力学及其影响，甚至可以通过过程各个阶段的视觉反馈来更好地理解肺泡复张操作。
Introduction
机械通气 （MV） 广泛用于重症监护病房 （ICU） 和外科中心。其监测对于帮助识别不同步和预防所有患者的损伤至关重要，尤其是当患者有严重的肺损伤时 1,2,3,4,5,6。监测呼吸力学还有助于临床了解疾病进展和治疗应用，例如使用呼气末正压通气 （PEEP） 或肺泡复张操作 （ARM）。然而，使用这些技术需要熟练了解曲线和基本的肺力学 3,4。
学生、住院医师和医疗专业人员对 MV 管理感到不安全，从打开呼吸机和初始调整到监测平台和驾驶压力，这种不安全感与缺乏知识和足够的先前培训有关 7,8,9,10。我们观察到，参与模拟并使用肺模型的专业人员报告了更高的信心、对参数的理解以及对肺力学组成部分的理解 8,11,12。
用于研究和训练具有测试肺、波纹管和活塞的MV的模型可以模拟不同的压力和体积，以及不同的肺力学条件13,14,15。计算和软件模型还通过生成可用于向卫生专业人员教授 MV11 原理的模拟来促进心肺相互作用的研究16,17。
虽然计算模型在表示肺滞后16 方面可能存在困难，但具有测试肺和波纹管13、14、15的模型可以产生类似于生理曲线的压力-容积曲线并显示肺动力学。作为一个优点， 离体 猪肺呈现出与人类相似的解剖结构18，还产生MV曲线，肺滞后，并在肺力学分析期间提供亚克力盒内肺的视觉反馈。可视化模型很重要，可以帮助理解难以想象的组件和概念。因此， 离体 肺模型代表了一种实用的教学方式。
对离体猪肺的研究，例如在正负压下对MV的研究19,20,21，气溶胶分布分析22,23，儿科模拟24和肺灌注25可以提高对MV的了解。最近分析正压和负压模型的研究表明，与负压相比，正压通气可导致突然募集，局部变形更大、膨胀更大、滞后曲线差异和可能的组织损伤 19,20,21。然而，正压模型是必要的，因为患者在 MV压力 19、20、21 期间处于正压之下。用于临床前研究的肺模型的开发为新的研究和应用提供了可能性，包括 MV 教学和培训。
在这里，我们提出了一个用于研究和训练目的 的离体 猪肺模型。我们的主要目的是描述在正压MV下生成这种 离体 猪肺模型的步骤。将来可以用它来研究和教授肺力学。
Protocol
该协议已获得我们机构动物研究伦理委员会的批准（协议编号 1610/2021）。 1.麻醉和动物准备 最初，将动物放在秤上并检查体重以调整手术所需的药物和镇静剂。 肌肉注射氯胺酮 5 mg/kg 和咪达唑仑 0.25 mg/kg。 用 20 G 静脉导管刺穿边缘耳静脉，静脉注射异丙酚 （5 mg/kg） 进行麻醉诱导。 静脉注射 3 mL 肝素进入边缘耳静脉，以协助心肺?…
Representative Results
我们使用了五头体重在23.4-26.9公斤之间的母猪，并按照所述方案进行心肺提取和肺力学分析。我们的目的是，该模型通过分析直接从机械呼吸机屏幕收集的峰值压力、平台压、阻力、驱动压力和动态顺应性变量，可用于肺力学研究。模型流程图如 图1所示。 连续五天对肺部进行分析，重复方案第 7.2、8.1、8.2、9.1、9.2 和 9.3 项中描述的整个过程。我们试?…
Discussion
所描述的方案可用于在正压MV下生产 离体 猪肺模型。它可用于研究和教授肺力学，在募集过程中通过肺部的视觉反馈以及分析投影在设备屏幕上的曲线和值。为了达到这一结果，需要进行试点研究，以了解肺在肋骨外的行为，并确定适应的必要性。
我们发现关键点是在连接机械呼吸机时在胸膜中形成气泡、瘘管和病变，以及吸入和呼气电视之间的差异以及体积曲线的?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
我们感谢所有为构建该 离体 猪肺模型方案做出贡献和支持的同事和专业人士。
这项研究没有资金来源。
Materials
| 0.9% Saline solution | 2500ml | ||
| Anesthesia machine – Primus | Drager | REF 8603800-18 | Anesthesia work station used in the procedure |
| Aspirator | For blood aspiration from thorax | ||
| Bedside Monitor – Life Scope | Nihon Kohden | BSM-7363 | Multiparameter monitor used during the procedure |
| Bonney Tissue Forceps | Any tissue forceps is suitable | ||
| Disposable scalper, #23 | Any scalper is suitable | ||
| Disposable syringe needles, 18G x 1 1/2", 23G x 1" | BD | 302814 | Widely available |
| Disposable syringes, 10ml | Widely available | ||
| Electrosurgical unit – SS-501 | WEM | For cutting and coagulation during thorax incision | |
| Fentanyl | 10 mcg/kg bolus + 10 mcg/kg/hour continuous infusion | ||
| Finochietto retractor | Any finochietto retractor is suitable | ||
| heparin | 3ml | ||
| Infusion set | Any infusion set is suitable | ||
| Isoflurane | 1.5% | ||
| Kelly Forceps Curved | Any kelly forceps is suitable | ||
| Ketamine | 5mg/kg | ||
| Lactated Ringer solution | 500ml | ||
| Mechanical ventilator – Servo I | Maquet | REF 6449701 | Mechanical ventilator used in the procedure |
| Metzenbaum Scissor (Straight and curved) | Any metzenbaum scissor is suitable | ||
| Midazolam | 0.25mg/kg | ||
| Orotracheal intubation cannula, #6.5 | Rusch | 112282 | Widely available |
| Plexiglass | Custom made plexiglass box: 30x45x60cm | ||
| Polyester suture, 2-0 | Widely available | ||
| Potassium choride | 10 ml, 19.1% potassium chloride. | ||
| propofol | 5mg/kg | ||
| Three way stopcock | Widely available | ||
| Venous catheter, G20 x 1" | BD | 38183314 | Widely available |
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Cite This Article
Parzianello Egúsquiza, M. G., Otsuki, D. A., Costa Auler Junior, J. O. Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics. J. Vis. Exp. (206), e64850, doi:10.3791/64850 (2024).