Gólczewski Tomasz, Stecka Anna M, Grabczak Elżbieta M, Michnikowski Marcin, Zielińska-Krawczyk Monika, Krenke Rafał
Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
Department of Internal Medicine, Pulmonary Diseases and Allergy, Medical University of Warsaw, Warsaw, Poland.
Front Physiol. 2025 Apr 11;16:1539781. doi: 10.3389/fphys.2025.1539781. eCollection 2025.
Computer simulations, enabling observations of variables inaccessible in living patients, provide a powerful approach to studying complex physiological phenomena. This study presents the use of a virtual patient to investigate the impact of large pleural effusion (PE) and therapeutic thoracentesis (TT) on hemidiaphragm function and arterial blood gases.
Inspired by unexpected phenomena observed in living patients undergoing large-volume TT, we formulated four questions regarding this impact. To answer these questions, we simulated right-sided PE in our virtual patient and studied changes in the pleural pressure in the ipsilateral hemithorax (Ppli) and lung volume during the respiratory cycle (exemplified by Ppli-V loops, where V is the volume of both lungs), airflows in the main bronchi, and alveolar O2 (PAO2) and CO2 (PACO2) partial pressures.
Simulations highlighted that: (a) mediastinal compliance critically affects hemidiaphragm work; (b) the 8-shaped Ppli-V loops are associated with hemidiaphragm inversion, where exhalation from the ipsilateral lung occurs during a part of both the inspiratory and expiratory phases, and vice versa; (c) pre-TT PAO2 may be elevated due to reduction of the tidal volume to end-expiratory lung volume ratio; and (d) pre-TT Ppli amplitudes during respiration can exceed post-TT values when mediastinal compliance is high.
Our findings emphasize the significance of mediastinal compliance in pleural effusion physiology and suggest insignificant influence of the ipsilateral hemidiaphragm inverted due to large PE on arterial gas tensions. This study underscores the utility of virtual patient models for elucidating unexpected physiological behaviors and optimizing clinical interventions.
计算机模拟能够观察活体患者中无法获取的变量，为研究复杂的生理现象提供了一种强大的方法。本研究展示了使用虚拟患者来探究大量胸腔积液（PE）和治疗性胸腔穿刺术（TT）对半膈肌功能和动脉血气的影响。
受在接受大容量TT的活体患者中观察到的意外现象启发，我们针对这种影响提出了四个问题。为了回答这些问题，我们在虚拟患者中模拟了右侧PE，并研究了呼吸周期中同侧胸腔（Ppli）的胸膜压力和肺容积的变化（以Ppli-V环为例，其中V是双肺的容积）、主支气管中的气流以及肺泡氧（PAO2）和二氧化碳（PACO2）分压。
模拟结果突出显示：（a）纵隔顺应性严重影响半膈肌做功；（b）8字形Ppli-V环与半膈肌反转有关，即同侧肺在吸气相和呼气相的一部分都会呼气，反之亦然；（c）TT前PAO2可能因潮气量与呼气末肺容积之比降低而升高；（d）当纵隔顺应性较高时，呼吸过程中TT前Ppli振幅可能超过TT后值。
我们的研究结果强调了纵隔顺应性在胸腔积液生理学中的重要性，并表明大量PE导致的同侧半膈肌反转对动脉血气张力影响不大。本研究强调了虚拟患者模型在阐明意外生理行为和优化临床干预方面的实用性。
