Modelling Inert Gas Exchange in Tissue and Mixed–Venous Blood Return to the Lungs

Whiteley, Jonathan; Gavaghan, David; Hahn, C.E.W.

doi:10.1006/jtbi.2001.2278

Cited by 7 publications

(11 citation statements)

References 20 publications

(47 reference statements)

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“…To study flux transformation phenomena, we consider the convection-diffusion equation in blood and tissue separately with interface conditions and some initial and boundary conditions as proposed by Whiteley et al, 17 and others. 29,35,36 In the blood phase, we consider both convection and diffusion, while in the tissue phase, we consider only diffusion.…”

Section: Governing Equationsmentioning

confidence: 99%

“…15 Here, the term partial pressure is defined as the pressure exerted by a particular gas alone. 16,17 Generally, in the process of respiration, we inhale a mixture of gases, which are exchanged between the air-blood barrier through the process of simple diffusion with the help of the partial pressure of gases. 18 In the context of blood gas analysis, the partial pressure of gases in oxygenated blood (upon entering the body) is referred to as "arterial blood partial pressure," while in deoxygenated blood (as it exits the body), it is termed "venous blood partial pressure."…”

Section: Introductionmentioning

confidence: 99%

“…18 In the context of blood gas analysis, the partial pressure of gases in oxygenated blood (upon entering the body) is referred to as "arterial blood partial pressure," while in deoxygenated blood (as it exits the body), it is termed "venous blood partial pressure." 17 Due to excess inhalation of inert gas and imbalance in anesthesia, the partial pressure affects the arterial blood as well as the venous blood, which causes impaired gas exchange not only in young people but also in elderly. 14,[19][20][21][22][23] In literature, there are various theoretical studies 5,6,8,9,24,25 on the attempt of suicide by inhalation of an excessive amount of inert gas.…”

Section: Introductionmentioning

confidence: 99%

“…Melo et al 30 applied the downhill simplex method and observed that accounting for diffusing capacity and ventilation-perfusion heterogeneity increased oxygen arterial pressure while decreasing total blood flow. Additionally, in the process of inert gas exchange between tissue and blood capillaries, Whiteley et al 17 used FEM to calculate the mixed-venous blood partial pressure, which is return to the lungs. Furthermore, Baker and Framery 31 used an analytical method to solve the transportation of inert gas between tissue and blood capillaries using a multi compartment model, while to calculate some values in the single compartment model author used some iterative method.…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the effect of inert gas on alveolar/venous blood partial pressure by using the operator splitting method

Jyoti,

Kwak,

Ham

et al. 2024

Numer Methods Biomed Eng

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This study aims to investigate how inert gas affects the partial pressure of alveolar and venous blood using a fast and accurate operator splitting method (OSM). Unlike previous complex methods, such as the finite element method (FEM), OSM effectively separates governing equations into smaller sub‐problems, facilitating a better understanding of inert gas transport and exchange between blood capillaries and surrounding tissue. The governing equations were discretized with a fully implicit finite difference method (FDM), which enables the use of larger time steps. The model employed partial differential equations, considering convection‐diffusion in blood and only diffusion in tissue. The study explores the impact of initial arterial pressure, breathing frequency, blood flow velocity, solubility, and diffusivity on the partial pressure of inert gas in blood and tissue. Additionally, the effects of anesthetic inert gas and oxygen on venous blood partial pressure were analyzed. Simulation results demonstrate that the high solubility and diffusivity of anesthetic inert gas lead to its prolonged presence in blood and tissue, resulting in lower partial pressure in venous blood. These findings enhance our understanding of inert gas interaction with alveolar/venous blood, with potential implications for medical diagnostics and therapies.

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Section: Governing Equationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Analysis of the effect of inert gas on alveolar/venous blood partial pressure by using the operator splitting method

Jyoti,

Kwak,

Ham

et al. 2024

Numer Methods Biomed Eng

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“…A heterogeneous lung was simulated by compartments, including three serial deadspace compartments (Harrison et al 2017), two alveolar compartments (tidal compartments) (Hahn and Farmery 2003, Whiteley et al 2003, Whiteley et al 2001 and five compartments to present the whole body (lung, viscera fast, viscera liver, lean and fat) (Baker and Farmery 2011). All compartments were linked together by conservation of mass equations.…”

Section: Lung Heterogeneity Simulation Modelmentioning

confidence: 99%

Lung heterogeneity and deadspace volume in animals with acute respiratory distress syndrome using the inspired sinewave test

et al. 2020

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Acute respiratory distress syndrome (ARDS) is associated with a high rate of morbidity and mortality, as patients undergoing mechanical ventilation are at risk of ventilator-induced lung injuries. Objective: To measure the lung heterogeneity and deadspace volume to find safer ventilator strategies. The ventilator settings could then offer homogeneous ventilation and theoretically equalize and reduce tidal strain/stress in the lung parenchyma. Approach: The inspired sinewave test (IST) is a non-invasive lung measurement tool which does not require cooperation from the patient. The IST can measure the effective lung volume, pulmonary blood flow and deadspace volume. We developed a computational simulation of the cardiopulmonary system to allow lung heterogeneity to be quantified using data solely derived from the IST. Then, the method to quantify lung heterogeneity using two IST tracer gas frequencies (180 and 60 s) was introduced and used in lung simulations and animal models. Thirteen anaesthetized pigs were studied with the IST both before and after experimental lung injury (saline-lavage ARDS model). The deadspace volume was compared between the IST and the SF6 washout method. Main results: The IST could measure lung heterogeneity using two tracer gas frequencies. Furthermore, the value of IST ventilation heterogeneity in ARDS lungs was higher than in control lungs at a positive end-expiratory pressure of 10 cmH2O (area under the curve = 0.85, p < 0.001 ). Values for the deadspace volume measured by the IST have a strong relationship with the measured values of SF6 (9 ml bias and limits of agreement from −79 to 57 ml in control animals). Significance: The IST technique has the potential for use in the identification of ventilation and perfusion heterogeneity during ventilator support.

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Inert Gas Transport in Blood and Tissues

Baker

Farmery

2011

Comprehensive Physiology

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This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues-first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper- and hypobaric conditions on inert gas transport.

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Modelling Inert Gas Exchange in Tissue and Mixed–Venous Blood Return to the Lungs

Cited by 7 publications

References 20 publications

Analysis of the effect of inert gas on alveolar/venous blood partial pressure by using the operator splitting method

Analysis of the effect of inert gas on alveolar/venous blood partial pressure by using the operator splitting method

Lung heterogeneity and deadspace volume in animals with acute respiratory distress syndrome using the inspired sinewave test

Inert Gas Transport in Blood and Tissues

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