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Taylor Z, English C, Cramberg M, Young BA. The influence of spinal venous blood pressure on cerebrospinal fluid pressure. Sci Rep 2023; 13:20989. [PMID: 38017027 PMCID: PMC10684553 DOI: 10.1038/s41598-023-48334-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/25/2023] [Indexed: 11/30/2023] Open
Abstract
In Alligator mississippiensis the spinal dura is surrounded by a venous sinus; pressure waves can propagate in the spinal venous blood, and these spinal venous pressures can be transmitted to the spinal cerebrospinal fluid (CSF). This study was designed to explore pressure transfer between the spinal venous blood and the spinal CSF. At rest the cardiac-related CSF pulsations are attenuated and delayed, while the ventilatory-related pulsations are amplified as they move from the spinal venous blood to the spinal CSF. Orthostatic gradients resulted in significant alterations of both cardiac- and ventilatory-related CSF pulsations. Manual lateral oscillations of the alligator's tail created pressure waves in the spinal CSF that propagated, with slight attenuation but no delay, to the cranial CSF. Oscillatory pressure pulsations in the spinal CSF and venous blood had little influence on the underlying ventilatory pulsations, though the same oscillatory pulsations reduced the ventilatory- and increased the cardiac-related pulsations in the cranial CSF. In Alligator the spinal venous anatomy creates a more complex pressure relationship between the venous and CSF systems than has been described in humans.
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Affiliation(s)
- Z Taylor
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO, 63501, USA
| | - C English
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO, 63501, USA
| | - M Cramberg
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO, 63501, USA
| | - B A Young
- Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO, 63501, USA.
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2
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Schranc Á, Diaper J, Südy R, Peták F, Habre W, Albu G. Lung recruitment by continuous negative extra-thoracic pressure support following one-lung ventilation: an experimental study. Front Physiol 2023; 14:1160731. [PMID: 37256073 PMCID: PMC10225513 DOI: 10.3389/fphys.2023.1160731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/03/2023] [Indexed: 06/01/2023] Open
Abstract
Lung recruitment maneuvers following one-lung ventilation (OLV) increase the risk for the development of acute lung injury. The application of continuous negative extrathoracic pressure (CNEP) is gaining interest both in intubated and non-intubated patients. However, there is still a lack of knowledge on the ability of CNEP support to recruit whole lung atelectasis following OLV. We investigated the effects of CNEP following OLV on lung expansion, gas exchange, and hemodynamics. Ten pigs were anesthetized and mechanically ventilated with pressure-regulated volume control mode (PRVC; FiO2: 0.5, Fr: 30-35/min, VT: 7 mL/kg, PEEP: 5 cmH2O) for 1 hour, then baseline (BL) data for gas exchange (arterial partial pressure of oxygen, PaO2; and carbon dioxide, PaCO2), ventilation and hemodynamical parameters and lung aeration by electrical impedance tomography were recorded. Subsequently, an endobronchial blocker was inserted, and OLV was applied with a reduced VT of 5 mL/kg. Following a new set of measurements after 1 h of OLV, two-lung ventilation was re-established, combining PRVC (VT: 7 mL/kg) and CNEP (-15 cmH2O) without any hyperinflation maneuver and data collection was then repeated at 5 min and 1 h. Compared to OLV, significant increases in PaO2 (154.1 ± 13.3 vs. 173.8 ± 22.1) and decreases in PaCO2 (52.6 ± 11.7 vs. 40.3 ± 4.5 mmHg, p < 0.05 for both) were observed 5 minutes following initiation of CNEP, and these benefits in gas exchange remained after an hour of CNEP. Gradual improvements in lung aeration in the non-collapsed lung were also detected by electrical impedance tomography (p < 0.05) after 5 and 60 min of CNEP. Hemodynamics and ventilation parameters remained stable under CNEP. Application of CNEP in the presence of whole lung atelectasis proved to be efficient in improving gas exchange via recruiting the lung without excessive airway pressures. These benefits of combined CNEP and positive pressure ventilation may have particular value in relieving atelectasis in the postoperative period of surgical procedures requiring OLV.
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Affiliation(s)
- Álmos Schranc
- Unit for Anesthesiological Investigations, Department of Anesthesiology Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - John Diaper
- Unit for Anesthesiological Investigations, Department of Anesthesiology Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Roberta Südy
- Unit for Anesthesiological Investigations, Department of Anesthesiology Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Ferenc Peták
- Department of Medical Physics and Informatics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anesthesiological Investigations, Department of Anesthesiology Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Gergely Albu
- Unit for Anesthesiological Investigations, Department of Anesthesiology Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
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3
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Nelson TM, Quiros KAM, Mariano CA, Sattari S, Ulu A, Dominguez EC, Nordgren TM, Eskandari M. Associating local strains to global pressure-volume mouse lung mechanics using digital image correlation. Physiol Rep 2022; 10:e15466. [PMID: 36207795 PMCID: PMC9547081 DOI: 10.14814/phy2.15466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/22/2022] [Accepted: 08/28/2022] [Indexed: 12/24/2022] Open
Abstract
Pulmonary diseases alter lung mechanical properties, can cause loss of function, and necessitate use of mechanical ventilation, which can be detrimental. Investigations of lung tissue (local) scale mechanical properties are sparse compared to that of the whole organ (global) level, despite connections between regional strain injury and ventilation. We examine ex vivo mouse lung mechanics by investigating strain values, local compliance, tissue surface heterogeneity, and strain evolutionary behavior for various inflation rates and volumes. A custom electromechanical, pressure-volume ventilator is coupled with digital image correlation to measure regional lung strains and associate local to global mechanics by analyzing novel pressure-strain evolutionary measures. Mean strains at 5 breaths per minute (BPM) for applied volumes of 0.3, 0.5, and 0.7 ml are 5.0, 7.8, and 11.3%, respectively, and 4.7, 8.8, and 12.2% for 20 BPM. Similarly, maximum strains among all rate and volume combinations range 10.7%-22.4%. Strain values (mean, range, mode, and maximum) at peak inflation often exhibit significant volume dependencies. Additionally, select evolutionary behavior (e.g., local lung compliance quantification) and tissue heterogeneity show significant volume dependence. Rate dependencies are generally found to be insignificant; however, strain values and surface lobe heterogeneity tend to increase with increasing rates. By quantifying strain evolutionary behavior in relation to pressure-volume measures, we associate time-continuous local to global mouse lung mechanics for the first time and further examine the role of volume and rate dependency. The interplay of multiscale deformations evaluated in this work can offer insights for clinical applications, such as ventilator-induced lung injury.
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Affiliation(s)
- Talyah M. Nelson
- Department of Mechanical EngineeringUniversity of CaliforniaRiversideCaliforniaUSA
| | | | - Crystal A. Mariano
- Department of Mechanical EngineeringUniversity of CaliforniaRiversideCaliforniaUSA
| | - Samaneh Sattari
- Department of Mechanical EngineeringUniversity of CaliforniaRiversideCaliforniaUSA
| | - Arzu Ulu
- BREATHE CenterSchool of Medicine University of CaliforniaRiversideCaliforniaUSA,Division of Biomedical SciencesSchool of Medicine, University of CaliforniaRiversideCaliforniaUSA
| | - Edward C. Dominguez
- BREATHE CenterSchool of Medicine University of CaliforniaRiversideCaliforniaUSA,Division of Biomedical SciencesSchool of Medicine, University of CaliforniaRiversideCaliforniaUSA
| | - Tara M. Nordgren
- BREATHE CenterSchool of Medicine University of CaliforniaRiversideCaliforniaUSA,Division of Biomedical SciencesSchool of Medicine, University of CaliforniaRiversideCaliforniaUSA
| | - Mona Eskandari
- Department of Mechanical EngineeringUniversity of CaliforniaRiversideCaliforniaUSA,BREATHE CenterSchool of Medicine University of CaliforniaRiversideCaliforniaUSA,Department of BioengineeringUniversity of CaliforniaRiversideCaliforniaUSA
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4
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Kreit J. Respiratory-Cardiovascular Interactions During Mechanical Ventilation: Physiology and Clinical Implications. Compr Physiol 2022; 12:3425-3448. [PMID: 35578946 DOI: 10.1002/cphy.c210003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Positive-pressure inspiration and positive end-expiratory pressure (PEEP) increase pleural, alveolar, lung transmural, and intra-abdominal pressure, which decrease right and left ventricular (RV; LV) preload and LV afterload and increase RV afterload. The magnitude and clinical significance of the resulting changes in ventricular function are determined by the delivered tidal volume, the total level of PEEP, the compliance of the lungs and chest wall, intravascular volume, baseline RV and LV function, and intra-abdominal pressure. In mechanically ventilated patients, the most important, adverse consequences of respiratory-cardiovascular interactions are a PEEP-induced reduction in cardiac output, systemic oxygen delivery, and blood pressure; RV dysfunction in patients with ARDS; and acute hemodynamic collapse in patients with pulmonary hypertension. On the other hand, the hemodynamic changes produced by respiratory-cardiovascular interactions can be beneficial when used to assess volume responsiveness in hypotensive patients and by reducing dyspnea and improving hypoxemia in patients with cardiogenic pulmonary edema. Thus, a thorough understanding of the physiological principles underlying respiratory-cardiovascular interactions is essential if critical care practitioners are to anticipate, recognize, manage, and utilize their hemodynamic effects. © 2022 American Physiological Society. Compr Physiol 12:1-24, 2022.
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Affiliation(s)
- John Kreit
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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5
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Dong S, Wang L, Chitano P, Coxson HO, Vasilescu DM, Paré PD, Seow CY. Lung resistance and elastance are different in ex vivo sheep lungs ventilated by positive and negative pressures. Am J Physiol Lung Cell Mol Physiol 2022; 322:L673-L682. [PMID: 35272489 DOI: 10.1152/ajplung.00464.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung resistance (RL) and elastance (EL) can be measured during positive or negative pressure ventilation. Whether the different modes of ventilation produce different RL and EL is still being debated. Although negative pressure ventilation (NPV) is more physiological, positive pressure ventilation (PPV) is more commonly used for treating respiratory failure. In the present study we measured lung volume, airway diameter and airway volume, as well as RL and EL with PPV and NPV in explanted sheep lungs. We found that lung volume under a static pressure, either positive or negative, was not different. However, RL and EL were significantly higher in NPV at high inflation pressures. Interestingly, diameters of smaller airways (diameters < 3.5 mm) and total airway volume were significantly greater at high negative inflation pressures compared with those at high positive inflation pressures. This suggests that NPV is more effective in distending the peripheral airways, likely due to the fact that negative pressure is applied through the pleural membrane and reaches the central airways via the peripheral airways, whereas positive pressure is applied in the opposite direction. More distension of lung periphery could explain why RL is higher in NPV (vs. PPV), because the peripheral parenchyma is a major source of tissue resistance, which is a part of the RL that increases with pressure. This explanation is consistent with the finding that during high frequency ventilation (>1 Hz, where RL reflects airway resistance more than tissue resistance), the difference in RL between NPV and PPV disappeared.
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Affiliation(s)
- Shoujin Dong
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Respiratory Department, Chengdu First People's Hospital, Chengdu, China
| | - Lu Wang
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | - Pasquale Chitano
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | - Harvey O Coxson
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada
| | | | - Peter D Paré
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Chun Y Seow
- The UBC Centre for Heart Lung Innovation, St. Paul's Hospital, Vancouver, BC, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
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Mariano CA, Sattari S, Maghsoudi-Ganjeh M, Tartibi M, Lo DD, Eskandari M. Novel Mechanical Strain Characterization of Ventilated ex vivo Porcine and Murine Lung using Digital Image Correlation. Front Physiol 2020; 11:600492. [PMID: 33343395 PMCID: PMC7746832 DOI: 10.3389/fphys.2020.600492] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022] Open
Abstract
Respiratory illnesses, such as bronchitis, emphysema, asthma, and COVID-19, substantially remodel lung tissue, deteriorate function, and culminate in a compromised breathing ability. Yet, the structural mechanics of the lung is significantly understudied. Classical pressure-volume air or saline inflation studies of the lung have attempted to characterize the organ’s elasticity and compliance, measuring deviatory responses in diseased states; however, these investigations are exclusively limited to the bulk composite or global response of the entire lung and disregard local expansion and stretch phenomena within the lung lobes, overlooking potentially valuable physiological insights, as particularly related to mechanical ventilation. Here, we present a method to collect the first non-contact, full-field deformation measures of ex vivo porcine and murine lungs and interface with a pressure-volume ventilation system to investigate lung behavior in real time. We share preliminary observations of heterogeneous and anisotropic strain distributions of the parenchymal surface, associative pressure-volume-strain loading dependencies during continuous loading, and consider the influence of inflation rate and maximum volume. This study serves as a crucial basis for future works to comprehensively characterize the regional response of the lung across various species, link local strains to global lung mechanics, examine the effect of breathing frequencies and volumes, investigate deformation gradients and evolutionary behaviors during breathing, and contrast healthy and pathological states. Measurements collected in this framework ultimately aim to inform predictive computational models and enable the effective development of ventilators and early diagnostic strategies.
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Affiliation(s)
- Crystal A Mariano
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Samaneh Sattari
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Mohammad Maghsoudi-Ganjeh
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | | | - David D Lo
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States.,BREATHE Center, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Mona Eskandari
- Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States.,BREATHE Center, School of Medicine, University of California, Riverside, Riverside, CA, United States.,Department of Bioengineering, Riverside, CA, United States
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7
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Arai TJ, Theilmann RJ, Sá RC, Villongco MT, Hopkins SR. The effect of lung deformation on the spatial distribution of pulmonary blood flow. J Physiol 2016; 594:6333-6347. [PMID: 27273807 PMCID: PMC5088230 DOI: 10.1113/jp272030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/31/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Pulmonary perfusion measurement using magnetic resonance imaging combined with deformable image registration enabled us to quantify the change in the spatial distribution of pulmonary perfusion at different lung volumes. The current study elucidated the effects of tidal volume lung inflation [functional residual capacity (FRC) + 500 ml and FRC + 1 litre] on the change in pulmonary perfusion distribution. Changes in hydrostatic pressure distribution as well as transmural pressure distribution due to the change in lung height with tidal volume inflation are probably bigger contributors to the redistribution of pulmonary perfusion than the changes in pulmonary vasculature resistance caused by lung tissue stretch. ABSTRACT Tidal volume lung inflation results in structural changes in the pulmonary circulation, potentially affecting pulmonary perfusion. We hypothesized that perfusion is recruited to regions receiving the greatest deformation from a tidal breath, thus ensuring ventilation-perfusion matching. Density-normalized perfusion (DNP) magnetic resonance imaging data were obtained in healthy subjects (n = 7) in the right lung at functional residual capacity (FRC), FRC+500 ml, and FRC+1.0 l. Using deformable image registration, the displacement of a sagittal lung slice acquired at FRC to the larger volumes was calculated. Registered DNP images were normalized by the mean to estimate perfusion redistribution (nDNP). Data were evaluated across gravitational regions (dependent, middle, non-dependent) and by lobes (upper, RUL; middle, RML; lower, RLL). Lung inflation did not alter mean DNP within the slice (P = 0.10). The greatest expansion was seen in the dependent region (P < 0.0001: dependent vs non-dependent, P < 0.0001: dependent vs middle) and RLL (P = 0.0015: RLL vs RUL, P < 0.0001: RLL vs RML). Neither nDNP recruitment to RLL [+500 ml = -0.047(0.145), +1 litre = 0.018(0.096)] nor to dependent lung [+500 ml = -0.058(0.126), +1 litre = -0.023(0.106)] were found. Instead, redistribution was seen in decreased nDNP in the non-dependent [+500 ml = -0.075(0.152), +1 litre = -0.137(0.167)) and increased nDNP in the gravitational middle lung [+500 ml = 0.098(0.058), +1 litre = 0.093(0.081)] (P = 0.01). However, there was no significant lobar redistribution (P < 0.89). Contrary to our hypothesis, based on the comparison between gravitational and lobar perfusion data, perfusion was not redistributed to the regions of the most inflation. This suggests that either changes in hydrostatic pressure or transmural pressure distribution in the gravitational direction are implicated in the redistribution of perfusion away from the non-dependent lung.
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Affiliation(s)
- Tatsuya J Arai
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rebecca J Theilmann
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA
- The Pulmonary Imaging Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Rui Carlos Sá
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- The Pulmonary Imaging Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Michael T Villongco
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- The Pulmonary Imaging Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Susan R Hopkins
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
- Department of Radiology, University of California, San Diego, La Jolla, CA, USA.
- The Pulmonary Imaging Laboratory, University of California, San Diego, La Jolla, CA, USA.
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Doras C, Le Guen M, Peták F, Habre W. Cardiorespiratory effects of recruitment maneuvers and positive end expiratory pressure in an experimental context of acute lung injury and pulmonary hypertension. BMC Pulm Med 2015; 15:82. [PMID: 26228052 PMCID: PMC4521467 DOI: 10.1186/s12890-015-0079-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 07/20/2015] [Indexed: 01/17/2023] Open
Abstract
Background Recruitment maneuvers (RM) and positive end expiratory pressure (PEEP) are the cornerstone of the open lung strategy during ventilation, particularly during acute lung injury (ALI). However, these interventions may impact the pulmonary circulation and induce hemodynamic and respiratory effects, which in turn may be critical in case of pulmonary hypertension (PHT). We aimed to establish how ALI and PHT influence the cardiorespiratory effects of RM and PEEP. Methods Rabbits control or with monocrotaline-induced PHT were used. Forced oscillatory airway and tissue mechanics, effective lung volume (ELV), systemic and right ventricular hemodynamics and blood gas were assessed before and after RM, during baseline and following surfactant depletion by whole lung lavage. Results RM was more efficient in improving respiratory elastance and ELV in the surfactant-depleted lungs when PHT was concomitantly present. Moreover, the adverse changes in respiratory mechanics and ELV following ALI were lessened in the animals suffering from PHT. Conclusions During ventilation with open lung strategy, the role of PHT in conferring protection from the adverse respiratory consequences of ALI was evidenced. This finding advocates the safety of RM and PEEP in improving elastance and advancing lung reopening in the simultaneous presence of PHT and ALI.
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Affiliation(s)
- Camille Doras
- Anesthesiological Investigation, University Medical Centre, University of Geneva, Geneva, Switzerland.
| | - Morgan Le Guen
- Department of Anesthesiology, Hospital Foch, University Versailles Saint-Quentin en Yvelines, Suresnes, France.
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
| | - Walid Habre
- Anesthesiological Investigation, University Medical Centre, University of Geneva, Geneva, Switzerland. .,Pediatric Anesthesia Unit, Geneva Children's Hospital, Rue Willy Donzé 6, 1205, Geneva, Switzerland.
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9
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Clipp R, Steele B. An evaluation of dynamic outlet boundary conditions in a 1D fluid dynamics model. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2012; 9:61-74. [PMID: 22229396 DOI: 10.3934/mbe.2012.9.61] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
When modeling the cardiovascular system, the use of boundary conditions that closely represent the interaction between the region of interest and the surrounding vessels and organs will result in more accurate predictions. An often overlooked feature of outlet boundary conditions is the dynamics associated with regulation of the distribution of pressure and flow. This study implements a dynamic impedance outlet boundary condition in a one-dimensional fluid dynamics model using the pulmonary vasculature and respiration (feedback mechanism) as an example of a dynamic system. The dynamic boundary condition was successfully implemented and the pressure and flow were predicted for an entire respiration cycle. The cardiac cycles at maximal expiration and inspiration were predicted with a root mean square error of 0.61 and 0.59 mm Hg, respectively.
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Affiliation(s)
- Rachel Clipp
- Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695-7115, USA.
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10
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Petersen TH, Calle EA, Colehour MB, Niklason LE. Bioreactor for the long-term culture of lung tissue. Cell Transplant 2010; 20:1117-26. [PMID: 21092411 DOI: 10.3727/096368910x544933] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In this article we describe the design and validation of a bioreactor for the in vitro culture of whole rodent lung tissue. Many current systems only enable large segments of lung tissue to be studied ex vivo for up to a few hours in the laboratory. This limitation restricts the study of pulmonary biology in controlled laboratory settings, and also impacts the ability to reliably culture engineered lung tissues in the laboratory. Therefore, we designed, built, and validated a bioreactor intended to provide sufficient nutrient supply and mechanical stimulation to support cell survival and differentiation in cultured lung tissue. We also studied the effects of perfusion and ventilation on pulmonary cell survival and maintenance of cell differentiation state. The final bioreactor design described herein is capable of supporting the culture of whole native lung tissue for up to 1 week in the laboratory, and offers promise in the study of pulmonary biology and the development of engineered lung tissues in the laboratory.
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Affiliation(s)
- Thomas H Petersen
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
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