Name: ex vivo porcine experimental model for studying and teaching lung mechanics
Uploaded: 2024-04-19T12:30:00
Description: Watch this Scientific Journal Video about Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics at JoVE.com

We thank all colleagues and professionals who contributed to and supported the construction of this ex vivo porcine lung model protocol.
This study had no funding sources.

The protocol was approved by the Animal Research Ethics Committee of our Institution (protocol no. 1610/2021).
1. Anesthesia and animal preparation
<ol>
	<li>Initially, place the animal on a scale and check the weight to adjust the medications and sedation necessary for the procedure.</li>
	<li>Administer ketamine 5 mg/kg and midazolam 0.25 mg/kg intramuscularly.</li>
	<li>Puncture the marginal ear vein with a 20 G venous catheter and administer intravenous propofol (5 mg/kg...

<ol>
	<li>Roberto, C., Carvalho, R., Toufen Jr, C., Franca, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+Ventilation:+Principles,+graphic+analysis+and+ventilation+modalities.">Mechanical Ventilation: Principles, graphic analysis and ventilation modalities.</a> Jornal Brasileiro de Pneumologia. 33 (2), 54-55 (2007).</li><li>Barbas, C. S. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brazilian+recommendations+for+mechanical+ventilation+2013.+Part+I.">Brazilian recommendations for mechanical ventilation 2013. Part I.</a> Revista Brasileira de Terapia Intensiva. 26 (2), 89-121 (2014).</li><li>Walter, J. M., Corbridge, T. C., Singer, B. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invasive+mechanical+ventilation.">Invasive mechanical ventilation.</a> Southern Medical Journal. 111 (12), 746-753 (2018).</li><li>Faustino, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Concepts+and+monitoring+of+pulmonary+mechanics+in+patients+under+ventilatory+support+in+the+intensive+care+unit.">Concepts and monitoring of pulmonary mechanics in patients under ventilatory support in the intensive care unit.</a> Revista Brasileira de Terapia Intensiva. 19 (2), 161-169 (2007).</li><li>Holanda, M. A., Vasconcelos, R. S., Ferreira, J. C., Pinheiro, B. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patient-ventilator+asynchrony.">Patient-ventilator asynchrony.</a> Jornal Brasileiro de Pneumologia. 44 (2), 321-333 (2018).</li><li>Rezoagli, E., Laffey, J. G., Bellani, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+lung+injury+severity+and+ventilation+intensity+during+mechanical+ventilation.">Monitoring lung injury severity and ventilation intensity during mechanical ventilation.</a> Seminars in Respiratory and Critical Care Medicine. 43 (3), 346-368 (2022).</li><li>Tallo, F. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+self-perception+of+mechanical+ventilation+knowledge+among+Brazilian+final-year+medical+students,+residents,+and+emergency+physicians.">Evaluation of self-perception of mechanical ventilation knowledge among Brazilian final-year medical students, residents, and emergency physicians.</a> Clinics. 72 (2), 65-70 (2017).</li><li>Schroedl, C. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+simulation-based+mastery+learning+on+resident+skill+managing+mechanical+ventilators.">Impact of simulation-based mastery learning on resident skill managing mechanical ventilators.</a> American Thoracic Society Scholar. 2 (1), 34-48 (2021).</li><li>Wilcox, S. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Academic+emergency+medicine+physicians'+knowledge+of+mechanical+ventilation.">Academic emergency medicine physicians' knowledge of mechanical ventilation.</a> The Western Journal of Emergency Medicine. 17 (3), 271-279 (2016).</li><li>Cox, C. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+medical+resident+education+in+mechanical+ventilation.">Effectiveness of medical resident education in mechanical ventilation.</a> American Journal of Respiratory and Critical Care Medicine. 167 (1), 32-38 (2003).</li><li>Keegan, R., Henderson, T., Brown, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+the+virtual+ventilator,+a+screen-based+computer+simulation,+to+teach+the+principles+of+mechanical+ventilation.">Use of the virtual ventilator, a screen-based computer simulation, to teach the principles of mechanical ventilation.</a> Journal of Veterinary Medical Education. 36 (4), 436-443 (2009).</li><li>Spadaro, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simulation+training+for+residents+focused+on+mechanical+ventilation:+A+randomized+trial+using+mannequin-based+versus+computer-based+simulation.">Simulation training for residents focused on mechanical ventilation: A randomized trial using mannequin-based versus computer-based simulation.</a> Simulation in Healthcare. 12 (6), 349-355 (2017).</li><li>Chase, J. G., Yuta, T., Mulligan, K. J., Shaw, G. M., Horn, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+mechanical+lung+model+of+pulmonary+diseases+to+assist+with+teaching+and+training.">A novel mechanical lung model of pulmonary diseases to assist with teaching and training.</a> BMC Pulmonary Medicine. 6 (21), 1-11 (2006).</li><li>Kuebler, W. M., Mertens, M., Pries, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+two-component+simulation+model+to+teach+respiratory+mechanics.">A two-component simulation model to teach respiratory mechanics.</a> Advances in Physiology Education. 31 (2), 218-222 (2007).</li><li>Heili-Frades, S., Peces-Barba, G., Rodr&#237;guez-Nieto, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+of+a+lung+simulator+for+learning+lung+mechanics+in+mechanical+ventilation.">Design of a lung simulator for learning lung mechanics in mechanical ventilation.</a> Archivos de Bronconeumolog&#237;a. 43 (12), 674-679 (2007).</li><li>Ngo, C., Dahlmanns, S., Vollmer, T., Misgeld, B., Leonhardt, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+object-oriented+computational+model+to+study+cardiopulmonary+hemodynamic+interactions+in+humans.">An object-oriented computational model to study cardiopulmonary hemodynamic interactions in humans.</a> Computer Methods and Programs in Biomedicine. 159, 167-183 (2018).</li><li>Lazzari, C. D., Genuini, I., Pisanelli, D. M., D'Ambrosi, A., Fedele, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interactive+simulator+for+e-Learning+environments:+a+teaching+software+for+health+care+professionals.">Interactive simulator for e-Learning environments: a teaching software for health care professionals.</a> Biomedical Engineering Online. 13 (172), 1-18 (2014).</li><li>Perinel, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+ex+vivo+human-porcine+respiratory+model+for+preclinical+studies.">Development of an ex vivo human-porcine respiratory model for preclinical studies.</a> Scientific Reports. 7, 1-6 (2017).</li><li>Aboelnazar, N. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negative+pressure+ventilation+decreases+inflammation+and+lung+edema+during+normothermic+ex-vivo+lung+perfusion.">Negative pressure ventilation decreases inflammation and lung edema during normothermic ex-vivo lung perfusion.</a> The Journal of Heart and Lung Transplantation. 37 (4), 520-530 (2018).</li><li>Sattari, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Introducing+a+custom-designed+volume-pressure+machine+for+novel+measurements+of+whole+lung+organ+viscoelasticity+and+direct+comparisons+between+positive-+and+negative-pressure+ventilation.">Introducing a custom-designed volume-pressure machine for novel measurements of whole lung organ viscoelasticity and direct comparisons between positive- and negative-pressure ventilation.</a> Frontiers in Bioengineering and Biotechnology. 8, 1-12 (2020).</li><li>Sattari, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Positive-+and+negative-pressure+ventilation+characterized+by+local+and+global+pulmonary+mechanics.">Positive- and negative-pressure ventilation characterized by local and global pulmonary mechanics.</a> American Journal of Respiratory and Critical Care Medicine. 207 (5), 577-586 (2023).</li><li>Montigaud, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+ex+vivo+preclinical+respiratory+model+of+idiopathic+pulmonary+fibrosis+for+aerosol+regional+studies.">Development of an ex vivo preclinical respiratory model of idiopathic pulmonary fibrosis for aerosol regional studies.</a> Scientific Reports. 9 (1), 17949 (2019).</li><li>Montigaud, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aerosol+delivery+during+invasive+mechanical+ventilation:+development+of+a+preclinical+ex+vivo+respiratory+model+for+aerosol+regional+deposition.">Aerosol delivery during invasive mechanical ventilation: development of a preclinical ex vivo respiratory model for aerosol regional deposition.</a> Scientific Reports. 9 (1), 17930 (2019).</li><li>Montigaud, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+ex+vivo+respiratory+pediatric+model+of+bronchopulmonary+dysplasia+for+aerosol+deposition+studies.">Development of an ex vivo respiratory pediatric model of bronchopulmonary dysplasia for aerosol deposition studies.</a> Scientific Reports. 9 (1), 5720 (2019).</li><li>Buchko, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+low-cost+perfusate+alternative+for+ex+vivo.+lung+perfusion.">A low-cost perfusate alternative for ex vivo. lung perfusion.</a> transplantation proceedings. 52 (10), 2941-2946 (2020).</li><li>Kondo, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+effective+method+utilizing+fibrin+glue+to+repair+pleural+defects+in+an+ex-vivo+pig+model.">Development of an effective method utilizing fibrin glue to repair pleural defects in an ex-vivo pig model.</a> Journal of Cardiothoracic Surgery. 15 (1), 110 (2020).</li><li>Gasek, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+alginate+and+gelatin-based+pleural+and+tracheal+sealants.">Development of alginate and gelatin-based pleural and tracheal sealants.</a> Acta Biomaterialia. 131, 222-235 (2021).</li><li>Li, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+individualized+positive+end-expiratory+pressure+combined+with+recruitment+maneuver+on+intraoperative+ventilation+during+abdominal+surgery:+a+systematic+review+and+network+meta-analysis+of+randomized+controlled+trials.">Effects of individualized positive end-expiratory pressure combined with recruitment maneuver on intraoperative ventilation during abdominal surgery: a systematic review and network meta-analysis of randomized controlled trials.</a> Journal of Anesthesia. 36 (2), 303-315 (2022).</li><li>Hu, M. C., Yang, Y. L., Chen, T. T., Lee, C. I., Tam, K. W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recruitment+maneuvers+to+reduce+pulmonary+atelectasis+after+cardiac+surgery:+A+meta-analysis+of+randomized+trials.">Recruitment maneuvers to reduce pulmonary atelectasis after cardiac surgery: A meta-analysis of randomized trials.</a> The Journal of Thoracic and Cardiovascular Surgery. 164 (1), 171-181 (2020).</li><li>Hu, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recruitment+maneuvers+in+patients+undergoing+thoracic+surgery:+a+meta-analysis.">Recruitment maneuvers in patients undergoing thoracic surgery: a meta-analysis.</a> General Thoracic and Cardiovascular Surgery. 69 (12), 1553-1559 (2021).</li><li>Zeng, C., Lagier, D., Lee, J. W., Melo, M. F. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perioperative+pulmonary+atelectasis:+Part+I.+Biology+and+mechanisms.">Perioperative pulmonary atelectasis: Part I. Biology and mechanisms.</a> Anesthesiology. 136 (1), 181-205 (2022).</li><li>Niman, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+recruitment+after+cardiac+arrest+during+procurement+of+atelectatic+donor+lungs+is+a+protective+measure+in+lung+transplantation.">Lung recruitment after cardiac arrest during procurement of atelectatic donor lungs is a protective measure in lung transplantation.</a> Journal of Thoracic Disease. 14 (8), 2802-2811 (2022).</li><li>Calvo, R. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+efficacy+of+two+alveolar+recruitment+maneuvers+in+improving+the+lung+mechanics+and+the+degree+of+atelectasis+in+anesthetized+healthy+sheep.">Comparison of the efficacy of two alveolar recruitment maneuvers in improving the lung mechanics and the degree of atelectasis in anesthetized healthy sheep.</a> Research in Veterinary Science. 150 (5), 164-169 (2022).</li><li>Pensier, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+lung+recruitment+maneuver+on+oxygenation,+physiological+parameters+and+mortality+in+acute+respiratory+distress+syndrome+patients:+a+systematic+review+and+meta-analysis.">Effect of lung recruitment maneuver on oxygenation, physiological parameters and mortality in acute respiratory distress syndrome patients: a systematic review and meta-analysis.</a> Intensive Care Medicine. 45 (12), 1691-1702 (2019).</li><li>Mariano, C. 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The described protocol is useful for producing an ex vivo porcine lung model under positive-pressure MV. It can be used for studying and teaching lung mechanics through visual feedback from the lungs during recruitment and analysis of the curves and values projected on the device screen. To achieve this result, pilot studies are needed to understand the behavior of the lungs outside the rib cage and to identify the need for adaptations.
We identified that the critical point was the fo...

Mechanical ventilation (MV) is widely used in intensive care units (ICUs) and surgical centers. Its monitoring is essential to help recognize asynchronies and prevent injuries for all patients, especially when the patient has serious lung injuries1,2,3,4,5,6. Monitoring respiratory mechanics can also contribute to the clinical understanding of the disease progression and therapeutic applications, such as the use of positive end-expiratory pressure (PEEP) or the alveolar recruitment maneuver (ARM). However, the use of these techniques requires a proficient understanding of curves and basic lung mechanics3,4.
Students, residents, and medical professionals feel insecure about MV management, from turning on the ventilator and initial adjustments to monitoring plateau and driving pressures, and this insecurity is associated with a lack of knowledge and adequate prior training7,8,9,10. We observed that professionals who participated in simulations and used a lung model reported greater confidence, understanding of the parameters, and understanding of the components of lung mechanics8,11,12.
Models for studying and training MV with test lungs, bellows, and pistons can simulate different pressures and volumes, as well as different lung mechanics conditions13,14,15. Computational and software models also contribute to the study of cardiopulmonary interaction by generating simulations that can be used to teach the principles of MV11 to health professionals16,17.
While computational models may present difficulties in representing pulmonary hysteresis16, models with test lung and bellows13,14,15can produce pressure-volume curves similar to the physiological curve and demonstrate pulmonary dynamics. As an advantage, the ex vivo porcine lung presents similar anatomy to humans18, also producing MV curves, pulmonary hysteresis, and providing visual feedback of the lungs inside the acrylic box during the lung mechanics analysis. Visual models are important and can help understand difficult-to-imagine components and concepts. Thus, ex vivo lung models represent a practical way of teaching.
Studies with ex vivo porcine lungs, such as those on MV with positive and negative pressure19,20,21, analysis of aerosol distribution22,23, pediatric simulations24, and lung perfusion25 can improve the knowledge on MV. Recent studies analyzing models in positive and negative pressure have shown that positive-pressure ventilation can lead to abrupt recruitment with greater local deformation, greater distension, hysteresis curve differences, and possible tissue lesions compared to negative pressure pressure19,20,21. Nevertheless, positive-pressure models are necessary because patients are under positive pressure during MV pressure19,20,21. The development of a lung model for preclinical studies opens possibilities for new research and applications, including MV teaching and training.
Here, we present an ex vivo porcine lung model for studying and training purposes. Our primary objective is to describe the steps for the generation of this ex vivo porcine lung model under positive-pressure MV. It can be used in the future to study and teach lung mechanics.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.9% Saline solution</td>
			<td></td>
			<td></td>
			<td>2500ml</td>
		</tr>
		<tr>
			<td>Anesthesia machine - Primus</td>
			<td>Drager</td>
			<td>REF 8603800-18</td>
			<td>Anesthesia work station used in the procedure</td>
		</tr>
		<tr>
			<td>Aspirator</td>
			<td></td>
			<td></td>
			<td>For blood aspiration from thorax</td>
		</tr>
		<tr>
			<td>Bedside Monitor - Life Scope</td>
			<td>Nihon Kohden</td>
			<td>BSM-7363</td>
			<td>Multiparameter monitor used during the procedure</td>
		</tr>
		<tr>
			<td>Bonney Tissue Forceps</td>
			<td></td>
			<td></td>
			<td>Any tissue forceps is suitable</td>
		</tr>
		<tr>
			<td>Disposable scalper, #23</td>
			<td></td>
			<td></td>
			<td>Any scalper is suitable</td>
		</tr>
		<tr>
			<td>Disposable syringe needles, 18G x 1 1/2&#34;, 23G x 1&#34;</td>
			<td>BD</td>
			<td>302814</td>
			<td>Widely available</td>
		</tr>
		<tr>
			<td>Disposable syringes, 10ml</td>
			<td></td>
			<td></td>
			<td>Widely available</td>
		</tr>
		<tr>
			<td>Electrosurgical unit - SS-501</td>
			<td>WEM</td>
			<td></td>
			<td>For cutting and coagulation during thorax incision</td>
		</tr>
		<tr>
			<td>Fentanyl</td>
			<td></td>
			<td></td>
			<td>10 mcg/kg bolus + 10 mcg/kg/hour continuous infusion</td>
		</tr>
		<tr>
			<td>Finochietto retractor</td>
			<td></td>
			<td></td>
			<td>Any finochietto retractor is suitable</td>
		</tr>
		<tr>
			<td>heparin</td>
			<td></td>
			<td></td>
			<td>3ml</td>
		</tr>
		<tr>
			<td>Infusion set</td>
			<td></td>
			<td></td>
			<td>Any infusion set is suitable</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td></td>
			<td></td>
			<td>1.5%</td>
		</tr>
		<tr>
			<td>Kelly Forceps Curved</td>
			<td></td>
			<td></td>
			<td>Any kelly forceps is suitable</td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td></td>
			<td></td>
			<td>5mg/kg</td>
		</tr>
		<tr>
			<td>Lactated Ringer solution</td>
			<td></td>
			<td></td>
			<td>500ml</td>
		</tr>
		<tr>
			<td>Mechanical ventilator - Servo I</td>
			<td>Maquet</td>
			<td>REF 6449701</td>
			<td>Mechanical ventilator used in the procedure</td>
		</tr>
		<tr>
			<td>Metzenbaum Scissor (Straight and curved)</td>
			<td></td>
			<td></td>
			<td>Any metzenbaum scissor is suitable</td>
		</tr>
		<tr>
			<td>Midazolam</td>
			<td></td>
			<td></td>
			<td>0.25mg/kg</td>
		</tr>
		<tr>
			<td>Orotracheal intubation cannula, #6.5</td>
			<td>Rusch</td>
			<td>112282</td>
			<td>Widely available</td>
		</tr>
		<tr>
			<td>Plexiglass</td>
			<td></td>
			<td></td>
			<td>Custom made plexiglass box: 30x45x60cm</td>
		</tr>
		<tr>
			<td>Polyester suture, 2-0</td>
			<td></td>
			<td></td>
			<td>Widely available</td>
		</tr>
		<tr>
			<td>Potassium choride</td>
			<td></td>
			<td></td>
			<td>10 ml, 19.1% potassium chloride.</td>
		</tr>
		<tr>
			<td>propofol</td>
			<td></td>
			<td></td>
			<td>5mg/kg</td>
		</tr>
		<tr>
			<td>Three way stopcock</td>
			<td></td>
			<td></td>
			<td>Widely available</td>
		</tr>
		<tr>
			<td>Venous catheter, G20 x 1&#34;</td>
			<td>BD</td>
			<td>38183314</td>
			<td>Widely available</td>
		</tr>
	</tbody>
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ex vivo porcine experimental model for studying and teaching lung mechanics

Mechanical ventilation is widely used and requires specific knowledge for understanding and management. Health professionals in this field may feel insecure and lack knowledge because of inadequate training and teaching methods. Therefore, the objective of this article is to outline the steps involved in generating an ex vivo porcine lung model to be used in the future, to study and teach lung mechanics. To generate the model, five porcine lungs were carefully removed from the thorax following the guidelines of the Animal Research Ethics Committee with adequate care and were connected to the mechanical ventilator through a tracheal cannula. These lungs were then subjected to the alveolar recruitment maneuver. Respiratory mechanics parameters were recorded, and video cameras were used to obtain videos of the lungs during this process. This process was repeated for five consecutive days. When not used, the lungs were kept refrigerated. The model showed different lung mechanics after the alveolar recruitment maneuver every day; not being influenced by the days, only by the maneuver. Therefore, we conclude that the ex vivo lung model can provide a better understanding of lung mechanics and its effects, and even of the alveolar recruitment maneuver through visual feedback during all stages of the process.

We used five female pigs weighing between 23.4-26.9 kg and followed the described protocol for cardiopulmonary extraction and lung mechanics analysis. Our intention is that the model is useful for the study of lung mechanics by analyzing peak pressure, plateau pressure, resistance, driving pressure, and dynamic compliance variables collected directly from the mechanical ventilator screen. The model flowchart is shown in Figure 1.
The lungs were analyzed for five c...

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Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics

We present an ex vivo pig lung model for the demonstration of pulmonary mechanics and alveolar recruitment maneuvers for teaching purposes. The lungs can be used for more than one day (up to five days) with minimal changes in pulmonary mechanics variables.

Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics

Mechanical ventilation is widely used and requires specific knowledge for understanding and management. Health professionals in this field may feel ...

Mechanical ventilation is widely used in respiratory failure, partially or completely replacing spontaneous ventilation. Its management requires prior knowledge and expertise. However, some studies show that professionals feel insecure in its management.Any claim, lack of training, or prior knowledge. The experimental models come to facilitate the concepts of mechanical ventilation and visualization of lung mechanics with visual feedback. Initially obtained the animal weight to adjust the medications and sedation necessary to the procedure.Administer ketamine five milligrams per kilogram, and midazolam point 25 milligram per kilogram intramuscularly. Then puncture the marginal ear vein with a 20 G venous catheter and administer intravenous propofol, five milligrams per kilogram for anesthesia induction. Administer three milliliters of heparin intravenously to eight cardiopulmonary block extraction and perfusion.After anesthesia, perform orotracheal intubation with a 6.5 millimeter cannula. The tracheal cannula must be securely fixed to prevent displacement during the procedure. After preparation, connect the NMO via cannula to mechanical ventilation, and maintain the NMO anesthesia with a 1.5%isofluorine in 50%of inspired fraction of oxygen.And fentanyl, 10 micrograms per kilogram bolus, plus 10 micrograms per kilogram per hour continuous infusion. The assessment of the depth of sedation is performed based on the monitoring of hemodynamic parameters and the use of a gas analyzer. Adjust the mechanical ventilator for volume controlled model with a tidal volume of eight milliliters per kilogram.The ventilation mode and other settings are selected on the mechanical ventilator screen. The respiratory rate must be adjusted to maintain end-tidal Co2 of 35 to 45 millimeters of mercury. Make a sternal incision large enough to access the thoracic cavity, two centimeters above the manubrium to two centimeters below the xifoide process of the sternum, and position the rib retractors, expanding the field of view during the procedure.Make a tracheal incision horizontally using the scalpel. The incision must be large enough to introduce a new tracheal cannula, removing the oral tracheal tube. Inflate the cuff of the newly introduced tracheal cannula.Attach the new tracheal cannula directly to the trachea. The tracheal cannula is not sutured, just tied, to avoid leaks and movement during the lungs placement in the ventilation box. With the scalpel dissect the tissues to remove the cardiopulmonary block from the thorax.At the end, increase the isoflourane concentration to 5%and administer 10 milliliters of potassium chloride. After tissue dissection, clamp the orotracheal cannula with the appropriate Cali forceps during the end of inspiration, keeping the lung inflated. Disconnect the mechanical ventilator.Section the aortic artery, and position the aspirator inside the thoracic cavity to remove extravasated blood, and maintain visualization of the cavity. The inferior pulmonary ligament should be carefully released to avoid pulmonary laceration. Remove the cardiopulmonary block from the ribcage with the orotracheal cannula clamped, and place it on a tray.Cannulate the pulmonary artery with a large bore single lumen catheter, and connect it to the infusion set to continuously administer 2000 milliliters of code 9%saline solution until clear liquid flows from the aorta. The saline solution should be administered at a normal rate. Avoiding squeezing the IV bag.After clearing the flow, suture the aortic artery and administer another a hundred milliliters of saline solution. The saline solution remains inside the lungs until the end of the experiment. After preparing the lungs, position them vertically inside the acrylic box and connect the tracheal cannula to the mechanical ventilator.Make sure the tracheal cannula is firmly secured in the trachea. Adjust the mechanical ventilator for volume controlled mode with the following parameters. Tau volume, six milliliters per kilogram.PEEP, five centimeters of water. Inspired fraction of oxygen, 21%Respiratory rate, 15. An inspiratory pause time, 10%Settings are selected on the mechanical ventilator screen.To start recruitment increase PEEP from five to six centimeters of water, and then increase it in step-by-step increments of two centimeters of water, until reaching 14 centimeters of water. PEEP is increased using the onscreen button on the mechanical ventilator. Each PEEP value is maintained for 10 minutes while recording lung mechanics.After reaching 14 centimeters of water, reduce PEEP step-by-step in decrements of two centimeters of water until reaching six centimeters of water, and then reduce it to five centimeters of water. During this decrease, the PEEP value is maintained for five minutes, while recording lung mechanics. At the end of the recruitment stage, gently clamp the tracheal cannula with the clamp during inspiration, keeping the lungs inflated.Open the acrylic box. Remove the lungs from the acrylic box and carefully place them in a glass container. After placing the lungs into the glass container, make sure the clamp is tightly closed, and pour 500 milliliters of 9%saline solution.Store the lungs in the refrigerator in a plastic wrapped glass container at a temperature of two to eight degrees Celsius for 24 hours. Repeat the process for mechanical ventilation, and the ovular recruitment maneuver for five consecutive days. After each time the process is completed, place the lungs in the glass container and store it in the refrigerator.We analyze the lungs for five consecutive days, repeating the entire process as described in the flow chart. We were able to show how the lung variables behaved before and after recruitment, and establish the durability of the ex vivo lung model in the study period. We observed significant differences between all variables before and after recruitment maneuvers.Peak pressure, plateau pressure, and driving pressure decreased after the maneuver, while dynamic compliance increased, demonstrating opening of the collapsed alveoli, and gain in lung area. Airway resistance also increased after recruitment. We show that the model is effective in demonstrating visual changes in lung mechanics through the Alveolar recruitment maneuver, and its effectiveness for the study and teaching of lung mechanics.In addition, we show that the model can be used for at least five consecutive days. In the pilot study, we started with a PEEP of five centimeters of water, and increased it in five centimeters of water increments up to 25 centimeters. However, the peak and plateau pressures reach values greater than 40 and 30 centimeters of water respectively, with fistula formation.Thus, we chose to perform a gradual increase in two centimeter increments to provide a better analyze of the behavior of pressures over time, and understand the PEEP limits in your ex-vivo logging model. There is no difference between sustained or incremental inflation in relation to mortality, but in addition to being the most used incremental inflation can facilitate the stepwise analyze of lung mechanics. There have been studies using XV over C models with positive and negative pressure with different initiatives, such as the development of a similar model of for preclinical studies, the verification of aerosol distributions, and establishment of pediatric simulations.Despite the different objectives, such studies open possibilities for our new research, aid applications for our learning model. Although studies have demonstrated that the use of positive pressure ventilation in the XV volume model can lead to abrupt recruitment, with a greater local deformation than negative pressure ventilation. It's necessary to create positive pressure models because our patients are usually submit to positive pressure during mechanical ventilation, as limitation of we have first, knowledge of any animal anatomy so the legs can be properly removed.Second, the model was not evaluated beyond five days. Third, this model, it fits well for just for ventilation teaching. And finally, to translate its results to all human beings, it is important to consider the limitations of animal model.The X vivo pulmonary model is viable and reproducible, it can submitted to recruitment maneuvers with visualization of the pulmonary mechanical variables. The model provides a new view of the lung under mechanical ventilation, facilitating the teaching of these concepts through visual feedback.

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