Negative Pressure Ventilation Research Articles

Biphasic Cuirass Ventilation During Anesthesia for Tracheobronchial Stent Insertion or Removal by a Rigid Bronchoscope: A Case Report.

Airway management and ventilation during a tracheobronchial stenting procedure are challenging given that mandatory positive pressure ventilation cannot be fully achieved while using a rigid bronchoscope due to leakage from the scope tip. Biphasic cuirass ventilation is a negative pressure ventilation method using an external cuirass fitted to the anterior chest, which could assist in spontaneous breathing and ventilation support. We report 3 successful anesthesia cases in which we could maintain adequate ventilation and oxygenation, supported by biphasic cuirass ventilation, in patients undergoing tracheobronchial stent placement or removal procedures using rigid bronchoscopy.

Ex Vivo Modeling of Perioperative Air Leaks in Porcine Lungs.

A novel ex vivo model is described to advance the understanding of prolonged air leaks, one of the most common postoperative complications following thoracic resection procedures. As an alternative to in vivo testing, an ex vivo model simulating the various physiologic environments experienced by an isolated lung during the perioperative period was designed and built. Isolated porcine lungs were perfused and ventilated during open chest and closed chest simulations, mimicking intra and postoperative ventilation conditions. To assess and validate system capabilities, nine porcine lungs were tested by creating a standardized injury to create an approximately 250 cc/min air leak. Air leak rates, physiologic ventilation, and perfusion parameters were continuously monitored, while gas transfer analysis was performed on selected lungs. Segmental ventilation was monitored using electrical impedance tomography. The evaluated lungs produced flow-volume and pressure-volume loops that approximated standard clinical representations under positive (mechanical) and negative (physiological) pressure ventilation modalities. Leak rate was averaged across the ventilation phases, and sharp increases in leak rate were observed between positive and negative pressure phases, suggesting that differences or changes in ventilation mechanics may strongly influence leak development. The successful design and validation of a novel ex vivo lung model was achieved. Model output paralleled clinical observations. Pressure modality may also play a significant role in air leak severity. This work provides a foundation for future studies aimed at increasing the understanding of air leaks to better inform means of mitigating the risk of air leaks under clinically relevant conditions.

The Year in Thoracic Anesthesia: Selected Highlights From 2017

THIS SPECIAL ARTICLE is the second in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors would like to thank the editor-in-chief, Dr. Kaplan; the associate editor-in-chief, Dr. Augoustides; and the editorial board for the opportunity to expand this series, the research highlights of the year that specifically pertain to the specialty of thoracic anesthesia. The major themes selected for 2017 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights in this specialty for 2017 begin with attempts to develop a scale to aid in the diagnosis and surgical management of patients with low-grade esophageal carcinoma and a composite score by the Society of Thoracic Surgeons (STS) General Thoracic Surgery Database Task Force to evaluate and rate the performance and outcomes of esophagectomy for esophageal cancer. The second section highlights the recent advancements in the treatment of thymomas for both benign and malignant disease, including robotic thymectomy, and is followed by a section discussing the role of truncal regional blocks and their use in thoracic surgery, especially in combination with enhanced recovery after surgery (ERAS) protocols. ClinicalTrials.gov. The University of Alberta Negative Pressure Ventilation Ex-Vivo Lung Perfusion (NPV-EVLP) Trial (UA NPV-EVLP). Available at: https://clinicaltrials.gov/ct2/show/NCT03293043. Accessed January 17, 2018.

Respiratory pump maintains cardiac stroke volume during hypovolemia in young, healthy volunteers.

Spontaneous breathing has beneficial effects on the circulation, since negative intrathoracic pressure enhances venous return and increases cardiac stroke volume. We quantified the contribution of the respiratory pump to preserve stroke volume during hypovolemia in awake, young, healthy subjects. Noninvasive stroke volume, cardiac output, heart rate, and mean arterial pressure (Finometer) were recorded in 31 volunteers (19 women), 19-30 yr old, during normovolemia and hypovolemia (approximating 450- to 500-ml reduction in central blood volume) induced by lower-body negative pressure. Control-mode noninvasive positive-pressure ventilation was employed to reduce the effect of the respiratory pump. The ventilator settings were matched to each subject's spontaneous respiratory pattern. Stroke volume estimates during positive-pressure ventilation and spontaneous breathing were compared with Wilcoxon matched-pairs signed-rank test. Values are overall medians. During normovolemia, positive-pressure ventilation did not affect stroke volume or cardiac output. Hypovolemia resulted in an 18% decrease in stroke volume and a 9% decrease in cardiac output ( P < 0.001). Employing positive-pressure ventilation during hypovolemia decreased stroke volume further by 8% ( P < 0.001). Overall, hypovolemia and positive-pressure ventilation resulted in a reduction of 26% in stroke volume ( P < 0.001) and 13% in cardiac output ( P < 0.001) compared with baseline. Compared with the situation with control-mode positive-pressure ventilation, spontaneous breathing attenuated the reduction in stroke volume induced by moderate hypovolemia by 30% (i.e., -26 vs. -18%). In the patient who is critically ill with hypovolemia or uncontrolled hemorrhage, spontaneous breathing may contribute to hemodynamic stability, whereas controlled positive-pressure ventilation may result in circulatory decompensation. NEW & NOTEWORTHY Maintaining spontaneous respiration has beneficial effects on hemodynamic compensation, which is clinically relevant for patients in intensive care. We have quantified the contribution of the respiratory pump to cardiac stroke volume and cardiac output in healthy volunteers during normovolemia and central hypovolemia. The positive hemodynamic effect of the respiratory pump was abolished by noninvasive, low-level positive-pressure ventilation. Compared with control-mode positive-pressure ventilation, spontaneous negative-pressure ventilation attenuated the fall in stroke volume by 30%.

Diffuse pollution characteristics of respirable dust in fully-mechanized mining face under various velocities based on CFD investigation

Abstract In order to grasp the partition diffusion and pollution of respirable dust under various turbulent velocities in fully-mechanized mining face, Finite Volume Method was adopted to simulate and study the diffusion behavior characteristics of respirable dust of 52305-1 fully-mechanized mining face in Daliuta coal mine at different areas under full section independent negative pressure ventilation conditions based on airflow streamline, airflow vector, and dust trace. Especially the dust particle movements under the impact of turbulent inlet velocity were defined accurately. The results show that a narrow and long high-speed zone is formed between the coal shearer and corresponding hydraulic pillars due to the blocking effect of coal shearer. At the height of breathing zone, the area with maximum air velocity is performed from the variable cross section, the maximum velocity reaches up to 1.44–2.52 times over inlet air velocity, also the value decreases as the inlet air velocity increases. Average respirable dust concentration of breathing zone height decreases with the increase of inlet air velocity, however the decreasing degree is weakened gradually. With the increase of turbulent inlet velocity, the settlement range of the dust from advancing support and the transverse diffusion range of the dust from drum cutting coal is gradually reduced, also the high concentration respirable dust area with more than 1440 mg/m3 gradually disappear. When the inlet air velocity is over 2.5 m/s, the effect of dust removal by ventilation is weakened gradually.

An Anesthesiologist’s Perspective on the History of Basic Airway Management

This third installment of the history of basic airway management discusses the transitional-"progressive"-years of anesthesia from 1904 to 1960. During these 56 yr, airway management was provided primarily by basic techniques with or without the use of a face mask. Airway maneuvers were inherited from the artisanal era: head extension and mandibular advancement. The most common maneuver was head extension, also used in bronchoscopy and laryngoscopy. Basic airway management success was essential for traditional inhalation anesthesia (ether, chloroform) and for the use of the new anesthetic agents (cyclopropane, halothane) and intravenous drugs (thiopental, curare, succinylcholine). By the end of the era, the superiority of intermittent positive pressure ventilation to spontaneous ventilation in anesthesia and negative pressure ventilation in resuscitation had been demonstrated and accepted, and the implementation of endotracheal intubation as a routine technique was underway.

Negative pressure ventilation enhances acinar perfusion in isolated rat lungs.

We compared acinar perfusion in isolated rat lungs ventilated using positive or negative pressures. The lungs were ventilated with air at transpulmomary pressures of 15/5 cm H2O, at 25 breaths/min, and perfused with a hetastarch solution at Ppulm art/PLA pressures of 10/0 cm H2O. We evaluated overall perfusability from perfusate flows, and from the venous concentrations of 4-µm diameter fluorescent latex particles infused into the pulmonary circulation during perfusion. We measured perfusion distribution from the trapping patterns of those particles within the lung. We infused approximately 9 million red fluorescent particles into each lung, followed 20 min later by an infusion of an equal number of green particles. In positive pressure lungs, 94.7 ± 2.4% of the infused particles remained trapped within the lungs, compared to 86.8 ± 5.6% in negative pressure lungs (P ≤ 0.05). Perfusate flows averaged 2.5 ± 0.1 mL/min in lungs ventilated with positive pressures, compared to 5.6 ± 01 mL/min in lungs ventilated with negative pressures (P ≤ 0.05). Particle infusions had little effect on perfusate flows. In confocal images of dried sections of each lung, red and green particles were co-localized in clusters in positive pressure lungs, suggesting that acinar vessels that lacked particles were collapsed by these pressures thereby preventing perfusion through them. Particles were more broadly and uniformly distributed in negative pressure lungs, suggesting that perfusion in these lungs was also more uniformly distributed. Our results suggest that the acinar circulation is organized as a web, and further suggest that portions of this web are collapsed by positive pressure ventilation.

Congenital central hypoventilation syndrome diagnosis and treatment

Congenital central hypoventilation syndrome(CCHS)is a rare disorder characterized by hypoventilation during sleep and blunted ventilatory responses to hypercapnia and hypoxemia.It is normally found in neonatal and infant.Late-onset cases have been reported recently.The paired-like homeobox gene PHOX2B is the disease-defining gene for CCHS; a mutation in the PHOX2B gene is requisite to the diagnosis of CCHS.As a lifelong disease, the key treatment is ensuring adequate ventilation and oxygenation, effective modalities include positive pressure ventilation, negative pressure ventilation and diaphragmatic pacing.The strategy of anti-mutant protein and the use of progestin open up clinical perspectives to enhance ventilation in CCHS patients. Key words: Children; Congenital central hypoventilation syndrome; Diagnosis; Treatment

Negative pressure ventilation decreases inflammation and lung edema during normothermic ex-vivo lung perfusion

Normothermic ex-vivo lung perfusion (EVLP) using positive pressure ventilation (PPV) and both acellular and red blood cell (RBC)-based perfusate solutions have increased the rate of donor organ utilization. We sought to determine whether a negative pressure ventilation (NPV) strategy would improve donor lung assessment during EVLP. Thirty-two pig lungs were perfused ex vivo for 12 hours in a normothermic state, and were allocated equally to 4 groups according to the mode of ventilation (positive pressure ventilation [PPV] vs NPV) and perfusate composition (acellular vs RBC). The impact of ventilation strategy on the preservation of 6 unutilized human donor lungs was also evaluated. Physiologic parameters, cytokine profiles, lung injury, bullae and edema formation were compared between treatment groups. Perfused lungs demonstrated acceptable oxygenation (partial pressure of arterial oxygen/fraction of inspired oxygen ratio >350 mm Hg) and physiologic parameters. However, there was less generation of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6 and interleukin-8) in human and pig lungs perfused, irrespective of perfusate solution used, when comparing NPV with PPV (p < 0.05), and a reduction in bullae formation with an NPV modality (p = 0.02). Pig lungs developed less edema with NPV (p < 0.01), and EVLP using an acellular perfusate solution had greater edema formation, irrespective of ventilation strategy (p = 0.01). Interestingly, human lungs perfused with NPV developed negative edema, or "drying" (p < 0.01), and lower composite acute lung injury (p < 0.01). Utilization of an NPV strategy during extended EVLP is associated with significantly less inflammation, and lung injury, irrespective of perfusate solution composition.

Negative-Pressure Ventilation in Pediatric Acute Respiratory Failure.

The objective of this work was to describe the use of negative-pressure ventilation (NPV) in a heterogeneous critically ill, pediatric population. A retrospective chart review was conducted of all patients admitted to a pediatric ICU with acute respiratory failure supported with NPV from January 1, 2012 to May 15, 2015. Two hundred thirty-three subjects at a median age of 15.5 months were supported with NPV for various etiologies, most commonly bronchiolitis (70%). Median (interquartile range) duration of support was 18.7 (8.7-34.3) h. The majority were NPV responders (70%), defined as not needing escalation to any form of positive-pressure ventilation. In non-responders, escalation occurred at a median (interquartile range) of 6.9 (3.3-16.6) h. More NPV non-responders had upper-airway obstruction (P = .02), and fewer had bronchiolitis (P = .008) compared with responders. A bedside scoring system developed on these data was 98% specific in predicting NPV failure by 4 h after NPV start (area under the curve 0.759, 95% CI 0.675-0.843, P < .001). Complications from NPV were rare (3%); however, delayed enteral nutrition (33%) and continuous intravenous sedation use (51%) in children while receiving NPV were more frequent. The annual percentage of pediatric ICU admissions requiring intubation declined by 28% in the 3 y after NPV introduction, compared with the 3 y prior. NPV is a noninvasive respiratory support for pediatric acute respiratory failure from all causes with few complications and a 70% response rate. Children receiving NPV often required intravenous sedation for comfort, and one third received delayed enteral nutrition. Those who required escalation from NPV worsened within 6 h; this may be predictable with a bedside scoring system.

Cardiac output in normal subjects: negative versus positive pressure ventilation

Spontaneous inspiration and Negative Pressure Ventilation (NPV) produce a negative pleural pressure, and this reduction in intrathoracic pressure is transmitted to the right atrium. In contrast, intermittent Positive Pressure Ventilation (PPV) produces inspiratory increases in intrathoracic pressure and therefore right atrial pressure. The comparison of the cardiopulmonary effects between NPV and PPV has been previously reported in physiologic researches carried out both in animal model and in paediatric patients. Our hypothesis was that in healthy adults the application of NPV by iron lung might result in hemodynamic advantages in comparison with PPV. The hemodynamic effects of NPV and PPV, administered through iron lung and mask-ventilation respectively, were studied in 10 normal subjects. Continuous and non-invasive blood pressure and heart rate measurements were recorded by digital oscillometric photoplethysmography both at baseline and during mechanical ventilation. Iron Lung Ventilation (ILV), using intermittent NPV/CNEEP (Continuous Negative Extrathoracic End-expiratory Pressure) in assist control mode, and mask-ventilation by Bi-Level in ST mode were administered at two different settings (NPV: -15/- 4 and -20/-4 cmH2O), (PPV: +15/+4 and +20/+4 cmH2O) respectively. The measurements lasted three minutes per setting without interruption. The mean values of all hemodynamic variables at baseline, during each step of ventilatory treatment and during the recovery phase, showed no statistically significant difference with ILV, on the contrary, during the application of mask-ventilation there was a significant decrease of diastolic, systolic, dicrotic and mean arterial pressure (p = 0.010, 0.002, 0.027, and 0.002 respectively), of cardiac output (p = 0.002), and dP/dtmax (p = 0.037), whereas stroke volume, pulse rate and systemic vascular resistance did not change. Our data show that both spontaneous breathing and mechanical breathing, during ILV, have the same effect on venous return in healthy subjects. In contrast, mask-ventilation produces transient hemodynamic effects due to a reduction in venous return. These results may represent the starting point for further investigation in patients with critical patients undergoing mechanical ventilation.

Improved Outcomes with Negative Pressure Ventilation (NPV) during Normothermic Ex Vivo Lung Perfusion

Improved Outcomes with Negative Pressure Ventilation (NPV) during Normothermic Ex Vivo Lung Perfusion

(171) - Improved Outcomes with Negative Pressure Ventilation (NPV) During Normothermic Ex Vivo Lung Perfusion

(171) - Improved Outcomes with Negative Pressure Ventilation (NPV) During Normothermic Ex Vivo Lung Perfusion

An Anesthesiologist's Perspective on the History of Basic Airway Management: The "Artisanal Anesthetic" Era: 1846 to 1904.

This second installment of the history of basic airway management covers the early-artisanal-years of anesthesia from 1846 to 1904. Anesthesia was invented and practiced as a supporting specialty in the context of great surgical and medical advances. The current-day anesthesia provider tends to equate the history of airway management with the history of intubation, but for the first 58 yr after the introduction of ether anesthesia, airway management was provided by basic airway techniques with or without the use of a face mask. The jaw thrust and chin lift were described in the artisanal years and used primarily with inhalation anesthesia in the spontaneously breathing patient and less often with negative-pressure ventilation in the apneic victim. Positive-pressure ventilation and intubation stayed at the fringes of medical practice, and airway techniques and devices were developed by trial and error. At the beginning of the 20th century, airway management and anesthetic techniques lagged behind surgical requirements.

The Utility of Preliminary Patient Evaluation in a Febrile Respiratory Infectious Disease Unit outside the Emergency Department.

A febrile respiratory infectious disease unit (FRIDU) with a negative pressure ventilation system was constructed outside the emergency department (ED) of the Samsung Medical Center in 2015, to screen for patients with contagious diseases requiring isolation. We evaluated the utility of the FRIDU during 1 year of operation. We analyzed 1,562 patients who were hospitalized after FRIDU screening between August 2015 and July 2016. The level of isolation recommended during their screening at the FRIDU was compared with the level deemed appropriate given their final diagnosis. Of the 1,562 patients screened at the FRIDU, 198 (13%) were isolated, 194 (12%) were reverse isolated, and 1,170 (75%) were not isolated. While hospitalized, 97 patients (6%) were confirmed to have a contagious disease requiring isolation, such as tuberculosis; 207 patients (13%) were confirmed to be immunocompromised and to require reverse isolation, mainly due to neutropenia; and the remaining 1,258 patients (81%) did not require isolation. The correlation coefficient for isolation consistency was 0.565 (P < 0.001). The sensitivity and negative predictive value of FRIDU screening for diagnosing contagious disease requiring isolation are 76% and 98%, respectively. No serious nosocomial outbreaks of contagious diseases occurred. During FRIDU screening, 114 patients were admitted to the resuscitation zone due to clinical instability, and three of these patients died. The initial isolation levels resulting from FRIDU screening were moderately well correlated with the isolation levels required by the final diagnosis, demonstrating the utility of pre-hospitalization screening units. However, the risks of deterioration during the screening process remain challenges.

The Utility of Preliminary Patient Evaluation in a Febrile Respiratory Infectious Disease Unit Outside the Emergency Department

Background Acute respiratory illnesses are the leading cause of death from infectious diseases around the world, and occasional outbreaks of particularly virulent strains are can be public health disasters. Recently, a large outbreak of fatal Middle East respiratory syndrome-coronavirus (MERS-CoV) occurred following a single patient exposure in the emergency department (ED) of the Samsung Medical Center, a tertiary-care hospital in South Korea, which resulted in significant public health and economic burden.After this outbreak, a febrile respiratory infectious disease unit (FRIDU) with a negative pressure ventilation system was constructed outside the emergency department (ED) in 2015, to screen for patients with contagious diseases requiring isolation.Methods This is a retrospective cohort study of patients who visited the ED with febrile illness between August 2015 and July 2016. Ultimately, 1562 patients who were hospitalized after FRIDU screening were analyzed. The level of isolation recommended during their screening at the FRIDU was compared with the level deemed appropriate given their final diagnosis.ResultsOf the 1562 patients screened at the FRIDU, 198 (13%) were isolated, 194 (12%) were reverse isolated, and 1170 (75%) were not isolated. While hospitalized, 97 patients (6%) were confirmed to have a contagious disease requiring isolation, such as tuberculosis; 207 patients (13%) were confirmed to be immunocompromised and to require reverse isolation, mainly due to neutropenia; and the remaining 1258 patients (81%) did not require isolation.The correlation coefficient for isolation consistency was 0.565 (P < 0.001). No serious nosocomial outbreaks of contagious diseases occurred. During FRIDU screening, 114 patients were admitted to the resuscitation zone due to clinical instability, and three of these patients died.Conclusion The initial isolation levels resulting from FRIDU screening were moderately well correlated with the isolation levels required by the final diagnosis, demonstrating the utility of pre-hospitalization screening units. However, the risks of deterioration during the screening process remain challenges.Disclosures All authors: No reported disclosures.

Pulmonary rehabilitation coupled with negative pressure ventilation decreases decline in lung function, hospitalizations, and medical cost in COPD: A 5-year study.

Pulmonary rehabilitation (PR) brings benefits to patients with chronic obstructive pulmonary disease (COPD). Negative pressure ventilation (NPV) increases ventilation and decreases hyperinflation as well as breathing work in COPD. We evaluated the long-term effects of a hospital-based PR program coupled with NPV support in patients with COPD on clinical outcomes.One hundred twenty-nine patients with COPD were followed up for more than 5 years, with the NPV group (n = 63) receiving the support of NPV (20-30 cm H2O delivery pressure for 60 min) and unsupervised home exercise program of 20 to 30 min daily walk, while the control group (n = 6) only received unsupervised home exercise program. Pulmonary function tests and 6 min walk tests (6MWT) were performed every 3 to 6 months. Emergency room (ER) visits and hospitalization with medical costs were recorded.A significant time-by-group interaction in the yearly decline of forced expiratory volume in 1 s in the control group analyzed by mixed-model repeated-measure analysis was found (P = 0.048). The 6MWT distance of the NPV group was significantly increased during the first 4 years, with the interaction of time and group (P = 0.003), the time alone (P = 0.014), and the quadratic time (P < 0.001) being significant between the 2 groups. ER exacerbations and hospitalizations decreased by 66% (P < 0.0001) and 54% (P < 0.0001) in the NPV group, respectively. Patients on PR program coupled with NPV had a significant reduction of annual medical costs (P = 0.022).Our hospital-based multidisciplinary PR coupled with NPV reduced yearly decline of lung function, exacerbations, and hospitalization rates, and improved walking distance and medical costs in patients with COPD during a 5-year observation.

Spread of nano-objects in the air as a result of switching-on a microwave

Switching-on a microwave results in the creation of nano-sized particles, which can spread through the air of a given premise, e.g., room. The study was carried out to determine the number and surface concentrations as well as the mean particles size using a DiscMini measurement device distributed in 6 measuring points to track changes of particle parameters, primarily at the source of particle creation and in the area of local ventilation (fume cupboard), and also in other places, e.g., near the window or in the middle of the room. Where the fume cupboard was switched-off, i.e., normal pressure ventilation in the room, switching-on the microwave caused a 9.42-14.14-fold increase in the number concentration of nano-sized particles relative to the background and a 3.51-4.81-fold increase in the surface concentration. Where the fume cupboard was switched-on, i.e., negative pressure ventilation in the room switching-on the microwave caused a 3.20-4.43-fold increase in the number concentration of nano-size particles relative to the background and a 1.61-1.89-fold increase in the surface concentration. The analysis of the data shows that switching-on a microwave for 5 min results in the creation of nano-objects already after about 3 min with the maximum concentration values after 12 min since switching-on the microwave in all 6 measurement points distributed in the test room. This applies to both situations, i.e., when the fume cupboard was switchedoff or switched-on. Med Pr 2016;67(3):353-363.

Biomimetic Culture Reactor for Whole-Lung Engineering.

Decellularized organs are now established as promising scaffolds for whole-organ regeneration. For this work to reach therapeutic practice, techniques and apparatus are necessary for doing human-scale clinically applicable organ cultures. We have designed and constructed a bioreactor system capable of accommodating whole human or porcine lungs, and we describe in this study relevant technical details, means of assembly and operation, and validation. The reactor has an artificial diaphragm that mimics the conditions found in the chest cavity in vivo, driving hydraulically regulated negative pressure ventilation and custom-built pulsatile perfusion apparatus capable of driving pressure-regulated or volume-regulated vascular flow. Both forms of mechanical actuation can be tuned to match specific physiologic profiles. The organ is sealed in an elastic artificial pleura that mounts to a support architecture. This pleura reduces the fluid volume required for organ culture, maintains the organ's position during mechanical conditioning, and creates a sterile barrier allowing disassembly and maintenance outside of a biosafety cabinet. The combination of fluid suspension, negative-pressure ventilation, and physiologic perfusion allows the described system to provide a biomimetic mechanical environment not found in existing technologies and especially suited to whole-organ regeneration. In this study, we explain the design and operation of this apparatus and present data validating intended functions.

Physiological parameters of the isolated perfused mouse lung and their dependency on age

BACKGROUND: The “Isolated lung perfusion system” has been established to study lung physiological parameters of mice or other small animals, but little is known about the influence of age on the lung function in mice. METHODS:We used a buffer-perfused lung system with negative-pressure ventilation to study the effect of age on physiological parameters in the isolated mouse lung. Our study included C57BL/6N mice when they were young (3 to 4 months), adult (5 to 9 months) or old (24 months). RESULTS: The ex vivo data indicated that maximal function of the lung is achieved in the early adulthood (5 to 6 months of age). In this period, lung developed highest maximal expiratory flow rate which declined steadily with increasing age. After this age (>7 months) the dynamic lung compliance increased with significant changes in the 24-month-old mice. However, mouse age had no effect on airway resistance and pulmonary artery pressure. Moreover, we did not find an influence of age on the integrity of the endothelial-epithelial barrier. CONCLUSION: Our findings indicate the importance of age, in particular on the respiratory mechanics in isolated mouse lungs, which should be considered in the pulmonary research using the “Isolated lung perfusion system”.