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William Van Bonn - One of the best experts on this subject based on the ideXlab platform.
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inflation and deflation pressure volume loops in anesthetized pinnipeds confirms compliant chest and lungs
2014Co-Authors: Andreas Fahlman, Vanessa Fravel, Martin Haulena, Shawn P. Johnson, William Van Bonn, Stephen H. LoringAbstract:We examined structural properties of the marine mammal respiratory system, and tested Scholander’s hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia (Pacific harbor seal, Phoca vitulina; northern elephant seal, Mirounga angustirostris; northern fur seal Callorhinus ursinus; California sea lion, Zalophus californianus; and Steller sea lion, Eumetopias jubatus). We found that the chest wall Compliance (CCW) of all five species was greater than lung Compliance (airways and alveoli, CL) as predicted by Scholander, which suggests that the chest provides little protection against alveolar collapse or lung squeeze. We also found that specific respiratory Compliance was significantly greater in wild animals than in animals raised in an aquatic facility. While differences in ages between the two groups may affect this incidental finding, it is also possible that lung conditioning in free-living animals may increase Pulmonary Compliance and reduce the risk of lung squeeze during diving. Overall, our data indicate that Compliance of excised pinniped lungs provide a good estimate of total respiratory Compliance.
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inflation and deflation pressure volume loops in anesthetized pinnipeds confirms compliant chest and lungs
2014Co-Authors: Andreas Fahlman, Vanessa Fravel, Martin Haulena, Shawn P. Johnson, William Van Bonn, Stephen H. Loring, Andrew W TritesAbstract:We examined structural properties of the marine mammal respiratory system, and tested Scholander’s hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia (Pacific harbor seal, Phoca vitulina; northern elephant seal, Mirounga angustirostris; northern fur seal Callorhinus ursinus; California sea lion, Zalophus californianus; and Steller sea lion, Eumetopias jubatus). We found that the chest wall Compliance (CCW) of all five species was greater than lung Compliance (airways and alveoli, CL) as predicted by Scholander, which suggests that the chest provides little protection against alveolar collapse or lung squeeze. We also found that specific respiratory Compliance was significantly greater in wild animals than in animals raised in an aquatic facility. While differences in ages between the two groups may affect this incidental finding, it is also possible that lung conditioning in free-living animals may increase Pulmonary Compliance and reduce the risk of lung squeeze during diving. Overall, our data indicate that Compliance of excised pinniped lungs provide a good estimate of total respiratory Compliance.
Robert H Bartlett - One of the best experts on this subject based on the ideXlab platform.
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evaluation of gas exchange Pulmonary Compliance and lung injury during total and partial liquid ventilation in the acute respiratory distress syndrome
1996Co-Authors: Ronald B Hirschl, Richard Tooley, Alan C Parent, Kent J Johnson, Robert H BartlettAbstract:Objective To investigate whether Pulmonary Compliance and gas exchange will be sustained during ``total'' perfluorocarbon liquid ventilation followed by ``partial'' perfluorocarbon liquid ventilation when compared with gas ventilation in the setting of the acute respiratory distress syndrome (ARDS). Study Design A prospective, controlled, laboratory study. Setting A university research laboratory. Subjects Ten sheep, weighing 12.7 to 25.0 kg. Interventions Lung injury was induced in ten young sheep, utilizing a right atrial injection of 0.07 mL/kg of oleic acid followed by saline Pulmonary lavage. Bijugular venovenous extracorporeal life support access, a Pulmonary artery catheter, and a carotid artery catheter were placed. When the alveolar-arterial O2 gradient was more than equals 600 torr and PaO2 less than equals 50 torr (less than equals 6.7 kPa) with an FIO2 of 1.0, extracorporeal life support was instituted. For the first 30 mins on extracorporeal life support, all animals were ventilated with gas. Animals were then ventilated with equal tidal volumes of 15 mL/kg during gas ventilation (n equals 5) over the ensuing 2.5 hrs, or with total liquid ventilation for 1 hr, followed by partial liquid ventilation for 1.5 hrs (total/partial liquid ventilation, n equals 5). Measurements and Main Results An increase in physiologic shunt (gas ventilation equals 69 plus minus 11%, total/partial liquid ventilation equals 71 plus minus 3%) and a decrease in static total Pulmonary Compliance measured at 20 mL/kg inflation volume (gas ventilation equals 0.48 plus minus 0.03 mL/cm H2 O/kg, total/partial liquid ventilation equals 0.50 plus minus 0.17 mL/cm H2 O/kg) were observed in both groups with induction of lung injury. Physiologic shunt was significantly reduced during total and partial liquid ventilation when compared with physiologic shunt observed in the gas ventilation animals (gas ventilation equals 93 plus minus 8%, total liquid ventilation equals 45 plus minus 11%, p less than .001; gas ventilation equals 95 plus minus 3%, partial liquid ventilation equals 61 plus minus 12%, p less than .001), while static Compliance was significantly increased in the total, but not the partial liquid ventilated animals when compared with the gas ventilated group (gas ventilation equals 0.43 plus minus 0.03 mL/cm H2 O/kg, total liquid ventilation equals 1.13 plus minus 0.18 mL/cm H2 O/kg, p less than .001; gas ventilation equals 0.41 plus minus 0.02 mL/cm H2 O/kg, partial liquid ventilation equals 0.47 plus minus 0.08, p equals .151). In addition, the extracorporeal life support flow rate required to maintain adequate oxygenation was significantly lower in the total/partial liquid ventilation group when compared with that of the gas ventilation group (gas ventilation equals 89 plus minus 7 mL/kg/min, total liquid ventilation equals 22 plus minus 10 mL/kg/min, p less than .001; gas ventilation equals 91 plus minus 12 mL/kg/min, partial liquid ventilation equals 41 plus minus 11 mL/kg/min, p less than .001). Lung biopsy light microscopy demonstrated a marked reduction in alveolar hemorrhage, lung fluid accumulation, and inflammatory infiltration in the total/partial liquid ventilation animals when compared with the gas ventilation animals. Conclusions In a model of severe ARDS, Pulmonary gas exchange is improved during total followed by partial liquid ventilation. Pulmonary Compliance is improved during total, but not during partial liquid ventilation. Total followed by partial liquid ventilation was associated with a reduction in alveolar hemorrhage, Pulmonary edema, and lung inflammatory infiltration.
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total liquid ventilation with perfluorocarbons increases Pulmonary end expiratory volume and Compliance in the setting of lung atelectasis
1996Co-Authors: Richard Tooley, Ronald B Hirschl, Alan Parent, Robert H BartlettAbstract:Objective To compare Compliance and end-expiratory lung volume during reexpansion of normal and surfactant-deficient ex vivo atelectatic lungs with either gas or total liquid ventilation. Design Controlled, animal study using an ex vivo lung preparation. Setting A research laboratory at a university medical center. Subjects Thirty-six adult cats, weighing 2.5 to 4.0 kg. Interventions Heparin (300 U/kg) was administered, cats were killed, and lungs were excised en bloc. Normal lungs and salinelavaged, surfactant-deficient lungs were allowed to passively collapse and remain atelectatic for 1 hr. Lungs then were placed in a plethysmogragh and ventilated for 2 hrs with standardized volumes of either room air or perfluorocarbon. Static Pulmonary Compliance and end-expiratory lung volume were measured every 30 mins. Measurements and Main Results Reexpansion of normal atelectatic lungs with total liquid ventilation was associated with an 11-fold increase in end-expiratory lung volume when compared with the increase in end-expiratory lung volume observed with gas ventilation (total liquid ventilation 50 plus minus 14 mL, gas ventilation 4 plus minus 9 mL, p less than .0001). The difference was even more pronounced in the surfactant-deficient lungs with an approximate 19-fold increase in end-expiratory lung volume observed in the total liquid ventilated group, compared with the gas ventilated group (total liquid ventilation 44 plus minus 17 mL, gas ventilation 2 plus minus 8 mL, p equals .0001). Total liquid ventilation was associated with an increase in Pulmonary Compliance when compared with gas ventilation in both normal and surfactant-deficient lungs (normal: gas ventilation 6 plus minus 1 mL/cm H2 O, total liquid ventilation 14 plus minus 4 mL/cm H2 O, p less than .0001; surfactant-deficient: gas ventilation 4 plus minus 1 mL/cm H2 O, total liquid ventilation 9 plus minus 3 mL/cm H2 O, p less than .01). Conclusions End-expiratory lung volume and static Compliance are increased significantly following attempted reexpansion with total liquid ventilation when compared with gas ventilation in normal and surfactant-deficient, atelectatic lungs. The ability of total liquid ventilation to enhance recruitment of atelectatic lung regions may be an important means by which gas exchange is improved during total liquid ventilation when compared with gas ventilation in the setting of respiratory failure.
Philip C. Withers - One of the best experts on this subject based on the ideXlab platform.
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Pulmonary Compliance and lung volume are related to terrestriality in anuran amphibians
2014Co-Authors: Philip C. Withers, Michael S. Hedrick, Robert C. Drewes, Stanley S. HillmanAbstract:AbstractDehydration tolerance of anuran amphibians is directly related to their ability to mobilize lymphatic reserves, with more terrestrial species having more effective lymph mobilization dependent on specialized skeletal muscles acting directly on the lymph sacs and via Pulmonary ventilation. Consequently, we tested the hypothesis that Pulmonary Compliance, lung volume, and femoral lymphatic sac volume were related to terrestriality—and, hence, lymph mobilization—for 18 species of aquatic, semiaquatic, or terrestrial anuran amphibians. Lung Compliance and volume were significantly related to body mass, but there was no significant phylogenetic pattern. There were significant habitat-related patterns for mass-corrected and phylogenetically corrected residuals for these Pulmonary variables. Femoral lymph volume was significantly related to body mass, with no significant phylogenetic pattern, and there was only a weak correlation for habitat with mass-corrected and phylogenetically corrected residuals. T...
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Pulmonary Compliance and lung volume varies with ecomorphology in anuran amphibians: implications for ventilatory-assisted lymph flux
2011Co-Authors: Michael S. Hedrick, Stanley S. Hillman, Robert C. Drewes, Philip C. WithersAbstract:SUMMARY Vertical movement of lymph from ventral regions to the dorsally located lymph hearts in anurans is accomplished by specialized skeletal muscles working in concert with lung ventilation. We hypothesize that more terrestrial species with greater lymph mobilization capacities and higher lymph flux rates will have larger lung volumes and higher Pulmonary Compliance than more semi-aquatic or aquatic species. We measured in situ mean and maximal Compliance (Δvolume/Δpressure), distensibility (%Δvolume/Δpressure) and lung volume over a range of physiological pressures (1.0 to 4.0 cmH2O) for nine species of anurans representing three families (Bufonide, Ranidae and Pipidae) that span a range of body masses and habitats from terrestrial to aquatic. We further examined the relationship between these Pulmonary variables and lymph flux for a semi-terrestrial bufonid (Rhinella marina), a semi-aquatic ranid (Lithobates catesbeianus) and an aquatic pipid (Xenopus laevis). Allometric scaling of Pulmonary Compliance and lung volume with body mass showed significant differences at the family level, with scaling exponents ranging from ∼0.75 in Bufonidae to ∼1.3 in Pipidae. Consistent with our hypothesis, the terrestrial Bufonidae species had significantly greater Pulmonary Compliance and greater lung volumes compared with semi-aquatic Ranidae and aquatic Pipidae species. Pulmonary distensibility ranged from ∼20 to 35% cmH2O–1 for the three families but did not correlate with ecomorphology. For the three species for which lymph flux data are available, R. marina had a significantly higher (P
Andreas Fahlman - One of the best experts on this subject based on the ideXlab platform.
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inflation and deflation pressure volume loops in anesthetized pinnipeds confirms compliant chest and lungs
2014Co-Authors: Andreas Fahlman, Vanessa Fravel, Martin Haulena, Shawn P. Johnson, William Van Bonn, Stephen H. LoringAbstract:We examined structural properties of the marine mammal respiratory system, and tested Scholander’s hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia (Pacific harbor seal, Phoca vitulina; northern elephant seal, Mirounga angustirostris; northern fur seal Callorhinus ursinus; California sea lion, Zalophus californianus; and Steller sea lion, Eumetopias jubatus). We found that the chest wall Compliance (CCW) of all five species was greater than lung Compliance (airways and alveoli, CL) as predicted by Scholander, which suggests that the chest provides little protection against alveolar collapse or lung squeeze. We also found that specific respiratory Compliance was significantly greater in wild animals than in animals raised in an aquatic facility. While differences in ages between the two groups may affect this incidental finding, it is also possible that lung conditioning in free-living animals may increase Pulmonary Compliance and reduce the risk of lung squeeze during diving. Overall, our data indicate that Compliance of excised pinniped lungs provide a good estimate of total respiratory Compliance.
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inflation and deflation pressure volume loops in anesthetized pinnipeds confirms compliant chest and lungs
2014Co-Authors: Andreas Fahlman, Vanessa Fravel, Martin Haulena, Shawn P. Johnson, William Van Bonn, Stephen H. Loring, Andrew W TritesAbstract:We examined structural properties of the marine mammal respiratory system, and tested Scholander’s hypothesis that the chest is highly compliant by measuring the mechanical properties of the respiratory system in five species of pinniped under anesthesia (Pacific harbor seal, Phoca vitulina; northern elephant seal, Mirounga angustirostris; northern fur seal Callorhinus ursinus; California sea lion, Zalophus californianus; and Steller sea lion, Eumetopias jubatus). We found that the chest wall Compliance (CCW) of all five species was greater than lung Compliance (airways and alveoli, CL) as predicted by Scholander, which suggests that the chest provides little protection against alveolar collapse or lung squeeze. We also found that specific respiratory Compliance was significantly greater in wild animals than in animals raised in an aquatic facility. While differences in ages between the two groups may affect this incidental finding, it is also possible that lung conditioning in free-living animals may increase Pulmonary Compliance and reduce the risk of lung squeeze during diving. Overall, our data indicate that Compliance of excised pinniped lungs provide a good estimate of total respiratory Compliance.
Ronald B Hirschl - One of the best experts on this subject based on the ideXlab platform.
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evaluation of gas exchange Pulmonary Compliance and lung injury during total and partial liquid ventilation in the acute respiratory distress syndrome
1996Co-Authors: Ronald B Hirschl, Richard Tooley, Alan C Parent, Kent J Johnson, Robert H BartlettAbstract:Objective To investigate whether Pulmonary Compliance and gas exchange will be sustained during ``total'' perfluorocarbon liquid ventilation followed by ``partial'' perfluorocarbon liquid ventilation when compared with gas ventilation in the setting of the acute respiratory distress syndrome (ARDS). Study Design A prospective, controlled, laboratory study. Setting A university research laboratory. Subjects Ten sheep, weighing 12.7 to 25.0 kg. Interventions Lung injury was induced in ten young sheep, utilizing a right atrial injection of 0.07 mL/kg of oleic acid followed by saline Pulmonary lavage. Bijugular venovenous extracorporeal life support access, a Pulmonary artery catheter, and a carotid artery catheter were placed. When the alveolar-arterial O2 gradient was more than equals 600 torr and PaO2 less than equals 50 torr (less than equals 6.7 kPa) with an FIO2 of 1.0, extracorporeal life support was instituted. For the first 30 mins on extracorporeal life support, all animals were ventilated with gas. Animals were then ventilated with equal tidal volumes of 15 mL/kg during gas ventilation (n equals 5) over the ensuing 2.5 hrs, or with total liquid ventilation for 1 hr, followed by partial liquid ventilation for 1.5 hrs (total/partial liquid ventilation, n equals 5). Measurements and Main Results An increase in physiologic shunt (gas ventilation equals 69 plus minus 11%, total/partial liquid ventilation equals 71 plus minus 3%) and a decrease in static total Pulmonary Compliance measured at 20 mL/kg inflation volume (gas ventilation equals 0.48 plus minus 0.03 mL/cm H2 O/kg, total/partial liquid ventilation equals 0.50 plus minus 0.17 mL/cm H2 O/kg) were observed in both groups with induction of lung injury. Physiologic shunt was significantly reduced during total and partial liquid ventilation when compared with physiologic shunt observed in the gas ventilation animals (gas ventilation equals 93 plus minus 8%, total liquid ventilation equals 45 plus minus 11%, p less than .001; gas ventilation equals 95 plus minus 3%, partial liquid ventilation equals 61 plus minus 12%, p less than .001), while static Compliance was significantly increased in the total, but not the partial liquid ventilated animals when compared with the gas ventilated group (gas ventilation equals 0.43 plus minus 0.03 mL/cm H2 O/kg, total liquid ventilation equals 1.13 plus minus 0.18 mL/cm H2 O/kg, p less than .001; gas ventilation equals 0.41 plus minus 0.02 mL/cm H2 O/kg, partial liquid ventilation equals 0.47 plus minus 0.08, p equals .151). In addition, the extracorporeal life support flow rate required to maintain adequate oxygenation was significantly lower in the total/partial liquid ventilation group when compared with that of the gas ventilation group (gas ventilation equals 89 plus minus 7 mL/kg/min, total liquid ventilation equals 22 plus minus 10 mL/kg/min, p less than .001; gas ventilation equals 91 plus minus 12 mL/kg/min, partial liquid ventilation equals 41 plus minus 11 mL/kg/min, p less than .001). Lung biopsy light microscopy demonstrated a marked reduction in alveolar hemorrhage, lung fluid accumulation, and inflammatory infiltration in the total/partial liquid ventilation animals when compared with the gas ventilation animals. Conclusions In a model of severe ARDS, Pulmonary gas exchange is improved during total followed by partial liquid ventilation. Pulmonary Compliance is improved during total, but not during partial liquid ventilation. Total followed by partial liquid ventilation was associated with a reduction in alveolar hemorrhage, Pulmonary edema, and lung inflammatory infiltration.
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total liquid ventilation with perfluorocarbons increases Pulmonary end expiratory volume and Compliance in the setting of lung atelectasis
1996Co-Authors: Richard Tooley, Ronald B Hirschl, Alan Parent, Robert H BartlettAbstract:Objective To compare Compliance and end-expiratory lung volume during reexpansion of normal and surfactant-deficient ex vivo atelectatic lungs with either gas or total liquid ventilation. Design Controlled, animal study using an ex vivo lung preparation. Setting A research laboratory at a university medical center. Subjects Thirty-six adult cats, weighing 2.5 to 4.0 kg. Interventions Heparin (300 U/kg) was administered, cats were killed, and lungs were excised en bloc. Normal lungs and salinelavaged, surfactant-deficient lungs were allowed to passively collapse and remain atelectatic for 1 hr. Lungs then were placed in a plethysmogragh and ventilated for 2 hrs with standardized volumes of either room air or perfluorocarbon. Static Pulmonary Compliance and end-expiratory lung volume were measured every 30 mins. Measurements and Main Results Reexpansion of normal atelectatic lungs with total liquid ventilation was associated with an 11-fold increase in end-expiratory lung volume when compared with the increase in end-expiratory lung volume observed with gas ventilation (total liquid ventilation 50 plus minus 14 mL, gas ventilation 4 plus minus 9 mL, p less than .0001). The difference was even more pronounced in the surfactant-deficient lungs with an approximate 19-fold increase in end-expiratory lung volume observed in the total liquid ventilated group, compared with the gas ventilated group (total liquid ventilation 44 plus minus 17 mL, gas ventilation 2 plus minus 8 mL, p equals .0001). Total liquid ventilation was associated with an increase in Pulmonary Compliance when compared with gas ventilation in both normal and surfactant-deficient lungs (normal: gas ventilation 6 plus minus 1 mL/cm H2 O, total liquid ventilation 14 plus minus 4 mL/cm H2 O, p less than .0001; surfactant-deficient: gas ventilation 4 plus minus 1 mL/cm H2 O, total liquid ventilation 9 plus minus 3 mL/cm H2 O, p less than .01). Conclusions End-expiratory lung volume and static Compliance are increased significantly following attempted reexpansion with total liquid ventilation when compared with gas ventilation in normal and surfactant-deficient, atelectatic lungs. The ability of total liquid ventilation to enhance recruitment of atelectatic lung regions may be an important means by which gas exchange is improved during total liquid ventilation when compared with gas ventilation in the setting of respiratory failure.
