The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
G Schmalisch - One of the best experts on this subject based on the ideXlab platform.
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Functional Residual Capacity measurement by heptafluoropropane in ventilated newborn lungs in vitro and in vivo validation
Critical Care Medicine, 2006Co-Authors: Hans Proquitte, Ariane Kusztrich, Volker Auwarter, Fritz Pragst, Roland R Wauer, G SchmalischAbstract:Objective: Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure Functional Residual Capacity and ventilation homogeneity. The aim of the present study was to validate Functional Residual Capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. Design: Prospective laboratory and animal trial. Setting: Animal laboratory in a university setting. Subjects: Sixteen newborn piglets (age <12 hrs, median weight 1390 g [705-4200 g]) before and after surfactant depletion (Pao 2 <100 torr in Fio 2 = 1.0) by lung lavage. Interventions: Heptafluoropropane was measured with a new infrared mainstream sensor connected with the flow sensor of the Drager Babylog 8000. Accuracy and precision of the measurement technique were tested in a mechanical lung model with a volume range from 11 to 35 mL. Reproducibility of the method and its sensitivity to detect changes of Functional Residual Capacity were assessed in vivo by variation of ventilatory variables. Measurements and Main Results: In vitro the absolute error of Functional Residual Capacity was <1 mL (relative errors <3%) with a coefficient of variation <4%. The coefficient of variation of consecutive in vivo measurements was only slightly higher (<5.1%). Measurement of heptafluoropropane concentrations in blood showed no significant accumulation for repeated Functional Residual Capacity measurements within short time periods. After lung lavage, the Functional Residual Capacity decreased from 20.9 mL/kg to 14.5 mL/kg (p <.05) despite increased ventilatory pressures, and lung clearance index (p <.001) and moment ratios (p <.01) increased significantly due to uneven alveolar ventilation. In healthy lungs, the increase in peak inflation pressure and positive end-expiratory pressure by 3-4 cm H 2 O had only a moderate effect on Functional Residual Capacity (20.9 ± 8.6 vs. 26.0 ±11.9 mL/kg, p =.17) and no effect on ventilatory homogeneity, whereas in surfactant-depleted lungs the Functional Residual Capacity increased from 14.5 ± 6.7 mL/kg to 29.9 ± 12.6 mL/kg (p <.001) and lung clearance index and moment ratios decreased significantly (p <.01). Conclusions: Heptafluoropropane is a suitable tracer gas for precise Functional Residual Capacity measurements tested in vitro and allows for reproducible measurements in ventilated small lungs without any adverse effects on mechanical ventilation. The sensitivity of the method is sufficiently high to demonstrate the effect of changes in ventilatory settings on the Functional Residual Capacity and ventilation homogeneity.
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Functional Residual Capacity measurement by heptafluoropropane in ventilated newborn lungs: in vitro and in vivo validation.
Critical Care Medicine, 2006Co-Authors: Hans Proquitte, Ariane Kusztrich, Volker Auwarter, Fritz Pragst, Roland R Wauer, G SchmalischAbstract:Objective: Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure Functional Residual Capacity and ventilation homogeneity. The aim of the present study was to validate Functional Residual Capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. Design: Prospective laboratory and animal trial. Setting: Animal laboratory in a university setting. Subjects: Sixteen newborn piglets (age
Terry P Clemmer - One of the best experts on this subject based on the ideXlab platform.
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automated sulfur hexafluoride washout Functional Residual Capacity measurement system for any mode of mechanical ventilation as well as spontaneous respiration
Critical Care Medicine, 1990Co-Authors: Thomas D. East, Nathan L. Pace, Paulien J Wortelboer, Erik Van Ark, Frederick H Bloem, Lisheng Peng, Robert O Crapo, Debbie Drews, Terry P ClemmerAbstract:A new sulfur hexalfluoride (SF6) washout Functional Residual Capacity (FRC) measurement system has been developed which will work with any mode of mechanical ventilation, as well as with spontaneous respiration. This system was evaluated in three different human studies. In the first two studies, th
Hans Proquitte - One of the best experts on this subject based on the ideXlab platform.
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Functional Residual Capacity measurement by heptafluoropropane in ventilated newborn lungs in vitro and in vivo validation
Critical Care Medicine, 2006Co-Authors: Hans Proquitte, Ariane Kusztrich, Volker Auwarter, Fritz Pragst, Roland R Wauer, G SchmalischAbstract:Objective: Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure Functional Residual Capacity and ventilation homogeneity. The aim of the present study was to validate Functional Residual Capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. Design: Prospective laboratory and animal trial. Setting: Animal laboratory in a university setting. Subjects: Sixteen newborn piglets (age <12 hrs, median weight 1390 g [705-4200 g]) before and after surfactant depletion (Pao 2 <100 torr in Fio 2 = 1.0) by lung lavage. Interventions: Heptafluoropropane was measured with a new infrared mainstream sensor connected with the flow sensor of the Drager Babylog 8000. Accuracy and precision of the measurement technique were tested in a mechanical lung model with a volume range from 11 to 35 mL. Reproducibility of the method and its sensitivity to detect changes of Functional Residual Capacity were assessed in vivo by variation of ventilatory variables. Measurements and Main Results: In vitro the absolute error of Functional Residual Capacity was <1 mL (relative errors <3%) with a coefficient of variation <4%. The coefficient of variation of consecutive in vivo measurements was only slightly higher (<5.1%). Measurement of heptafluoropropane concentrations in blood showed no significant accumulation for repeated Functional Residual Capacity measurements within short time periods. After lung lavage, the Functional Residual Capacity decreased from 20.9 mL/kg to 14.5 mL/kg (p <.05) despite increased ventilatory pressures, and lung clearance index (p <.001) and moment ratios (p <.01) increased significantly due to uneven alveolar ventilation. In healthy lungs, the increase in peak inflation pressure and positive end-expiratory pressure by 3-4 cm H 2 O had only a moderate effect on Functional Residual Capacity (20.9 ± 8.6 vs. 26.0 ±11.9 mL/kg, p =.17) and no effect on ventilatory homogeneity, whereas in surfactant-depleted lungs the Functional Residual Capacity increased from 14.5 ± 6.7 mL/kg to 29.9 ± 12.6 mL/kg (p <.001) and lung clearance index and moment ratios decreased significantly (p <.01). Conclusions: Heptafluoropropane is a suitable tracer gas for precise Functional Residual Capacity measurements tested in vitro and allows for reproducible measurements in ventilated small lungs without any adverse effects on mechanical ventilation. The sensitivity of the method is sufficiently high to demonstrate the effect of changes in ventilatory settings on the Functional Residual Capacity and ventilation homogeneity.
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Functional Residual Capacity measurement by heptafluoropropane in ventilated newborn lungs: in vitro and in vivo validation.
Critical Care Medicine, 2006Co-Authors: Hans Proquitte, Ariane Kusztrich, Volker Auwarter, Fritz Pragst, Roland R Wauer, G SchmalischAbstract:Objective: Heptafluoropropane is an inert gas commercially used as propellant for inhalers. Since heptafluoropropane can be detected in low concentrations, it could also be used as a tracer gas to measure Functional Residual Capacity and ventilation homogeneity. The aim of the present study was to validate Functional Residual Capacity measurements by heptafluoropropane wash-in/wash-out (0.8%) during mechanical ventilation in small, surfactant-depleted lungs using a newborn piglet model. Design: Prospective laboratory and animal trial. Setting: Animal laboratory in a university setting. Subjects: Sixteen newborn piglets (age
Thomas D. East - One of the best experts on this subject based on the ideXlab platform.
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automated sulfur hexafluoride washout Functional Residual Capacity measurement system for any mode of mechanical ventilation as well as spontaneous respiration
Critical Care Medicine, 1990Co-Authors: Thomas D. East, Nathan L. Pace, Paulien J Wortelboer, Erik Van Ark, Frederick H Bloem, Lisheng Peng, Robert O Crapo, Debbie Drews, Terry P ClemmerAbstract:A new sulfur hexalfluoride (SF6) washout Functional Residual Capacity (FRC) measurement system has been developed which will work with any mode of mechanical ventilation, as well as with spontaneous respiration. This system was evaluated in three different human studies. In the first two studies, th
O Werner - One of the best experts on this subject based on the ideXlab platform.
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Functional Residual Capacity and ventilation homogeneity in mechanically ventilated small neonates
Journal of Applied Physiology, 1992Co-Authors: Carsten Vilstrup, Burkhard Lachmann, Lars J Bjorklund, Anders Larsson, O WernerAbstract:A modification of a computerized tracer gas (SF6) washout method was designed for serial measurements of Functional Residual Capacity (FRC) and ventilation homogeneity in mechanically ventilated very-low-birth-weight infants with tidal volumes down to 4 ml. The method, which can be used regardless of the inspired O2 concentration, gave accurate and reproducible results in a lung model and good agreement compared with He dilution in rabbits. FRC was measured during 2–4 cmH2O of positive end-expiratory pressure (PEEP) in 15 neonates (700–1,950 g), most of them with mild-to-moderate respiratory distress syndrome. FRC increased with body weight and decreased (P less than 0.05) with increasing O2 requirement. Change to zero end-expiratory pressure caused an immediate decrease in FRC by 29% (P less than 0.01) and gave FRC (ml) = -1.4 + 17 x weight (kg) (r = 0.83). Five minutes after PEEP was discontinued (n = 12), FRC had decreased by a further 16% (P less than 0.01). The washout curves indicated a near-normal ...
