학술논문
Effect of PEEP and I:E ratio on cerebral oxygenation in ARDS: an experimental study in anesthetized rabbit
acute respiratory distress syndrome
acute respiratory distress syndrome
Document Type
Report
Source
BMC Anesthesiology. June 19, 2019, Vol. 19 Issue 1
Subject
Language
English
ISSN
1471-2253
Abstract
Author(s): Federica Lovisari[sup.1,2] , Gergely H. Fodor[sup.1] , Ferenc Peták[sup.3] , Walid Habre[sup.1,4] and Sam Bayat[sup.1,5,6] Background Positive-pressure mechanical ventilation is the mainstay of respiratory supportive therapy in patients with [...]
Background Although PEEP and inversed I:E ratio have been shown to improve gas exchange in ARDS, both can adversely affect systemic hemodynamics and cerebral perfusion. The goal of this study was to assess how changes in PEEP and I:E ratio affect systemic and cerebral oxygenation and perfusion in normal and injured lung. Methods Eight anesthetized Chinchilla-Bastard rabbits were ventilated at baseline with pressure-regulated volume control mode, V.sub.T = 6 ml/kg, PEEP = 6 cmH.sub.2O, FIO.sub.2 = 0.4; respiratory rate set for ETCO.sub.2 = 5.5%, and I:E = 1:2, 1:1 or 2:1 in random order. Ultrasonic carotid artery flow (CF), arterial (PaO.sub.2), jugular venous blood gases and near infrared spectroscopic cerebral oxygenation ([DELA]HBO.sub.2) were recorded for each experimental condition. After induced lung injury, the animals were ventilated with PEEP = 9 followed by 6 cmH.sub.2O. Results At baseline, inverse-ratio ventilation (IRV) significantly reduced cerebral oxygenation ([DELA]O.sub.2HB; - 27 at 1:2; - 15 at 1:1 vs. 0.27 [mu]mol/L at 2:1; p < 0.05), due to a significant reduction in mean arterial pressure and CF without modifying gas exchange. In injured lung, IRV improved gas exchange but decreased cerebral perfusion without affecting brain oxygenation. The higher PEEP level, however, improved PaO.sub.2 (67.5 [+ or -] 19.3 vs. 42.2 [+ or -] 8.4, p < 0.05), resulting in an improved [DELA]HBO.sub.2 (- 13.8 [+ or -] 14.7 vs. -43.5 [+ or -] 21.3, p < 0.05), despite a drop in CF. Conclusions Our data suggest that unlike moderate PEEP, IRV is not effective in improving brain oxygenation in ARDS. In normal lung, IRV had a deleterious effect on brain oxygenation, which is relevant in anesthetized patients. Keywords: Mechanical ventilation, Near-infrared spectrometry, Blood flow/regional, Acute respiratory distress syndrome, Lung function, Hemodynamics
Background Although PEEP and inversed I:E ratio have been shown to improve gas exchange in ARDS, both can adversely affect systemic hemodynamics and cerebral perfusion. The goal of this study was to assess how changes in PEEP and I:E ratio affect systemic and cerebral oxygenation and perfusion in normal and injured lung. Methods Eight anesthetized Chinchilla-Bastard rabbits were ventilated at baseline with pressure-regulated volume control mode, V.sub.T = 6 ml/kg, PEEP = 6 cmH.sub.2O, FIO.sub.2 = 0.4; respiratory rate set for ETCO.sub.2 = 5.5%, and I:E = 1:2, 1:1 or 2:1 in random order. Ultrasonic carotid artery flow (CF), arterial (PaO.sub.2), jugular venous blood gases and near infrared spectroscopic cerebral oxygenation ([DELA]HBO.sub.2) were recorded for each experimental condition. After induced lung injury, the animals were ventilated with PEEP = 9 followed by 6 cmH.sub.2O. Results At baseline, inverse-ratio ventilation (IRV) significantly reduced cerebral oxygenation ([DELA]O.sub.2HB; - 27 at 1:2; - 15 at 1:1 vs. 0.27 [mu]mol/L at 2:1; p < 0.05), due to a significant reduction in mean arterial pressure and CF without modifying gas exchange. In injured lung, IRV improved gas exchange but decreased cerebral perfusion without affecting brain oxygenation. The higher PEEP level, however, improved PaO.sub.2 (67.5 [+ or -] 19.3 vs. 42.2 [+ or -] 8.4, p < 0.05), resulting in an improved [DELA]HBO.sub.2 (- 13.8 [+ or -] 14.7 vs. -43.5 [+ or -] 21.3, p < 0.05), despite a drop in CF. Conclusions Our data suggest that unlike moderate PEEP, IRV is not effective in improving brain oxygenation in ARDS. In normal lung, IRV had a deleterious effect on brain oxygenation, which is relevant in anesthetized patients. Keywords: Mechanical ventilation, Near-infrared spectrometry, Blood flow/regional, Acute respiratory distress syndrome, Lung function, Hemodynamics