2004 Fiscal Year Final Research Report Summary
Mechanism of ventilator-induced lung injury and lung protective approach
Project/Area Number |
15591628
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Anesthesiology/Resuscitation studies
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Research Institution | The University of Tokushima (2004) Osaka University (2003) |
Principal Investigator |
NISHIMURA Masaji The University of Tokushima, Graduate School Institute of Health Bioscience, Professor, 大学院・ヘルスバイオサイエンス研究部, 教授 (10172701)
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Co-Investigator(Kenkyū-buntansha) |
FUJINO Yuji Osaka University, Hospital, Intensive Care Unit, Associate Professor, 医学部附属病院, 講師 (50252672)
UCHIYAMA Akinori Osaka University, Hospital, Intensive Care Unit, Assistant Professor, 医学部附属病院, 助手 (00324856)
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Project Period (FY) |
2003 – 2004
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Keywords | mechanical ventilation / lung injury / lung protective approach / pressure control ventilation / volume control ventilation / inspiratory flow |
Research Abstract |
A lung-protecting strategy is essential when ventilating acute lung injury/acute respiratory distress syndrome patients. Current emphasis is on limiting inspiratory pressure and volume. This study was designed to investigate the effect of peak inspiratory flow on lung injury. Methods : Twenty-four rabbits were anesthetized, tracheostomized, ventilated with a Siemens Servo 300, and randomly assigned to three groups as follows : 1) the pressure regulated volume control group received pressure-regulated volume control mode with inspiratory time set at 20% of total cycle time, 2) the volume control with 20% inspiratory time group received volume-control mode with inspiratory time of 20% of total cycle time, and 3) the volume control with 50% inspiratory time group received volume-control mode with inspiratory time of 50% of total cycle time. Tidal volume was 30 ml/kg, respiratory rate was 20 breaths/min, and positive end-expiratory pressure was 0 cmH_2O. After 6 h mechanical ventilation, th
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e lungs were removed for histologic examination. Results : When mechanical ventilation started, peak inspiratory flow was 28.8±1.4 l/min in the pressure regulated volume control group, 7.5±0.5 l/min in the volume control with 20% inspiratory time group, and 2.6±0.3 l/min in the volume control with 50% inspiratory time group. Plateau pressure did not differ significantly among the groups. Gradually during 6 h, PaO_2 in the pressure regulated volume control group decreased from 688±39 to a significantly lower 304±199 mm Hg (P<0.05) (mean±SD). The static compliance of the respiratory system for the pressure regulated volume control group also ended significantly lower after 6 h (P<0.05). Wet to dry ratio for the pressure regulated volume control group was larger than for other groups (P<0.05). Macroscopically and histologically, the lungs of the pressure regulated volume control group showed more injury than the other groups. Conclusion : When an injurious tidal volume is delivered, the deterioration in gas exchange and respiratory mechanics, and lung injury appear to be marked at a high peak inspiratory flow. Less
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Research Products
(1 results)