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Spatial and temporal heterogeneity of ventilator-associated lung injury after surfactant depletion
- Source :
- Journal of applied physiology (Bethesda, Md. : 1985). 104(5)
- Publication Year :
- 2008
-
Abstract
- Volutrauma and atelectrauma have been proposed as mechanisms of ventilator-associated lung injury, but few studies have compared their relative importance in mediating lung injury. The objective of our study was to compare the injury produced by stretch (volutrauma) vs. cyclical recruitment (atelectrauma) after surfactant depletion. In saline-lavaged rabbits, we used high tidal volume, low respiratory rate, and low positive end-expiratory pressure to produce stretch injury in nondependent lung regions and cyclical recruitment in dependent lung regions. Tidal changes in shunt fraction were assessed by measuring arterial Po2 oscillations. After ventilating for times ranging from 0 to 6 h, lungs were excised, sectioned gravitationally, and assessed for regional injury by evaluation of edema formation, chemokine expression, upregulation of inflammatory enzyme activity, and alveolar neutrophil accumulation. Edema formation, lung tissue interleukin-8 expression, and alveolar neutrophil accumulation progressed more rapidly in dependent lung regions, whereas macrophage chemotactic protein-1 expression progressed more rapidly in nondependent lung regions. Temporal and regional heterogeneity of lung injury were substantial. In this surfactant depletion model of acute lung injury, cyclical recruitment produced more injury than stretch.
- Subjects :
- Pathology
medicine.medical_specialty
Ventilator-associated lung injury
Physiology
Nitric Oxide Synthase Type II
Inflammation
Enzyme-Linked Immunosorbent Assay
Pulmonary Edema
Respiratory physiology
Lung injury
Physiology (medical)
medicine
Animals
Interleukin 8
Lung
Chemokine CCL2
Peroxidase
Ventilators, Mechanical
business.industry
Respiratory disease
Interleukin-8
Pulmonary Surfactants
Lung Injury
respiratory system
medicine.disease
Pulmonary edema
respiratory tract diseases
Oxygen
medicine.anatomical_structure
Neutrophil Infiltration
Calibration
Respiratory Mechanics
Cytokines
Fluid Therapy
Female
Rabbits
medicine.symptom
Blood Gas Analysis
Chemokines
business
Subjects
Details
- ISSN :
- 87507587
- Volume :
- 104
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Journal of applied physiology (Bethesda, Md. : 1985)
- Accession number :
- edsair.doi.dedup.....6ce35b905c438a746f0f64d66197d9ad