Comparison between effects of pressure support and pressure-controlled ventilation on lung and diaphragmatic damage in experimental emphysema
نویسندگان
چکیده
BACKGROUND In patients with emphysema, invasive mechanical ventilation settings should be adjusted to minimize hyperinflation while reducing respiratory effort and providing adequate gas exchange. We evaluated the impact of pressure-controlled ventilation (PCV) and pressure support ventilation (PSV) on pulmonary and diaphragmatic damage, as well as cardiac function, in experimental emphysema. METHODS Emphysema was induced by intratracheal instillation of porcine pancreatic elastase in Wistar rats, once weekly for 4 weeks. Control animals received saline under the same protocol. Eight weeks after first instillation, control and emphysema rats were randomly assigned to PCV (n = 6/each) or PSV (n = 6/each) under protective tidal volume (6 ml/kg) for 4 h. Non-ventilated control and emphysema animals (n = 6/group) were used to characterize the model and for molecular biology analysis. Cardiorespiratory function, lung histology, diaphragm ultrastructure alterations, extracellular matrix organization, diaphragmatic proteolysis, and biological markers associated with pulmonary inflammation, alveolar stretch, and epithelial and endothelial cell damage were assessed. RESULTS Emphysema animals exhibited cardiorespiratory changes that resemble human emphysema, such as increased areas of lung hyperinflation, pulmonary amphiregulin expression, and diaphragmatic injury. In emphysema animals, PSV compared to PCV yielded: no changes in gas exchange; decreased mean transpulmonary pressure (Pmean,L), ratio between inspiratory and total time (Ti/Ttot), lung hyperinflation, and amphiregulin expression in lung; increased ratio of pulmonary artery acceleration time to pulmonary artery ejection time, suggesting reduced right ventricular afterload; and increased ultrastructural damage to the diaphragm. Amphiregulin correlated with Pmean,L (r = 0.99, p < 0.0001) and hyperinflation (r = 0.70, p = 0.043), whereas Ti/Ttot correlated with hyperinflation (r = 0.81, p = 0.002) and Pmean,L (r = 0.60, p = 0.04). CONCLUSIONS In the model of elastase-induced emphysema used herein, PSV reduced lung damage and improved cardiac function when compared to PCV, but worsened diaphragmatic injury.
منابع مشابه
Pressure-support improves lung protection and reduces cardiovascular dysfunction compared to pressure-controlled ventilation in experimental emphysema
Introduction Acute exacerbations of pulmonary emphysema lead to increased morbidity, mortality and, in some cases, requirement of invasive mechanical ventilation (MV) [1]. So far, no study has compared the biological impact of pressurecontrolled ventilation (PCV) versus pressure-support ventilation (PSV) in experimental emphysema. Our aims were to develop an elastase-induced emphysema model in ...
متن کامل0435. Pressure-support ventilation compared to pressure-controlled ventilation in experimental emphysema
Introduction Emphysema is characterized by irreversible enlargement of the airspaces distal to the terminal bronchiole, accompanied by destruction of their walls, and impairment of cardiac function. Acute exacerbation of emphysema leads to increased morbidity, mortality and, in some cases, requirement of invasive mechanical ventilation (MV). So far, no study has compared the impact of pressure-...
متن کاملComparison of the effect of pressure support ventilation and volume assured pressure support ventilation on weaning patients off mechanical ventilation after cardiac surgery
Background: Weaning from mechanical ventilation in the intensive care unit is an important step in the treatment process. More patients in less than 6 hours after cardiac surgery can be separated from mechanical ventilation and extubated. However, 20-40% of patients after cardiac surgery, due to dysfunctional ventilator weaning response (DVWR), still remain under mechanical ventilation. Therefo...
متن کاملComparison of the Effects of Prone and Supine Positions on Abdominal Distention in the Premature Infants Receiving Nasal Continuous Positive Airway Pressure (NCPAP)
Background: Premature infants with respiratory distress syndrome (RDS) are in dire need of respiratory support with a ventilator. However, the high tidal volume of mechanical ventilation may cause lung injury, and researchers have been concerned with the use of nasal continuous positive airway pressure (NCPAP). NCPAP has concomitant side effects, such as abdominal distention, which might disrup...
متن کاملEarly Effectiveness of Noninvasive Positive Pressure Ventilation on Right Ventricular Function in Chronic Obstructive Pulmonary Disease Subjects with Acute Hypercapnic Respiratory Failure
Introduction: Noninvasive positive pressure ventilation (NIPPV) has become an integral tool in the management of acute hypercapnic respiratory failure (AHRF) in chronic obstructive pulmonary disease (COPD). This study was performed to evaluate the early effects of NIPPV on pulmonary artery pressure (PAP), serum N-terminal pro BNP (NT-proBNP), and ventilatory parameters in the COPD patients with...
متن کامل