Resolution of pulmonary edema with variable mechanical ventilation in a porcine model of acute lung injury

• Published in: Canadian journal of anesthesia 2011-08, Vol.58 (8), p.740-750
• Main Authors: Graham, M. Ruth, Gulati, Harleena, Kha, Lan, Girling, Linda G., Goertzen, Andrew, Mutch, W. Alan C.
• Format: Article
• Language: English
• Subjects: Acute Lung Injury - pathology; Acute Lung Injury - therapy; Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthesiology; Animals; Biological and medical sciences; Cardiology; Critical Care Medicine; Disease Models, Animal; Edema; Extravascular Lung Water - metabolism; Hemodynamics; Intensive; Mechanics; Medical sciences; Medicine; Medicine & Public Health; Oleic Acid - toxicity; Pain Medicine; Pediatrics; Pneumology/Respiratory System; Pulmonary Edema - diagnosis; Pulmonary Edema - etiology; Pulmonary Edema - pathology; Pulmonary Gas Exchange; Reports of Original Investigations; Respiration, Artificial - methods; Respiratory distress syndrome; Respiratory Distress Syndrome, Adult - pathology; Respiratory Distress Syndrome, Adult - therapy; Swine; Thermodilution; Time Factors; Tomography; Tomography, X-Ray Computed; Variables
• ISSN: 0832-610X; 1496-8975
• DOI: 10.1007/s12630-011-9517-3

Objective Resolution of the acute respiratory distress syndrome (ARDS) requires clearance of pulmonary edema. Biologically variable ventilation (BVV) strategies that improve gas exchange, lung mechanics, and inflammatory mediators in ARDS may be beneficial in this regard. We used quantitative computed tomography (CT), a single indicator thermodilution system (PiCCO®) to determine extravascular lung water (EVLW), and the change in edema protein concentration over time to compare edema clearance with BVV vs conventional mechanical ventilation (CMV) in a porcine ARDS model. Methods Sixteen pigs with oleic acid lung injury were randomized to four hours of ventilation with either CMV ( n  = 8) or BVV ( n  = 8) at identical low tidal volume and minute ventilation over time. Hemodynamic variables, gas exchange, lung mechanics, and PiCCO derived EVLW were determined hourly. Computed tomography images and edema fluid samples were obtained at baseline lung injury and after four hours of ventilation. Wet and dry lung weights were determined postmortem. Results At four hours with BVV, peak airway pressure was decreased significantly and lung compliance improved compared with CMV ( P  = 0.003; P