Electrical impedance tomography compared with thoracic computed tomography during a slow inflation maneuver in experimental models of lung injury

OBJECTIVE:To determine the validity of functional electric impedance tomography to monitor regional ventilation distribution in experimental acute lung injury, and to develop a simple electric impedance tomography index detecting alveolar recruitment. DESIGN:Randomized prospective experimental study. SETTING:Academic research laboratory. SUBJECTS:Sixteen anesthetized, tracheotomized, and mechanically ventilated pigs. INTERVENTIONS:Acute lung injury was induced either by acid aspiration (direct acute lung injury) or by abdominal hypertension plus oleic acid injection (indirect acute lung injury) in ten pigs. Six pigs with normal lungs were studied as a control group and with endotracheal suction-related atelectasis. After 4 hrs of mechanical ventilation, a slow inflation was performed. MEASUREMENTS AND MAIN RESULTS:During slow inflation, simultaneous measurements of regional ventilation by electric impedance tomography and dynamic computed tomography were highly correlated in quadrants of a transversal thoracic plane (r = .63–.88, p < .0001, bias