Real Time Lung Imaging for the Detection of Lung Injury and AlveolarFluid Movement During Mechanical Ventilation

摘要

Experimental ventilator-induced lung injury (VILI) is characterized by alterations in alveolar epithelial andmicrovascular permeability that favors the systemic dissemination of lung borne cytokines or bacteria. Animal models ofVILI have been shown relevant to patient care and outcome and help explaining why most patients with the acuterespiratory distress syndrome do not die from respiratory failure but from multiple organ dysfunction. Recentexperimental studies also showed that adverse ventilator patterns may propel airway secretions and bacteria to previouslyhealthy lung regions. Noninvasive imaging techniques were used for years to study the net rate of protein flow across thepulmonary microvascular endothelium and the alveolar epithelium in vivo, during normal breathing and lung inflation.More recently, the two-way protein fluxes across the alveolo-capillary barrier and the intra-pulmonary dispersion ofalveolar edema have been monitored during mechanical ventilation. These experiments have provided new insights on themechanisms of experimental VILI that may be of clinical value. This review will describe the evolution of thesetechniques and their main physiological and pharmacological applications in the era of VILI