Controlled perfusion decreases reperfusion injury after high-flow reperfusion

Introduction: Some investigators have suggested that high pulmonary artery flow rates increase the risk of severe reperfusion injury after lung transplantation. We hypothesized that controlling the initial flow rate and pulmonary artery pressure would decrease the severity of lung dysfunction in the setting of high-flow reperfusion. Methods: Using our isolated, ventilated, blood-perfused rabbit lung model, all groups underwent lung harvest, 4-hour storage (4°C), and blood reperfusion. We measured pulmonary artery pressure, peak inspiratory pressure, arterial oxygenation, and wet-to-dry weight ratio. Group 1 (control, n = 8) underwent reperfusion at 60 ml/min for 30 minutes. Group 2 (high flow, n = 8) underwent reperfusion at 120 ml/min for 30 minutes. Group 3 (controlled flow, n = 8) underwent initial reperfusion at 60 ml/min for 5 minutes, followed by reperfusion at 120 ml/min for 25 minutes. Results: Group 1 had significantly improved pulmonary artery pressure, peak inspiratory pressure, arterial oxygenation, and wet-to-dry weight ratio measurements compared with groups 2 and 3 after 30 minutes of reperfusion. However, Group 3 had improved pulmonary artery pressure, peak inspiratory pressure, arterial oxygenation, and wet-to-dry weight ratio measurements compared with Group 2. Conclusions: High-flow reperfusion results in severe reperfusion injury after lung transplantation. Controlled reperfusion using a low initial flow rate decreases the severity of reperfusion injury associated with high-flow rates.