PURPOSE: To evaluate the FiO2 effect at 0,21, 0,40 and 1,00 on the lung ischaemia-reperfusion injury. METHODS: Forty Wistar rats were randomly allocated in 4 groups. The group I was the control one, and in groups II, III, IV rats were ventilated during the ischaemia-reperfusion at 0,21, 0,40 and 1.00 FiO2 respectively. The ischaemia time was 30 minutes and the reperfusion time was 10 minutes. The model used was normothermic ischaemia-reperfusion, in situ. As assessment parameters, the systemic average arterial pressure (PAM), the oxygen arterial partial pressure/ inspired oxygen fraction relation (PO2/FiO2), the level of reduced glutathione (GSH) and barbituric acid substances reactive measure (TBARS) in the lung tissue and the lung wet/dry weight ratio were used. RESULTS: The results showed that the ventilation with FiO2 at 0,21, when compared with the ventilation at 0,40 and 1,00 FiO2 during the ischaemia-reperfusion period, presented lower PAM, better PO2/FiO2 relation, higher values in the reduced glutathione measures, lower production of the TBARS and lower formation of lung edema. CONCLUSION: The ventilation with low FiO2 (0.21) showed better results when compared to those performed with higher FiO2 (0,40 and 1,00) on the lung ischaemia-reperfusion injury.
Lung transplantation; Organ preservation; Reperfusion; Oxygen free radicals; Rats
