Effects of mechanical ventilation preconditioning on ventilator-induced lung injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of mechanical ventilation preconditioning on ventilatorinduced lung injury in rats.Methods Forty-eight healthy male Sprague-Dawley rats,weighing 250-300 g,were randomly assigned into 6 groups (n =8 each) using a random number tablecontrol group (group C),normal ventilation group (group N),mechanical ventilation with large tidal volume (VT) group (group L) and mechanical ventilation preconditioning group (group P).The animals were anesthetized with intraperitoneal 2 ％ pentobarbital sodium 0.2 ml/100 g.Tracheal intubation was performed.In group C,the animals kept spontaneous breathing after intubation.In group N,the animals were mechanically ventilated for 3 h with the VT of 8-10 ml/kg.The animals were mechanically ventilated for 3 h with the VT of 40 ml/kg in group L.In group P,the animals were mechanically ventilated for 30 min with the VT of 6 ml/kg,and then were mechanically ventilated for 3 h with the VT of 40 ml/kg (RR 40 bpm,IE =ll,PET CO2 35-45 mmHg).The animals were sacrificed at the end of ventilation,and the lungs were removed for measurement of wet to dry lung weight ratio (W/D ratio) and cell apoptosis and for microscopic examination of the pathological changes of the lung and the lung injury was scored.The apoptosis.index was calculated.Results Compared with group C,the lung injury score,W/D ratio,and apoptosis index were significantly increased in L and P groups,and no significant change was found in the parameters mentioned above in group N.Compared with group L,the lung injury score,W/D ratio,and apoptosis index were significantly decreased in group P.Conclusion Mechanical ventilation preconditioning can reduce ventilator-induced lung injury in rats.