Fig. 6. Shunt fraction before and after unilateral ventilator-induced lung injury to the test lung of animals in the negative end-expiratory pressure (NEEP) group ( filled symbols ) and in the positive end-expiratory pressure (PEEP) group ( open symbols ). Horizontal dashes indicate means. * P < 0.05 test versus control lung, within group. † P < 0.05 test lung of the NEEP group versus test lung of the PEEP group.