Comparison of lung protection strategies using conventional and high-frequency oscillatory ventilation

This study compared pathophysiological and biochemical indexes of acute lun g injury in a saline-lavaged rabbit model with different ventilatory strate gies: a control group consisting of moderate tidal volume (VT) (10-12 ml/kg ) and low positive end-expiratory pressure (PEEP) (4-5 cmH(2)O); and three protective groups: 1) low VT (5-6 ml/kg) high PEEP, 2-3 cmH(2)O greater tha n the lower inflection point; 2) low VT (5-6 ml/kg), high PEEP (8-10 cmH(2) O); and 3) high-frequency oscillatory ventilation (HFOV). The strategy usin g PEEP > inflection point resulted in hypotension and barotrauma. HFOV atte nuated the decrease in pulmonary compliance, the lung inflammation assessed by polymorphonuclear leukocyte infiltration and tumor necrosis factor-alph a concentration in the alveolar space, and pathological changes of the smal l airways and alveoli. Conventional mechanical ventilation using lung prote ction strategies (low VT high PEEP) only attenuated the decrease in oxygena tion and pulmonary compliance. Therefore, HFOV may be a preferable option a s a lung protection strategy.