[Oleic acid-induced interstitial lung edema in the dog: comparison of PEEP with high-frequency jet superimposed ZEEP...

Oleic acid (0.12 ml/kg) was used to induce pulmonary edema in 10 mongrel dogs. To treat the consequent hypoxaemia we used either positive end expiratory pressure (PEEP) ventilation (n = 5) or zero end expiratory pressure ventilation (ZEEP) plus additional high frequency jet support (n = 5). Hypoxaemia, which paralleled the dramatic increase in lung water, was significantly improved (aADO2) by PEEP but not by ZEEP plus jet. Also venous admixture was significantly lowered by PEEP only. Cardiac output and pulmonary arterial pressure in the two groups were not significantly different. This demonstrates that ZEEP plus jet is not superior to PEEP in the case of oleic acid induced edema, though we obtained good clinical results with the former system in the treatment of atelectasis. In addition, histological evaluation of the dog lungs showed emphysematous lung injury by the jet system, which indicates that such a jet system should be used with caution.