PEEP VENTILATION DOES NOT CAUSE HUMORALLY MEDIATED CARDIAC-OUTPUT DEPRESSION IN PIGS

Objective. This study was designed to see if humorally mediated negati ve inotropism contributes to the cardiac output (CO) depression seen d uring positive endexpiratory pressure (PEEP) ventilation. Design: 8 pa irs of piglets were used and a combined blood circulation was establis hed between the two animals in each pair. One animal was ventilated wi th a PEEP of 15 cmH2O (donor) and the other was ventilated without PEE P (recipient). Measurement and results: CO and stroke volume deteriora ted in the donors by 32% and 44%, respectively, while no change was se en in the recipients. Conclusion: As humorally mediated negative inotr opism during PEEP ventilation has earlier been demonstrated in dogs, t he results suggest that this mechanism might be species-dependent.