“…Another possible explanation is that 12 mmHg of CO 2 PP does not affect young pigs in the same way as it does humans. Lentschner et al [13] failed to show any effect of up to 15 mmHg of CO 2 PP in MAP, CO, PAP, or systemic arterial resistance in pigs, and they concluded that PPinduced hemodynamic changes are dependent on species. Others, who have studied piglets, such as Graham et al [4], have found alterations in at least some of these parameters, so species differences cannot be the only factor.…”