Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and the progressive nature heightens the calamity of the disease. In existing COPD studies, lung mechanics are often reported under positive-pressure ventilation (PPV) and extrapolations made from these studies pose restrictions as recent works have divulged disparate elastic and energetic results between PPV and more physiological negative-pressure ventilation (NPV) counterparts. This nonequivalence of PPV and NPV must be investigated under diseased states to augment our understanding of disease mechanics. To assess the comparability of diseased pulmonary mechanics in PPV and NPV, we pose a novel study to parse out the currently entangled contributions of ventilation mode and diseased state by analyzing murine PV curves from porcine pancreatic elastase (PPE) and hog dust extract (HDE) induced COPD models under positive and negative pressures. We find that, for PPE-exposed, under NPV, volume, compliance (