Table 1 ‘Motors’ of the lung and chest wall during positive and negative ventilation
From: The future of mechanical ventilation: lessons from the present and the past
| Â | Positive pressure ventilation | Negative pressure ventilation | |
|---|---|---|---|
Spontaneous | Artificial | ||
Respiratory system motor | Energy from ventilator generating the airway pressure (P aw) | Energy from muscular contraction generating muscular pressure (P musc) | Energy from device generating negative pressure (P neg) |
Lung motor | Transpulmonary pressure (P L) generated by positive increase of P aw and pleural pressure (P pl) | Transpulmonary pressure (P L) generated by decrease of pleural pressure (P pl) | Transpulmonary pressure (P L) generated by decrease of pleural pressure (P pl) |
Chest wall motor | Pleural pressure (P pl = P aw – P L) | Wall pressurea (P W = P musc – P pl) | Wall pressurea (P W = P neg – P pl) |