Table 1.
Terminology for Mechanical Ventilation
| Driving pressure (ΔP) | ΔP = Pplat - PEEP or ΔP = VT / CRS |
| Plateau pressure (Pplat) | Measured during an inspiratory pause on the ventilator, it reflects the mean pressure in the alveoli and small airways. |
| Respiratory system compliance (CRS) | Crs = VT / (Pplat - PEEP) |
| Ventilator-induced lung injury (VILI) | The term coined to emphasize that while the ventilator can be life saving it can also be injurious depending on the settings. VILI refers to worsening lung function caused by application of mechanical ventilation to predisposed lungs. |
| Elastance (E) | Elastance (stiffness): change in pressure for a given change in volume (E = ΔP / ΔV). Elastance is the inverse of Compliance (E = 1 / Compliance) |
| Transpulmonary pressure (PTP) | Airway pressure - pleural pressure or pressure difference inside versus outside the lung (PTP = Pairway - Ppleural). This is the pertinent distending pressure of the lung. |
| Pleural pressure (PPI) | Pressure within the pleural space surrounding the lung sometimes estimated using esophageal manometry. |
| Atelectrauma | Lung injury caused by high shear forces from cyclic opening and collapse of atelectatic but recruitable lung units. |
| Biotrauma | Extrapulmonary organ injury caused by proinflammatory and other circulating mediators systemically released during injurious ventilation. |
VT, tidal volume.