(see also Ventilator Management; Ventilator Modes; Weaning Parameters)

Lung volumes are divided into four “volumes” and four “capacities.” A capacity is a calculated value, based on the sum of two parameters. The most important for adequate gas exchange are:

• Inspiratory reserve volume (IRV)
• Tidal volume (VT)
• Functional residual capacity (FRC)

Figure 3.15

Figure 3.16