Question

What is the Cs when the returned tidal volume is 700 mL, the PEEP is 10 cm H2O, the PIP is 45 cm H2O, and the Pplat is 35 cm H2O?

a.0.160 L/cm H2O
b.0.020 L/cm H2O
c.0.028 L/cm H2O
d.0.735 L/cm H2O

Answer 1

The compliance (Cs) is 0.028 L/cm H2O.

The compliance (Cs) can be calculated using the formula Cs = Vt / (Pplat - PEEP), where Vt is the tidal volume, Pplat is the plateau pressure, and PEEP is the positive end-expiratory pressure. Given that the tidal volume is 700 mL, the PEEP is 10 cm H2O, the Pplat is 35 cm H2O, we can substitute these values into the formula:

Cs = 700 mL / (35 cm H2O - 10 cm H2O)

Cs = 700 mL / 25 cm H2O

Cs = 28 mL/cm H2O

Therefore, the compliance (Cs) is 0.028 L/cm H2O, which is option c.