Question

What is the airflow resistance (Raw) when the PIP is 50 cm H2O, the Pplat is 15 cm H2O, and the set ventilator gas flow rate is 60 L/min?

a.1 cm H2O/L/s
b.17 cm H2O/L/s
c.35 cm H2O/L/s
d.58 cm H2O/L/s

Answer 1

To calculate airflow resistance (Raw), subtract Pplat from PIP, and divide by the flow rate converted to L/s. The calculation yields a Raw of 35 cm H2O/L/s, making option c the correct answer.

Step-by-step explanation:

The question involves calculating the airflow resistance (Raw) in a mechanical ventilation setting. The resistance can be calculated using the formula Raw = (PIP - Pplat) / Flow, where PIP is the peak inspiratory pressure, Pplat is the plateau pressure, and Flow is the gas flow rate converted to L/s. To solve this:

• First, convert the flow rate from L/min to L/s: 60 L/min × (1 min / 60 s) = 1 L/s.
• Next, subtract the Pplat from the PIP: 50 cm H20 - 15 cm H20 = 35 cm H20.
• Finally, divide the pressure difference by the flow rate: 35 cm H20 / 1 L/s = 35 cm H20/L/s.

The airflow resistance is therefore 35 cm H20/L/s, making option c (35 cm H2O/L/s) the correct answer.