What is the I:E ratio for a ventilator set at a rate of 20 breaths/minute with an inspiratory time of 0.6 seconds?

To determine the I:E ratio, you first need to calculate the total cycle time, which consists of both the inspiratory time and the expiratory time. The ventilator is set to deliver 20 breaths per minute, meaning each breath is given a cycle time calculated as follows:

1. Calculate the total cycle time (TCT) in seconds:
   • TCT = 60 seconds / 20 breaths = 3 seconds per breath.

2. Since the inspiratory time is given as 0.6 seconds, the remaining time for exhalation can be found by subtracting the inspiratory time from the total cycle time:

   • Expiratory Time (ET) = TCT - Inspiratory Time = 3 seconds - 0.6 seconds = 2.4 seconds.

3. Now, you can calculate the I:E ratio by comparing the inspiratory time to the expiratory time:

   • I:E ratio = Inspiratory Time : Expiratory Time = 0.6 seconds : 2.4 seconds.

4. To simplify this ratio, divide both sides by 0.6:

   • 0.6 / 0.6 : 2.4 / 0.6 =