Principles of Mechanical Ventilation 8: I:E ratio example 2 in VC constant flow

[@purdycreekstables115]

I'm a student , just getting into MV...your videos are extremely helpful and user friendly...Thank You so much for taking the time to do these for us...much appreciated !!!

[@RespiratoryReview]

Got a question about how we calculated I:E of 1:5.7 from Ti of 0.6 and Te of 3.4. You have to ask "how many times greater than inspiration is expiration?" in this case the expiration (3.4sec) is 5.7 x greater than the inspiration (0.6sec). So the I:E is 1:5.7. 3.4sec/0.6sec = 5.7sec. As a convention we report the I:E ratio as 1:(x) when the expiration is longer than the inspiration (most of the time). In this case the (x) is 5.7.

[@guitar-jp9rp]

On my test it had a 1:1 and they wanted to know what flow would give me a 1:2. The only info of choices were different flows. I didn't have vt or rr, how do I figure this out. ty

[@meronleggese2892]

Thank you It was very helpful.

[@sofamoh5203]

how this can be applicable in the ventilator? I think there is a choice to change manuplate the ratio to be 1:2 or 1:3 whatever the time of inspiration and expiration>> is this right?

[@RespiratoryReview]

There is that option on a lot of ventilators (to control your I:E ratio). Many anesthesia machines ONLY let you control I:E ratio (you can't manipulate the flow). Here's how its applicable: Think about what would happen if you had a FIXED I:E ratio (of 1:3 for example) and you began to increase your RR. The TCT would become shorter as you increase your RR, meaning inspiration would have to take place faster to ensure the same ratio of inspiration to expiration. But in VC we still have to deliver the same tidal volume each breath. To do this the vent will deliver the tidal volume we've chosen at a higher flow, to ensure there is enough time to give expiration its portion of the 1:3 ratio. This increased inspiratory flow will increase your peak inspiratory pressures. You have the choice in volume control on most ventilators to either have a fixed I:E ratio, or a fixed flow (with various flow patterns). I'm not saying one way is better than the other. You just need to understand the principles so you know what will happen in both situations. Maybe i'll do a video on VC with fixed I:E ratio, rather than fixed flow. Hope that helps OP

[@sofamoh5203]

I get it ,, thank you very much , i really appreciate , waiting for your most valuable vidios , thank you sir

[@kayy4511]

This is answered in the video

[@CyberJuanito]

Thank you so much!

[@NoNo-zj5hx]

thank you!!!!!!!

[@sinclair657]

Thank you, the volume is very low

[@rahulsoren8419]

What is IE stands for ?