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Old 04-13-2011
podebrad's Avatar
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Help Artificial Ventilation

Can someone please help me with learning about Mechanical Ventilation?

I would like to know about PEEP, minute ventilation, and the different settings that need to be achieved according to different situations.

It would be very helpful to know about some source for learning this too. I am finding it very difficult at the moment.

Thanks in advnz.....

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Old 04-13-2011
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Send me your email
Ill share knowledge with you my friend...
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Old 04-13-2011
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Arrow sure

Hi pinedamp,
ok, in order to mechanically ventilate any one you have 2 considerations:
1. Oxygenation
2. Ventilation

each of these 2 are influenced by different factors:
When you think of oxygenation, you are talking O2 issues. so how can this happen?
1) decrease O2 available ( ex. CO poisoning)
-----> if problem is pure lack of O2 then just increasing O2 will help
2) oxygenation is also effected by your alveolar- capillary , surface area and thickness, so anything that effects that will effect oxygenation. You need to change you PEEP and PIP( depending on ventilator mode, could be volume or I:E ratio) as for exam just think peep.
This can be in form of emphysema decreased surface area or fibrosis increased thickness for exchange. This in turn effects your compliance ( ability of lungs to expand given certain pressure) and recoil ( resistance)
Compliance decreases in some conditions (such as ARDS, or any fluids) in lungs, in this case it takes alot of prssure to open alveoli and this will not happen every breath for all alveoli and eventually leads to --> Atelectasis.
To avoid this you use PEEP, it keeps a certain p. (ex. 5 cm H2O) at the end of each breath in the lungs to prevent fully closing alveoli and thus prevent further damage and impove oxygenation.

when you talk Ventilation, it is CO2 exchange. and mainly you will effect this by :
Tidal Volume and Respiratory rate.
What is important however is Minute volume which is TV x RR
so you want to increase CO2 clearance---> increase Minute vol. and decrese MV to retain CO2.
now should you do this by TV or RR increase depends on the case:
Example: ARDS you would want to use lower volumes such 6ml/kg because you want to avoid barotrauma and volutrauma so if you need more ventilation you increase RR.
if no exceptions just think of the normal values and try to fix the one that is not set properly.

a note on peep-> be careful on setting peep at higher than 5, always evaluate effect on cardio.

lol,... having said all the crazy explanation, which i hope it helps, here is
AARC guidelines for adjusting ventilator settings, if you just wanna know #:
1. PaCo2 greater than 45 (or EtCo2 greater than 50)
  • Increase RR
  • Increase VT
2. PaCo2 less than 35 (or EtCO2 less than 30)
  • Decrease Rate
  • Decrease VT
3. PO2 less than 60 (or SpO2 less than 90%)
  • Increase FiO2 to 60%
  • Increase PEEP
  • Increase FiO2 to 100%
4. SpO2 greater than 95% (or appropriate oxygenation for patient)
  • Reduce FiO2 to 60%
  • Reduce PEEP to 5
here is sources you might find helpful:

hope this was helpful to you
Carpe Diem
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Old 04-14-2011
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Smile Thnks

thanks a lot buddy....
tht really helps...
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Old 04-17-2011
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Default thx a lot

Originally Posted by Medtobe View Post
Hi pinedamp,.....hope this was helpful to you
thx this is very useful
“Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. ”
Albert Einstein
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