is it possible to differentiate air leak vs auto PEEP from graphs only?

[ketap]

hi, i am studying about ventilator waveform..and i want to ask questions:
1. i notice that air leak and auto PEEP have many similar waveform.. is it possible to differentiate between these two only from the waveform?

2. with pressure volume loop, if our patient has an increased resistance..what should happen with the loop?some sources said that the inspiratory limb will be dragged right downward..
but some sources told me that it depends on which part of the loop has the increased resistance.
(ex. if there is increased expiratory resistance, the expiratory limb size should be increased,
but if it is an increased inspiratory resistance, the size of inspiratory limb will be the one who increased..)

i don't really understand this...isn't the resistance of the airway affect both inspiratory and expiratory phase?is there any such thing that cause only increased inspiratory resistance ( and not expiratory) or only expiratory resistance(and not inspiratory)?

please help..thank you

sincerely,Ketap

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[Hernandez]

hi, i am studying about ventilator waveform..and i want to ask questions:
1. i notice that air leak and auto PEEP have many similar waveform.. is it possible to differentiate between these two only from the waveform?

2. with pressure volume loop, if our patient has an increased resistance..what should happen with the loop?some sources said that the inspiratory limb will be dragged right downward..
but some sources told me that it depends on which part of the loop has the increased resistance.
(ex. if there is increased expiratory resistance, the expiratory limb size should be increased,
but if it is an increased inspiratory resistance, the size of inspiratory limb will be the one who increased..)

i don't really understand this...isn't the resistance of the airway affect both inspiratory and expiratory phase?is there any such thing that cause only increased inspiratory resistance ( and not expiratory) or only expiratory resistance(and not inspiratory)?

please help..thank you

sincerely,Ketap

1) not if all you have is a waveform without other maneuvers or clinical exam.

2. Chest wall compliance can affect airway inspiratory pressures without a proportional affect on expiratory pressures.

 

[jdh71]

ITT: dorks

 

[jdh71]

Funny thing about waveforms for me is I really end up using them very intuitively. I can't just sit there and explain them, wax philosophical about the physics, but I know when they're not right and I do things with the vent to fix them. I can't explain it. It's just the way I work.

 

[Hernandez]

 

[tartesos]

Funny thing about waveforms for me is I really end up using them very intuitively. I can't just sit there and explain them, wax philosophical about the physics, but I know when they're not right and I do things with the vent to fix them. I can't explain it. It's just the way I work.

And I hide the vent from other people with my body so they don't start asking questions and getting me out of my groove.



Sent from my iPhone using SDN mobile app

 

[ketap]

@ hernandez:the volume- time waveform shows air leak and air trapping but the expiratory flow does reach the baseline..so is this just a leak?or could it be an auto peep?
what kind of maneuver do you often use if u find the above display while patient is still on ventilator?thank you


best regards,Ketap

 

[Hernandez]

You won't see this often, it was a machine/sensor issue giving the nurses grief with the alarms. I had to replace the machine. Auto-peep and air leak should show continued flow on the flow scalar.

 

[ketap]

hi.hernandez:thx for sharing the case n explanation. i have one more question if u don't mind: in the pic below..the loop show us only an increase in expiratory limb suggesting that only the exp reistance is increased..but how is that possible without affecting the inspiratory limb?

 

[ketap]

shouldn't it be like this?an increased in both insp and exp limb?
thank you

sorry for bothering..best regards,Ketap

 

[Hernandez]

I'm far better with scalar over loops as loops have little help in a active breathing pt on vent Only thing I can think of off top of my head would be strider which you won't see on vent.

 

[mochief2000]

I would think a increase in airway resistance on the expiratory loop without the inspiratory loop would be a variable intrathoracic obstruction.

Thanks @Hernandez for the image above. I was scratching my head and confused at hell...