Time for answers! As many of you surmised, this patient is not happy with the current settings.
Also, the ventilator *might* be lying to you about its mode... #SoMe4MV
Also, the ventilator *might* be lying to you about its mode... #SoMe4MV
The most obvious issue here is flow starvation. The patient's effort suggests they want a much higher flow and/or Vt. Compare the waveform to the idealized VC waveform of a passive patient. The flow goes below the PEEP baseline! 
Not only is this uncomfortable, and probably deleterious, but it will lead you to believe your Ppeak and maybe your Pplat are lower than they actually are!
More on flow starvation here coemv.ca/flow-starvatio…
More on flow starvation here coemv.ca/flow-starvatio…
Notice also the hump in the flow waveform - certainly not standard looking for VC!
Given the robust inspiratory flow, the machine switched into *pressure support*! See the Servo manual for details. Compliments to @Thind888 on the ref
Given the robust inspiratory flow, the machine switched into *pressure support*! See the Servo manual for details. Compliments to @Thind888 on the ref
@Thind888 This is where ventilator mode taxonomy comes into play.
The canonical reference is here (in #FOAMcc form)
doi.org/10.4187/respca…
The canonical reference is here (in #FOAMcc form)
doi.org/10.4187/respca…
@Thind888 @emireles_c A rational way to name modes includes these variables. Notably, they are not fancy brand names or confusing titles like PRVC...
@Thind888 @emireles_c VC on this Servo ventilator is actually
VC-
IMV (!)
d,d (dual, dual)
"Dual" means the mode of ventilation can change *within* a breath! And that is what is happening here with the "hump" in the waveform
VC-
IMV (!)
d,d (dual, dual)
"Dual" means the mode of ventilation can change *within* a breath! And that is what is happening here with the "hump" in the waveform
@Thind888 @emireles_c We need a common language to communicate amongst ourselves, and amongst different vents. Look at all the names for modes and how they mean different things on different vents!
@Thind888 @emireles_c Think of the implications of this (essential) misnaming.
As an example, what is PRVC actually?
As an example, what is PRVC actually?
@Thind888 @emireles_c "Pressure Regulated Volume Control" is super confusing!
This is
PC
CMV
a (adaptive)
The machine adjusts pressure (based on Pmusc) to reach a target Vt. There are major implications to this!
This is
PC
CMV
a (adaptive)
The machine adjusts pressure (based on Pmusc) to reach a target Vt. There are major implications to this!
@Thind888 @emireles_c Summary:
- Know the control variable, sequence, and targeting scheme for your ventilator(s)! It may be different than what you think
- Please don't leave a patient in flow starvation! Decide if you can liberalize their settings, or if you need tight control, take over!
- Know the control variable, sequence, and targeting scheme for your ventilator(s)! It may be different than what you think
- Please don't leave a patient in flow starvation! Decide if you can liberalize their settings, or if you need tight control, take over!
@Thind888 @emireles_c Compliments to @emireles_c who not only made me aware of all these issues as a fellow, but was of course one of the first correct respondents to the question!
@threadreaderapp please unroll
