Ventilator Modes (Mechanical Ventilation - Lecture 7)

[@rbekele]

Great video and thanks for sharing. I don't know why anyone would dislike any kind of helpful video on youtube. This is a guy who put his time and effort to help others and he gets a " dislike" from somebody.

[@abdulrhmanalzoman1169]

Thank you so much doctor, this video helps me a lot as biomedical engineer responsible of anesthesia machine. Wish you all the best

[@sunving]

Thank you Dr Strong ,this is my second time watching this. Your lecture series are the best out there.

[@Tararrtma777]

This man is GREAT! Easy to understand, thorough and to the point.

[@peterfslife]

HIS VIDEOS ARE JUST THROUGH THE ROOF. I speak for all the students of him, and anyone who knows him when I say, "HE IS JUST PURELY GENIUS!!!!." We need more people like this, and MUCH MORE videos like this on YOuTube.

[@StrongMed]

Traditionally, "assist control" mode implied a volume-targetted form of ventilation, however, many modern ventilators have a "A/C pressure control" mode which is similar to what I refer to as "pressure control" ventilation in the video. In general, for most patients, volume-targetted ventilation (e.g. "A/C volume control") is preferred since it will guarantee a certain minute ventilation. In pressure-targetted ventilation, unnoticed changes in lung compliance can result in hypoventilation.

[@StrongMed]

Adding some clinical scenarios is a great suggestion! I'm adding it to my to-do list, though it may take a while to get to it...

[@agd712]

bump !

[@goerizal1]

i would like to be nonderogatory to the three who dislike this but they are really unfortunately putting it kindly. this is teaching only for the sake of teaching, free to be taken in any way. his students are most fortunate. what i would give to have him as an attending in my internship/resident life.. but that was very long ago. thanks for the post

[@slraccord99]

OMG!!! I find this video very easy to follow and understand. I have to read certain chap of Egan 2-3 times at least, just to absorb the concept. This is in like 20 min versus 8 hours X 3 days! lol. Anyhow, my sister is currently a RCP at the VA Palo Alto and she has done her clinical rotations at Stanford also. I get some help from her but I rarely see her since she works FT at VA and PT at UCSF, so I read solo, study w/ classmates, and youtube videos. Thank-you in posting these helpful videos.

[@StrongMed]

goerizal1, thanks for your comment. Don't worry, I don't take the "dislikes" personally. Not every lecture resonates with every viewer. Glad you enjoyed it though!

[@tobym6491]

thank you so much, lucky are your students( i am a med student) and people working around you! you are a wealth of knowledge,!

[@StrongMed]

J Kaur, I'm glad you found these videos helpful. To be honest, the reason that the series of videos on mechanical ventilation are among the earliest I've posted is because I couldn't find a good general resource for this information already out there (either on the web, or in print). I'm not convinced there is any one great up-to-date ICU textbook out there, and much of the info in these videos is taken from literature. If anyone has suggestions for books, please feel free to post them here.

[@sunving]

Thank you very much Doctor strong, I once again watch this video.

[@cedomird.petrovic9687]

I have difficulties with terminology. What is synchronized with wich? And what is nature of that synchronization?

[@StrongMed]

...To be honest, I can't remember the last time I did not defer the trigger setting to respiratory therapy, but I'm fairly certain that non-synchronized breaths in SIMV can be either flow or pressure triggered. (By definition, non-synch'd breaths can't be time triggered, so they must be either flow and/or pressure triggered.) If there are any RTs here that know for certain, feel free to comment!

[@yusranaz2872]

This video is very informative

[@StrongMed]

It's impossible to generalize how to manage a situation in which a traumatic brain injury pt also has high risk of barotrauma. Most of the time, these patients will probably be treated with volume-targetted ventilation with an eye on the pCO2 (and also on O2 sat and PEEP), but it's all dependent on how difficult ventilating the patient is, what the peak pressures are like, and how high risk the pt is for barotrauma. Best advice is to consult a neuro-critical care specialist or experienced RT.

[@StrongMed]

strings11235, great question! There is a relationship between pressure, flow, and resistance that is analogous to Ohm's law in electricity, whereby (airway pressure - intraalveolar pressure) is approx. equal to (flow x resistance). As the lungs expand during inspiration, the increase in volume is proportional to the increase in intraalveolar pressure in a ratio that is defined by the respiratory system's (lung + chest wall) compliance...

[@StrongMed]

...As the intraalveolar pressure increases, as airway resistance is roughly constant, in order to maintain constant flow, the airway pressure must increase by the same amount as intraalveolar pressure (in order to satisfy the Ohm's law relationship). So with the most basic approximation, when the flow is constant, airway pressure should increase linearly with delivered volume...

[@tammiewanless4899]

Hi Eric, I'm a new RN and I would like to print out the graphs on the modes to use as a reference while on the floor. Is their a way to print a slide?

[@StrongMed]

If you send me a personal message through KZbin and include your email, I'll be happy to send you a pdf version of the video from which you can print off whichever diagrams/charts you find most helpful. (Be sure to not post your email as a public comment unless you love getting spam...)

[@subtoneskumalo2875]

[e-mail]

[@strings11235]

Dear Dr. Strong, thank you very much for your amazing lectures and for the time you've spent to create all of this lectures. If you don't mind, I have a question regarding Assist/Control mode. You said that A/C mode is flow (volume) control, so can I assume that the pressure value will be determined by airway resistances,compliance and patient's inspiratory effort? If I'm correct, then doesn't the pressure waveform in the A/C chart wouldn't remain the same through all of the ventilation process?

[@letouh]

thank you for this video, excuse my english, I am from france... in SIMV mode, when the patient triggers , the machine give him a flow or pressure control? and in 13:35 non-synch.breaths , trigger: pressure or flow? i thought that pressure and flow triggers are always associeted with synchronized cycles thank you for response

[@strings11235]

So, which mode and variable should we control in those situation? If I may suggest, could you add some clinical scenario like in your ABG's lecture so we can know which mode is better in some patient should we encounter those situation.

[@strings11235]

Thank you very much Dr. Strong for the answers. I'm terribly sorry to bother you by asking many questions. I really do appreciate your help. Once again, thank you Dr. Strong!

[@paygondapatil8341]

strings11235 Matingtimeinbodyproses

[@gaiaderegibus8837]

Thank you from Italian Med Students too! :D

[@Kay_2016]

I like those historical pecture videos

[@strings11235]

Thank you Dr. Strong! Your explanation is really great. I have another question. I've read that some book say that in A/C mode we can choose to set the pressure instead the volume, so from what I understood that in A/C mode there is pressure control too. Is that right, Dr. Strong? If that's right, then when should we choose to control the volume or pressure? Is it just for the reason when the change in volume or pressure is undesirable?

[@sunving]

Thank you Doctor Strong ! may be i need to watch couple more time .

[@s.s6404]

Perfect job

[@lenalidayag2717]

Dr.i am a rt student can i ask how does the PIP and Pplat of the NMD affected when there are hook in MV it i will increase or decrease!thnks

[@jkaur5246]

i just joined icu 2 months ago and seriously im in a shock state. im a registered nurses and im trying to catch up with icu setting esp the ventilators. this really helps. please do send me more on this and books if there is any to my email.

[@jbeckwithnbacer]

Is there a maximum flow that you can not go beyhound . And if there is what would be theses figures . I know there's a lot of factors dead space injury ect , just was wondering .

[@StrongMed]

I'm not familiar with any specific number for a maximum flow in conventional mechanical ventilation. Increasing high flow is typically limited by high pressures, with higher pressures (high plateau pressure probably more so that high peak pressures) being predictive of increased risk of barotrauma. In other words, it's usually the max desired plateau pressure that determines the max flow. Although there isn't even any specific cutoff for max recommended plateau pressure (it's just higher numbers lead to more barotrauma), but around a plateau pressure of 35 H2O is where the risk of barotrauma is anecdotally found to start to increase significantly in ARDS. Some experts recommend trying to keep P plateau below 30 H2O in ARDS.

[@jbeckwithnbacer]

Thank you that helped with the question I was having .

[@GJKSTUDIO]

can someone help me... If the machine is controlling pressure is it always " time cycled "? If the machine is controlling volume is it always "volume cycled"?

[@blaschito1]

outstanding resource

[@dr.nageshparekar3869]

Amazing. Thanks

[@StrongMed]

...Pressure-targetted ventilation (e.g. A/C pressure control) is better when a patient is at uncommonly high risk of barotrauma.

[@strings11235]

Maybe, such in a patient with the high risk of barotrauma then it's better to control the pressure? If we encounter some situations which changes in both pressure and volume is undesirable, such as in a patient with severe traumatic brain injury patient and high risk of barotrauma, in that patient shouldn't we limit the tidal volume so that CO2 level wouldn't be too high to cause increase in intracranial pressure ; but shouldn't we limit the pressure applied too.

[@criticalmass500]

Pressure control assist control mode is common. You should specify while describing assist control that you are describing volume controlled assist control mode.

[@ahmology]

in AC why does the airway resistance increase and what does airway resistance have to do with hypotension? pls help

[@StrongMed]

What specific part of the video are you referring to? Do you actually mean auto-PEEP instead of airway resistance?

[@ahmology]

Strong Medicine to the disadvantages of AC, here in hyperventilated pat. Hypotension occures. The mechanism is rather Not clear. Thanks alot and sorry for the disturbance

[@mohammedalameen4540]

Good teaching method 10q

[@StrongMed]

...In reality, the increase in airway pressure isn't as perfectly linear as the volume delivered because both lung compliance and airway resistance vary at different lung volumes.

[@pavasphysio]

So helpful in my physical therapy review!

[@ozam35]

Do you have website ?

[@limmeilanlim3216]

Excellent!

[@StrongMed]

slraccord99, I'm glad you found the videos helpful. I know just about all of the RTs at the Palo Alto VA, so I'm sure I know your sister too.

[@sabrinarosli366]

Helpful for physiotherapist working in the ICUs =D

[@myradeleon8618]

thank you so much for this great lecture

[@Stonefalconetti]

You should improve the volume of sound in your videos..... I'm on my laptop and my volume is at Max and still can't hear well.... Lol

[@StrongMed]

In SIMV, if the patient triggers a breath that the vent decides (based on an algorithm) to synchronize with the "mandatory" breaths, the vent will give a breath that is flow controlled (guaranteeing a specific volume for that breath). If the vent decides that the breath will be non-synchronized (i.e. it is a breath above the vent's set respiratory rate), it is pressured controlled...

[@purnashrestha2377]

u presentation is nice

[@knunniek.9304]

Thanks

[@drrevision964]

Thank you sir

[@letouh]

thank you very much for you answer...it's very clear now...

[@drhamidmaqury8476]

sound is low

[@Suzi_P]

Thank you so much for this

[@katieoldham804]

Hard to hear what is being said

[@Suzi_P]

Thank you so much

[@ravindrasinghchouhan8712]

nice

[@ithagonimallikarjun4198]

Thanx for lecture it is informative and useful.

[@parthasarathidas7279]

Thank you so much sir :) Would like to know more about dual control modes

[@ResidentSIAnes]

Great

[@shadow33abram]

Thanks!

[@GROKA1984]

Der Ton ist sehr leise

[@drhariprasadkrishnamurthy1775]

Vhb

[@mohammedalameen4540]

Good teaching method 10q