How to report Vent settings in the SICU

[ThinkFast007]

Hey guys.

i'm doing my SICU rotation right now.....got 2 patients that are on ventilators....could someone tell me how i should present to an attending? I know they need to know? I was told it once, but forgot and cant really find any sites that show the way one should write the values. As i recall it went something like:

Saturation|tidal vol|pH|resp rate?

Ok thats probably wrong...but i know u need to report 02 sat and TV in there. Also what else is 'important' to report? When does a pt get to get off the vent (is it when their RR is below 35? )

sorry...only a third year and this things got me working like crzy.

thanks for the input

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[jetproppilot]

Typically vent settings are reported by tidal volume, respiratory rate, FiO2, and, if in SIMV mode, amout of pressure support.
Sounds something like this:
"Mr. Migilicutty is a 65 year old gentleman in here for CHF exacerbation. Hospital day number three. He was intubated yesterday, and his ventilator settings are eight hundred, SIMV of twelve, fifty percent, and plus five. His saturations have been holding in the low nineties." Present in an organized, concise fashion..

 

[jetproppilot]

Look in one of you books for WEANING PARAMETERS. Theres different components, like a respiratory rate of less than twenty on an FiO2 of .5 or less, NIF (negative inspiratory effort) of -40, etc

 

[rn29306]

Common extubation criteria:

NIF greater than -20
resp rate less than 30/minute
TV>5cc/kg
VC>10cc/kg
PaO2 > 65 - 70 on FIO2 < 40%
PaCO2<50
Resting minute ventilation<10L/min

Handbook of Anesthesiology, a Current Clinical Strategies series

 

[ThinkFast007]

Thanks both of you!!!

Yah, perhaps I should buy that CCS Anesthesiology book...that whole series is generally real good.

I remember someone saying that you should report SIMV or AC or whatever it is the pt is on.

Thanks again!

 

[GasPundit]

...Resp rate of >30/min in an adult should signal not only ineligibility to extubate, but some vent settings need changing (increased PS, for instance).

 

[2ndyear]

1) Day of intubation/ventilation. When you get to about 10-12 days with a tube then you have to start thinking trach in the near future.
2) Current settings. Start with the mode (AC, PSV, etc), relevant numbers (PSV 12, CPAP 5; AC 10 PEEP 5), any troubling numbers (PIP 40). Don't forget the FiO2.
3) Current CXR if there is one and how it has changed from previous. Always look for the tube placement.
4) Recount previous 24 hours on the vent. For example: "He spent the day on PSV 12 and then developed an increased resp rate so we switched him to AC for the night."
5) Where you plan to go on the vent today. Example: "I think we should try to wean sedation and try PSV again today, if he tolerates that then we will try a 3 minute spontaneous breathing trial, if he passes we will go on to 30 minutes. As the FiO2 is down to 30% if he is awake enough to follow commands then we will consider extubation."

As for weaning, look for a good source and read it. Marino's ICU book has a great chapter on this. Several journal articles have been written and it sums them up nicely. Dr. Martin Tobin at Loyola University in Chicago did much of the work on this subject. Basically the key number is resp rate/tidal volume (f/Vt), also called the rapid shallow breathing index (RSBI), or even the Tobin index or the Yang-Tobin index depending on where you're at. The point is that when we are working hard to breathe, we breathe rapidly and shallow. Thus a high RR and low Vt. A number less than 100 is favorable providing that the FiO2 is low enough as is the PEEP.

In general, pts on vents should undergo a spontaneous breating trial (SBT) daily on a minimal level of pressure support, about 8 to overcome the tube and vent circuit and breathe spontaneously. If they pass the 3 min trial with a good f/Vt then they progress to a 30 min trial. If they pass this then extubation may be considered.

Of course passing the SBT and extubation are two different things. Especially in the SICU where you deal with a lot of head trauma, you may have someone breathing spontaneously with a GCS of 4-5. The issue of airway protection then arises. I can provide several articles on this if you wish, but obviously it can get to be a sticky situation.

 

[undecided05]

agree with 2nd year... also important to report ABG ph/CO2/O2/HCO/etc and also take a look at the Bicarb on the BMP/Chem8/chem14... remember calculated vs measured...

 

[Skip Intro]

Generally speaking and for most of what I've seen so far, there are only really four things that people care about when you round (and in this order):

Vent mode / set rate / tidal volume / FiO2

Of course, if the mode is assist-control and the patient is taking more than the set rate, then you should report what the actual respiratory rate is. Otherwise, if you are PEEPing the patient, then you can tack that on at the end. Or, if there is an issue with peak pressures, you should report that as well. SpO2 should also be reported if there is a continuing issue with oxygenation at the current settings. As others have said, the ABG is still the best test (and should be reported regardless, if recently done or done serially) for oxygenation and acid/base status. But, the latter three things become a bit academic after you've had a patient on a vent for a few days. At that point, the more important issue then becomes whether or not you're ready to try to wean them or trach them.

Hope that helps. As you can see, this is a really complex question you asked that, as this thread clearly demonstrates, has no real easy answer. Since you are an MS3 doing a SICU rotation, my recommendation is that it's probably best to demonstrate that you have mastered the basics.

-Skip

 

[ThinkFast007]

thanks again!

yah so far what i've been reporting is the
mode/RR/PEEP/FiO2 with of course the ABGs. theyve generally been satisfied with it so far. Nothing drastic has occurred yet (obviously she had issues or wouldnt be in the SICU). But all of ur thoughts on weaning are great. I need to start to incorporate that into my presentation somehow to show that i know what i'm doing with vents. its just that my pt's GCS is around 6T....

dont know how much twirking i can do with someone like that, i'll have to read.

 

[VentdependenT]

Mode/rate/TV/Fio2/peep
peak (compliance n' resistance)/plateau (compliance)
I include the patients actual rate as well when flyen over the gas (present ala maxwells).

Tidal volume is 10cc/kg
VC is 60-70cc/kg (start thinken tube time when you are in 30's)
I still don't exactly know what NIF is?

oxygen saturation affected by: Peep and Fio2
CO2 levels affected by: Minute volume (RR and TV) and DEAD SPACE (easy to manipulate).
Autopeepen is air trapping seen in bronchorestrictive dz states.
Use directional suction when appropriate per CXR's
Haldol is cool but propofol is the coolest

Marino is great for understanding vents and basically all yer ICU physiology basics. Pocket medicine section on respiratory failure is a nice source for quick reference but is far from complete. For what I believe is an excelent review of ABG's, check out the corresponding acid/base chapter in Basics of Anesthesia. Lange current critical care is a great book as well.

 

[VentdependenT]

Mode/rate/TV/Fio2/peep
peak (compliance n' resistance)/plateau (compliance)
I include the patients actual rate as well when flyen over the gas (present ala maxwells).

Tidal volume is 10cc/kg
VC is 60-70cc/kg (start thinken tube time when you are in 30's)
I still don't exactly know what NIF is?

oxygen saturation affected by: Peep and Fio2
CO2 levels affected by: Minute volume (RR and TV) and DEAD SPACE (easy to manipulate).
Autopeepen is air trapping seen in bronchorestrictive dz states.
Use directional suction when appropriate per CXR's
Haldol is cool but propofol is the coolest

Marino is great for understanding vents and basically all yer ICU physiology basics. Pocket medicine section on respiratory failure is a nice source for quick reference but is far from complete. For what I believe is an excelent review of ABG's, check out the corresponding acid/base chapter in Basics of Anesthesia. Lange current critical care is a great book as well.

For weaning: Do they want the tube out? Best predictor for success next to the shallow breathing index. Start by placing the pt on bipap for 30 min once a day and see if they can tolerate grab a gas at the end of the bipap trial and calculate the index. Your sedation is off of course..right?

 

[Skip Intro]

During my Pulm ICU month, Vent, we had a guy who only used the T-piece when attempting to wean. He was pretty anti-CPAP, and he seemed to think (at least anecdotally in his own experience) that he had better success predicting who was going to be successfully weaned that way. His logic was that the T-piece, in effect, created about an extra 20cm of anatomic dead space. If the patient could overcome this on a trial, then their complete respiratory mechanism was strong enough for them to breathe on their own. He said he just had too many re-intubations after what he thought was an adequate CPAP trial. Of course, the other pulmonologists in the service completely disagreed with him and thought he was off his rocker.

-Skip

 

[ThinkFast007]

During my Pulm ICU month, Vent, we had a guy who only used the T-piece when attempting to wean. He was pretty anti-CPAP, and he seemed to think (at least anecdotally in his own experience) that he had better success predicting who was going to be successfully weaned that way. His logic was that the T-piece, in effect, created about an extra 20cm of anatomic dead space. If the patient could overcome this on a trial, then their complete respiratory mechanism was strong enough for them to breathe on their own. He said he just had too many re-intubations after what he thought was an adequate CPAP trial. Of course, the other pulmonologists in the service completely disagreed with him and thought he was off his rocker.

-Skip

interesting....did this guys 'method' always work? creating artificial dead space seems to be a bright idea

 

[2ndyear]

The t-piece was actually what Dr. Tobin used in his original trial, so the attending that used that was a purist in the most true sense. I haven't seen it used as much as plain old minimal PSV though.

As for NIF's the only time I've seen those used are in the setting of myasthenia gravis where you measure them to see if the patient will buy the tube.

As for SpO2 just always remember that you can oxygenate dead people just fine. Ventilation is key.

The whole issue of weaning wouldn't even be important were it not for the fact that each day on a vent increases risks of vent associated pneumonia, and that re-intubation carries a very high morbidity and mortality.

 

[HunterGatherer]

I used the few pages in Step Up to Medicine to read up on Vent settings, weaning parameters, etc. Is there anything else out there that is short but a little more prose and descriptive that I can read during a lunch break or two in the medical library?

I'm in 3rd year medicine now but will be doing Peds ICU next month and 2 weeks of anesthesiology during my surgery rotation. What extra reading do I need for for peds vent settings? Thanks.

 

[RT2MD]

Mode/rate/TV/Fio2/peep
peak (compliance n' resistance)/plateau (compliance)
I include the patients actual rate as well when flyen over the gas (present ala maxwells).

Tidal volume is 10cc/kg
VC is 60-70cc/kg (start thinken tube time when you are in 30's)
I still don't exactly know what NIF is?

oxygen saturation affected by: Peep and Fio2
CO2 levels affected by: Minute volume (RR and TV) and DEAD SPACE (easy to manipulate).
Autopeepen is air trapping seen in bronchorestrictive dz states.
Use directional suction when appropriate per CXR's
Haldol is cool but propofol is the coolest

Marino is great for understanding vents and basically all yer ICU physiology basics. Pocket medicine section on respiratory failure is a nice source for quick reference but is far from complete. For what I believe is an excelent review of ABG's, check out the corresponding acid/base chapter in Basics of Anesthesia. Lange current critical care is a great book as well.

Dang it... as an RT, I was drawn to this thread... I saw this post above from Vent and got all excited - HE HAS RETURNED, I thought to myself. Then I saw the date of 3/05... crap.

Just made me think, as a *mostly* lurker... hope all is going well in his life.



JPP - you heard any good things? Hope you are hanging in there with this weather, as well.

-RT2MD

 

[RT2MD]

I used the few pages in Step Up to Medicine to read up on Vent settings, weaning parameters, etc. Is there anything else out there that is short but a little more prose and descriptive that I can read during a lunch break or two in the medical library?

I'm in 3rd year medicine now but will be doing Peds ICU next month and 2 weeks of anesthesiology during my surgery rotation. What extra reading do I need for for peds vent settings? Thanks.

Here is something that I posted a while back on another forum. Don't know if it will help you or not.

CPAP: This stands for "continuous positive airway pressure". This is a therapy that is adequate for obstructive sleep apnea, acute exacerbation of CHF with some pulmonary edema, etc. It is usually delivered by a face mask and is measured in cmH2O. This is a STRICTLY spontaneous mode: meaning that the patient is not getting ANY ventilatory support. If you have a patient whose ABG shows "normal" acid-base/CO2, but hypoxemia (that is refractory to increased FiO2) then CPAP might be a good place to go.

BIPAP: This stands for "Bilevel positive airway pressure". This is basically the same as having 2 levels of CPAP, a high and a low. The notation is usually written as follows: "Bipap 14/6" where 14 is the high level of pressure and 6 is the low (14 and 6 are just examples!). You can think of there being a base level of 6 cmH2O, but then when the patient either triggers a breath, or the machine is time cycled (a set rate), then the machine "kicks it up a notch" to the higher level of 14 cmH2O. This mode can be used with a facemask to provide NIPPV (non-invasive positive pressure ventilation). You can also set a back up rate, so your order would look like this: Bipap 14/6 rate of 12 FiO2 of 60%. If somebody is a DNR/DNI but wants to have something done to help alleviate work of breathing, then this is a good choice (say they had some respiratory acidosis perhaps with some hypoxemia). This can also get you through a CHF exacerbation while you pump out the Lasix! A big issue with this is the fact that a lot of people won't tolerate the mask (has to be very snug fit).

If the patient can't maintain their own airway, then obviously we have to put in an artificial airway (ET tube/trach/etc). Then you have to go to the vent terminology.

PEEP: The same as CPAP... just on a vent!
FiO2: Hopefully self explanatory!
Rate: Minimum frequency that the vent provides.
Tidal Volume: Vt - size of breath delivered (usually in mL)

CPAP trial: used as a weaning strategy to see how the patient can breathe spontaneously. CANNOT be sedated for this. Some people like to work patients daily (if they are stable enough), others like less frequently. I, personally, believe that daily CPAP trials aren't a bad thing if the patient is stable (as tolerated)... but I ALSO believe in NOT getting an ABG (unless pt has an A-line) on daily CPAP trials - judge them clinically. Usually a CPAP of 5 cmH2O is used, either with or without pressure support.

Pressure support: Basically the same as BIPAP on the vent. There is a set level of PEEP (low level of CPAP) and Pressure support (like the high level of CPAP in BIPAP). The pressure support helps the patient overcome the resistance of the ETT. This can also be used with higher levels for patients who might not be QUITE strong enough to completely support their own ventilation. Also, BE SURE NOT TO USE ON SOMEBODY WHO IS SEDATED!

Assist Control: Abbreviated AC, A/C, CMV. This is the basic mode of mechanical ventilation where we are doing ALL the work for the patient. You set a rate, tidal volume, PEEP and FiO2. If you have a set rate of 12 and the patient is breathing 16, then that is okay - the machine will give them 16 fully supported machine breaths a minute. There is also pressure control, where you set a inspiratory pressure instead of a tidal volume. On this mode the patients muscles aren't doing any work at all (even if they are over breathing the vent, the vent is still doing the work for them). You want to be sure to keep your plateau airway pressures below 30 cmH2O and also keep your tidal volume less then 10 ml/kg.

SIMV: This stands for "synchronized intermittent mechanical ventilation". This is like a mix between assist control and pressure support. You set a tidal volume (or pressure), a rate, PEEP and FiO2 for the machine breaths... but then you ALSO set a pressure support for if the patient over breathes the vent. EXAMPLE: You write an order "SIMV rate of 8, Vt: 750, PEEP: 5, FiO2: 60% Pressure support: 10" This means that the machine will give 8 breaths a minute at 750mL tidal volume. If the patient wants more than that then they can trigger more breaths, but they won't be 750ml breaths... they will be pressure supported at 10 cmH2O (like bipap).

Weaning: RSBI is the best predictor (although still not perfect) of successful extubation. You calculate it by taking RR/Vt (in Liters). So somebody who was breathing 20 times/min with a 200mL tidal volume would have a RSBI of 20/.2 = 100. You want the RSBI to be below 105 with a good NIF (maximal negative inspiratory force - measured in cmH2O) LESS than -20 and good ABG on the CPAP trial. Some say if you don't have at least a 10-12% re-intubation rate then you are not agressive enough.


That is all that I can write now... I worked all day today and tomorrow and have had a couple glasses of wine . There are more modes, but they are a bit more advanced. This is a good place to start. There is also a good website that I recommend: http://www.ccmtutorials.com/rs/mv/index.htm

I probably should have just given you this website instead of writing everything that I did... would have been more coherent, I imagine!

Let me know if this helps, or if you have any questions! Good luck to you!

-RT2MD

 

[FuzzyBK]

Peep is not the same as "CPAP... just on a vent."

 

[leviathan]

Peep is not the same as "CPAP... just on a vent."

The goals of the two are essentially the same.

 

[RT2MD]

Peep is not the same as "CPAP... just on a vent."

Please let me know of any regular clinical instance where you cannot just think of them being the exact same. If you have a PEEP of 5 and CPAP of 5, then as long as flows are high enough to meet the patient demand they are doing the same thing. They both are increasing mean airway pressure, FRC and improve V/Q mismatch.

I understand that if you are going into the definitions then there are some differences, your inhalation on PEEP could be negative whereas on CPAP IPAP and EPAP will always be positive.

Thank you.

 

[militarymd]

Peep is not the same as "CPAP... just on a vent."

No?????

then what's the difference?

perhaps you could post up a pressure/time pressure/flow and pressure/volume curve to educate us.

 

[fakin' the funk]

Peep is not the same as "CPAP... just on a vent."

Correct me if I'm wrong, but my mental shortcut on this topic is:

CPAP = PEEP + PS

 

[VentdependenT]

No?????

then what's the difference?

perhaps you could post up a pressure/time pressure/flow and pressure/volume curve to educate us.

I'm with MMD on this one. They function the same. CPAP is via an uncomfortable mask that is gonna buy you at most a few hours. Once your patient becomes combative then you can intubate and then apply the continuous positive airway pressure via a tube. When a patient is on a vent its all positive pressure ventilation anyways, end expiration or not.

CPAP may work great for OSA. I wouldn't know because 90% of the people I've encountered don't use their machines. "Oh yeah, I got one at home." Its crap in the unit from my limited experience. There is some push to get em used post-op by some pulm dudes. Thought is to decrease atelectasis and "optimize" respiratory function in the obese. Best of luck.

 

[Hernandez]

During my Pulm ICU month, Vent, we had a guy who only used the T-piece when attempting to wean.
-Skip

Tobin did a comparison of 4 types of weaning. and he lumped T-piece and CPAP together. I had an attending who preferred the T-piece method as well because "if they can overcome the 7cmH20 Required to breath through a tube, they'll extubate just fine" but I've not taken the time to see if Tobin has compared CPAP to t-piece.

 

[RT2MD]

Tobin did a comparison of 4 types of weaning. and he lumped T-piece and CPAP together. I had an attending who preferred the T-piece method as well because "if they can overcome the 7cmH20 Required to breath through a tube, they'll extubate just fine" but I've not taken the time to see if Tobin has compared CPAP to t-piece.

One of our Pulmonologists here says that the patient really needs to be under 10cmH2O to extubate. This is total pressure, so your PEEP and PSV would be considered here.

I think that the t-tube is fine for normally healthy patients, but the more chronically ill (several days on vent, maybe with a bunch of comorbidities) require more help than that - and those are the people that I see mostly. Figure for your resistance equation the radius is taken to the power of 4.

One thing to look at, though, is on the Draegers (XL and E2) there it the possibility of ATC (automatic tube compensation). This can be thought of as an "electronic extubation". You dial in the size of artificial airway and the % compensation you want. Supposedly the machine varies levels of pressure support to make it feel like the tube isn't even there. This means that somebody could be on 5 of PEEP, no set PSV, and still be assisted with ventilation due to ATC.

Sorry if this is disjointed... writing at work, and I have to run.

 

[VentdependenT]

Tobin did a comparison of 4 types of weaning. and he lumped T-piece and CPAP together. I had an attending who preferred the T-piece method as well because "if they can overcome the 7cmH20 Required to breath through a tube, they'll extubate just fine" but I've not taken the time to see if Tobin has compared CPAP to t-piece.

I just put on tube comp and see how they pull. The RT has to go get a T-piece and hook it up which is a pain. I do my trials on pre-rounds and all I gotta do is push a button and watch.

The only time I've used T-piece were on those folks who failed extubation several times after what appeared to be acceptable clinical and "gut-feeling" paramaters. Why use it? Cause they are gonna get a trach tomorrow or the next day and they don't need a total ventillatory support anymore.

 

[MTGas2B]

thanks again!

yah so far what i've been reporting is the
mode/RR/PEEP/FiO2 with of course the ABGs. theyve generally been satisfied with it so far. Nothing drastic has occurred yet (obviously she had issues or wouldnt be in the SICU). But all of ur thoughts on weaning are great. I need to start to incorporate that into my presentation somehow to show that i know what i'm doing with vents. its just that my pt's GCS is around 6T....

dont know how much twirking i can do with someone like that, i'll have to read.

So for example when you report: "Mr. Smith is on AC rate of 12, tidal volume of 600 with peep of five and, FIO2 of 0.4. On those setting his last gas was 7.4, 43, 26, and 120"

Now that low tidal volume is the way to go you can also report tidal volumes in ml/kg PBW (predicted body weight). Personally, that's how I order vent setting when I'm in the ICU. Our RTs with get the height and figure out pbw.

The best way to get people extubated is to wake them up and give them a spontaneous breathing trial every day. Either CPAP (Peep plus 3 above) or just PS. If thier gas is okay and they look comfy go for it. No predictor is that good, if you're not reintubating a few people every now and then your not extubating (or liberating) enough patients. If you think about it, what's the worst thing that can happen to someone they aren't ready to extubate, you reintubated them. As long as they have straighfoward airway, and you recognize they need to be reintubated in a prompt timeframe the harm is pretty minimal. Sometimes you just have to go for it, just make sure your ducks are in a row and you eliminated all the risks you can.

 

[lfesiam]

Here is something that I posted a while back on another forum. Don't know if it will help you or not.

CPAP: This stands for "continuous positive airway pressure". This is a therapy that is adequate for obstructive sleep apnea, acute exacerbation of CHF with some pulmonary edema, etc. It is usually delivered by a face mask and is measured in cmH2O. This is a STRICTLY spontaneous mode: meaning that the patient is not getting ANY ventilatory support. If you have a patient whose ABG shows "normal" acid-base/CO2, but hypoxemia (that is refractory to increased FiO2) then CPAP might be a good place to go.

BIPAP: This stands for "Bilevel positive airway pressure". This is basically the same as having 2 levels of CPAP, a high and a low. The notation is usually written as follows: "Bipap 14/6" where 14 is the high level of pressure and 6 is the low (14 and 6 are just examples!). You can think of there being a base level of 6 cmH2O, but then when the patient either triggers a breath, or the machine is time cycled (a set rate), then the machine "kicks it up a notch" to the higher level of 14 cmH2O. This mode can be used with a facemask to provide NIPPV (non-invasive positive pressure ventilation). You can also set a back up rate, so your order would look like this: Bipap 14/6 rate of 12 FiO2 of 60%. If somebody is a DNR/DNI but wants to have something done to help alleviate work of breathing, then this is a good choice (say they had some respiratory acidosis perhaps with some hypoxemia). This can also get you through a CHF exacerbation while you pump out the Lasix! A big issue with this is the fact that a lot of people won't tolerate the mask (has to be very snug fit).

If the patient can't maintain their own airway, then obviously we have to put in an artificial airway (ET tube/trach/etc). Then you have to go to the vent terminology.

PEEP: The same as CPAP... just on a vent!
FiO2: Hopefully self explanatory!
Rate: Minimum frequency that the vent provides.
Tidal Volume: Vt - size of breath delivered (usually in mL)

CPAP trial: used as a weaning strategy to see how the patient can breathe spontaneously. CANNOT be sedated for this. Some people like to work patients daily (if they are stable enough), others like less frequently. I, personally, believe that daily CPAP trials aren't a bad thing if the patient is stable (as tolerated)... but I ALSO believe in NOT getting an ABG (unless pt has an A-line) on daily CPAP trials - judge them clinically. Usually a CPAP of 5 cmH2O is used, either with or without pressure support.

Pressure support: Basically the same as BIPAP on the vent. There is a set level of PEEP (low level of CPAP) and Pressure support (like the high level of CPAP in BIPAP). The pressure support helps the patient overcome the resistance of the ETT. This can also be used with higher levels for patients who might not be QUITE strong enough to completely support their own ventilation. Also, BE SURE NOT TO USE ON SOMEBODY WHO IS SEDATED!

Assist Control: Abbreviated AC, A/C, CMV. This is the basic mode of mechanical ventilation where we are doing ALL the work for the patient. You set a rate, tidal volume, PEEP and FiO2. If you have a set rate of 12 and the patient is breathing 16, then that is okay - the machine will give them 16 fully supported machine breaths a minute. There is also pressure control, where you set a inspiratory pressure instead of a tidal volume. On this mode the patients muscles aren't doing any work at all (even if they are over breathing the vent, the vent is still doing the work for them). You want to be sure to keep your plateau airway pressures below 30 cmH2O and also keep your tidal volume less then 10 ml/kg.

SIMV: This stands for "synchronized intermittent mechanical ventilation". This is like a mix between assist control and pressure support. You set a tidal volume (or pressure), a rate, PEEP and FiO2 for the machine breaths... but then you ALSO set a pressure support for if the patient over breathes the vent. EXAMPLE: You write an order "SIMV rate of 8, Vt: 750, PEEP: 5, FiO2: 60% Pressure support: 10" This means that the machine will give 8 breaths a minute at 750mL tidal volume. If the patient wants more than that then they can trigger more breaths, but they won't be 750ml breaths... they will be pressure supported at 10 cmH2O (like bipap).

Weaning: RSBI is the best predictor (although still not perfect) of successful extubation. You calculate it by taking RR/Vt (in Liters). So somebody who was breathing 20 times/min with a 200mL tidal volume would have a RSBI of 20/.2 = 100. You want the RSBI to be below 105 with a good NIF (maximal negative inspiratory force - measured in cmH2O) LESS than -20 and good ABG on the CPAP trial. Some say if you don't have at least a 10-12% re-intubation rate then you are not agressive enough.


That is all that I can write now... I worked all day today and tomorrow and have had a couple glasses of wine . There are more modes, but they are a bit more advanced. This is a good place to start. There is also a good website that I recommend: http://www.ccmtutorials.com/rs/mv/index.htm

I probably should have just given you this website instead of writing everything that I did... would have been more coherent, I imagine!

Let me know if this helps, or if you have any questions! Good luck to you!

-RT2MD

good post RT2MD!

 

[lvspro]

So for example when you report: "Mr. Smith is on AC rate of 12, tidal volume of 600 with peep of five and, FIO2 of 0.4. On those setting his last gas was 7.4, 43, 26, and 120"

Aother useful thing to report is peaks and actual rate along with above, b/c it helps to give an idea of how much work you're actually doing for the pt.

Above was how I usually dropped my sets during rounds.

 

[rocuronium]

Functionally PEEP and CPAP are exactly the same. CPAP, however, refers to a positive pressure baseline in a spontaneous breathing mode while PEEP refers to a positive pressure baseline in a mandatory breathing mode.

Therefore, volume assist control would use PEEP, while pressure support would use CPAP.

 

[HunterGatherer]

can we add a link to this post in one of the stickies? an oldie but goodie and lots of new info.

 

[jetproppilot]

Dang it... as an RT, I was drawn to this thread... I saw this post above from Vent and got all excited - HE HAS RETURNED, I thought to myself. Then I saw the date of 3/05... crap.

Just made me think, as a *mostly* lurker... hope all is going well in his life.



JPP - you heard any good things? Hope you are hanging in there with this weather, as well.

-RT2MD

Hey Bro......been insanely busy with kids, work, and oh yeah....hurricane fatigue...