Questions on Mechanical Ventilators

GreyGull · Dec 31, 2010

I do not know why YOU would desire higher peak airway pressures over lower airway pressures if you had a choice and the immediate clinical results are the same. It is usually not a 'goal' of the pulmonologist to WANT higher mean averaged airway pressures as it can have deliterious effects. If your experiences are different, please do expound as to why your pulmonogist and/or RT department desires higher mean averaged airway pressures as a desired goal over NOT having to have them, as to educate me and others, please.

In some patients achieving a higher MAP might be desirable for oxygenation and this is obtained by manipulating the factors or setting that are part of the MAP equation. This will be within reasaon with the Plateau Pressure monitored clossed. The PIP and the Plateau pressure will give you an indication at to what the reason for the increased PIP might be. If the MAP is high and the goal of oxygenation still has not been achieved, time for a different mode or a different ventilator such as a HFOV. But even on the HFOV, the initial MAP setting will be at 2 (neonatal) - 5 cmH20 (adult) higher than the conventional ventilator.

OXYGENATION is proportional to MAP x FiO2

MAP =

(Ti x PIP)+(Te x PEEP)

-------------------------------

Ti + Te

This equation assumes Pressure vs. Time is a square wave or a Pressure Control Mode.

Ways to increase MAP

Increase PEEP
Increase PIP
Increase Ti
Increase RR
Increase Flow

Pressure controlled ventilation is just that--it delivers a pressure, no guaranteed volume (in its purest sense. remember, their are algorithms used by these ventilators now which can make changes based on results, ntm other modalities that can be implemented, which is why i had to post twice in regard to simv. but, in isolation, there is no guaranteed volume). Just because you have pressure controlled ventilation does not mean you somehow want or desire HIGHER averaged mean airway pressures vs. achieving the necessary clinical outcome without needing those higher airway pressures. Generally speaking, we try to achieve the desired goals while keeping in mind the mean airway pressure/peak airway pressure--as in not letting them go higher unnecessarily, as it is not a goal/desirable.

Pressure controlled ventilation will give you a slightly higher MAP because it is a square wave delivery.

Yes, SIMV can have an increased work of breathing--depending on the clinical situation, you may want this. You dont usually want to go from assist control to extubation. We want to exercise the diaphragm, see the results, make adjustments, etc. Many times the next logical step from AC is SIMV to do just that--to increase the work of breathing as a step in a process that makes one closer to the extubation process, ntm mean airway pressures.

SIMV is rarely used for weaning today. The days of "decrease the rate of SIMV by one each day" are gone as we now wean patients quicker to reduce ventilator days. Each morning hospitals across the country may do a sedation vacation on a patient in the AC mode and place the patient into an SBT (Spontaneous Breathing Trial) which is Pressure Support. If the patient tolerates it, they may allow them to continue and even consider extubation at that time.

GreyGull · Dec 31, 2010

That is what i was talking about. In the clinical setting, SIMV is augmented. I mean, think about it.........we have a 7.0 ETT, all this circuit length to overcome.........pi r squared and length are related to resistance. In the clinical setting we are going to overcome this resistance thru implementation of other settings. But, simv in its purest sense allows the patient to breath on their own, in between, without guarantee-ing a set volume, thereby lowering the averaged mean airway pressures, exercising the diaphragm, building up phosphodiesterase levels, and a step in the weaning process as the clinical condition dictates.
You and I know that SIMV in the clinical setting WILL be augmented as necessary.........you and i also know that cpap is sometimes used also, which is a lot more difficult than augmented simv..........and we then do serial abgs, assess clinical outcome, etc etc. all in an attempt to assess readiness for extubation or whatever.
Even bipap is used on these ventilators nowadays.......again, more difficult to breathe than unaugmented simv.
But, you CAN give SIMV wherein there is NO augmentation. We all need to get past this. In its purest sense, simv allows the patient to 'breathe on their own' so to speak.
Overthinking the question is probly not a good idea just because we know that we dont necessarily implement simv without pressure support to overcome the beforementioned resistance formula to at least give them a similar environment as what it would be like to breathe on their own.

Why would you put anyone on SIMV without a pressure supported breath after you description of resistance?

Do you know how you would appropriately set up SIMV? When would you place a patient on no spontaneous support at all? I am asking this only because of your given explanation of resistance. What is appropriate supported or PSV breaths? What do your RTs set the spontaneous Low Volume alarm at?

SIMV and the PSV breaths generate two different flow patterns. You may also have the machine giving a VT of 700 and then as you are describing having a PSV of 0 or some only do 5 which may only generate a spontaneous breath of 50 ml.

BIPAP is two different levels of pressure and has a very different flow and delivery from what SIMV is or even Pressure Support.

The days of serial ABGs for ventilator weaning should also be a thing of the past. SpO2, MV and ETCO2 are what you need once you have established a baseline and that may only be required for a hard to wean patient. Even if you don't have ETCO2 you can still look at the minute volume and the work of breathing. Modern ventilators also do many of the calculations for you. It is very rare that we do an ABG for every mode, rate and FiO2 change today.

zcoq72mehs · Dec 31, 2010

The use of the word always.......i stepped back from that, but we do always use the least mean and peak airway pressures possible for the desired goal/clinical outcome as it in itself, in isolation, is not a desirable concept and is rarely the goal or objective of the pulmonogist or RT. Instead, the goal is optimal oxygenation, and you presented a case wherein by increasing the airway pressures improved the oxygenation status, albeit along with the deliterious possible effects that the literature is full of in regard to higher pressures--a necessary step to maintain oxygenation.

But it is not a goal in itself, and it is undesirable to have high airway pressures--just because it is necessary to make changes on a ventilator (just increasing the fio2 can be harmful) does not mean they are the goal in themselves........you want to use the lowest fio2 for the clinical outcome,or we would just keep ppl on 100%.

SIMV is used. It is frequently used when someone has been on a ventilator for a lengthy period of time on assist control.

In a typical ICU setting with a typical patient (which may have been on the ventilator less than 24hrs even, ie post surgery) the process can be rapid and it would probably be a waste of time going to simv as it is unlikely these patients have had any atrophy nor have a strong pulmonary insult as their primary diagnosis was something other than that.

But there are many long term patients in and outside the icu setting wherein the natural progression toward weaning is simv.

Furthermore, simv IS used by some practitioners, and frequently by those same practitioners, even for short term cases of intubation--perhaps because that is what they have felt comfortable with the previous 30years, who knows.

I do agree that with today's ventilators there is so much one can do, more effectively (faster, easier for the patient, etc) than to go from AC to SIMV, esp. with short term intubation.

I dont know where you got this decrease by one a day thing--i think you must be becoming aggravated or something, as i can not see that i typed that.

No, dont decrease by one breath a day on simv, thereby taking a week to extubate, and accept all the associated risks with prolonged intubation.

Instead, I was thinking something like this: A 40 year old was in an MVA, pneumothorax/hemothorax, chest tubes, had a subdural hematoma, has been hospitalized 9 days, etc etc. and the clinical condition, based on serial abgs, hemodynamics, etc etc, dictated the patient to be on AC14 for several days...........it was also learnt that the patient was a smoker for 20+ years

This patient can be a candidate for a slower weaning process that may entail the utilization of an simv trial mode.

Contrast that for cardiac surgery patient, prescheduled, no mi, no complications, ideal body weight, no other underlaying medical conditions other than the coronary blockages.

this patient stands a good chance of bypassing simv.

The use of any ventilatory mode is dependent on the patient situation, but simv is still used today in the weaning process, esp. in the long term care setting that are frequently right next to many hospitals nowadays.........there are many thousands of these patients in these facilities, and simv is frequently used.............

In some patients achieving a higher MAP might be desirable for oxygenation and this is obtained by manipulating the factors or setting that are part of the MAP equation. This will be within reasaon with the Plateau Pressure monitored clossed. The PIP and the Plateau pressure will give you an indication at to what the reason for the increased PIP might be. If the MAP is high and the goal of oxygenation still has not been achieved, time for a different mode or a different ventilator such as a HFOV. But even on the HFOV, the initial MAP setting will be at 5 higher than the conventional ventilator.
OXYGENATION is proportional to MAP x FiO2
MAP =
(Ti x PIP)+(Te x PEEP)
-------------------------------
Ti + Te
This equation assumes Pressure vs. Time is a square wave.
Pressure controlled ventilation will give you a slightly higher MAP because it is a square wave delivery.
SIMV is rarely used for weaning today. The days of "decrease the rate of SIMV by one each day" are gone as we now wean patients quicker to reduce ventilator days. Each morning hospitals across the country may do a sedation vacation on a patient in the AC mode and place the patient into an SBT (Spontaneous Breathing Trial) which is Pressure Support. If the patient tolerates it, they may allow them to continue and even consider extubation at that time.

zcoq72mehs · Dec 31, 2010

I would like to entertain you more, but alas i have things to do.

If your opinions differ than mine, that is ok..........

I am not a pulmonogist or an RT, and I defer to them in these situations as they are more qualified than myself, as it is outside my scope of practice--i was just trying to help answer a few questions and share some information

I merely attempted to expound on the answered questions.

I left it to the readers to understand that there are an infinite amount of variables nowadays esp. with these newer multi-mode, algorithmic, ventilators.

You do not do things in isolation, as i believe we both can agree to.

We should get back to the original post that i tried to answer. By all means, answer them, disagree as you may with my solutions.

My true intent was to try to help the poster, not to be a RT or pulmonogist, and i did try to give that disclaimer near the top of my post.

thank you for your dialog as it probably has helped ppl who do want to know more about these concepts, even if we did digress.

Why would you put anyone on SIMV without a pressure supported breath after you description of resistance?
Do you know how you would appropriately set up SIMV? When would you place a patient on no spontaneous support at all? I am asking this only because of your given explanation of resistance. What is appropriate supported or PSV breaths? What do your RTs set the spontaneous Low Volume alarm at?
SIMV and the PSV breaths generate two different flow patterns. You may also have the machine giving a VT of 700 and then as you are describing having a PSV of 0 or some only do 5 which may only generate a spontaneous breath of 50 ml.
BIPAP is two different levels of pressure and has a very different flow and delivery from what SIMV is or even Pressure Support.
The days of serial ABGs for ventilator weaning should also be a thing of the past. SpO2, MV and ETCO2 are what you need once you have established a baseline and that may only be required for a hard to wean patient. Even if you don't have ETCO2 you can still look at the minute volume and the work of breathing. Modern ventilators also do many of the calculations for you. It is very rare that we do an ABG for every mode, rate and FiO2 change today.

zcoq72mehs · Dec 31, 2010

re:

It is very rare that we do an ABG for every mode, rate and FiO2 change today.

I am going to stop replying to these posts now because this is the second time you have implied i have said something i have not.

No, not for every change for heaven sake.......there are other things we look out [at], ntm SVO2 in the case of swanganz catheters etc.

Yes, we can look at the patient response, independent of abgs, but abgs generally are regarded as the gold standard.

Clinical situation is everything..........you obviously would not do serial abgs on that post heart surgery patient scenario i discussed.

Patients who have been on the ventilator for a short period of time do well with rapid extubation protocols, or they simply would not exist.

Trauma patients who have been in the hospital for a week with many underlaying processes (multisystem) do not fare as well, and serial abgs can be in order when changing modes of ventilation (AC to simv or whatever), but certainly not necessary with a rate change of '1' a day like you previously typed in my behalf. There are many tools at are [our] orificenal, including having the patient tell us how they feel..............

Why would you put anyone on SIMV without a pressure supported breath after you description of resistance?
Do you know how you would appropriately set up SIMV? When would you place a patient on no spontaneous support at all? I am asking this only because of your given explanation of resistance. What is appropriate supported or PSV breaths? What do your RTs set the spontaneous Low Volume alarm at?
SIMV and the PSV breaths generate two different flow patterns. You may also have the machine giving a VT of 700 and then as you are describing having a PSV of 0 or some only do 5 which may only generate a spontaneous breath of 50 ml.
BIPAP is two different levels of pressure and has a very different flow and delivery from what SIMV is or even Pressure Support.
The days of serial ABGs for ventilator weaning should also be a thing of the past. SpO2, MV and ETCO2 are what you need once you have established a baseline and that may only be required for a hard to wean patient. Even if you don't have ETCO2 you can still look at the minute volume and the work of breathing. Modern ventilators also do many of the calculations for you. It is very rare that we do an ABG for every mode, rate and FiO2 change today.

GreyGull · Dec 31, 2010

I am going to stop replying to these posts now because this is the second time you have implied i have said something i have not.

You commented on serial ABGs which were done in the past to document a trend with the changes in SIMV which would be one for the PSV, one for the rate and one for the FiO2. Since you are talking about SIMV, it is easy to take it that you are still following the protocols of yesteryear.

Apologies for the misinterpretation.

The use of the word always.......i stepped back from that, but we do always use the least mean and peak airway pressures possible for the desired goal/clinical outcome as it in itself, in isolation, is not a desirable concept and is rarely the goal or objective of the pulmonogist or RT. Instead, the goal is optimal oxygenation, and you presented a case wherein by increasing the airway pressures improved the oxygenation status, albeit along with the deliterious possible effects that the literature is full of in regard to higher pressures--a necessary step to maintain oxygenation.
But it is not a goal in itself, and it is undesirable to have high airway pressures--just because it is necessary to make changes on a ventilator (just increasing the fio2 can be harmful) does not mean they are the goal in themselves........you want to use the lowest fio2 for the clinical outcome,or we would just keep ppl on 100%.

I don't think you understand the factors of MAP and how it is associated with oxygenation. For an ARDS protocols we optimize MAP by increasing PEEP to increase oxygenation and lower FiO2 while protecting the lungs with a decreased tidal volume. MAP and oxygenation go hand in hand. It is just a matter of manipulating the correct factors to optimize the MAP.

SIMV is used. It is frequently used when someone has been on a ventilator for a lengthy period of time on assist control.
In a typical ICU setting with a typical patient (which may have been on the ventilator less than 24hrs even, ie post surgery) the process can be rapid and it would probably be a waste of time going to simv as it is unlikely these patients have had any atrophy nor have a strong pulmonary insult as their primary diagnosis was something other than that.
But there are many long term patients in and outside the icu setting wherein the natural progression toward weaning is simv.
Furthermore, simv IS used by some practitioners, and frequently by those same practitioners, even for short term cases of intubation--perhaps because that is what they have felt comfortable with the previous 30years, who knows.

For some, change is difficult. HFOV has been around since the 80s for neonates and over 10 years for adults with good results for certain patients but some neonatologists, pulmonologist and practitioners would never dream of using it primarily because they have not take the time to educate themselves about it.

Many of the ventilators used today, still, in LTC are not capable of SIMV or PSV. For the past 30 years it has been AC to trach collar in many places with no problem.

With the modern ventilators we skip the SIMV and adjust the PSV to maintain a desired VT while the patient is on a Spontaneous Breathing Trial. This is done in acute and subacute units.

I dont know where you got this decrease by one a day thing--i think you must be becoming aggravated or something, as i can not see that i typed that.
No, dont decrease by one breath a day on simv, thereby taking a week to extubate, and accept all the associated risks with prolonged intubation.

In previous years and even now, when SIMV was used that was the protocol or what the physician may write because that is how SIMV weaning was presented years ago. I believe Eagan and Burton both mentioned this in their books.

Instead, I was thinking something like this: A 40 year old was in an MVA, pneumothorax/hemothorax, chest tubes, had a subdural hematoma, has been hospitalized 9 days, etc etc. and the clinical condition, based on serial abgs, hemodynamics, etc etc, dictated the patient to be on AC14 for several days...........it was also learnt that the patient was a smoker for 20+ years
This patient can be a candidate for a slower weaning process that may entail the utilization of an simv trial mode.

Even if the patient was coming off of an ARDS protocol, he would get a sedation vacation and an SBT. We do this in the Trauma ICU, the Neuro ICU and the Med-Surg ICUs. There is enough literature across the globe, since the U.S. still lags behind other countries in technology and new techniques, to support this and it has been successful in weaning patients. Again, instead of SIMV, we may enter into an APRV or BiLEVEL mode for spontaneous breathing of a sicker patient if they have been heavily sedated and/or on a paralytic for awhile and then just lower the high and low pressures to where they can be just on PSV. Even PCV for a short time would be appropriate depending on the patient's breathing demand for increased flow.

There are so many newer modes on the ventilators which offer more advantages than those Egan first discussed in his book almost 30 years ago. (1982) Yes, the RT room still has a copy for the memories.

The use of any ventilatory mode is dependent on the patient situation, but simv is still used today in the weaning process, esp. in the long term care setting that are frequently right next to many hospitals nowadays.........there are many thousands of these patients in these facilities, and simv is frequently used.............

The only use we have for SIMV here, and we average over 100 ventilators in the acute hospital each day in just the adult world, is for hiccups. The hiccup (spontaneous breath) will initate PSV and not activate the high pressure alarm.

We also have a fairly large subacute (40 ventilator patients) with about 40 ventilators and it is AC, PSV or trach collar. They also have an excellent success at weaning the patients even to decannulation.

There are good respiratory journals for RTs and pulmonologists online which can give you much more updated information. If the Respiratory Therapy part of patient care interests you, it might be worth your while to read some of the advancements over the past 20 years.

GreyGull · Dec 31, 2010

Me bad.

zcoq72mehs,

I guess I should have asked which ventilators your hospital was using before assuming they were from within the past 20 years. Since you mentioned RTs I did assume you were either from the U.S. or Canada.

GilaRRT · Dec 31, 2010

To be fair, SIMV is still very popular in some areas.

zcoq72mehs · Dec 31, 2010

GreyGull, thank you for sharing your knowledge. It is interesting information.

I am just an average nurse. GreyGull, answer the questions, as will I, again, and let us let the poster get back to us with the answers. The questions are very simplistic and do not take into account the complexities of real-world situations, we can both agree on that.

I will refrain from providing any type of rationale, as it may lead to a full-blown digression from the original questions:

i need help with 3 questins concerning a ventilator.

1) In the SIMV mode, all patient breaths are delivered by the ventilator.

true or false

2) The amount of pressure needed to keep the lungs from totally collapsing after exhalation is peak inspiratory pressure (PIP).

true or false

3) The secondary low-pressure alarm may alert the caregiver that the tubing may be kinked.

true or false

1. False

2. False

3. False

Now it is your turn, GreyGull. Please do help the person who asked for the help, thereby truly being helpful.

912smith, please do get back to us with the 'correct' answers, albeit poor in nature the questions may be...

Me bad.
zcoq72mehs,
I guess I should have asked which ventilators your hospital was using before assuming they were from within the past 20 years. Since you mentioned RTs I did assume you were either from the U.S. or Canada.

GreyGull · Dec 31, 2010

I am just an average nurse. GreyGull, answer the questions, as will I, again, and let us let the poster get back to us with the answers. The questions are very simplistic and do not take into account the complexities of real-world situations, we can both agree on that.
I will refrain from providing any type of rationale, as it may lead to a full-blown digression from the original questions:
Now it is your turn, GreyGull. Please do help the person who asked for the help, thereby truly being helpful.
912smith, please do get back to us with the 'correct' answers, albeit poor in nature the questions may be...

This was stated earlier:

How about you tell us what you think the answers and why, then we can discuss. Sorry, I'm not going to give you answers without any discussion.

If this was a take home test where the OP was to look up the questions, just giving the answers would not do any good. Just giving out answers is truly not being helpful. It also has nothing to do with real world complexities but just a basic understanding of ventilators and the principles of ventilation such as MAP and PIP.

The OP did not get back to the forum after Gila asked them to show what their understanding of the questions was and especially since these questions were not that difficult.

zcoq72mehs · Dec 31, 2010

Point taken, but nonetheless the original poster asked a question, and somebody else, who i as not directly answering at that moment, made a request or whatever you want to call it.

GreyGull, I do appreciate your conversation, altho it seems it got a little pointed, unnecessarily.

I do think we are on the same page.

I would never try to wean a patient from a ventilator since i am a nurse, not an RT or pulmonologist.

I did a google search on something, and came across this thread, by accident, and thought i would try to help, and it became quite belabored.

I rarely ever come to this place, and it actually seems a bit hostile anyway.

I do think we are on the same page.

I dont think i have ever, ever seen somebody placed on pure SIMV with no other ventilator actions to overcome the negative load the tube and vent circuit places on the patient--frequently i see peep and pressure support, which are taylored to the patient, esp. feedback provided by the patient, as ABGs can vary quite a bit from the norm in the books, as can other paramaters frequently used to assess clinical condition. The best source is the patient, when available, history, then our textbook values.

Indeed I have seen patients placed from their current settings straight to a t-piece cpap trial or what have you. Each pulmonologist can vary their procedures. This can be done for 1 minute, 5 minutes, or whatever is necessary to evaluate the given circumstance......many values are assessed, including the patient, labs, and ventilatory values that can indicate level of work of breathing, etc etc.

I cant even possibly list all the different ways i have seen ppl attempt to 'wean' or assess a level of a patient to tolerating possible extubation.

Even with many standard protocols that are driven by RT departments (just do the research), there can be a huge disparity in success, from 5% failure to 40% failure--variables not only that department faces (equipment), but patient population (homeless, malnourished, drug-infested, etc etc).

That process has most definitely included SIMV mode. I understand that you rarely come across it. That is fine. In some hospitals, it is used as a stepping stone from AC.............

As you know, the latest ventilators have algorithms that can practically extubate patients themselves, when directed by the most rudimentary-educated practitioner in their correct usage/implementation.......the 'art' of successful extubation is encroaching moreso to pure data, algorithms, and computerized smart ventilators that do just about anything nowadays (hundreds of possiblilities now that they can are pressure, volume, cpap, bipap devices rolled into one--if you weigh 5kg or more, they got an algorithm for you!) except for pulling the tube and putting on the desired noninvasive mode of support (which, uh, they also do now).

Some places do abgs before the change, during the change, and after the change (serial abgs) depending on clinical presentation, length of intubation (have they been intubated for two weeks), multisystem involvement (nutritional, neurological, hemodynamic, etc), etc etc.

If your place doesnt, no problem. I have seen it done at some locations with a degree of frequency.

As for airway pressures and the like..........in my opinion, just because we may have to use an fio2 of 60% to maintain a given clinical presentation does not mean it is what we want. IMO, the same goes for airway pressures. Just because we use a higher mean average/peak airway pressure to achieve a desired clinical outcome, does not mean it is our goal, objective, or what have you. We all need to be cognizant of the associated risks of ventilator management/interventions and balance it accordingly. It is not desireable, IMO, as a goal or objective, to maintain high airway pressures--it may be our best implementation for a given situation, but that doesnt mean we should not try to avoid it.

In addition to causing direct issues with the pulmonary system, there are can be indirect involvement of the cardiovascular system wherein altho 'oxygenation' was improved on paper, now the cardiac output has diminished, and the oxygen consumption has increased. By increasing these airway pressures we have now reduced oxygen delivery and increased its consumption, but with an increased sp02 and a seemingly 'improved' abg result.

This is just one of many potentials with ventilatory changes.

Nothing should be done in isolation, no value should be desired in isolation.

If I have mistated myself thru the aging process or whatever, I do apologize: I am sorry.

I am sorry that my education leads me to different statements, opinions, or conclusions.

I am always willing to learn more, and i have read your words, and i do find much of it valid and interesting, albeit extraneous from answering the initial questions.

I also understand my limitations, and I do not impose my opinions onto the RT department or the other pulmonogists (i am just an entry-level nurse, not a clinical specialist)........they are the ones that makes these changes, without my input, and i wouldnt desire to give that input unless i could CLEARLY associate that said intervention with an unrealized untoward effect that may be related to their action--and off hand, i can not ever remember such a situation.

take care.

This was stated earlier:
If this was a take home test where the OP was to look up the questions, just giving the answers would not do any good. Just giving out answers is truly not being helpful. It also has nothing to do with real world complexities but just a basic understanding of ventilators and the principles of ventilation such as MAP and PIP.
The OP did not get back to the forum after Gila asked them to show what their understanding of the questions was and especially since these questions were not that difficult.

GreyGull · Dec 31, 2010

As for airway pressures and the like..........in my opinion, just because we may have to use an fio2 of 60% to maintain a given clinical presentation does not mean it is what we want. IMO, the same goes for airway pressures. Just because we use a higher mean average/peak airway pressure to achieve a desired clinical outcome, does not mean it is our goal, objective, or what have you. We all need to be cognizant of the associated risks of ventilator management/interventions and balance it accordingly. It is not desireable, IMO, as a goal or objective, to maintain high airway pressures--it may be our best implementation for a given situation, but that doesnt mean we should not try to avoid it.
In addition to causing direct issues with the pulmonary system, there are can be indirect involvement of the cardiovascular system wherein altho 'oxygenation' was improved on paper, now the cardiac output has diminished, and the oxygen consumption has increased. By increasing these airway pressures we have now reduced oxygen delivery and increased its consumption, but with an increased sp02 and a seemingly 'improved' abg result.

I understand you limitation which is evident by your use of MAP and PIP or PAP. I showed you how MAP is determined and why as well as all the factors influencing MAP. I also wrote about ARDS and lung protection protocols.

Managing a ventilator is very complex and it is more than just turning knobs. This is why protocols such as ARDS and Sepsis are written to cover both the RN and RT portions of patient care. If it is known the RT will have to increase the PEEP to increase MAP and oxygenation, the RN will have to make whatever adjustments to maintain adequate Mean Arterial Pressure. The SvO2 will also be of concern if running a sepsis protocol or SjvO2 for brain injuries with the appropriate adjustments to pressors and fluids. There may also be THAM or Bicarb running for permissive hypercapnia.

The only way the old is going to be replaced by the new is through education and change. Some hospitals are like stepping into 1970 with outdated equipment and methodologies. Some places do not readily implement EBM. Some MDs don't trust the staff or themselves enough to try something new. It is also disheartening to pick up or receive patients who have been poorly managed or even just mismanaged on a ventilator to where the damage will be permanent.

I am not being hostile but if the person posing those questions will be left alone in a subacute or home care situation without an RT and only knows the answers to the test and not the whys or hows, they could be caught in a very bad situation.

We wouldn't want this to happen to anyone.

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