# Mechanical Ventilation



## Carlos Danger (May 22, 2014)

What ventilators are you guys using?

What modes and settings do your protocols call for?

Are there any differences in your protocols for mechanical ventilation of interfacility patients vs. ones intubated in the field?


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## TransportJockey (May 22, 2014)

We see transitioning to the impact 731. And I used LTV 1200s at my old service. For transfers, we try to take patients at whatever they are on at facility. For field, it generally starts out AC, mainly because the majority of our field tubes are paralyzed
Protocol allows us provider choice of mode


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## rmabrey (May 22, 2014)

We use the impact 731. No protocol per say,  we only use it IFT at whatever settings the RT says.  I used it for the first time today (as a medic). It truly is idiot proof. We rarely change anything other than FiO2 and BPM. I change alarm maximums as needed dependant on whether the patient is breathing or not.


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## SeeNoMore (May 23, 2014)

What do you mean idiot proof? 

LTV1200 set as appropriate for pt's condition. No difference in field/vs IF.


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## Handsome Robb (May 23, 2014)

We use the ReVel but only for IFTs, otherwise it's the "ALS CareVent" and it's 6-8cc/kg of IBW

Our protocol is basically use the settings that they're on or work with the MD or RRT if we don't have that option. 

We can do A/C, SIMV +\- PS, PVC and PRVC.

Here's a picture of our flight service's protocol for initial vent settings. The yellow highlights are the updates that were released in our latest revision. 








I've never used the Impact before but I've played with it a little bit and I wouldn't call it idiot proof...it's got plenty enough settings for someone to cause some severe damage if they ****ed with the settings not knowing the ramifications.


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## SeeNoMore (May 23, 2014)

In my experience, it is not uncommon to encounter patients who require adjustment in their ventillation strategy prior to transport. I think it would be very trying to have to meet with the RT or MD to make those changes. Of course I would typically mirror transferring settings if the patient is doing well on them and they seem appropriate, but many times inadequate settings are maintained in emergent situations or with a lack of close attention.

I think it makes more sense to consider Plateau Pressure before one adjusts tidal volume or I time.

EDIT: I would add the caveat that I would certainly consult with the pt's RT/MD team as needed for very complicated cases where I felt I needed some imput. That seems very different to me than making reasonable adjustments based on your assessment.


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## Carlos Danger (May 23, 2014)

MSDeltaFlt said:


> It's about time I read a thread here that peaked my interest.  Good stuff guys except for the SIMV bit which makes my skin crawl so I won't hijack.  Keep it coming.





FiremanMike said:


> Can you elaborate? I took a pretty decent airway class that made me a believer in SIMV>AC, I'd love to hear some counterpoints..



I don't think there is any question that SIMV is far better than Control for patients who are spontaneously breathing.

For long term ventilation, of course spontaneous breathing must be encouraged and vent support should be minimal. But there is an art and a science to that, which is completely separate from what we do in EMS. In the short-term acute/emergent transport setting, I think you generally want a patient as still and compliant and consuming as little oxygen as possible.

The reason I don't think it matters much in the field is because most patients who are intubated in the field are (or should be, IMO) either paralyzed or deeply sedated to the point that they are barely breathing, if at all. In the apneic patient, SIMV is the same exact mode as AC.

When I was doing transport I used SIMV almost exclusively, even in paralyzed patients, just so that if they happened to wake up a little they would be a little more synchronous with the vent for the few moments until I got them relaxed again. That was a habit that the RRT's that I flew with got me into. So there is certainly nothing wrong with using SIMV over AC. I just don't think it offers any advantages outside of what I just described.


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## MSDeltaFlt (May 23, 2014)

Here's why I like AC over SIMV.  Brief history.  Mechanical ventilation was invented why?  Anyone?  Beuller?  For surgery.  Which was control mode.  But some pts couldn't needed to stay on the gent because they were that sick.  Control mode wouldn't let them breathe on their own so somebody figured a way to let the vent assist with spontaneous breaths.  So AC was I vented for pt tolerance.   SIMV was invented for weaning.  Because patients couldn't tolerate going straight from AC to a T-piece.  So they created IMV.  But the darn thing wouldn't synch with the patient enough.  So they invented SIMV which would synch with pt's spontaneous resp... to a point.  And yet some still wouldn't tolerate it very well.  So somebody figured out a way to be able to support the pt's spontaneous breaths and pressure support was born.

Don't get me wrong.  SIMV + PS does work and works fine.  If you have the right amount of PS dialed in.  How much is the right amount, you ask?  Good question.   The ideal amount of PS must be enough for the exhaled PS Vt to equal the dialed in Vt exhaled volume.  How much is that?  It varies from patient to patient and from disease process to disease process. 

I frequently hear medics tell me they were taught or nust don't like AC because of breath stacking.  I respond with the question, "What's the auto-PEEP?  What's the I:E ratio?"  It is physically impossible to stack breaths and have any auto-PEEP whatsoever.  Breathing over the vent is fine.  Breathing against the vent is whole other story.  Now the pt might be setting off the high pressure alarm.  But that would a sedation/vent settings issue.  I, myself, have never had a problem using AC.

I prefer vent settings appropriate for what the patient needs and not arbitrary settings that prove that the clinician might still need remedial training.


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## MSDeltaFlt (May 26, 2014)

Now for clarification on my last post.  I mentioned that SIMV was invented for weaning.  It is also quite "knobby".  And you can get the same results with AC with pushing half of the buttons you would for SIMV.  I don't wean on the highway.  I didn't even wean at altitude.  So why even use it unless they've been on it for several days and you're taking them to LTAC?


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## Carlos Danger (May 26, 2014)

MSDeltaFlt said:


> Now for clarification on my last post.  I mentioned that SIMV was invented for weaning.  It is also quite "knobby".  And you can get the same results with AC with pushing half of the buttons you would for SIMV.  I don't wean on the highway.  I didn't even wean at altitude.  *So why even use it unless they've been on it for several days and you're taking them to LTAC?*



As I explained before, the only added potential benefit of SIMV over control in the acute setting is perhaps better patient comfort if the NMB wears off and/or their sedation gets a little light. Which really shouldn't happen, but sometimes does. It might be the difference between bucking the vent and not bucking the vent for a few seconds.


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## FiremanMike (May 26, 2014)

I guess my take (which coincides with how I was taught) is that it should be preferable to give the patient every opportunity possible to breath for themselves so as to minimize the potential for atrophy of any of the muscles involved in respiration.  If I can keep a patient sedated enough so that they are apparently comfortable (as far as I can tell based on vitals and patient activity) but still breathing on their own, I would think that'd be preferable.  To me it's similar to giving a patient solu-medrol early during a 911 call.  Yes, it's absolutely true that we will never personally see the benefit we gave our patient by giving the solu-medrol early, but it is ultimately beneficial to our patient for a faster recovery.

Yes, this requires more attention on the part of the providers to ensure the patient is tolerating the rate and pressures, but for the transport setting it doesn't have to be that difficult.  I am not opposed to A/C 100% and it does have it's uses, but I do try to avoid it if possible.

In our latest protocol update in my critical care gig, we are told to evaluate for post-intubation RASS scores with the ideal score being -2 to -4, which cannot be obtained with paralysis.  I'm not sure I agree with keeping someone at -2 (patient awakens with eye opening to voice with positive eye contact, but it's not maintained), and I feel -3 or -4 would be ideal.  In that protocol, paralytics are strongly discouraged.


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## MSDeltaFlt (May 26, 2014)

Halothane said:


> As I explained before, the only added potential benefit of SIMV over control in the acute setting is perhaps better patient comfort if the NMB wears off and/or their sedation gets a little light. Which really shouldn't happen, but sometimes does. It might be the difference between bucking the vent and not bucking the vent for a few seconds.



In what world would bucking the vent for a few seconds cause harm?  Unless your high pressure alarm is too high.


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## CANMAN (May 27, 2014)

MSDeltaFlt said:


> In what world would bucking the vent for a few seconds cause harm?  Unless your high pressure alarm is too high.



Yeah this...???? Each provider and or Medical Director has their own thoughts on prolonged paralysis or aggressive use. In my service we try not to unless we cannot get the patient appropriately sedated, or are venturing down the paths of complex modes like APRV or placing a patient prone etc. 

In my service we utilize LTV's across the system however are in the process of evaluating new vents. Our current protocols differ between Scene vs. Interfacility calls. Scene calls everyone gets A/C after RSI and 100% Fio2 with ability to wean. Interfacility we will evaluate what the patient is on, and if that is working or not and fo from there, with stipulations in the protocol for when we will contact medical direction for certain changes.


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## Carlos Danger (May 27, 2014)

Can anyone name a single good reason not to keep a patient paralyzed during transport?


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## CANMAN (May 27, 2014)

Again, I think this varies based off provider and more importantly Medical Director's opinions. I can say that while I don't always agree with every single protocol we have, I understand why some of protocols are written as such. I also believe that my specific medical director, who makes our protocols, is extremely knowledgeable and experienced, far more then myself. With that being said I will follow what protocols he writes because A: I like my job, and B: our system is an evidence based practice from both current literature and practices they have seen either work/not work in our system. 

That being said Trauma center's would preferably like to establish their own neuro exam upon arrival which may be inhibited if the patient is paralyzed vs. sedated. 

I also don't know any Critical Care MD's who love the practice of paralyzing intubated asthmatics, DKA patient's, or other patients with profound acidosis.

I will also add that every intubated patient in our system gets aggressive sedation, wrist restraints, and a commerical tube holder device..... So I guess I am missing the point of putting every single intubated patient down for nothing else other then provider convenience.


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## MSDeltaFlt (May 27, 2014)

Halothane said:


> Can anyone name a single good reason not to keep a patient paralyzed during transport?



Sure.  If their sympothetic response renders sedation with analgesia alone I adequate.  Otherwise, why?

Treat the patient.  Not the protocol.


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## FLdoc2011 (May 27, 2014)

Being in the receiving end, most of the folks I would receive intubated are either post cardiac arrest or intracranial hemorrhages.... both of which we like to get a good idea of their neuro status upon arrival.  

Granted, where I'm at in an urban/suburban area transport times are pretty short.... being out in the country may be a different matter.


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## FiremanMike (May 28, 2014)

Halothane said:


> Can anyone name a single good reason not to keep a patient paralyzed during transport?



I think the reverse question is more pertinent, can you give me a good reason why paralysis+sedation is better than just adequate sedation?


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## ThadeusJ (May 28, 2014)

I don't understand the need for paralysis if you have proper analgesia AND anaesthesia.  I have seen far too many issues with mechanical ventilators and circuits where the patient's own spontaneous breaths saved them despite the efforts of the attending staff.  Most patients require support, not full-on venting.  You have to provide anaesthesia for paralysis anyway, so that should suffice if you're doing it properly.


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## MSDeltaFlt (May 28, 2014)

ThadeusJ said:


> I don't understand the need for paralysis if you have proper analgesia AND anaesthesia.  I have seen far too many issues with mechanical ventilators and circuits where the patient's own spontaneous breaths saved them despite the efforts of the attending staff.  Most patients require support, not full-on venting.  You have to provide anaesthesia for paralysis anyway, so that should suffice if you're doing it properly.



There are times when the pt's presentation will require so much sedation and analgesia that it bottoms their BP and still won't work.  That's when paralysis is required.  As I said, treat the patient.  Not the protocol.


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## FiremanMike (May 28, 2014)

I should rephrase my question to say "why is paralysis+sedation ALWAYS better?"  Obviously I see that there are cases when paralysis is appropriate..


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## Merck (May 28, 2014)

Our program takes an approach of education over protocols.  We don't have any written guidelines save for what is found in medical literature.  Vent strategies are chosen based on patient presentation, diagnosis, and physiology.  Paralysis is certainly not warranted for every patient and we spend a lot of time with our intensivists and anesthetists training in anesthesia and vent management.  Overall I'd say the majority of our patients are on A/C Volume or PSV, but it's variable based on the patient.

We're using the LTV and I've always found it to be quite capable.  We've taken a look at the Hamilton but have gotten mixed reviews from our group and the various RT groups around.  We would like to go Revel but don't think it's available in Canada.  We're also shortly going to start utilizing esophageal bulb monitoring prn.


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## Carlos Danger (May 28, 2014)

FLdoc2011 said:


> Being in the receiving end, most of the folks I would receive intubated are either post cardiac arrest or intracranial hemorrhages.... both of which we like to get a good idea of their neuro status upon arrival.
> 
> Granted, where I'm at in an urban/suburban area transport times are pretty short.... being out in the country may be a different matter.



This is definitely a consideration. I probably wouldn't give a long-acting at all if I were only 10 or 15 minutes from the hospital; if I did it would be a small dose.

Figure a 0.1 mg/kg dose of vec normally lasts roughly 45 minutes or so and you have, say, a 30 minute transport. You give the vec right after intubation and start transport 5 minutes later. In 30 minutes you are at the ED, and the vec only has 10 minutes left. By the time you get the patient unloaded, into the ED, moved over to the bed, and give report, it's been 45 minutes since it was given. Even if it's only a 20 minute transport, that's only a 10 minute difference. It doesn't need to be completely worn off in order for a patient to follow simple commands, and if you really need to, you can always just reverse it. And I'm not sure almost-worn-off vec would really give a worse neuro exam than if there were a bunch of versed and fentanyl on board.

No one else has a reason other than "I just use lots of sedation"? Is lots of sedation better than a little less sedation and NM relaxation?


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## MSDeltaFlt (May 28, 2014)

Halothane said:


> No one else has a reason other than "I just use lots of sedation"? Is lots of sedation better than a little less sedation and NM relaxation?



And what patient assessment techniques do you use in order to be able to tell that your paralyzed patient is still adequately sesated and hasn't regained consciousness?


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## Merck (May 28, 2014)

Paralytics are never off the table - they're just part of critical care.  But suggesting that everyone should be paralyzed is like saying that everyone with chest pain should get morphine and nitro.  In the context of a trauma sure, paralyze for the short term if appropriate.  If a patient is profoundly hypotensive perhaps they can not tolerate normal doses of RSI agents.  An asthmatic will likely have to be paralyzed depending on the vent.  On the other side, someone intubated for hypercapneic respiratory failure may tolerate an awake intubation and PSV.  Intubating and paralyzing a DKA patient could have nasty consequences.  Regardless of the case, as is pretty much anything in medicine, a one-size-fits-all approach isn't necessarily the best way to go.


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## Handsome Robb (May 28, 2014)

DKA patients were the first thing I thought of. If we're going to intubate one I'd prefer to do it without paralytics and on SIMV so they could maintain their minute volume.  

I'm going to agree with patient dependent rather than a blanket statement however is lean towards paralyzing vs not in most if we had that option.


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## FiremanMike (May 28, 2014)

Halothane said:


> No one else has a reason other than "I just use lots of sedation"? Is lots of sedation better than a little less sedation and NM relaxation?



I believe I made my point a few times and it's not that.


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## FLdoc2011 (May 28, 2014)

Outside of RSI or extenuating circumstances I would lean away from pre-hospital NMB use.   

I'll give you that considerations for NMB use in the ICU are probably slightly different than use in EMS, but they still have serious potential side effects and complications.   I just think the risk:benefit ratio here needs to be weighed carefully. 

If absolutely indicated and you are trained on their use and recognizing complications then go for it.   If it's just for "adequate sedation" then I don't think the risk is worth it.


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## FLdoc2011 (May 28, 2014)

I certainly wouldn't use it solely to be able to use "a little less sedation"


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## Carlos Danger (May 30, 2014)

Over my 12+ year HEMS career, I've always had liberal protocols that allowed much leeway and room for judgement in terms of choosing between NMB's, sedatives, and analgesics. I would never work someplace that wasn't like that.

My personal experience has been that paralyzed patients are simply easier to manage, and present fewer potential safety issues. You only need to wrestle a patient's hand away from the ET tube or the helicopter door handle a couple of times before you learn that in the stimulus-rich transport environment, with a patient you don't know well, your ability to judge how well sedated they are / how long that last dose is going to last is actually much more limited than you would like. Those problems don't happen every day of course, but in healthcare there are lots of uncommon events that we put a lot of effort into taking precautions against because when they do happen, they can be catastrophic. 

The reason I asked the question to begin with was not because I think every intubated patient needs to be paralyzed for every transport. I asked because over my career, I've heard many paramedics, transport RN's, and MD's say things to the effect of "I only use paralytics if I really need them", and "if your patient is properly sedated, you don't need paralytics", without ever hearing anyone give a good explanation as to why it's better to avoid paralysis in transport.

Clearly there are lots of good reasons to avoid NMB in the ICU, and also no need for it with most patients. But transport is very different from the ICU. In transport, assessment of sedation level is difficult, and duration and effects of drugs are less predictable. I have had many patients who seemed well-sedated wake up and start moving unexpectedly, sometimes breaking through even large doses of sedation. They reach for their ET tube or their Cordis, breath against the vent, or flex limbs that pinch off A-lines or infusions of vasoactive meds. Most of us aren't as skilled at managing vents as the RRT's in the ICU are, so we may have a harder time syncing the patient and the vent with any less than deep sedation, which really sick patients often don't tolerate hemodynamically. Also, in transport there is no concern for the negative effects of long-term paralysis, because transports are generally brief; it's really no different at all than being relaxed for an hour or so long surgical procedure. 

Here's the really important part that seems lost on many transport clinicians: it takes a lot less sedation to keep a paralyzed patient unaware and amnestic than it does to keep a non-paralyzed patient still. That is exactly why I think a "balanced approach" using sedatives, analgesics, and paralytics - rather than just larger doses of sedative and/or analgesics -  is the best approach. You get a patient who is still and compliant with lower total doses of drug. 

I know using NMB is not the only way to safely transport an intubated patient; it just seems like there are an awful lot of people who dismiss or avoid that option without even being able to articulate a good reason why.


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## MSDeltaFlt (May 30, 2014)

Transporting an intubated patient at altitude is a safety issue.  Especially when the patient is on the same side as the tailrotor.  If the kick and punch out the window it can easily fly into it and the whole crew can become what I became: a lawndart.  Trust me.  It ain't fun.  For those pts paralyzing is a safety concern.  But not so much when you're already on the ground.


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## CANMAN (May 30, 2014)

We went from a patient receiving sedation in which they may have some periods of light sedation to now a patient is awake enough to punch out an aircraft window or open a door? Did I miss something? I think a few of us stated points why we wouldn't want that to be our first line or daily practice and there wasn't any acknowledgment of those reasons, just simply asking again why we wouldn't? 

Unless you have ability with an EPOC or istat to measure ABG's on transport then any patient, as stated before, that has some profound acidosis, DKA, or certain short transport trauma patients are ones that I, my medical director, and receiving MD's generally do not want paralyzed for stated and obvious reasons. 

As I stated before we aggressively sedate, commercial tube holder, and wrist restrain all intubated patients. That solves 90% of your problems. For the other 10% we will paralyze as needed and it's always in our minds and we  an pull the trigger quickly on it if need be but in my years of flying it doesn't happen to often where we can't effectively manage the patient without it.

I am on both 145s and 135s, patient same side as tail rotor. For the patient to open a door means they are completely displacing me
from the airway seat, and to punch a window out means they have broken the restraint, we are behind the 8 ball on sedation, and they are sitting up enough to have that range of motion. Pretty far fetched scenario, at least in my
program and particular airframe. Other airframes may present more of an issue I guess. 

If that's your practice then I am ok with it, like I said we all have different training, protocols, and work in different programs.  I just personally don't see a justifiable need to practice this more often then not.


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