Mechanical Ventilation

[Carlos Danger]

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?

 

[TransportJockey]

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

 

[rmabrey]

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.

 

[SeeNoMore]

What do you mean idiot proof?

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

 

[Handsome Robb]

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.

 

[SeeNoMore]

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.

 

[Carlos Danger]

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.

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.

 

[MSDeltaFlt]

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.

 

[MSDeltaFlt]

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?

 

[Carlos Danger]

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.

 

[FiremanMike]

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.

 

[MSDeltaFlt]

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.

 

[CANMAN]

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.

 

[Carlos Danger]

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

 

[CANMAN]

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.

 

[MSDeltaFlt]

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.

 

[FLdoc2011]

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.

 

[FiremanMike]

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?

 

[ThadeusJ]

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.

 

[MSDeltaFlt]

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.