Why bag when vent available?

[JJR512]

Now that I'm working with a critical care team, I'm seeing and learning a lot of stuff that I've never been exposed to before. As a BLS provider, I have a question about something I saw today.

We went to another hospital ED to pick up a 15 y/o cardiac arrest patient. Between the 911 unit and the ED, she had been recovered from arrest; she had had CPR performed on her for about 20 minutes. She had been intubated, and when we arrived to transfer her to the PICU at Univ. of MD Med Ctr (UMMC), she was on a ventilator.

This pt. had quite a bit of pulmonary edema coming up the tube (the nurse and paramedic I was with commented to each other that it must have been a very traumatic intubation). The nurse and paramedic wanted to suction this. The paramedic readied a bag while the nurse readied suction. Then they had me hold the tube in place with one hand while disconnecting the vent tube with the other; the nurse would suction for several seconds; then the paramedic would attach the bag and bag several times. This was repeated several times. When the nurse determined that she was done suctioning, she had me reattach the vent tube to the patient.

So my question is why did they bag the patient during suctionings, rather than just reattach the vent tube? The vent was just as easy to attach/detach as the bag. I assume the vent breathes for the patient better than a bag, so why not use it when it's literally right there?

Also, some further information to help paint this picture is that the patient was actually breathing above the vent, indicating she had a respiratory drive. She actually had some nasal flaring.

 

[Ridryder911]

Some vents have pre-suctioning mode to allow hyperventillation and increase Fi02 level to 100% prior to suctioning. The problem attaching vent between suctioning is the pressure required to adequately ventilate the patient may not be high enough to ventilate and as well it is much easier to ventilate quickly with a BVM to feel compliance too. Dependent upon the mode that the vent is set at, if there is much resistance there will not be a ventilation to occur. One of the indicators to suction is pressure alarm and increasing resistance to adequately ventilate.


It appears that the patient was on an assist mode that will assist respiratory pattern or "step in" if the patient does not produce enough respiration's.

Many of the ventilators in hospital setting now has "sleeve" type suction devices that are enclosed and attached to the ventilator as well sterility is not as much an issue.

I am sure Vent can describe more....

R/r 911

 

[MSDeltaFlt]

Also, you can use the BVM to get a larger breath to get air/lavage deeper into the lungs more controllably so, when you let go of the breath to start exhalation, it will assist secretions to come closer to the cariini to facilitate better suctioning.

Now, if there was an inline suction on the vent circuit (Ballard Suction), they probably wouldn't have bagged the pt but would have just left the circuit on and suctioned like that. I would have. I do.

 

[VentMedic]

JJR512, you didn't mention what type of ventilator the patient was on. That makes a big difference. Single limb transport ventilator are definitely not the same as the ICU style ventilators. Their capability of achieving a large amount of flow is not there. Thus, the patient will be like trying to drink from a water fountain that is a trickle. That is where you can get the over breathing and increased work of breathing or should I say one of many reasons.

The pulmonary edema is probably not from a traumatic intubation. How much fluid did they use during resuscitation and/or what is the ethiology of the cardiac arrest? Also over zealous bagging and improper ventilator settings can quickly trash the lungs along with multiple other things can cause pulmonary edema. Traumatic intubations of a young person are a bloody mess with damage to the soft tissues.

Hyperoxygenation is important as Rid mentioned during suctioning and depending on the ventilator the pt was on, it may not have had a hyperoxygenate button which lasts for 2 minutes. Reason for this button rather than turning the FiO2 knob to 1.0: It is too easy to walk off and leave it on 100%. That may not mean much to you on an adult transport (except for extra O2 out of your tank) but in ICU especially NICU or PICU, it is a big deal.

I do not like to break the circuit especially with pulmonary edema for infection purposes, both the healthcare providers and the patient. The inline suction devices that MSDeltaFlt and Rid described are nice. The less times a circuit is broken the better.

The other reason for not breaking a circuit is losing PEEP especially with pulmonary edema. However, if the patient was on a single limb transport vent with a "resistive valve" for PEEP, that can be place on a bag. The resistive valve is not as effective as a ventilator that can provide end expiratory flow for PEEP.

Reasons to bag:
Trouble shooot pt vs machine
Exception: in ICU experienced clinicians have high tech ventilators and many other monitors as well as a base line physical assessment to point them toward a problem hopefully.
Also, always start at the patient side first. If the tube is out, no need to trouble shoot the ventilator.

Transferring from bed to stretcher
If you don't know if your circuit will reach or you don't have one person solely free to watch lines and airway, disconnect from vent or use a bag until you are in a less awkard position. This includes when there is not a designated place on the stretcher for the ventilator. Nothing like a busted $5000 transport ventilator and an extubated pt to screw up a transport.

Feeling compliance
This is how I know how the transport is going to go and what I am going to have to ask of the transport ventilator. You must know your ventilator's limits. If you are doing interfacility from an established ICU ventilator on a lung sparing protocol such as ARDSnet, you may be asking alot out of your machine. It may not be able to achieve the setting due to flow limitations. Also at lower tidal volumes on an ICU vent, the ICU vent compensates for compressible volume lost in the circuit. Transport vents do not. You could lose another 50 - 100 cc of tidal volume pending on the PIP and type of circuit.

If you can not get the ICU vent and transport vent to translate into workable settings
ICU vents have many different modes and variations within those modes. Often, if the ICU RRT knows what vent you are using they may take the patient out of the ICU mode and try something conventional to mimic your ventilator. If they've got a worried look on their face, keep the bag handy.

Some RRTs on transport carry different adaptors to allow them to run off the hospital's O2 source until they are certain of their transport ventilator's settings are capatible with the patient and may get an ABG if prior to departing. Usually, if they have a recent ABG and are getting similiar Minute Volumes, good breath sounds and stable VS, they are good to go.

You don't understand your technology well enough
Instead of trying to do knobology in the back of a truck when things aren't working you may need to bag until you are more fluent. Also, some changes such as PEEP take up to 20 minutes to recruit but can have fairly rapid hemodynamic effects. Every ventilator change (except FiO2) leads to a change in other parameters such as flow, I-time and I:E ratio.

Also, every ventilator contains a micro chip that records all changes made. This is for QA and legal purposes. If anything happens, that ventilator will take the witness stand.

And, when transporting, make sure the equipment is secure in the ambulance. I just hate having a good ventilator damaged on somebody's head. Of all the team members, you will probably have the most expertise at securing patient, passengers (crew) and equipment.

In conclusion, the ventilator is definitely better to maintain pH and minute ventilation consistency during transport. However, when in doubt of the pt, machine or yourself - bag.

I am going to link to another forum's recent thread that I know MSDeltaFlt is familiar with.
Flightweb: Ambu vs Ventilator
http://www.flightweb.com/forums/index.php?showtopic=650

Also, don't worry if you don't understand everything I wrote. Just keep asking questions and don't stop learning.
However, there will be a quiz for Rid and MSDeltaFlt later.

If you want to do a little more reading:
http://www.ccmtutorials.com/rs/index.htm

And here's one for ABGs:
http://www.orlandoregional.org/pdf folder/Inter of Arterial Blood Gas.pdf

 

[VentMedic]

Let me give you a shorter answer to your question:

If the patient had an inline suction catheter I would not have used the Bag first. If it was pulmonary edema I would have suctioned quickly with or without hyperoxygenating just to clear the airway. For hyperoxygenation, I would have used the button or turned the machine to 100% O2. If pt tolerated that, I would continue to use the ventilator.

If no inline suction device, I would use the vent to hyperoxygenate first if possible. Then, making sure no one is at risk of getting sprayed, I would make a pass down the tube to clear secretions and check patency. If the patient has copious secretions I may use the bag to continue suctioning. As Rid mentioned, the ventilator will "high pressure" with airway obstruction/secretions and terminate the ventilation cycle, thus the patient will become more anxious with air hunger.

If the patient is on a wimpy model of transport ventilator, I may bag when suctioning unless there are minimal secretions.

If the patient was on an ICU ventilator, I may have used it unless the high pressuring didn't cease after the first pass or two.

What you don't want to do is rapid hard breaths with the bag into the patient in the name of "hyperventilating, hyperoxygenating". I'm sure you'll see people working the bag like they've got 10 seconds to get 20 - 1000cc breaths into the patient. NOT good!


Nasal flaring and over breathing: (provided the air way is clear of secretions)
air hunger: flow to low, ventilator settings not appropriate, anxiety, asynchronous with the ventilator (vent not sensitive to patient's demands or pt's breathing is too erratic - also can be anxiety or in some situations neuro),
Ventilation/perfusion mismatch causing the air hunger (PNA, Pulm Edema, ARDS)
Pt may need to maintain more Minute Volume in attempts to stabilize oxygenation, CO2, or pH from a metabolic acidosis.

 

[JJR512]

Thanks for explaining all that. I actually did understand some of it!

You mentioned what kind of ventilator the pt. was on. It was a Servo-i (not sure if universal or adult). The settings that I observed were 100%, PEEP=7, RR=24, Tidal Volume=400 (those are the only settings I paid attention to because our transport vent is a LTV-1000, and those are the only settings I have been taught to care about so far). Her actual RR was 28-32. There was no inline suction catheter in place as far as I could see.

Everything I've mentioned was performed with pt. on ED's trauma room bed, with the ED's Servo-i vent.

After everything else that needed to be done was done, we moved the pt. to our stretcher and switched to our LTV-1000. I'm not sure what the problem was but the nurse determined the pt. did not like the LTV, so they decided to bag her during transport instead of fussing with the vent. The destination was only four minutes away, which I'm sure had something to do with their decision to just bag her instead of trying to get her to take our vent.

 

[bonedog]

Obviously Ventmedic has a great handle on ICU medicine, very sage advice.

Personally I find it common that patients are under medicated which causes tachypnea, along with sympathetic overdrive.

High peak pressures with normal or low plateau pressures indicates obstruction, suctioning should help.

Inline suctioning is the way to go, I prefer to set everything up at the sending facility, get the patient settled prior to transport, try different settings, confirm all my lines and tubes, recruitment etc.,if we are talking about a situation that doesn't require surgical interventions.

PEEP valves on BVM's are minimal at best, if you can use the vent all the better, and you get tangible numbers you can play with.



Paralytics can simplify things

 

[VentMedic]

You mentioned what kind of ventilator the pt. was on. It was a Servo-i (not sure if universal or adult). The settings that I observed were 100%, PEEP=7, RR=24, Tidal Volume=400 (those are the only settings I paid attention to because our transport vent is a LTV-1000, and those are the only settings I have been taught to care about so far). Her actual RR was 28-32. There was no inline suction catheter in place as far as I could see.

Servo-i? Definitely top of the line ICU ventilator! It can do everything but Cappuccino and is used on all ages including neonates. It would be difficult to match the comfort a skilled clinician can achieve for a patient on that machine. The LTV-1000 is definitely one of the better transport ventilators but still uses an external PEEP valve. The newer model has PEEP internally driven.

Again, without more clinical data such as ABG, anion gap and CXR, it would be difficult to pinpoint the actual cause of tachypnea.

Also, remember the monitored PIP on an ICU ventilator may not translate even closely to a transport ventilator. The ICU ventilator may be in some type of "pressure sparing" mode that delivers flow to minimize pressures. Transport ventilators are not that sophisticated. Most transport ventilators do not offer the capability to do Plateau Pressures. Even if they did, there is little one can or should do in the field or on transport. Initiating an ARDSnet protocol on transport is not wise because you may also need buffering protocols, such as THAM, to accompany it. Our ARDSnet protocol (ICU) is 12 pages long. We also have 3 other lung sparing protocols as well as many that are not "written".

That is why I love Respiratory Medicine, something new either in technology, the literature or technique everyday to explore. And since the heart is affected by everything we do on the ventilator, one must be extremely knowledgeable about the cardiac system as well as all the others.

Also, since everything you do on the ventilator affects other systems, you'll have to watch your meds. Again, ARDSnet or high PEEP levels should not be initiated in transport unless you are able fluid balance or have vasopressors ready to titrate as well as being an expert clinician and having a detailed ARDSnet protocol signed by your medical director. The protocol you pull off the internet is only a guideline for facilities to set up their protocols. And, that one has be restudied and reworked again. That is why we always have plans; B, C, D and E ready to impliment.

http://www.ardsnet.org/

Paralytics are seldom used in the ICU. Even for extreme cases we try different sedation meds and ventilator modes to keep from using paralytics. Of course, short term and especially for Flight, paralytics may be necessary. However, paralytics should not be used to compensate for lack of expertise with the meds or equipment.

Unfortunately many people doing transport are not ventilator trained in theory but in a study we call knobology. "Turn this to get that and if this happens turn this knob" with no explanation of why that works, why you get that or why that shouldn't be done. I can almost bet that nearly every transport ventilator is set on a High Pressure alarm at 60 cmH20. Why? or Should it be?

I have downloaded data from transport ventilators for QA and have seen some scary setting changes. Yet, when questioning the RN or EMT-P, they had what to them sounded like "logical" explanations. RRTs get accustomed to having ventilators keeping "tabs" on their changes as they are constantly monitored especially if a research project is running. Also every change they make must be documented and why. There is very little random changes except in special circumstances and then a lengthy narrative is required detailing the whys.

When a Sentinel (unexpected very bad outcome) event occurs involving a ventilator, a hardcopy of settings and alarms is printed from the ventilator to be matched against the charting and CR monitor downloaded hardcopy. That is why RTs get hysterical in the ICU when a nurse or physician makes a ventilator change and does not document it on the ventilator sheet.

So, in summary, uncomplicated ventilatory support patients with no V/Q mismatches or respiratory diseases processes are the easiest. All else, don't expect smooth sailing everytime.

One more very very important thing; Always make sure the transport ventilator is protected from contamination by placing a filter at the port leaving to the circuit. I don't care if someone tells you "it's a single limb going in one direction". Different pressure gradients and flow during disconnect of high pressure sources will suck contaminants into your machine. Then, it will infect every patient you transport. This happened this past year to a CCT when a hospital started coming up with bugs that weren't in the previous hospital's cultures. The transport ventilator was identified as the common factor and was swabbed. That ambulance service had some answering to do. If we see a patient brought to our facililty without a filter on the ventilator, we will swab that machine and let the legal eagles battle it out. We like our VAP (Vent Associated PNA) to stay at 0. We do not want a hit from Medicare in our ICU.

Also, protect yourself. Whatever is in that patient's lungs is in your face through the exhalation valve. ICU machines have elaborate exhalation filters. Transport vents are usually single limb. I use an HME (Heat and Moisture Exchanger) on all transports, not for the humidification, but as a germ catcher. I also keep it between the pt and bag when not on the ventilator since the exhalation valve is near your face. The HME can stay on the ETT momentarily while transferring a pt from bed to bed and prevent spray. Of course, I deal with a population of TB and R/O every type of exotic flu imaginable in a teaching hospital located in a multi-national city. And, there is that MRSA, VRSE, pseudomonas, etc stuff also.

JJR512, I am again just throwing out alot of information to get you thinking about the whole process and not looking at a ventilator as just another skill. That is where prehospital and critical care medicine start to differ.

Good luck!

 

[Ridryder911]

That is where prehospital and critical care medicine start to differ.

This reminds me when I switched from ER nursing to an ICU/CCU setting. I presumed they were the same or similar in approach. I was horribly wrong. They are about as similar as orthopedics and labor & delivery have in common.

This is why I caution CCP's and those entering from the field into the nursing profession for the first time.

I admit, I consider myself above par in EMS and emergency nursing and maybe more knowledgeable than some in critical care, but I still study weekly due to the ever changes. Definitely an unlimited area.

R/r 911

 

[JJR512]

Thanks again...most of that stuff was way over my head at the BLS level, but, as you said, it definitely gets me thinking. I'm not someone who just wants to learn only the things on a list that are considered what I need to know. I like to know the how and why behind everything I need to know, and then the related stuff as well. I'm going to keep this page bookmarked so that as I learn more, I can refer back here.

For the record, :sad: the patient died at midnight this morning. She had been down without CPR at least five minutes prior to the 911 paramedics getting to her. After we got her to UMMC, it was determined that she was brain dead. Life support was withdrawn around midnight this morning, and of course she did not survive. It's my understanding that this was a foregone conclusion before we ever became involved. Still... :sad: