Prehospital sedation

[mobey]

when I see the numbers begin to rise I "check in" and then re-bolus with versed the pt goes down for another 10 min and never regains consciousness. I find it important to do this, as it allows the thorax to return to a negative pressure inspiration assisting blood return to the heart and maintains well perfused muscles of respiration making it easier to eventually wean the patient off the tube.

I love this way of thinking ^..... It never even crossed my mind.

Anyone else have any imput on this quote?

transport is a stimulation rich environment - it's tough to keep them happy

Did not really think of that either. Ya, one infusion rate may be adequate for a certain hwy, but turn onto the secondary road and the stimulus of a rough ride may be enough to arouse them.... (not that kind of arouse).

[kevkei]

I love this way of thinking ^..... It never even crossed my mind.

Anyone else have any imput on this quote?

Did not really think of that either. Ya, one infusion rate may be adequate for a certain hwy, but turn onto the secondary road and the stimulus of a rough ride may be enough to arouse them.... (not that kind of arouse).

I liken the idea to utilizing pressure support on a vent, where they have to have active respiration and require enough negative pressure to trigger the vent.

As for keeping them happy, I agree. I do find though that as delicate a balancing act it can be, I just prefer to keep them deep and if possible, knock out a respiratory drive as my transports at the longest are 15-20 minutes at best. At least then, they don't lighten and I can control most quantitative and qualitative values. If I have to RSI someone, it's for good reason.

We used to carry Etomidate and Ketamine but had Etomidate removed due to the cortisol issues but Ketamine remains. There was a question asked regarding analgesia with Ketamine. Depending on the reason for RSI, if analgesia is indicated, yes I would use it.

[Just Plain Ruff]

Or we could look at agents that are much better for the task of RSI induction agents. Currently, no better agent than etomidate exists. It acts very quickly (one arm brain cycle essentially), has a predictable duration (100 seconds for every 0.1 mg/kg dose), and it has no effect on hemodynamics. The next best would be ketamine IMHO. We must remember that sedatives such as Diprivan and diazepam do not provide analgesia. Sedation and analgesia are different topics.

So, I typically use etomidate, then follow up with diazepam and fentanyl.

Take care,

chbare.

So true CHBARE, but unfortunately etomidate and ketamine are found in no services near where I work. The only service that would have the two listed are the flight services.

I would love to have both of those agents in my arsenal but I don't see that happening.

Later.

[chbare]

Additionally, I would like to emphasize that yes etomidate is well known to cause transient adrenal suppression after one dose. However, I am unaware of any evidence that definitively says etomidate leads to poor outcomes in patients where this may be a problem. There are studies and allot of talk; however, the fact remains that etomidate is still a viable agent. While some providers has started to stress dose people with steroids, I am unsure if this practice actually improves outcomes. The thought that steroids lead to up regulation to adrenergic receptors in septic patients appears to be falling out of favor and may not be effective.

Regarding "waking"people up to allow for negative pressure. It is a good thought in that the ultimate idea is to liberate the patient from the ventilator as soon as possible. Clearly, spontaneous "awake" trials are performed in the hospital prior to the decision to liberate and ultimately extubate. However, the transport environment is tricky. I think the practice of keeping patients light needs to be considered carefully. If you have even the slightest patient/ventilator dys-harmony, having an awake patient who is not interacting well with the ventilator is a setup for disaster. Many of the transport ventilators are simply not able to physiologically meet the needs of many patients, and many providers are not keen in this area of management. In conclusion, good concept with the caveat of having a capable provider and ventilator, therefore it is not as applicable in the transport environment.

Additionally, many patients who are intubated at point of care have conditions where physiological strain could be quite harmful. Head injuries, cardiogenic shock, and septic shock are all conditions where you do not want a patient awake with increased oxygen consumption and demand. Therefore, I tend to keep my point of care patients rather heavily sedated with liberal analgesia. I am aware of my limitations as a provider and the limitations of my equipment and feel this approach is safer than attempting to keep my patient "light" while attempting to setup perfect patient/ventilator interaction with a crossvent four.

Take care,

chbare.

[Just Plain Ruff]

Additionally, I would like to emphasize that yes etomidate is well known to cause transient adrenal suppression after one dose. However, I am unaware of any evidence that definitively says etomidate leads to poor outcomes in patients where this may be a problem. There are studies and allot of talk; however, the fact remains that etomidate is still a viable agent. While some providers has started to stress dose people with steroids, I am unsure if this practice actually improves outcomes. The thought that steroids lead to up regulation to adrenergic receptors in septic patients appears to be falling out of favor and may not be effective.

Regarding "waking"people up to allow for negative pressure. It is a good thought in that the ultimate idea is to liberate the patient from the ventilator as soon as possible. Clearly, spontaneous "awake" trials are performed in the hospital prior to the decision to liberate and ultimately extubate. However, the transport environment is tricky. I think the practice of keeping patients light needs to be considered carefully. If you have even the slightest patient/ventilator dys-harmony, having an awake patient who is not interacting well with the ventilator is a setup for disaster. Many of the transport ventilators are simply not able to physiologically meet the needs of many patients, and many providers are not keen in this area of management. In conclusion, good concept with the caveat of having a capable provider and ventilator, therefore it is not as applicable in the transport environment.

Additionally, many patients who are intubated at point of care have conditions where physiological strain could be quite harmful. Head injuries, cardiogenic shock, and septic shock are all conditions where you do not want a patient awake with increased oxygen consumption and demand. Therefore, I tend to keep my point of care patients rather heavily sedated with liberal analgesia. I am aware of my limitations as a provider and the limitations of my equipment and feel this approach is safer than attempting to keep my patient "light" while attempting to setup perfect patient/ventilator interaction with a crossvent four.

Take care,

chbare.

Hey CH

any chance of giving us a little tutorial about the differences between keeping a patient light and one heavily sedated. I'm used to snowing them with little regard to keeping them light, I want a patient where my ventillator can do it's job rather than a patient who might be fighting the vent with minimal sedation.

[kohlerrf]

Hey CH

any chance of giving us a little tutorial about the differences between keeping a patient light and one heavily sedated. I'm used to snowing them with little regard to keeping them light, I want a patient where my ventillator can do it's job rather than a patient who might be fighting the vent with minimal sedation.

CH brings a good point, particularly with trauma patients or even with CVA patients. In uncomplicated cases though, and even in more complicated cases an anesthesiologist will at times ask the surgeon to stop so he can lighten the patient up. “Lighten” meaning reducing the level of sedation momentarily to restore the normal circulatory mechanisms and to exercise the brain. The proven benefits short and long term to the patient have been proven.

It must be remembered that a patient breaths for himself better than you or anyone else ever can. Although minimal, the respiratory system plays a key role in circulating not only blood but lymph. As we walk throughout the day our leg muscles squeeze our veins and the squeezing pushed blood through the one way valves back to the heart. However the larger vessels in the thorax and abdomen don’t have valves. During inspiration the diaphragm descends into the abdomen and the chest walls expand. This causes pressure changes. The thorax becomes a vacuum and the diaphragm pushing into the abdomen raises the pressure in the abdomen which compresses the inferior vena cava pushing the blood into the vacuum created in the thorax before pressure is equalized by the in rushing air. During the first part of exhalation the right atrium is now filled with blood and so the cycle continues. The lymph circulation is also aided in similar way.

When a patient is intubated, apnic and being ventilated they never have this negative pressure(or vacuum)cycle in their ventilation and the thorax is always under positive pressure as you push air in to inflate the lungs and the thorax pushes air out to deflate the lungs. The state of being “snowed “and ventilated can only be tolerated with a supine pt with minimal cardiac demand for a short period of time. One very common problem on vented patients is a sudden hypotension cause by air trapping due to a poor I:E ratio or excessive PEEP. In general if a pt does not exhale fully with a timed vent or volume controlled vent air will be trapped by the incoming breath and over successive ventilations pressure will build in the chest compressing the vena cava and cutting of the blood return to the heart.

While it may be comfortable for the practitioner to “snow” them to prevent arguments it is a dramatic departure from what the body was born to do. There are many many considerations to controlling the way somebody breaths as CH pointed out not the least of which is ICP.

Yes you can get a way with drugging your patient and just pumping some air into them for your 20 min transport but with that mind set why waist your time giving morphine to a patient in pain if their not annoying you?

[HellsBells]

...but turn onto the secondary road and the stimulus of a rough ride may be enough to arouse them.... (not that kind of arouse).

Wise move Mobey, I may have had more evidence of your perverse proclivities, had you not cleared that up.

This is a very good topic, and it has got me thinking. In my urban setting we really don't have to worry too much about resedation, usually one or two doses of fentanyl/versed are all thats needed. In my recent ER practicum at a major trauma centre, it seemed that most doctors order sedation by bolus doses of fentanyl/versed. I'm not sure why this is so common in the hosp, as it keeps the nurse quite busy sedating the pt, a drip would maintain more even sedation.

Interestingly, Mobey, I have heard that Ketamine is supposed to be approved in Alberta's scope of practice for ground ambulance when the new protocols do come out, no official word on that yet of course.

[DartmouthDave]

Hello,

HB.....that is different. From my experience at a few different hospitals an infusion is always hung asap for a tubed patients with a sedation goal.

Two common ones I have seen are;

Richmond Agitation And Sedation Scale (RASS)

http://www.icudelirium.org/delirium/training-pages/RASS.pdf

Ramsay Scale (RS)

http://www.aic.cuhk.edu.hk/web8/sedation%20scale.htm

They are useful because you have a goal. An ARDS patient needs a RASS of -4. Want to wean..... a RAAS -1 on PSV overnight then a vacation in the AM . From my experience it prevents people in the ICU from snowing a patient too deep (to have a easy shift). Or worse, keeping a patient too light.

For transport (depending on your vent) I think a RAAS of -3 or -4 would be ideal in most cases. We had a Dragger Oxylog 1000 that was ok. Then we got a LTV 1000 that was more dynamic.

Cheers....

David

[fireflymedic]

Great resources to post there Dave - thanks !

[DartmouthDave]

Hello,

Here is a copy of one of our sedation protocols (Part One).

Cheers,

David