Starting neuromuscular blockers

calivianya, BSN, RN · Nov 16, 2015

Well, if the patient is truly being paralyzed, a RASS isn't going to tell you much about awareness. The patients would be -5 whether they are aware or not. We titrate the paralytics independently of awareness - we just look for muscle twitches. We set up train of four machines where we give four electrical impulses and see how many times out of four the muscle twitches in response to the stimulation to assess how well the paralytic is working.

To actually assess awareness in a paralyzed patient, we need to look directly at the brain since there is going to be no outward sign of the patient's awareness. A BIS monitor, which looks at electrical activity in the brain, is going to be hooked up to the patient's forehead. We like to keep the BIS scores around 40 where I work now. We typically use Versed or Propofol to get the BIS score where we want it to be so we know the patients are truly not aware while they are being paralyzed.

spacemonkey15 · Nov 16, 2015

It only tends to be our sickest patients that we paralyse here (I'm in the UK), often when our ventilation strategy is failing in spite of the patient being deeply sedated. These patients will already be on a truck load of sedation and scoring a RASS of -4 to -5, so awareness when starting neuromuscular blockade shouldn't be an issue. Once paralysed there's no point in trying to get a RASS score, you're not going to see any sort of a response because you've deliberately stopped the patient from being able to make any sort of movement.

mcubed45 · Nov 17, 2015

We titrate paralytics to 1/4 train of four

We titrate sedation (when used in conjunction with a paralytic) to a BIS of 40-60.

Sedation without paralytic is titrated to RASS of 0 to (-1)

Here.I.Stand, BSN, RN · Nov 17, 2015

All paralyzed pts in my ICU are on BIS monitors. A score between 40-60 is an indicator that they are unaware and will have amnesia of the events once they wake up. If the number is trending up close to 60, and of course if it goes over 60, we up the sedation.

Great question -- I love that you're cognizant of the pt's need for adequate sedation while completely unable to express their needs.

Edited to add: we document BIS scores hourly on the VS/infusions flowsheet (Epic.) So a PharmD or provider wondering about this could look it up there, rather than on the MAR.

spacemonkey15 · Nov 17, 2015

Though I must add to my previous post, this thread has got me interested. I've seen BIS monitoring used in the operating theatre as part of a research trial, but not routinely. A quick search has shown a bit of NICE guidance on it's use in surgery where there's risk of awareness (so patients with high ETOH intake etc) but nothing on critical care.

Looks like I'm going to be asking some questions tomorrow and seeing what I can find out :)

Glad I found this discussion, thanks OP

Mully · Dec 6, 2015

Interestingly enough, the BIS was never actually tested on patients who were paralyzed when it originally came out. So a few crazy anesthetists in Australia did a study where they paralyzed each other, placed a tourniquet on an arm so they could still move their arm to answer simple math questions, and put a BIS on there head to see what it would say.

In some patients, it read less than 60 with a perfect SQI while they were answering questions correctly.

In other words, the BIS is worthless.

Check it out...

http://bja.oxfordjournals.org/content/115/suppl_1/i95.long

spacemonkey15 · Dec 7, 2015

Interestingly enough, the BIS was never actually tested on patients who were paralyzed when it originally came out. So a few crazy anesthetists in Australia did a study where they paralyzed each other, placed a tourniquet on an arm so they could still move their arm to answer simple math questions, and put a BIS on there head to see what it would say.
In some patients, it read less than 60 with a perfect SQI while they were answering questions correctly.
In other words, the BIS is worthless.
Check it out...
Response of bispectral index to neuromuscular block in awake volunteers

Thanks for the article, it makes for interesting reading.

eCCU · Dec 26, 2015

TOF 1/4...2 is ideal 1 too much, 4 up the paralytic. We paralyze all pts on controlled mandatory ventilation, hypothermia therapy, extreme ards the list is long.

qaqueen · Feb 3, 2016

Epic software was mentioned, Cerner Millenium basically the same thing. TOF and BIS scores are documented hourly, but not on the MAR, it is in the flowsheet.

qaqueen · Feb 3, 2016

TOF 1/4...2 is ideal 1 too much, 4 up the paralytic. We paralyze all pts on controlled mandatory ventilation, hypothermia therapy, extreme ards the list is long.

Thank you for this, it brings up a question I have as a new to service icu RN. When using the TOF, if you see 2 strong twitches and a hint of a third do you count the last wimpy "near twitch"? Sounds crazy, but I have been told so many different things by multiple peers, I would really like an outside opinion. Thank you

hotcoffee · Feb 5, 2016

Very interesting that BIS isn't useful.

i read that somewhere else also