Twitch monitoring (13) Flashcards
twitch monitoring bitches
depolarizes such as sux’s is 2 molecules acting like ACh at the post synaptic receptor and is characterized by two phases! what occure in phase 1
- decreased single twith
- No fade (decrease but sustained response) to continuous stimuli
- TOF ratio greater than 0.7
- potentiation by anti-cholinesterase drugs
- causes fasculations
depolarizes such as sux’s is 2 molecules acting like ACh at the post synaptic receptor and is characterized by two phases! what occure in phase 2
resembles non-depolarizers characteristics
- decreased twitch to a single stimulus
- produce FADE (unsustained response) to continual stimulus
- TOF ratio < 0.7
- post tetanic facilitations
Non-depolarizeres act on at least 1 alpha subunit to block conduction what are their characteristics
- decreased twitch to a single stimulus
- produce FADE (unsustained response) to continual stimulus
- TOF ratio < 0.7
- post tetanic facilitations
- potentiation by other non-depolarizers
- antagonism by anticholinesterase drugs
why do we relax muscles
- for optimal intubation conditions
- facilitate surgical exposure/manipulation
- improve mechanical ventilation
- to compensate for inadequate or light anesthesia
what is teh purpose of nerve monitoring
to evaluate the degree of muscle paralysis or recovery from paralysis
Hz for a single twitch
0.1-0.15 Hz one time
how does TOF work with nerve monitoring
2Hz 0.5 sec apart
what do the twitches look like if you could see them in the form a a line (real practical) single TOF TOF with fade
single
_________
TOF \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_
TOF with fade \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_ \_\_\_\_\_\_ \_\_\_\_
(i know looks just like real life real easy to invision)
Non-depolarizers fade 2 characteristics
–exhibit FADE on TOF
–the fade may progress to no twitches if enough NDMR is given
ex::
| I __________ FIRST DOSE
| N ________
| C ______
| R ____
| E
| A
| S ________ CONT’D DOSING
| I ______
| N ____
| G __
|
| N
| D ____ ANOTHER DOSE
| M __
| R
|
| D
| O __ WHAT THE HELL MORE
| S
| E
| NONE AHHH GONE
V
************************************must know How do you know the degree of block with TOF use R1 R2 R3 R4 R=response to nerve monioring with TOF questions see slide 45
R4--decreaes at 75% receptors blocked R3--decreaes at 85% receptors blocked R2--decreaes at 90% receptors blocked R1--decreaes at 95% receptors blocked ex::: with TOF R1 \_\_\_\_\_\_\_\_\_\_ R2 \_\_\_\_\_\_\_\_\_\_ R3 \_\_\_\_\_\_\_\_ R4 \_\_\_\_\_\_
so this shows the first decrease was at R3 so that indicates this individual hypothetical made up patient is 85% blocked!!!!
so just remember if you are checking to see is someone is blocked and you do TOF and only the very last twitch is slightly faded your still at least 75% block thats still alot!!!
clinical application to nerve monitoring %
- surgical relaxation is appretiated at
- intubation facilitated at what
- total flaccidity
- surgical relaxation is appretiated at >90%
- intubation facilitated at 95%
- total flaccidity at 99%
Examples of TOF with depolarizing blockade (SUXs) TOF baseline TOF \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_
baseline TOF \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_
Phase 1 \_\_\_\_\_ \_\_\_\_\_ \_\_\_\_\_ \_\_\_\_\_
(notice no fade, but all are at about half strength of baseline) (called 4/4 TOF with less amplitude)
Phase 2
(no I didn’t forget any lines thats it, when depolarizers go into phase 2 usually there are no twitches)
recorded as 0/4
quick reveiw
- do NDMR have fade?
- Depolarizes have 2 phases describe their TOF
- do NDMR have fade?
- -yes
- Depolarizes have 2 phases describe their TOF
- phase 1-seen as TOF 4/4 with less amplitude
- phase 2 seen as TOF 0/4 NO TWITCHES
way to go if your correct pat yourself on the back!! if your wrong kick yourself in the nuts for not paying attention and do it again dumbass
3 most frequently used musles for nerve monitoring
no specific order
1) ulnar-adductor pollicis
2) facial- Currigator Supercilii
3) posterior tibial- flexor hallucis
this was not in our notes but from all of the pictures and a CRNA I asked what lead goes where for nerve monitoring (Red and Black)
black -distal
red closest to heart.
just an fYI dont memorize
where are the leads for the adductor pollicis (hmm where is that muscle) and what should you see to show proper twitch eval
ulnar (palmar) side of distal forearm.
the thumb should show adduction
hmm lets find a hint:
ok so we are testing the ADDUCTOR pollicis and the proper eval is ADDUCTION of the thumb!!!!!!! skadush (sir wizard Atkins, J., 2012) ( I have to give credit to the Skaduch)
what would be seen in the adductor pollicis twitch if the placement of the leads are wrong for example on the median nerve or direct muscle
finger contraction
what is the facial nerve we access for with twitch
Curragator Supercillii
(in his notes he places emphisis on NOT THE ORBICULARIS OCULI)
HOW TO REMEMBER- this is a streatch so if you have a better one place let me know- Curragator= Cornea
superCILLII= Cilli (hairy projections) your eyebrow????
Facial nerves efferent or afferent
primarily efferent (motor control)
the facial nerve is cranial nere number???
XII
**5 branches of the cranial nerve
temporal zygomatic maxillary mandibular buccal
where is placement of nerve leads for posterial tibial nerve (flexor Hallucis) monitoring
behind the medial malleolus
stimulation of the posterior tibial nerve (flexor hallucis) causes what response
flexion of the big toe by contraction of the flexor hallucis
what is teh nerve we monitor in the posterior tibia
flexor hallucis
which nerve is best to monitor??? and why
the corrugator supercilli (face) is relatively resistant to blockade and very similar to diaphragm resistance
so monitor the facial nerve for intubation and abd rectus paralysis
-the ulnar (adductus pollicis) is very easliy blocked so monitor for extubation adequacy
hint:
go to sleep and stay asleep with eyes closed, and wake up with thumbs up!!!
again to ensure you grasped it’s importance when do you monitor the face and ulnar nerve
go to sleep and stay asleep with eyes closed, and wake up with thumbs up!!!
name the % of receptors occupied (you need to know this)
Normal TV
Holds tetanus 50Hz
Equal TOF, DBS
Holds tetnas 100Hz
Head lift x 5 secs
Normal TV–0-80% may be blocked
Holds tetanus 50Hz–0-75%or80% may be blocked
Equal TOF, DBS–0-75% or 80% may be blocked
Holds tetnas 100Hz–0-50% may be blocked
Head lift x 5 secs–0-33% may be blocked
just remember these are UP TO amounts a very wide range.
What is single twicth monitoring for
allows continual eval of DEPOLARIZING block
what is TOF for
allows est of DEGREE on NON-DEPOLARIZERS
what is DBS for
easier visual eval of fade, give same info as TOF
what is tetanic stimulation for
more detailed assessment of degree of NON-DEPOLARIZERS block
what is post tetanic stimulation count (PTC) for
allows quantifaction of block if no TOF
est what cholinesterase inhibitor reversal drugs may acheive for you
does giving tetany affect suxs
no!!
do you monitor NDMbD the same as DMBD
no
suxs has no post tetanic and no fade
