Neuromuscular Blockade Monitoring

Question 1

Reasons to Monitor:

1) Wide inter-patient variability in ?
2) Facilitates ?
3) Allows careful ?
4) Allows assessment of ?

Answer 1

1) dose requirements
2) timing of intubation
3) titration to effect
4) readiness for reversal

Question 2

Reasons to Monitor:

1) Allows assessment of ?
2) Differentiates ?
3) Facilitates early recognition of ?

Answer 2

1) adequacy of reversal
2) type of block
3) pseudocholinesterase activity

Question 3

When should we monitor?

1) When a ___ is used.
2) In neuromuscular disease?
3) When post-op ___ must be maximal.
4) When continuous infusion of ___ is used.

Answer 3

1) long acting muscle relaxant
2) Myasthenia gravis
3) muscle power
4) muscle relaxant

Question 4

Post-op muscle strength maximal need patient fully awake, full TVs.
Ex: 2

Answer 4

Respiratory compromise elderly

young

Question 5

The most commonly used nerve?

• may also use median, posterior tibial, common peroneal and facial nerves.
• We monitor peripherally because our primary concern for emergence is the ___, which recovers faster than the peripheral muscle groups.
• ____ is needed to guarantee diaphragm paralysis post induction (establishes ?)

Answer 5

Ulnar nerve

• diaphragm
• post tetanic count (PTC)
• intense blockade

Question 6

___ how quickly the muscle recovers from paralysis. The ___ recovers very quickly from paralysis whereas the ___ recovers slower.

Don’t confuse this with ___ with the drug this is the time from injection until there is a measurable effect.
-The measured onset time of muscle groups to muscle relaxant varies. These 3 all have faster onset times than other muscles?

Answer 6

Sensitivity

• diaphragm
• adductor pollicis
• Onset time
• Diaphragm, vocal cords and larynx

Question 7

TOF:

• ___ = the twitch height for all 4 twitches reduces at the same time. TOF ratio for these drugs is constant at ?
• ___ = these will have fade, goal for reversal is to have all 4 back to baseline.

Answer 7

-Depolarizing Block
one
-Non-depolarizing block

Question 8

Most precise form of neuromuscular monitoring?

*Considers?

Answer 8

Peripheral Nerve Stimulator

*individual variation

Question 9

If ___ is back you know the diaphragm has returned to functioning.

Answer 9

obicularis oculi

Question 10

1) Battery operated - no twitches may indicate loss of ___.
2) More than ___ is uncomfortable in conscious patient.
3) ___ is negative and ___ is positive.

Answer 10

1) battery power
2) 80 mA
3) red/negative, black/positive

Question 11

1) ___ = continuous/intermittent stimulation (__ or __ hz)
2) ___ = Four supramaximal stimuli over 2 seconds. Presence of ___ is the assessment. Best for ?
3) __ = ___ to ___ hz supramaximal stimulation. Presence of fade is noted. Otherwise without a baseline the test is hard to interpret. Is not valid when performed repeatedly on the same muscle group. Very difficult to rule out ___ with this monitor.

Answer 11

1) Single Twitch stimulation
0.1 or 1 hz (0.1 most common)
2) Train of Four stimulation
fade
non-depolarizing blockade
3) Tetanic stimulation
50 hz to 200 hz
residual blockade

Question 12

• ___ = tetany for 5 seconds, ___ second delay and single twitch stimulation follows. Useful for determining time to response to ___. It is a very good monitor of ___. Should not be performed more than every ___.
• ___ = Two, three twitch salvos, 600 milliseconds apart. This method makes it easier to detect residual neuromuscular blockade by ___, more than the TOF method.

Answer 12

*Post Tetanic stimulation 
3 second
train of four
intense block
6 minutes
*Double Burst stimulation
feel

Question 13

Use as the mode to assess muscle response on induction?

• The ___ is set by the machine itself, not by you.
• Assess at the ___, by the time you have lost single twitch here you can be sure the vocal cords and diaphragm are paralyzed because onset for relaxation of vocal cords and diaphragm is faster than ___.

Answer 13

Single Twitch Stimulation

• frequency
• thumb
• adductor pollicis

Question 14

Pattern of Electrical Stimulation ~
Depolarizing Block vs. Non-depolarizing Block:

Except for the time difference - __ occurs faster than ___. There is no difference in actual response or in the strength of the response.

Answer 14

Depolarizing Block

Non-depolarizing Block

Question 15

Disadvantages of Single Twitch:

1) Need to have pre-relaxant ___.
2) Can’t distinguish ?
3) Presence of ___ does not guarantee that full recovery from NMB has occurred.
4) Not ___ enough so not used for ___. Have no other twitches to compare to for height differences.

Answer 15

1) “control twitch”
2) btw Non-depolarizing and Depolarizing neuromuscular blockade
3) full twitch height
4) specific
emergence

Question 16

With this frequency the immediately available store of AcH is depleted and the amount released by the nerve decreases with each successive stimulus?

Answer 16

Train of Four

Question 17

Can compare the first twitch to the last twitch, gives you an indicator of depth and degree of block?

___ on PNS looks just like a non-depolarizer. In this block, DOA of ___ prolonged. The bad news is cannot reverse it.

Answer 17

Train of Four
Phase II Block
succinylcholine

Question 18

___ is a ratio comparing the value of the 4th to the 1st twitch?
-Peak level = ?

Answer 18

Train of Four

-zero twitches

Question 19

Train of Four:

1) Get ___ after induction drug.
2) Need to wait ___ for ___ to reaccumulate to get an accurate first twitch.

Answer 19

1) Baseline
2) 12 seconds
AcH

Question 20

___ = these will have fade. Goal for reversal is to have all 4 twitches back to baseline.

___ = The twitch height for all 4 twitches reduces at the same time.
TOF ratio for depolarizers is constant at ONE.

Answer 20

• Non-depolarizers

- Depolarizers

Question 21

During ___ or ___ progressive depletion of Ach output is balanced by increased synthesis and transfer from its mobilization stores in normal, non-paralyzed patient.
This is known as ___.

Answer 21

Tetany or TOF

Fade

Question 22

*Use when there is a deep block (have zero twitches, want to know where am I? When is that single twitch going to come back)?

• If you give a TOF after tetany (tetany will mobilize ___) ___, you will see more than what you have seen with just a TOF.
• Do not want to start redosing with maintenance dose until we have at least a ? also do not want to ___ until we have this as well.

Answer 22

*Tetanic Stimulation
-Ach
post-tetanic facilitation
-single twitch back
reverse

Question 23

Want to administer a ___ to see if there is any response, if there is zero response then you have a ___.

Answer 23

Tetany

Profound block

Question 24

*___ = we have FADE and we have POST TETANIC facilitation also called ___.

*___ = we do not have fade, we do not have post-tetanic facilitation. If using ___ and you do have post tetanic facilitation probably due to ___.

Answer 24

*Non-depolarizers
potentiation
*Depolarizers 
succinylcholine
phase 2 block

Question 25

Tetanic Stimulation:

• Generally used to evaluate?
• Useful in determining?

Answer 25

• residual NM blockade (adequacy of reversal)

- Phase 2 block

Question 26

Infusion, for example an atracurium infusion - all responses to TOF are obliterated at a ___ of less than 10. This will help you predict time to reappearance of first response to TOF, thus useful in predicting an appropriate time to turn off drip.

Answer 26

Post-tetanic count (PTC)

Question 27

Non-depolarizing Muscle Blockade:
After injection of non-depolarizer TOF will demonstrate 3 Phases of Blockade. What are they?

#2 = When you get the one twitch back, if you do not redose you will get a second twitch back, now not in a good place for surgical stimulation. Need to start your maintenance dosing of NMB. 
#3 = Get all 4 twitches back to baseline height, do not give \_\_\_ until you have at least one twitch.

Answer 27

1) Intense Block Phase
2) Moderate or Surgical Block Phase
3) Recovery Phase
reversal

Question 28

At this phase, even when we have 4 responses back we are in a very gray area. This gray area is important because the duration of the reversal agent NEEDS to be as LONG as duration of the residual NMB. Or drug may still be at the site blocking the receptors and when the reversal wears off will experience muscle weakness.

Answer 28

Recovery phase

Question 29

Monitoring During Reversal:

• If ___ are present, full reversal is almost assured within ___ of reversal agent administration.
• Double burst stimulation (DBS) most useful?

Answer 29

-4 twitches
10 minutes
-post reversal

Question 30

*An abnormal response to a depolarizing agent in a genetically abnormal individual?

• Can also occur after?
• Manifests as ___ or ___

Answer 30

• Phase 2 Block
• prolonged succinylcholine infusion
• Post-tetanic fade or very prolonged blockade

Question 31

Note in a genetically normal patient anticholinesterase drugs will reverse the blockade. In genetically abnormal patient they will not. With unpredictable results?

Reversal of Phase 2 Blockade should only be done in known cases of drug induced Phase 2 Blockade. Can ___ or ___ the block in mutants.

Answer 31

Phase 2 Blockade

potentiate or only partially reverse

Question 32

Need to document.
Need to document the clincal sign that we determine for our reversal.
-Document every ___ a TOF
-Denominator is always 4 - looks like a fraction
-Recording on the record is number of twitches you see -> which will be #/4
-This documentation is different then the ratio of TOF which is based on ?
-___ prolongs NMB as well as drugs (ex: ?)

Answer 32

• 15 minutes
• height of the 4 twitches
• hypothermia
• lithium

Question 33

1) Used to determine baseline strength PRIOR to administration of any blocker?
2) Generally used to evaluate residual NM blockade (adequacy of reversal)?
3) Useful for determining degree of NDMR blockade?
4) After injection of non-depolarizer there will be no response twitch to TOF or single twitch. Quantifying intensity of blockade done by tetanic stimulation?
5) Most useful post reversal?

Answer 33

1) Single twitch stimulation
2) Tetanic stimulation
3) Train of four stimulation
4) Post tetanic count stimulation
5) Double burst stimulation

Question 34

~Main application is in evaluating degree of blockade when there is no reaction to single twitch or TOF?
-Used to ensure bucking and coughing from intubation eliminated.
Must have ??
-Used during ?

Answer 34

~Post Tetanic Count Stimulation

• intense block and zero PTC
• NDMR infusions