Lecture 4 Test 3 Flashcards
If you want to keep tabs on your paralytics and check how deep your NM block is, what can you do?
Neuromuscular monitoring (TOF)
How does neuromuscular monitoring work?
Place 2 electrodes on top of a nerve and when you run a current through these, it should cause a depolarization.
How can you generate an action potential externally?
TOF
What does it mean when you see a reaction after running a current through the ulnar nerve?
Your paralytic on board isn’t that deep.
What does it mean when you don’t see a reaction after running a current through the ulnar nerve?
Your block is deep
What does it mean when you see a minimal reaction after running a current through the ulnar nerve?
Your block may be wearing off.
What happens when you run a current of electrons outside of the cell.
Generate an action potential.
What does polarity mean?
There’s a charge difference between inside and outside the cell.
If there’s no difference between the charges inside and outside of a cell, this mean….
It is depolarized!
Are EKG’s looking at the current inside or outside of the heart cells?
Outside of the heart cells
What is the required voltage needed to dial in for your neuromuscular monitoring called?
Supramaximal stimuli
Term for “strong enough to recruit all the motor neurons in the underlying nerve”.
Supramaximal stimuli
TOF setting
2Hz / 2 secs = 2 impulses/1 sec = 4 impulses / 2 secs
How can you tell if you’re using a non depolarizing block based on the TOF?
The first twitch is stronger and gets weaker each time.
How can you tell if you’re using a Depolarizing neuromuscular blocker?
Equal strength on all 4 twitches.
What is Tetanic contractions?
High frequency stimulation for a short period of time. More than 4 impulses.
Causing continuous depolarizations for a period of time.
Unable to fully relax between depolarizations.
Checking for impulses the muscle generates after High frequency impulses to see the health of the synapse
Post tetanic count
What is double burst stimulation?
High frequency stimulation for a couple of secs, lay off and then do it again. In order to check for different characteristics of the neuromuscular block.
What happens when the ulnar nerve is stimulated?
Thumb comes forward and pinky twitches.
What does the ulnar nerve innervate when stimulated?
Adductor pollicis muscle
What other sites for TOF
Facial nerve
Peroneal nerve
Posterior tibial nerve
Which blocking agent takes into effect faster? NDMR or DMR
DMR (Succs)
What’s another reason why Succs is good to use?
It’s fast onset, short acting and it’s cheap! per Dr. Schmidt
Based on NDMR meds, how does your twitches return as the meds wear off?
You get one twitch at a time, first being stronger and the others get weaker and weaker until all 4 twitches are equal.
B/A is closer to 1 = recovered
As the drugs wear off for an NDMR agent how do you measure the ratio of each twitch?
The first twitch is labeled as A and the 4th twitch is B. Initially, the B over A ratio is very small. As the drug wears off, the ratio gets closer to 1.
Why’s is the first twitch of the TOF always stronger in a NDMR?
The first twitch has enough ACh to release on the first depolarization while the next subsequent depolarizations have lesser and lesser ACh being released from the neuron.
What’s the difference between the B over A ratio of a DMR block vs NDMR?
DMR: It is always closer to 1 since the A and B twitches are the same.
NDMR: Has a B/A ratio that’s less than 1 and it gets closer to 1 the closer the meds wear off.
