(SS25) NMBD Reversal Agents (Exam 4) Flashcards
1
Q
What was discovered in the early 2000s on NMB blockade postop residual?
A
- No NM monitoring or reversal = Post op residual NM Blockade: 33%
- Early 2000s: Showed the use of NM monitoring & reversal ↓ residual blockade to 4%
2
Q
Other names for NMBDs
A
-AcetylycholineEsterase (AchE) Inhibitors:
- Cholinergic Agents: Paired w/ anti-cholinergics
- Competitive Antagonists: Compete at site of action
3
Q
AchE MOA
A
- Rapid hydrolysis of Ach @ NMJ
- Inhibititon of AchE = ↑ Ach
4
Q
- What receptor subunit does Ach bind to?
- Location(s) of receptors
A
- 𝛼lpha subunits
- Preganglionic (SNS & PNS)
- NMJ: requires action potential
5
Q
What is another name for NM monitoring?
A
- Acceleromyography
6
Q
What is the most common NM monitoing site? List the location, nerve, and muscles being monitored?
A
- Adductor Policis = muscle
- Ulnar = nerve
- Hand = location
7
Q
Generally, how long until NMJ blockade is fully reversed with Neostigmine?
A
20-30 min
8
Q
Aminosteroids are metabolized in the ___________.
- Which NMBD does this include (4)?
A
- Liver
- d-Tubocurarine: Long- acting
- Pancuronium: Long- acting
- Rocuronium: Intermediate
- Vecuronium: Intermediate
9
Q
Benzylisoquinolines are metabilized by_________
- Which NMBD does this include (3)?
A
- Plasma cholinesterase
- Atracurium: Intermediate
- Cisatracurium: Intermediate
- Mivacurium: only short-acting
10
Q
Clinical Duration of Response (mins) for the folllowing:
- d-Tubocurarine: Long- acting
- Pancuronium: Long- acting
- Rocuronium: Intermediate
- Vecuronium: Intermediate
- Atracuonium: Intermediate
- Cisatracurium: Intermediate
- Mivacurium: only short-acting
A
- d-Tubocurarine: 81
- Pancuronium: 86 (Longest)
- Rocuronium: 36 (2nd shortest)
- Vecuronium: 44
- Atracuonium: 46
- Cisatracurium: 45
- Mivacurium: 16.8 (shortest)
11
Q
Do AChE inhibitors work with deep neuromuscular blockade?
A
- No
- Ceiling effect
12
Q
Reversal of NMJ blockade is dependent on these 5 factors:
A
- Depth of block
-Look @ fade/twitches - Drug choice (neostigmine vs edrophonium)
-slow v fast action - Dose of reversal administered
- Rate of plasma clearance
-Clinical response duration tells when drug is out of blood & should expect twitches - Anesthetic agent and depth
-Postop Residual NM Blockade: need to get gas out of system so it doesn’t contribute to this
13
Q
What would a fade of 4 out 4 with equal strength possibly indicate?
A
- May indicate that you do not to reverse if all impulses are present and of equal strength
14
Q
T/F: Train of four (TOF) 2 out of 4 twitches or a fade of 1-3 strong impulses of equal strength indicates a reversal is needed.
A
- True. Due to re-absorption effects, if patient has any diminished or absent nerve stimulation, need reversal to be safe
15
Q
Which paralytic has to be reconstituted with 10mL of H₂O ?
A
Vecuronium
16
Q
What drugs would be coupled with NMBD reversal agents to prevent adverse side effects from these drugs?
A
- Atropine - Anti-muscarinics
- Glycopyrrolate - Anti-cholinergic
17
Q
Which reversal agent can be given with DEEP blocks?
A
- Sugammadex
18
Q
__________ potentiates NM blockade.
A
Volatiles (Iso Sevo,Des)
- Have muscle relaxant properties
19
Q
Neostigmine:
- Dose:
- Max dose:
A
- 0.04 - 0.07 mg/kg or 40 - 70 mcg/kg
- Per Castillo, just use 50 mcg /kg
- Max 5 mg
20
Q
Neostigmine:
- onset
- duration
A
Onset: 5 - 10 min
Duration: 60 mins
Typically given around 2nd to last suture
21
Q
What is the recommended anti-cholinergic to be given w/ Neostigmine during reversal?
- dose?
A
- Glycopyrrolate
- 0.2 mg per 1 mg of Neostigmine
22
Q
Explain the importance of ceiling effect with Neostigmine?
- Per lecture, what are 2 important requirements to prevent the patient going back into Phase 1?
A
- Can push patient back into Phase 1 Blockade (same thing as Succs fasciculations or non-depolarizing paralytic OD)
1. Do not give more than max dose of Neostigmine (5 mg = max)
2. Must reverse with twitches (TOF)
-Don’t give reversal if patient has 0 twitches
23
Q
Which nerve stimulator is not acceptable for reversal?
A
- Do not use Post tetany: Already propagating impusles (false reading)
24
Q
Edrophonium:
- Dose:
- Max dose:
A
- 0.5 - 1 mg/kg
- 1 mg/kg
25
Edrophonium:
- onset
- duration
- Onset: 1-2 min "**Fast Eddy**"
- Duration: 5-15 min
26
What anti-muscarinic is given with Edrophonium?
**Atropine Sulfate**
27
What is the dose of Atropine?
7 - 10 mcg/kg
28
Atropine should be given __________ (*before/after*) Edrophonium.
- Why?
- **before**
- You want to avoid the anti-cholinergic effects so wait for HR to increase then give Edrophonium.
29
What are expected effects to be seen right after Atropine is given?
- Mydriasis (pupil dilation)
- Initial Tachycardia
30
A 41 y/o, 100 kg female patient underwent TAHBSO & surgeon is closing.TOF 2/4 twitches & other 2 have fade. Neostigmine 1 mg/ mL vial available. How much will you admin in mLs?
- **5 mL**
- 5 mg total so this is our max
- In practice: Per Castillo, Could give dose based off TOF/fade
-So if 2/4 twitches = 50%, he would give 1/2 of this dose (2.5 mg).
## Footnote
**For exam: answer is the 100% dose**
31
Renal Excretion rates (%) for the following:
- Neostigmine
- Pyridostigmine
- Edrophonium
- Neostigmine = **50%**
- Pyridostigmine & Edrophonium = **75%**
- Chronic renal failure ↓ plasma clearance & prolongs action
32
- How are NMB reversal agents cleared if the patient has no innate renal function?
30 - 50% cleared hepatically
33
NMBD Reversal Side effects:
(Hint: Reversal = ↑ Nicotinic/Muscarinic Activity)
Systems effected: CV, Pulmonary, GI, Eyes
- CV: **↓SVR**, **↓HR**, dysrhythmias, asytole,
- Pulmonary: **Bronchoconstriction, ↑ airway resistance,↑ salivation**
- GI: Hyperperistalsis "**code brown**", ↑ gastric fluid secretion, PONV
- Eyes: Miosis (**pupil constriction**)
## Footnote
Caution: Recent MI/valve sx, Asthmatics, COPD
34
If you're concerned about someone's cardiac status due to existing disease, which Anticholinergic drug would you use?
- **Glycopyrrolate**
- Given to counteract cholinergic effects (Ex. prevents ↓ HR)
35
What NMBD(s) is glycopyrrolate used with?
- **Neostigmine**
- Pyridostigmine - we don't use this one
36
Glycopyrrolate:
dose:
max:
use:
- 7 -15 mcg/kg (**10 mcg/kg** per Castillo)
- **Max 1mg**
- Given w/ Neostigmine
37
How long does glycopyrrolate need to be administered over?
- Why?
- Slowly over **2 - 5 min**
- Prevents direct action on cardiac level
38
41 y/o, 100 kg female patient underwent TAHBSO & surgeon is closing.TOF 2/4 twitches & the other 2 have fade. Glycopyrrolate 0.2 mg/ mL vial available. How much will you admin in mLs?
- **5 mL**
- Glycopyrrolate dose ~ 10 mcg/kg→ 10 * 100 = 1000 mcg → 1 mg
- 1 mg / 0.2 mg/mL = 5
39
What causes persistent NM blockade?
- How do you manage it?
- MOA: **Maximal inhibition of AchE**= ineffective
- Prolonged blockade
- Postop ventilation (bipap/intubate) & sedation until cleared
- Importance for checking twitches baseline
40
Factors that influence NMBD Reversal
- intensity of block
- NMBD used
- continued volatile anesthetic
- reversal drug used
- patient conditions (**metabolic or respiratory acidosis, hypothermia**, etc.)
41
What reversal drug is specific to Mivacurium?
**Purified Human Plasma Cholinesterase**
42
What reversal drug is specific to Gantacurium?
**Cystiene**
43
What reversal drug is very specific to Rocuronium?
**Sugammadex**
44
What type of drug is sugammadex?
- **Selective relaxant-binding agent**
- selective to **aminosteroids only (-roniums)**
45
Sugammadex:
- Classification?
- What is it made from?
- Solubility properties?
- Excretion via?
- **gamma (γ) -cyclodextrin**
- **Dextrose units from starch**: safe for diabetics
- **Very H₂O-soluble**: likes to stay in plasma
- 100% excreted by kidneys
46
Sugammadex is eliminated via urine with ________ % gone in 6 hours and _________ % within 24 hrs.
- 70% , 90%
47
Sugammadex:
- onset
- duration
- E ½
- onset = **1- 4 mins**
- duration = **1.5 - 3 hrs**
- E ½ = 2 hours
48
Sugammadex: MOA
**Encapsulation of aminosteroid** via:
- Intermolecular Van der Waals forces
- Thermodynamic Hydrogen-bonds
- Hydrophobic interactions
49
What drugs does sugammadex work on?
- Roc > Vec > Pancuronium
50
T/F: Sugammadex binds to plasma proteins?
False
- Sugammadex does NOT bind to plasma proteins.
- Either it's binded to free NMBD in plasma or making it's way to excretion via kidneys
51
Differentiate a moderate block vs a deep block.
- **Moderate**: Spontaneous recovery of **train of four response** 2/4 twitches on TOF (T2)
- **Deep**: Spontaneous recovery of twitch response has reaches 1-2 **POSTtetanic** counts OR **NO** twitches on TOF
52
Sugammadex - Dose for Moderate block:
**2 mg/kg**
53
Sugammadex - Dose for Deep block:
**4 mg/kg**
54
Sugammadex - Dose for Extreme (OD) block:
**8 - 16 mg/kg**
55
What are the side effects of Sugammadex?
- Marked Bradycardia
- dose-related N/V
- dose-related Pruritis
- dose-related Urticaria
- Anaphylaxis
- Doesn't work
## Footnote
dose-related = ↑ dose = ↑ risk of SE
56
What drugs/conditions are contraindications to sugammadex?
- **Renal Impairment: C/I w/ dialysis**
- Encapsulation of **Contraceptives**: Binds to progesterone x7 days
- **Toremifene**: Cancer drug that displaces NMBD from sugammadex → reversal won't work
- **Coagulopathy/Bleeding:** Heparin / LMWH; ↑PTT, PT, INR
57
What education needs to be given to child-bearing age women on birth control who received Sugammadex?
- Patient should use alt. BC method for 7 days
58
What may occur if you give less Sugammedex than recommeded dose for a moderate or deep block reversal?
- Recurarization
59
What is recurarization?
- Resumption of NMJ blockade after period of reversal (**Re-paralyzation)**
60
What are the signs & symptoms of Recurarization?
-When do you expect to see them?
Immediately apparent in PACU
- **↓O2 sats** (hypoxemia)
- **Ineffective abdominal & intercostal activity**
- **Unresponsive**
- **Floppy/uncoordinated**
Other S&S
- ""suffocating"" feeling
- unable to sustain head lift or hand grasp
- Worse case: pharyngeal collapse & respiratory obstruction
61
Treatment goals of Recurarization
- Treat urgently & aggressively
- Re-sedate the patient
- Give additional; reversal agents in divided doses (Ex: Neostigmine 0.05 mg/kg IV = longer duration of action)
- If at max Neostigmine dose, go to Phyostigmine
62
What is a critical requirement when selecting your reversal agent?
- Must make sure that the **reversal DOA out last the clincal duration of response of NMBD** to prevent Recurarization
63
T/F: Recurarization is observed with Sugammadex use.
False
- Recurarization **not observed** with appropriate doses
64
Explain clinical significance of Sugammadex v. Neostigmine when reversing Vec.
- Graph shows that the use of Sugammadex results in a significantly shorter recovery time from Vec, compared to Neostigmine (2 min v. 29 min)
65
Explain clinical significance of Sugammadex v. Neostigmine when reversing Roc.
- Graph shows that the use of Sugammadex results in a significantly shorter recovery time from Roc, compared to Neostigmine.
- Faster recovery from Rocuronium > Vecoronium as well b/c Sugammadex is more Roc-specific.
66
If you need to re-paralyze / intubate after reversal given, what can you do?
- Re-administer Roc or Vec
or
- Use a benzylisoquinoline (-curiums)
67
After waiting a **minimum of 5 mins**, what is the r**e-administration dose for Rocuronium**?
**1.2 mg/kg (max 4 mg/kg)**
68
The surgeon tells you they have to re-open abdomen **4 hours post surgery.** What NMBA(s) could you give and the corresponding dosages?
- Roc **0.6 mg/kg**
or
- Vec **0.1 mg/kg**
69
What type of NMBA is recommended for re-administration if it's before minimum waiting period or no Roc available?
- Nonsteroidal NMBA
- benzylisoquinoline (-curium) then reverse with anticholinergics
70
What drug and dose would be a good choice for a recurarizing patient in the PACU?
Why might this be a good choice?
- Neostigmine 0.05 mg/kg IV
- Longer duration of action
71
NMBD & Reversal Tables for reference
## Footnote
Per Castillo, may be off from book; but this is what we will be tested over
