Exam 4 - NMB Reversals

Question 1

What is another name for neuromuscular monitoring?

Answer 1

Acceleromyography

Question 2

What does it mean for NMB reversal drugs to have a ceiling effect?
How does this effect reversal?

Answer 2

“Once the inhibition of acetylcholinesterase is complete, administering additional doses of neostigmine will serve no useful purpose because the concentration of acetylcholine that can be produced at the neuromuscular junction is finite.” - Stoelting p. 1052

This means that NMB drugs will not be able to reverse deep blockade (no twitches)

Question 3

Max dose for neostigmine and edrophonium?

Answer 3

Neostigmine: 50 mcg/kg or 5 mg
Edrophonium: 1 mg/kg

Question 4

Reversal of NMJ blockade is dependent on these 5 factors:

Answer 4

1. Depth of block
2. Drug choice (neo vs edro)
3. Dose
4. Rate of plasma clearance
5. Anesthetic agent and depth

Question 5

What is the onset and duration of neostigmine?

Answer 5

Onset: 5 - 10 min
Duration: 60 min

Question 6

What is the dosage of edrophonium?

Answer 6

1 mg/kg

Question 7

What is the onset and duration of edrophonium?

Answer 7

Onset: 1-2 min
Duration: 5-15 min

Question 8

What is the formula for glycopyrrolate to be used with a NMB reversal drug?

Answer 8

0.2 mg of glycopyrrolate / mg of neostigmine

Question 9

What is the max dose for glycopyrrolate?

Answer 9

1 mg

Question 10

A 100 kg patient has 2/4 twitches. Neostigmine is available in 1 mg/mL vials. How much neostigmine will you give in mL?

Answer 10

5 mL (max dose of 5 mg)

Question 11

What percentage of neostigmine is renally excreted?

Answer 11

50%

Question 12

What percentage of both pyridostigmine and edrophonium are renally excreted?

Answer 12

75%

Question 13

How are NMB reversal agents cleared if the patient has no innate renal function?

Answer 13

30 - 50% cleared hepatically

Question 14

What is the major side effect of NMBD reversal agents?

Answer 14

↑PSNS activity (from increased nACh and mACh activity)

Question 15

What drugs would be coupled with NMBD reversal agents to prevent adverse side effects from these drugs?

Answer 15

Anti-cholinergic / Anti-muscarinics

• Atropine for edrophonium
• Glycopyrrolate for neostigmine and pyridostigmine

Question 16

If you’re concerned about someone’s cardiac status due to existing disease, which Anticholinergic drug would you use?

Answer 16

Glycopyrrolate

Question 17

What is the dose of atropine for use with edrophonium?

Answer 17

10 mcg/kg

Question 18

What common side effects are seen right after atropine administration?

Answer 18

• Mydriasis
• Tachycardia

Question 19

How long does glycopyrrolate need to be administered over?

Answer 19

2 - 5 min

Question 20

Mechanism of persistant NM blockade?
Treatment?

Answer 20

• Maximum AChesterase inhibition
• Sedation and post op ventilation

Question 21

What patient conditions may effect NMBD reversal?

Answer 21

• Metabolic acidosis
• Respiratory acidosis
• Hypothermia

Question 22

What reversal drug is specific to mivacurium?

Answer 22

Purified human plasma cholinesterase

Question 23

What reversal drug is specific to gantacurium?

Answer 23

Cystiene

Question 24

What reversal drug is very specific to aminosteroids?

Answer 24

Sugammadex

Question 25

What type of drug is sugammadex?

Answer 25

Selective relaxant-binding agent

Question 26

What should be known about sugammadex's organic structure and physical properties?

Answer 26

- γ-cyclodextrin - Dextrose units from starch - Very H₂O-soluble

Question 27

What is the MOA of Sugammadex?

Answer 27

Encapsulates rocuronium via: - Van der Waals forces - H-bonds - Hydrophobic interactions

Question 28

What drugs does sugammadex work with best?

Answer 28

**Roc** > Vec > Pancuronium

Question 29

Where does suggamadex work?

Answer 29

It binds to NMB drug in the plasma

Question 30

What is the E ½ time of sugammadex?

Answer 30

2 hours

Question 31

How is sugammedex eliminated?

Answer 31

Urine: - 70% gone in 6 hours - 90% gone in 24 hours

Question 32

When is sugammadex contraindicated?

Answer 32

Renal impairment on dialysis

Question 33

Differentiate a moderate block vs a deep block.

Answer 33

- Moderate: 2/4 twitches on TOF - Deep: No twitches to TOF, but will have a twitch w/ post tetanic stimulation

Question 34

What is the Sugammadex dose for a moderate block?

Answer 34

2 mg/kg

Question 35

What is the Sugammadex dose for a deep block?

Answer 35

4 mg/kg

Question 36

What is the sugammadex dose for an extreme (overdose) block?

Answer 36

8 - 16 mg/kg

Question 37

What are the side effects of Sugammadex?

Answer 37

- dose-related N/V - dose-related Pruritis - dose-related Urticaria * Anaphylaxis * Bradycardia

Question 38

If 1.2 mg/kg of rocuronium needs to be re-administered after reversal with sugammedex. What is the minimum waiting time?

Answer 38

5 min

Question 39

If 0.6 mg/kg of rocuronium needs to be re-administered after reversal with sugammedex. What is the minimum waiting time?

Answer 39

4 hours

Question 40

If 0.1 mg/kg of vecuronium needs to be re-administered after reversal with sugammedex. What is the minimum waiting time?

Answer 40

4 hours

Question 41

What drugs/conditions are relative contraindications to sugammadex?

Answer 41

- Contraceptives (7 days) - Toremifene (displaces roc from sugammadex) - Coagulopathy (↑ bleeding - not clinically significant)

Question 42

What is recurarization?

Answer 42

Resumption of NMJ blockade after period of reversal

Question 43

What s/s would indicated recurarization? *Say you just brought the patient to PACU*.

Answer 43

- ↓ SpO₂ - ↓ respiratory effort - Floppy/uncoordinated - Unresponsive

Question 44

What drugs and dose would be a good choice for a recurarizing patient in the PACU? Why might this be a good choice?

Answer 44

- Neostigmine 0.05 mg/kg IV - Longer duration of action - Re-sedate the patient so they don't remeber being paralyzed while awake