Anesthetic Emergence

Question 1

Anesthetic Emergence

“Every textbook tells you how to put someone to sleep, no book will ever tell you how to:

Answer 1

wake someone up.”

_{Amy Masiongale, CRNA}

Question 2

Anesthetic Emergence

“I put people to sleep for free.

Answer 2

I charge to wake them up”

_{Jim Masiongale, CRNA}

Question 3

Anesthetic Emergence

Objectives

Answer 3

Plan/implement appropriate emergence technique

Assess depth of neuromuscular blockade

Discontinue maintenance anesthetics (IA or IV)

Verify reversal of neuromuscular blockade

Ensure adequate post-op analgesia

Extubate patient safely

Potential problems

Question 4

_{Anesthetic Emergence}

Emergence Philosophy

^{Most anesthesia providers & surgeons will place a premium on:}

Answer 4

“SMOOTH” emergence

Free of coughing

Free of Straining

Free of Arterial Hypertension​

Question 5

_{Anesthetic Emergence}

Emergence Philosophy

^{It should be acknowledged that there is paucity of clinical data to give any perspective to the actual magnitude of risks associated with:}

Answer 5

an Emergence that is not smooth

Question 6

_{Anesthetic Emergence}

Planning Emergence

^{When do you start to prepare for emergence?}

Answer 6

Prior to induction of Anesthesia

Question 7

_{Anesthetic Emergence - Planning Emergence}

Prior to induction of Anesthesia

Answer 7

Shorter acting agents for shorter cases

Avoid excessive premedications

Prepare to switch techniques or agents at the end of a longer case

Time your medications and doses

Question 8

_{Anesthetic Emergence - Planning Emergence}

Assess Depth of NMB

^{How can you assess depth of neuromuscular blockade - Objectively?}

Answer 8

Train of Four-

Adductor Pollicis or Orbicularis Oculi?

Question 9

_{Anesthetic Emergence - Assess Depth of NMB}

Train of Four

^{0 twitches}

Answer 9

100% blockade

Question 10

_{Anesthetic Emergence - Assess Depth of NMB}

Train of Four

^{1 twitch}

Answer 10

95% blockade

Question 11

_{Anesthetic Emergence - Assess Depth of NMB}

Train of Four

^{2 twitches}

Answer 11

90-95% blockade

Question 12

_{Anesthetic Emergence - Assess Depth of NMB}

Train of Four

^{3 twitches}

Answer 12

80-85% blockade

Question 13

_{Anesthetic Emergence - Assess Depth of NMB}

Train of Four

^{4 twitches}

Answer 13

75-80% blockade

Question 14

_{Anesthetic Emergence - Planning Emergence}

Assess Depth of NMB

^{How can you assess depth of neuromuscular blockade - Subjectively?}

Answer 14

Timing and amount last dose

Spontaneous respiratory effort

Question 15

_{Anesthetic Emergence - Planning Emergence}

Assess Depth of NMB

^{Objectively - When can I reverse?}

Answer 15

Post-tetanic stimulation and return of 1 twitch = 10”

At least 1 twitch represents 95% blockade and no free drug

Therefore, reliably reversible

Different for sugammadex

Question 16

Anesthetic Emergence - Planning Emergence

Assess Depth of NMB

Subjectively - When can I reverse?

Answer 16

Spontaneous respiratory effort

Less than 100% blockade

Therefore, reliably reversible

Question 17

_{Anesthetic Emergence}

Reverse NMB

^{How do I reverse NMB? (What agents used?)}

Answer 17

Anticholinesterase Inhibitors

Edrophonium 1 - 1.5 mg/kg

Neostigmine 0.04 - 0.08 mg/kg

Pyridostigmine 0.1 - 0.25 mg/kg

Question 18

_{Anesthetic Emergence}

Drugs used to Reverse NMB

^{How do these agents work?}

Answer 18

These agents increase Ach EVERYWHERE

Ideally want to isolate only nicotinic receptors and

Avoid muscarinic action and

Cholinergic crisis

Question 19

_{Anesthetic Emergence}

Reverse NMB

^{Drugs used along with Anticholinesterase Inhibitors - <em>why?</em>}

Answer 19

Anticholinergics

Atropine 0.4 - 1 mg

Glycopyrrolate 0.2 - 1 mg

To avoid muscarinic action and cholinergic crisis

Question 20

_{Anesthetic Emergence}

Reverse NMB

^{How fast does reversal work is dependent on which five factors?}

Answer 20

• Depth of block
• Type of anticholinesterase
• Dose of anticholinesterase
• Spontaneous reversal and metabolism of NMB agent
• Concentration of anesthetic gas

Question 21

_{Anesthetic Emergence - Factors affecting NMB speed of Reversal}

Depth of block

^{Greater blockade =}

Answer 21

more to reverse

Question 22

_{Anesthetic Emergence - Factors affecting NMB speed of Reversal}

Type of anticholinesterase

Answer 22

Edrophonium > Neostigmine > Pyridostigmine

Question 23

_{Anesthetic Emergence - Factors affecting NMB speed of Reversal}

Dose of anticholinesterase

Answer 23

Maximum dose

Too much Ach can cause depolarizing blockade

Question 24

_{Anesthetic Emergence - Factors affecting NMB speed of Reversal}

Spontaneous reversal and metabolism of NMB agent

Answer 24

Intermediate vs. Long

Patient factors

Question 25

_{Anesthetic Emergence - Factors affecting NMB speed of Reversal}

Concentration of anesthetic gas

Answer 25

Increased depth of inhaled anesthetic gas augments blockade