Emergence & Extubation

Question 1

Definition of emergence

Answer 1

Awakening from the effects of an anesthetic drug. CNS is waking up, much less predictable than induction, now will see stage 2 of excitation. Neurotransmitter “Orexin” involved in arousal.

Question 2

Goals of E&E

Answer 2

Stable vitals / spontaneous respiration / ability to protect airway / alertness/purposeful/responsive / normal NM function.

Question 3

Complications of Emergence

Answer 3

Delirium / unstable vitals (tachycardia, HTN) / delayed emergence / poor/dysfxnl resp effort / residual paralysis / diffusion hypoxia

Question 4

How to promote emergence:

Answer 4

Halting admin of anesthetic in appropriate time, don’t wake up while paralyzed. May need reversal agent or more time (no reversal for volatile, allow time to blow off). Maintain some level of analgesia.

Question 5

Definition of Delayed Emergence:

Answer 5

failure of pt to regain expected LOC w/i 20-30 min of end of anesthetic. Must think through diff Dx. Pt usually wake up w/i 5-10 minutes. Checking pt hx and timing of last dosing.

Question 6

What Populations are at greatest risk for delayed emergence?

Answer 6

Pts rec sedative meds / cognitive/psych disease / intoxication @ anesthetic / physical exhaustion @ anesthetic / ? narcoleptics ? / elderly

Question 7

R/O ALOC/delayed emergence diagnoses

Answer 7

1 - hypoxia! #2 - airway obstruction #3 - hypercarbia #4 - hypothermia

Question 8

What is proper evaluation of delayed emergence?

Answer 8

Evaluate: Patient history –> Review meds administered –> Consider Sx/Anesth complications –> assessment of vitals (hypothermia)

Question 9

Categorical causes of delayed emergence

Answer 9

Anesthetic drugs / medications / electrolyte disorder / metabolic disorder / systemic effects

Question 10

Delayed Emergence Causes: Anesthetic Rx

Answer 10

CNS sensitivity / drug clearance altered by hepatic/renal disease / elevated free frxn of rx d/t low albumin –> Tx’s = improve ventilation, reversal agents, allow time

Question 11

Reversal agents/doses

Answer 11

Naloxone: 40cmg q2 min up to 200mcg / Flumazenil 0.2mg up to 1mg / physiostigmine 1.25mg (raise orexin levels?)

Question 12

Delayed Emergence Causes: Electrolyte Disorder

Answer 12

Hyponatremia = lethargy, Sz, cerebral edema / Hypercalcemia/Hypermagnesemia = mild to severe CNS depression

Question 13

Delayed Emergence Causes: Metabolic Disorder

Answer 13

Hyperglycemia = hyperosmolar coma / hypoglycemia = sz, etc / hypothyroid/adrenal deficit = poss coma

Question 14

Delayed Emergence Causes: Systemic Effects

Answer 14

Hypercarbia / Cerebral Vasc event/stroke / Seizure / hypothermia (threshold around 36*C)

Question 15

Delayed Emergence Causes: Dysfunctional Respiration/Apnea

Answer 15

Residual NM blockage = nerve stim / narcotic effect = last dose? reversal / Blunted hypoxic drive = chronic retention, lower FiO2 / hypocarbia = too low to stim resp drive, hypovent pt / CNS injury = brain swelling alter resp centers

Question 16

Timing of extubation

Answer 16

Prior to emergence (stage 3) or when patient awake/alert (stage 1). Never extubate while in pt is “light” aka delirium/excitation (stage 2)

Question 17

Characteristics of Stage 2

Answer 17

CV instability / dysconjugate eye mvmts / retching/emesis / breath holding / exaggerated responses to stimuli / not coop or alert

Question 18

Deep Extubation: advantages/disadvantages

Answer 18

Adv: less coughing (ideal for plastics, head/neck, eye and Nsurgery), attenuated HD response, decr bronchospasm risk
DisAdv: AW obstruction, aspiration, laryngospasm RSI or DIff AW = no deep exbation

Question 19

Awake Extubation: Neuro parameters

Answer 19

Adequate NM fxn (no fade, sust tetany, 5 sec head lift), LOC stable, Stage 1, awake, purposeful, following commands

Question 20

Awake Extubation: Pulm parameters

Answer 20

NL ABG/SpO2 on 40%, RR 10-30, Vt/RR >10, NIF -20-30 cm water, VC > 10-1ml/kg, Vt > 5ml/kg, no evidence of v/q mismatch

Question 21

Awake Extubation: Misc parameters

Answer 21

HD stable, normothermia, NL labs, acceptable pain control

Question 22

Equipment Trick/process for extubation

Answer 22

100%, close pop off valve a little, suxn trach/oral cavity as needed, hyperinflate to create mandatory exhale upon tube removal, place oral AW

Question 23

Extubation complications

Answer 23

1 is obstruction / AW relaxation, edema / hematoma / laryngospasm (stage 2) / vocal cord dysfxn / Foreign body(aspiration)

Question 24

Extubation complications: Larygnospasm

Answer 24

D/T stage 2 extubation, light with hyperactive reflexes, presence of secretions. Tx with pos pressure, lidocaine, small dose of succinylcholine. Possibly causing neg press pulmo edema.

Question 25

Extubation complications: edema

Answer 25

usually tongue is culprit, croup in pediatrics. Prone position, long case, excess fluid volumes create glossal edema. Tx w/ cool mist, racaemic epi. Can check with cuff leak test.

Question 26

Extubation complications: hematoma

Answer 26

Poss life threatening situation, swelling may compl occlude AW. Must evac hematoma prior to att re-intubation.

Question 27

Extubation complications: Vocal cord dysfunction

Answer 27

Poss paralysis d/t recurrent laryngeal nerve damage. Creates passive vocal cord closure, varying degrees of AW blockage, depends on unilateral vs bilateral.

Question 28

Extubation complications: non AW complications

Answer 28

tachycardia, HTN, coughing/bucking , aspiration, bronchospasm.

Question 29

Extubation complications: tachycardia/HTN

Answer 29

Common occurence, worrisome w/ CAD, NeuroVasc disease patients. 10-30% transient increase in numbers. Tx with lido, esmolol, NTG

Question 30

Extubation complications: Coughing/bucking

Answer 30

Increased intrathoracic, intracranial, intraocular pressures. Increase tension on surgical sites/incisions/sutures. Tx with narcotics, Lidocaine via LTA, IV lido prior to extubation.

Question 31

Extubation complications: Bronchospasm

Answer 31

Provoked by light anesthesia as ETT is mechanical irritant. Use beta agonists, LMA. Asthmatics think LMA, bronchodilators, heavy gas. Rept albuterol prior to emergence. Poss deep exchange of ETT for LMA.

Question 32

Extubation complications: Extubation with LMA

Answer 32

Less stimulating than ETT, less side effects, tachy/htn/bucking/bronchospasm. Remove when pt awake, squeeges AW clean, use with bite block for removal. Usually a smoother wake up.

Question 33

Extubation complications: Diff AW extubation

Answer 33

Awake extubation, careful eval of clinical conditions prior to removal, have back up plans. Want aspiration, obstruction risks removed/decreased with pt being awake, coop, + reflexes, NM intact with good resp effort.