Emergence From Anesthesia Flashcards
What three things are considered smooth emergence?
Free of coughing, straining, or HTN
What is causes a dehiscence of an abdominal or inguinal incision?
Coughing
4 things to consider before induction:
- Pt maturity and personality
- Ability to metabolize drugs
- Pre-op/post-op pain level
- Post-op airway maintenance, analgesic, hemodynamics
When do you start to prepare for emergence?
Prior to induction of anesthesia
Where do you place the train of four?
Adductor pollicis or orbicularis oculi
0 twitches 1 twitch 2 twitches 3 twitches 4 twitches
>90% 90% 80% 75% <75%
Subjectively depth of NMB
Timing and amount of last dose
Spontaneous respiratory effort
Objectively when to reverse with Neostigmine?
- post-tetanic stimulation and return of 1 twitch = 10min
- at least 1 twitch represents 90% blockade and no free drug
Subjectively to reverse with Neostigmine?
- spontaneous respiratory effort
- less than 100% blockade
6 factors that affect how fast Neostigmine works
- Depth of block
- Dose of anti cholinesterase
- How much spontaneous reversal
- Metabolism
- Coexisting disease
- Concentration of anesthetic gas
What can too much anti cholinesterase cause?
Depolarizing blockade
Is atropine or glycopyrrolate quicker onset?
Atropine
What would you give to children, atropine or glycopyrrolate?
Atropine because children can’t handle a drop in CO
What would you give to elders, atropine or glycopyrrolate?
Glycopyrrolate because can’t handle increase in HR
MOA for Sugammadex
Encapsulation of rocuronium and vecuronium causing reversal
Why can’t Sugammadex bind with mivacurium and atracurium?
Size of the cavity is too small to accommodate the bulky molecules
What can be used in a rocuronium induced anaphylactic reaction?
Sugammadex
Recurrence of NMB may occur with Neostigmine where the reversal effects wear off before a muscle relaxant is completely eliminated?
Recurarization
7 special considerations with sugammadex:
- Renal impairment
- Hepatic impairment
- Obese pts
- Elderly
- Peds pts
- Pregnancy and lactation
- Contraceptive steroids
3 assessments to satisfy recovery of sugammadex
- Skeletal muscle tone
- Respiratory measurements
- Response to peripheral nerve stimulation
How much sugammadex with no twitches under roc and vec?
4mg/kg
How much sugammadex with 2 twitches under roc and vec?
2mg/kg
How much sugammadex to reverse roc soon after administration?
16mg/kg
5min waiting time to admin how much NMBA and dose?
1.2 mg/kg of roc
4hrs waiting time to admin how much NMBA and dose?
- .6mg/kg of roc
- .1mg/kg of vec
Objective fully reversed pt
- TOF of 4 twitches
- sustained tetanus 50-100Hz >5sec
- TOF ratio >.7-.9
Subjective fully reversed pt
- 5sec head lift
- tongue protrusion
- forced hand grip
- spontaneous breathing with adequate tidal volumes
Threshold of TOF needs to be at least what to minimize risk of post-op complications
.9
4th twitch is 90% as strong as 1st twitch
<70% blockade of receptors
4 things to prevent waking up in pain?
- timing of narcotics
- use longer acting narcotics early
- titrate shorter acting narcotics to respiratory rate
- use doses appropriate for ‘awake’ pts
Avoiding nauseating anesthetics to prevent puking from pt:
Opioid
Nitrous oxide
Anti cholinesterase inhibitors
Using antiemetic appropriately to prevent pt from puking (3)
- dexamethasone 4mg pre-incision
- ondansetron 4mg pre-induction or 30min prior to emergence
- propofol 20-30mg close to emergence
When to pull the tube with respiratory mechanics
Strong
-SpO2 >93% on FiO2
Primitive reflex of elicited by repetitive tapping on the forehead and pt blinks in response to 1st several taps
Glabellar tap (glabellar tap sign)
Traditional wake up method with Neostigmine:
- Reverse NMB (10min early)
- “Lighten” anesthetic (decrease volatile, low flow if early and high flow if late)
- Decrease min vent to increase EtCO2
- Return to spontaneous breathing (adequate VT and titrate narcotics to RR)
- Extubation when pt is awake and following commands
Traditional wake up with sugammadex:
- “Lighten” anesthetic (decrease volatile, low flow if early and high flow if late)
- Decrease min vent to increase EtCO2
- Reverse NMB
- Return to spontaneous breathing (adequate VT and titrate narcotics to RR)
- Extubate when pt awake and following commands
Advantages of traditional wake up
Smooth
Adequate analgesia
Comforting
Disadvantages to traditional wake up
Requires breathing pt
Hypoventilation slows elimination of anesthetic gas
Increase side effects of narcotics
Rapid emergence:
- Reverse NMB
- Hyperventilate out volatile anesthetic (10L FGF and 10-15 RR)
- Dose narcotics appropriately
- Extubate when pt is awake and following commands
Advantages to rapid emergence:
Fast
Smooth when timed correctly
Disadvantages to rapid emergence
Frequently not smooth
May not adequately ensure post-op analgesia (overdose or under dose)
What to push if pt is too tight
- Propofol 20-50mg
- Lidocaine 1-1.5mg/kg
- Sux 20-30mg
- ED95 of muscle relaxant is ~1/3intubating dose
What to do when pt is just too tight:
Hyperventilate
Increase inhaled volatile concentration
N2O
When can emergence delirium happen (3)
- Wake up too fast
- Inadequate pain control
- Tube is still in and no LTA
What to rule out when pt is waking up crazy (4)
- Hypercarbia
- Hypoxia
- Hypotension
- Stage II anesthesia
What to do if pt is waking up crazy (5)
- Don’t pull ETT
- Lido
- Propofol
- Fentanyl
- Avoid benzos
increasing doses of Sux where continuous activation of ACh receptors leads to ongoing shifts of Na into cell and K out of cell
Mechanism of Phase II block
Diagnosis of Phase II block
Non-depolarizing block (fade is seen with tetanic and TOF stimulation; post-tetanic potentialtion)
8 bad things about sux
- Fasciculations hurt
- Hyperkalemia
- Cardiac arrest
- Profound bradycardia
- MH trigger
- Pseudocholinesterase deficiency
- Not give 24-72hrs after burns, trauma, or enervation
- Can cause arrest in kids with undiagnosed muscular dystrophy
Ultrashort-acting nondepolarizing NMB agent
-alternative to sux
Gantacurium chloride
How long does administration of Neostigmine take to peak?
10min
CO2 <35
Narcotics
CO2 >50
NOT narcotics
CO2 35-50
Titrate to effect
Step that need to be taken to put tube back in:
- Positive pressure
- Jaw thrust
- Lidocaine/propofol
- Sux
If all else fails, what to do to provide emergency oxygenation
Emergency cricothyrotomy
2 reasons why colloids are good
- Hyperproteinemia
2. Malbourished pts who need plasma volume expansion
When to use colloid (3)
Renal failure
Large trauma
Microsurgical
Why to use colloid
Expand intravascular volume by plugging leaking capillaries and increasing the colloid oncotic pressure
What percent does blood volume increase with colloid
20%
When should crystalloid fluids be used?
In pts with dehydration (loss of both interstitial and intravascular fluid)
Primitive reflex where elicited by repetitive tapping on the forehead and pt blinks in response
Glabellar tap
what to avoid if pt is waking up all crazy?
Benzos (versed)
Rapidly diminishing response to successive doses of a drug, rendering it less effective (common with drugs acting on the nervous system)
Tachyphylaxis
What 2 drugs can sugammadex reverse?
Rocuronium
Vecuronium
How much sugammadex to give with shallow/medium blockade?
2mg/kg
How much sugammadex to give with deep blockade?
4mg/kg
How much sugammadex to give 3 min after administration of max 1.2mg/kg Roc?
16mg/kg
For TOF, is black lead distal or proximal?
Distal
