Emergence from Anesthesia

Question 1

How to assess the depth of NMB objectively?

Answer 1

Train of Four – Adductor Pollicis or Orbicularis Oculi

>90%- 0 twitches

90% – 1 twitch

80% - 2 twitches

75% - 3 twitches

<75% - 4 twitches (Will allow you to breathe with small tidal volume)

Question 2

When is it okay to reverse with Neostigmine?

Answer 2

Objectively
Post-tetanic stimulation and return of 1 twitch = 10 mins
At least 1 twitch represents 90 % blockade and no free drug therefore, reliably reversible

Subjectively
Spontaneous respiratory effort
Less than 100% blockade, therefore, reliably reversible

Question 3

Symptoms of cholinergic crisis?

Answer 3

Wet

Bronchospasm

Paralysis

Bradycardia

Question 4

Symptoms of anti-cholinergic crisis?

Answer 4

Dry

Hyperthermia

Urinary Retention

Tachycardia

Delayed emergence

Question 5

What is the minimum waiting time is necessary before administration of a steroidalneuromuscular blocking agent after administration of Sugammadex?

Answer 5

Question 6

If rocuronium is reversed with Sugammadex, and rocuronium is readmistered within 30 minutes how long will the onset be delayed? How much shorter will the duration of action?

Answer 6

Onset delayed 4 minutes

Duration shortened 15 minutes

Question 7

What is the recommended waiting time for patients with renal impairment that used rocuronium and reversed with 4mg/kg suggamadex? Or in healthy patients that were reversed with 16mg/kg suggamadex?

Answer 7

24 hours

Question 8

What can you sometimes use to see if a patient is at baseline respiratory values?

Answer 8

Write respirometer

Question 9

T or F. Spontaneous breathing with adequate TV is a reliable way to assess NMB reversal

Answer 9

Spontaneous breathing with adequate TV is still unreliable as diaphragm much more resistant to NMB than airway muscles (i.e. tongue)

False

Question 10

Sustained tetanus 50-100Hz >5s without fade indicates only ____ blockade

Answer 10

50%

Question 11

TOF, seeing 4 twitches are subjective and indicate only ___ blockade

Answer 11

75%

Question 12

TOF ratio of _____is the gold standard and suitable for extubating*

Answer 12

>0.7-0.9

*Really not that reliable nor available

Question 13

Okay to pull the tube? SpO2 > 93% on FiO2 < 0.5

Answer 13

Yes, as long as it is stong respirations and they are not hypertensive

Question 14

Glabellar tap

Answer 14

Glabellar reflex (also known as the “glabellar tap sign”)

Primitive reflex

Elicited by repetitive tapping on the forehead

Patient blinks in response to the first several taps

Question 15

Appropriate steps if surgeon needs a little more time

Answer 15

Propofol 20-50mg
Lidocaine 1-1.5mg/kg
ED95 of muscle relaxants is usually 1/3 intubating dose

Hyperventilate
Increase inhaled volatile concentration
N2O
Communicate with surgeon

Question 16

Ruling out hypercarbia, hypoxia, hypotension - why would a patient wake up all crazy? What are appropriate treatments?

Answer 16

Emergence delerium

Treatment:
Don’t pull out ETT if haven’t already
Propofol
Fentanyl
Avoid verbal commands, and try not to use benzos

Question 17

If you have to do a repeat does of succinylcholine, what should you be aware of?

Answer 17

Can cause bradycardia/arrest so give glycopyrrolate or atropine before redosing

Question 18

What is the main mechanism behind a phase II block of succinylcholine?

Answer 18

This is due to increased activity of the sodium-potassium ATPase pump, which brings potassium into the cell in exchange for sodium. The receptor does not respond appropriately to acetylcholine, and neuromuscular blockade is prolonged.

Phase II has features of a non-depolarizing block on a nerve stimulator (fade)

Question 19

How deeply paralyzed should a patient be for intraabdominal surgery?

Answer 19

In general, a 90% reduction of the twitch response or elimination of 2 or 3 in the TOF should suffice for intra-abdominal surgery

Question 20

Name some negative effects of succinylcholine

Answer 20

asciculation’s hurt!!

Hyperkalemia

Cardiac arrest

Profound bradycardia (second dose) especially in kids

MH trigger

Pseuodocholinesterase deficiency

Should not be given 24 to 72 hours after burns, trauma, or denervation

Can cause arrest in kids (especially boys) with undiagnosed muscular dystrophy [Rosenberg Anesthesiology 77: 1054, 1992].

Question 21

Threshold for TOF: need at least ___ to minimize riskof post operative complications

Answer 21

0.9

Question 22

If the 4th twitch is 90% as strong as the first twitch then there is less than ___ blockade of receptors

Answer 22

70%

Question 23

If the 4th twitch is less than 90% of the first twitch then there is greater than ____ blockade of receptors

Answer 23

70%

Question 24

If quantitative TOF is not available, use tetanus- 5 seconds of ____. With a non-depolarizing NMBD, the response fades

Answer 24

50Hz

Question 25

About how long does it take neostigmine to peak?

Answer 25

~10 min

Question 26

If respiratory center is triggered, and patient is still at maintenance level of anesthesia:

If triggering CO2 <35, patient probably needs ________

If triggering CO2 > 50, patient probably does not need _________

If between 35-50, _____________________

Answer 26

If triggering CO2 <35, patient probably needs narcotics

If triggering CO2 > 50, patient probably does not need narcotics

If between 35-50, who knows (titrate to effect later)

Question 27

Benefits of colloids

Answer 27

Contain large molecules that do not pass through semipermeable membranes

Remain in the vascular system to expand volume

Draws fluid from extravascular spaces by oncotic pressure

Work like hypertonic crystalloids but don’t require as much volume

Last longer than crystalloids

Question 28

When would you use colloids?

Answer 28

Hyperproteinemia, malnourished pts who need plasma volume expansion but can’t tolerate the large infusions of crystalloids

Renal failure
Large trauma
Microsurgical

Expand intravascular volume by plugging leaking capillaries and increasing the colloid oncotic pressure

Question 29

What is the natural colloid?

Answer 29

Human albumin solution

5% solution is iso-oncotic, leads to 80% initial volume expansion

25% solution is hyper-oncotic, leads to 200 - 400% increase in volume within 30 minutes. The effect persists for 16 - 24 h

Question 30

What is a synthetic colloid?

Answer 30

Dextran

Highly branched polysaccharide molecules which are available for use as an artificial colloid

Used mainly to improve micro-circulatory flow in microsurgical re-implantations.

Question 31

What colloid led to reduction in circulating factor VIII and von Willebrand factor levels, impairment of platelet function, prolongation of partial thromboplastin time and activated partial thromboplastin time, and increases bleeding complications?

Duration of volume expansion is 8-24hrs

Answer 31

Hetastarches, Hydroxyethyl starches (Hespan/ Hextend)- Synthetic

Question 32

Third generation HES

Answer 32

6 % TETRASTARCH- VOLUVEN (waxy maize and potato)

Significantly less bleeding associated compared to second generations (15%), decrease in renal impairment, less accumulation in tissue

Among the safest and most cost efficient compared to Albumin

Dose-Up to 50 mL of Voluven® per kg of body weight per day (equivalent to 3 g hydroxyethyl starch and 7.7 mEq sodium per kg of body weight). This dose is equivalent to 3500 mL of Voluven® for a 70 kg patient..

Question 33

When to use crystalloids?

Answer 33

Should be used in patients with dehydration, i.e., with loss of both interstitial and intravascular fluid