Basics Review

Question 1

How do volatile agents (and nitrous oxide) change the pattern of spontaneous ventilation?

Answer 1

Increase RR, decrease Vt, decrease Minute ventilation

Question 2

How does nitrous oxide affect MAP, HR, and CO?

Answer 2

No change or slight increase

Question 3

How do volatiles affect MAP, HR, and CO?

Answer 3

Decrease MAP (des=iso>sev), increase HR(iso>des>sevo), decrease CO (sevo>des>iso)

Question 4

What is the redistribution half life of propofol?

Answer 4

3-5 minutes

Question 5

What are the clinical effects of hypercarbia?

Answer 5

• Stimulation of sympatho-adrenal system (increase HR, CO, pulm pressure, BP, SV)
• peripheral vasodilation, pulmonary vasoconstriction
• hypercarbic narcosis (becomes anesthetic)
• dysrhythmias

Question 6

How much does a dose of succinylcholine raise the plasma K+ concentration?

Answer 6

Approx. 0.5-1.0 mEq/dL

Question 7

Which NMB monitoring site is best during intubation?

Answer 7

Orbicularis oculi

Question 8

Which NMB monitoring site is best during emergence?

Answer 8

Adductor pollicis

Question 9

Which muscles are most resistant to NMB? Most sensitive?

Answer 9

• vocal cord (most resistant)
• diaphragm
• Orbicularis oculi
• abdominal rectus
• adductor pollicis
• masseter
• pharyngeal
• extraocular (most sensitive)

Question 10

Which type of NMB drug exhibits post-tetanic potentiation?

Answer 10

Non depolarizing

Question 11

Why doesn’t sustained ventilation = sufficient reversal?

Answer 11

Upper airway structures are weak, posing risk of upper airway obstruction

Question 12

What percentage of receptors are blocked with TOF 0-4?

Answer 12

4/4 = 75%
3/4 = 85%
2/4 = 90%
1/4 = 95%
0/4 = 99%

Question 13

How can you use a post-tetanic count to determine ability to reverse NMB?

Answer 13

If no response to single twitch,

• 50 hz tetany for 5 sec
• wait 3-5 sec
• one twitch/sec
• if >10 twitches present, there are sufficient receptors for reversal

Question 14

What are some common extubation criteria?

Answer 14

• sustained head lift >5 seconds
• RR 5-30
• tidal volume >5cc/kg
• PaO2 >65 on FiO2 <10L/min
• level of consciousness
• NMB reversed

Question 15

Contraindications of deep extubation

Answer 15

• difficult mask ventilation
• difficult intubation
• aspiration risk
• airway edema

Question 16

Criteria for deep extubation

Answer 16

• MAC 1.3
• NMB completely reversed
• SV at reg rate and rhythm
• no airway reflexes (check with cuff deflation AFTER suctioning)
• 100% O2
• lidocaine 0.5mg/kg
• consider fentanyl