EXAM 2 Review

Question 1

1. What is the mechanism of action of succinylcholine?

Answer 1

Ach agonist, mimics Ach binding to Ach receptors at ALPHA subunit causing sustained depolarization (opening of receptor ion channels)

Question 2

2.What is the mechanism for the metabolism of succinylcholine?

Answer 2

Marjority metabolized before reaching NMJ
Hydrolysis by plasma cholinesterase (pseudocholinesterase)
Metabolism on dependent of DIFFUSION away from the NMJ

Question 3

3.What metabolites are formed from the metabolism of succinylcholine?

Answer 3

Broken down into Acetate and Choline

or NO metabolites

Question 4

4.What inhalation agent is associated with diffusion hypoxia?

Answer 4

Nitrous Oxide

occurs when N2O d/c abruptly leading to reversal of partial pressure gradients, leave blood to enter alveoli

Question 5

5.What steps can be done to prevent diffusion hypoxia caused by ______?

Answer 5

Giving 100% oxygen for several minutes at the end of the case can help avoid diffusion hypoxia from occurring

Question 6

6.What anticholinesterase inhibitor can be used to treat psychosis due to anticholinergic drugs?

Answer 6

Physostigmine 15-60mck/kg/IV

Question 7

7.What drug characteristic is responsible for this effect of diffusion Hypoxia

Answer 7

Low Blood gas coefficient 0.46 so rapidly reversible with rapid onset. Leaves blood 34 times more rapidly

Question 8

8.What condition can result in an exaggerated long duration of action with the use of succinylcholine?

Answer 8

Atypical Plasma Cholinesterase

Question 9

9.Explain the difference between heterozygous and homozygous genetic alterations?

Answer 9

Heterozygous dibucaine #40-60 slightly prolonged block, 20-30 mns, only 1 ABNORMAL GENE
Homozygous dibucaine #20, very LONG block 6-8 hours due to 2 ABNORMAL GENES

Question 10

10.What test can be used to diagnosis this condition of heterozygous and homozygous?

Answer 10

Dibucaine Test

Question 11

11.What steps can the anesthesia care provider use to prevent an exaggerated long duration of action with the use of succinylcholine?

Answer 11

DIbucaine test
Check twitches before giving NMB
Avoid in pseudocholinesterase deficiency
Use TOF
Reversal agents
Neogstimine before SCH can prolong block (don't do this ) if in phase 1 can go to phase 2
Obtain hx of patient.

Question 12

12.Do all volatile anesthetics blunt the ventilatory stimulation evoked by arterial hypoxemia?

Answer 12

yes; all anesthetics including nitrous oxide profoundly depress the ventilatory response to arterial hypoxemia that is normally mediated by carotid bodies

Question 13

13.What are the recommended steps used to avoid residual paralysis with the use of NDNMB?

Answer 13

Avoid long acting NDNMB (Pancuronium)
Use intermediate acting
Do not use unreliable indicators such as head lift, jaw clenching, grip strength and tidal volume leg lift
Use quantitative and objective (AMG, KMG, EMG) better legal ground in court

Question 14

14.What volatile agents undergo the least amount of metabolism?

Answer 14

N2O

Question 15

15.Which Inhalation agent undergoes the least amount of metabolism?

Answer 15

Nitrous Oxide (0.004%) –> Des 0.02, ISo 0.2 sevo 3-5% HALOTHANE –>20%

Question 16

16.What is the clinical significance VA that undergoes the least amount of metabolism?

Answer 16

Produces less free fluorides and is therefore safer for the kidneys
Sevo does not produce TFA

Question 17

17.What steps can the anesthesia care provider take to prevent myopathy associated with the use of succinylcholine?

Answer 17

may be prevented by prior administration of a NON paralyzing dose of NDNMB agent or by going to high dose Sch 3mg/kg straight to Block II

Question 18

18.What is the intubation dose for each NDNMB agent?

Answer 18

Atracurium 0.5mg/kg IV over 60 seconds
Cisatracurium 0.1mg/kg
Mivacurium 0.15 mg/kg
Pancuronium 0.08-0.12 mg/kg 
Rocuronium 0.6 - 1.0 mg/kg
Vecuronium 0.08-0.12mg/kg

Question 19

19.What would the expected result be from the use of succinycholine and a patient with myastenia gravis?

Answer 19

Resistant to Sch due to destruction of ACh receptors by antibodies

Question 20

20.What would the expected result be from the use of NDNMB agents and a patient with myastenia gravis?

Answer 20

Very sensitive to NDNMB

Question 21

21. How should the neuromuscular blocker dosage to cause adequate muscle relaxation be altered when you administer volatile anesthetics?

Answer 21

Volatiles dose dependent increases in neuromuscular blockade
volatile enhances effects of NMB
DECREASE THE Dose

Question 22

22.Which volatile anesthetic agent causes the greatest/least degree of bonchodilation?

Answer 22

Great –> SEVOFLURANE

Least –> DESFLURANE

Question 23

23.What clinical scenarios may lead to a phase block with the use of succinylcholine?

Answer 23

low dose 0.5 - 1mg/kg phase I fasciculations 5 minutes duration
high dose 2-4 mg/kg phase II rapid 20-30 minutes,

Question 24

24.What volatile anesthetic is most likely to cause nephrotoxicity?

Answer 24

Sevoflurane and Enflurane

Question 25

25.Which volatile anesthetics are non-pungent and can be used for a mask induction?

Answer 25

SEVOFLURANE

Question 26

26.What volatile agent is considered to be the most pungent?

Answer 26

DESFLURANE

Question 27

27. What are the volume of distribution for neuromuscular blocking agents? smallest --Cisatracurium

Answer 27

``` Quarternary ammonium Vd 200ml/kg Atracurium 182-282 ml/kg Cisatracurium 31 ml/kg Mivacurium 211-278ml/kg Rocuronium 194-207 ml/kg Pancuronium 261 ml/kg ``` Succinylcholine

Question 28

29. Which induction agent has the highest context sensitive half life?

Answer 28

Halothane Isoflurane 86 min sevoflurane 65 min Desflurane 14 min

Question 29

30. What is the onset of action for each NDNMB agent? | fastest? longest?

Answer 29

``` 3-5 minutes PVAC Atracurium 3-5 minutes Cisatracurium 3-5 minutes Vecuronium 3-5 minutes Pancuronium 3-5 minutes ``` 1-2 minutes Rocuronium 1-2 minutes

Question 30

31. What are the absolute contraindications for nitrous oxide? (VPIAP)

Answer 30

``` Venous or arterial air embolism Pneumothorax Intraocular air / surgeries Acute INTESTINAL OBSTRUCTION Pernicious anemia B12 deficiency , N2O decrease B12 in liver. ```

Question 31

32.At different times during the case, what is the predicted percentage of receptors occupied by NDNMB agent?

Answer 31

See other

Question 32

33.How many receptor occupied right after administration with 0/4?

Answer 32

>95% , no fade

Question 33

34. How many receptor occupied right after administration with 1/4?

Answer 33

90% no fade

Question 34

35. How many receptor occupied right after administration with 2/4?

Answer 34

85%, no fade

Question 35

36. How many receptor occupied right after administration with 3/4?

Answer 35

80% no fade

Question 36

37. How many receptor occupied right after administration with 4/4?

Answer 36

75% receptors blocked (recovery), 4th twitch is 0.2 (20%) of the 1st twitch , 4 twitches then there is FADE

Question 37

38. How many receptor occupied right after admin? with/without fade?

Answer 37

75% with fade

Question 38

39. What volatile anesthetic has a chloride in its molecular structure?

Answer 38

Isoflurane (1 fluoride substituated with chloride)

Question 39

40. What volatile anesthetic has a bromine in its molecular structure?

Answer 39

Halothane

Question 40

41. What effect does each of the volatile agents have on hepatic blood flow?

Answer 40

Hepatic blood flow decrease | or inhibition of drug metabolizing enzymes

Question 41

42. Do NMBA have sedative/analgesic effects?

Answer 41

ABSOLUTELY NO

Question 42

43. What are the potentially toxic compounds produced by the breakdown of volatile

Answer 42

TFA Sevo --> Compound A at low flow, no TFA Desflurane> ISo = CO Des and ISO can be metabolized to acyl halides which are hepatotoxic

Question 43

44. What is the least amount of twitch required before attempting reversal for NDNMBA blockade?

Answer 43

During anesthetic techniques that do not enhance the effects of muscle relaxants (TIVA) a minimum TOF count of 2 should be present before administration of anticholinesterases During anesthetic techniques that enhance the effects of muscle relaxants (such as inhaled Volatile anesthesia) a TOF count of 4 should be present before administration of anticholinesterases

Question 44

45. What is responsible for the faster onset of rocuronium?

Answer 44

The lack of potency of rocuronium to vecuronium is the Important reason for RAPID onset large number of molecules given with a LESS potent agent are available to occupy a greater number of receptors

Question 45

46. What NMBA is recommended for rapid sequence intubation?

Answer 45

DNMB : RSI succinylcholine | NDNMB : Roc can also be used

Question 46

47. What volatile agent has the greatest effect on EEG?

Answer 46

Enflurane

Question 47

48. What pathological conditions may result in up-regulation of acetylcholine receptors?

Answer 47

Muscular dystrophies GBS Burns

Question 48

49. What patient characteristics can prolong the effects of atracurium?

Answer 48

Hypothermia | Acidosis

Question 49

lack vec roc cis have atracurium miva Histamine release - What NDNMBA would be best for a patient with liver failure?

Answer 49

Atracurium | Cisatracurium

Question 50

52. How does each Sevoflurane affect CVP?

Answer 50

NO INCREASE in RAP or CVP

Question 51

53.How does Desflurane affect CVP?

Answer 51

INCREASE CVP

Question 52

54.How does Isoflurane affect CVP ?

Answer 52

INCREASE CVP

Question 53

55.What are absolute contraindications for the use of succinylcholine?

Answer 53

Hx MALIGNANT hyperthermia Myotonia congenita and dystrophica Duschenne muscular dystrophy

Question 54

56.In a patient with renal failure, what agent would have the greatest degree of duration of action prolongation?

Answer 54

Pancuronium, Vecuronium

Question 55

57.In a patient with renal failure, what agent would have the LEAST degree of duration of action prolongation?

Answer 55

Atracurium and Cisatracurium (undergoes Hoffman)

Question 56

58.What are the clinical characteristics of nitrous oxide?

Answer 56

``` INCREASE in CMRO2 Produces either NO effect or MODEST increase in BP CO modestly increased by Nitrous oxide Increase RAP Does not increase PaCO2 ```

Question 57

59.What drugs will prolong the duration of action of NMBA?

Answer 57

``` VA ABT LA Cardiac dysrhythmias Diuretics Mag Lithium Ganglionic Blockers Cyclosporin ```

Question 58

60. Which volatile anesthetic can be safely used above 1.5MAC without causing apnea?

Answer 58

Isoflurane

Question 59

61.Which volatile agent can cause an isoelectric EEG at 2 MAC?

Answer 59

Isoflurane produces isoelectric EEG at 1.5 MAC and 2 MAC

Question 60

62.What is the best way to manage a patient that has a significantly long prolonged block from succinycholine?

Answer 60

Keep them sedated and ventilated

Question 61

63.What inhalation agents have greatest least degree of muscle paralysis?

Answer 61

Most -->Desflurane | Least --> NITROUS

Question 62

64.What are triggers for MH?

Answer 62

Volatile anesthetics | SUCCINYLCHOLINE

Question 63

65.What anticholinesterase agent can be used to treat CNS side effects from anticholinergic agents?

Answer 63

Physostigmine 15-60mcg/kg IV, increased risk of NV though

Question 64

66.What anticholinergic agent is classified an a quatinary ammonium compound? What about their VD?

Answer 64

Glycopyrrolate Quarternary ammonium compound; DOES NOT CROSS CNS and Is highly ionized DECREASED VD

Question 65

67.How does this change the volume of distribution of quaternary compared to tertiary ammonium compounds.

Answer 65

Quarternary - Decreased Vd | Tertiary - Increased Vd

Question 66

68.How does VD affect the clinical effects of this agent of quaternary compound?

Answer 66

Does not Cross CNS, no sedation

Question 67

69.What are all of the clinical effects anticipated after the administration of any anticholinergic agent?

Answer 67

Increase HR Smooth Muscle Relaxation Decrease gastric H+ Ions (increase pH) Antisialalogue

Question 68

70. What anticholinergic agent has greatest antisialagogue effects?

Answer 68

SCOPOLAMINE then glycol -> Atropine

Question 69

71.What anticholinergic agent has fastest onset of action?

Answer 69

Atropine

Question 70

72.What anticholinergic agent has slowest onset of action?

Answer 70

Glycopyrrolate

Question 71

73.Which anticholinergic agent is the most sedating?

Answer 71

SCOPOLAMINE

Question 72

74.Which anticholinergic agent is the LEAST sedating?

Answer 72

GLYCOPYRROLATE

Question 73

75. Do any of the anti-cholinergic agents effect fetal heart rate?

Answer 73

No

Question 74

76.What anticholinergic agent causes greatest amount of mydriasis?

Answer 74

SCOPOLAMINE

Question 75

77.What anticholinergic agent causes LEAST amount of mydriasis?

Answer 75

GLYCOPYRROLATE

Question 76

78.What is the mechanism by which each of the anticholinesterase agents attaches to cholinesterase?

Answer 76

Reversible Electrostatic attachment to anticholinesterase by EDROPHONIUM

Question 77

79.What is the mechanism of action of suggamadex?

Answer 77

- Modified gamma cyclodextrin, selective relaxant binding agent specifically designed to encapsulate the STEROIDAL NMBAs vec and Roc - Work by forming a complex with the NMBs by preventing their binding to nicotinic receptors at the NMJ, resulting in reversal of NMB

Question 78

80.What are the indications for suggamadex?

Answer 78

Indicated for reversal of blockade done by STEROIDAL NMBA

Question 79

81.What are major precautions/contraindications with the use of suggamadex?

Answer 79

Clearance decrease in RENAL IMPAIRMENT | Avoided in patients with a creatinine clearance of <30ml/min

Question 80

Conscious memory is suppressed by

Answer 80

Volatile anesthetics

Question 81

How much of MAC of ISOFlurANE suppresses memory

Answer 81

0.45 MAC

Question 82

How much of MAC of Nitrous suppresses memory

Answer 82

0.6 MAC