NMB: Part 1 Flashcards Preview

Anesthesia Pharmacology > NMB: Part 1 > Flashcards

Flashcards in NMB: Part 1 Deck (65)
Loading flashcards...
1
Q

what are the uses of NMB?

A

Facilitate tracheal intubation
IMprove surgical working conditions
Mechanical ventilation of lungs
laryngospasm

2
Q

In terms of ED95, how much NMB should be given for intubation?

A

2xED95

3
Q

How do volatile anesthetics affect NMBD?

A

Decrease ED95

4
Q

NMBD effects __________(small/large), ________ (rapidly moving, Slowly moving) muscles first

A

small, rapidly moving muscles are affected first

5
Q

ONset of block depends on _______ type and _____receptor density

A

Fiber, ACh

6
Q

Which is more sensitive to NMBD, fast or slow fibers?

A

fast

7
Q

Obicularis occuli is useful for predicting paralysis of _____________, while the adductor pollicis is more reflective of ___________.

A

vocal cords, diaphragm

8
Q

Are NMBD lipid soluble? What is the volume of distribution?

A

Highly ionized therefore limited lipid solubility with limited volume of distribution

9
Q

What effects do NMBD have on CNS, renal and fetus?

A

none, since they are ionized, they cant cross lipid membranes

10
Q

How does age affect NMBD clearance?

A

Elderly pts have less blood flow to the liver and therefore clear NMBD more slowly. Volatile anesthetics also decrease bf and will slow clearance

11
Q

Benzylisoquinolinium drugs end in ________ and aminosteroid drug names end in ___________.

A

-curium, -ronium

12
Q

how do NMBD bind? at the neuromuscular junction block to interrupt transmission of nerve impulses?

A

the + nitrogen binds to the - alpha subunit of the receptor

13
Q

besides the neuromuscular junction, where else might NMBD have effects?

A

cardiac muscarinic receptors

autonomic ganglia nicotinic receptors

14
Q

Acetylcholine is stored in ________ aka ________

A

packets, quanta

15
Q

Which subunit of the nicotinic receptor does succinylcholine attach to?

A

alpha

16
Q

What is the dose of sux?

A

1-2 mg/kg

17
Q

what is onset and duration of sux?

A

30-60s, 3-5 min

18
Q

How is sux metabolized?

A

plasma cholinesterase

19
Q

Extremely high doses of sux may _________ duration.

A

increase

20
Q

what does the TOF look like in phase I blockade?

A

4 twitches that may be decresed, but have no fade
TOF 4 ration >0.7
Decreased amplitude during tetany
NO posttetanic facilitation

21
Q

What happens when you give anticholinesterase to reverse sux?

A

Enhances block, since cholinesterase breaks down sux too.

22
Q

What does a phase 2 blockade look like?

A

Resembles non depolarizing NMB

has fade and posttetanic potentiation

23
Q

How do repeated doses of sux manifest?

A

tachyphylaxis

24
Q

Is the transition from phase I to phase II fast or slow?

A

abrupt

25
Q

What drugs may decrease plasma cholinesterase activity?

A

Anticholinesterases

Metoclpramide

26
Q

what is the normal dibucaine number?

A

80

27
Q

What are examples of patients that are susceptible to hyperkalemia from sux?

A
Burns
Skeletal muscle trauma
Intrabdominal infection
Muscle atrophy
Muscular dystrophy
T4-T6 lesions
28
Q

How does sux affect ICP and IOP?

A

increases both

29
Q

Why should you avoid sux for patients with small bowel obstruction, pyloric stenosis, or bleeding varices?

A

Sux causes increase intragastric pressure

30
Q

What are the characteristics of NDPNMB?

A
Decresed single twitch
Fade with tetanus
TOF <0.7
Post tetanic potentiation
Antagonized by anticholinesterase
31
Q

What is the mechanism of NDPNMB?

A

Compet with ACh at alpha subunits at postjunctioal nicotinic receptor. Also has some action at pre-junctional receptor

32
Q

What effect does Sux have on HR?

A

dysrythmias
bradycardia from sux mimicing ACh at cardiac muscarinic cholinergic receptors, especially if a second dose is given 5 minutes after first
(Tachycardia and increased BP may occur if sux mimic ACh at autonomic nervous system ganglia)

33
Q

Side effects from NDPNMB are ______. (rare/common)

A

rare

34
Q

Which NMB is associated with histamine release?

A

atricurium

35
Q

Which NMB is associated with tachycardia?

A

pancuronium–vagolytic

36
Q

Pancuronium has a _____ autonomic margin of safety.

A

low

37
Q

Name drugs that enhanece NDNMB (6)

A
Volatile anesthetics
Amino glycosides
Local anesthetics
Anti dysrhythmics
Diuretics
Ganglionic blockers (trimethaphan)
38
Q

How do phenytoin and other seizure meds affect NMB?

A

Increased metabolism, may need to use a drip

39
Q

Hypokalemia and hypothermia _________ blockade

A

prolong

40
Q

How do thermal injury/burns affect blockade (nondepolarizing)

A

resistant

41
Q

How does magnesium affect NM blockade?

A

Magnesium inhibits ACh release so therefore potentiates block

42
Q

What happens if you mix a steroid relaxant with a Isoquinolone relaxant?

A

they are synergistic. YOu can get a real long block

43
Q

What if you give roc before the sux has worn off?

A

synergistic. always check twitches

44
Q

What is the onset and duration of pancuronium?

A

3-5 minutes, 60-90 minutes

45
Q

What are the CV effects of pancuronium?

A

Increased HR, MAP and CO

46
Q

The dose for pancuronium is the same as_______

A

vecuronium

47
Q

Clearance of pancuronium is decreased up to ___% with renal failure

A

50

48
Q

What is the onset and duration of Atracurium?

A

3-5 minutes, 20-35 minutes

49
Q

How is atracurium cleared?

A

Hoffman elimination and ester hydolysis

not dependent on kidney or liver

50
Q

What are the side effects of atracurium

A

Histamine release
-may lead to bronchoconstriction, should avoid in asthmatics
Cardiovascular effects-vasodilation

51
Q

How does metabolism of atracurium differ in peds vs elderly?

A

No different since it is not dependent on liver BF

52
Q

What is the metabolite of atracurium and what effect does it have?

A

Laudanosine–CNS stimulant–probably not clinically significant

53
Q

What is the dose of cisatracurium?

A

0.1-0.15 mg/kg

infusion 1-2 ug/kg/min

54
Q

Does cisatracurium cause histamine release?

A

No

55
Q

How is Cisatracurium metabolized?

A

Hoffman degradation

56
Q

How does pH and temperature affect hoffman degradation?

A

INcreased pH increases elimination

decreased body temperature decreases elimination

57
Q

What is the intra op dose of vecuronium?

A

0.01mg/kg q 15-20 min for maintenance

INfusion: 1-2 mcg/kg/min

58
Q

How is vecuronium metabolized and cleared?

A

predominantly metablolized and excreted by liver.

59
Q

What is the RSI and maintenance dose for roc?

A

0.6-1.2 mg/kg
0.1 mg/kg maintenance
5-12mcg/kg/min infusion

60
Q

How is roc metabolized and cleared?

A

No metabolism

All is cleared in bile and kidneys

61
Q

Mivacurium is a _________-acting NMBD that is no longer in production

A

short

62
Q

How is mivacurium cleared?

A

plasma cholinesterase

63
Q

Which NMBD would you use for renal or severe hepatic failure?

A

Mivacurium, cisatracurium, atracurium

64
Q

Which NMDB would be the best choice for long cases?

A

Pancuronium

65
Q

Which NMDB would you choose for plasmacholinesterase deficient cases?

A

roc/vec