Flashcards in NMB: Part 1 Deck (65)
what are the uses of NMB?
Facilitate tracheal intubation
IMprove surgical working conditions
Mechanical ventilation of lungs
In terms of ED95, how much NMB should be given for intubation?
How do volatile anesthetics affect NMBD?
NMBD effects __________(small/large), ________ (rapidly moving, Slowly moving) muscles first
small, rapidly moving muscles are affected first
ONset of block depends on _______ type and _____receptor density
Which is more sensitive to NMBD, fast or slow fibers?
Obicularis occuli is useful for predicting paralysis of _____________, while the adductor pollicis is more reflective of ___________.
vocal cords, diaphragm
Are NMBD lipid soluble? What is the volume of distribution?
Highly ionized therefore limited lipid solubility with limited volume of distribution
What effects do NMBD have on CNS, renal and fetus?
none, since they are ionized, they cant cross lipid membranes
How does age affect NMBD clearance?
Elderly pts have less blood flow to the liver and therefore clear NMBD more slowly. Volatile anesthetics also decrease bf and will slow clearance
Benzylisoquinolinium drugs end in ________ and aminosteroid drug names end in ___________.
how do NMBD bind? at the neuromuscular junction block to interrupt transmission of nerve impulses?
the + nitrogen binds to the - alpha subunit of the receptor
besides the neuromuscular junction, where else might NMBD have effects?
cardiac muscarinic receptors
autonomic ganglia nicotinic receptors
Acetylcholine is stored in ________ aka ________
Which subunit of the nicotinic receptor does succinylcholine attach to?
What is the dose of sux?
what is onset and duration of sux?
30-60s, 3-5 min
How is sux metabolized?
Extremely high doses of sux may _________ duration.
what does the TOF look like in phase I blockade?
4 twitches that may be decresed, but have no fade
TOF 4 ration >0.7
Decreased amplitude during tetany
NO posttetanic facilitation
What happens when you give anticholinesterase to reverse sux?
Enhances block, since cholinesterase breaks down sux too.
What does a phase 2 blockade look like?
Resembles non depolarizing NMB
has fade and posttetanic potentiation
How do repeated doses of sux manifest?
Is the transition from phase I to phase II fast or slow?
What drugs may decrease plasma cholinesterase activity?
what is the normal dibucaine number?
What are examples of patients that are susceptible to hyperkalemia from sux?
Skeletal muscle trauma
How does sux affect ICP and IOP?
Why should you avoid sux for patients with small bowel obstruction, pyloric stenosis, or bleeding varices?
Sux causes increase intragastric pressure
What are the characteristics of NDPNMB?
Decresed single twitch
Fade with tetanus
Post tetanic potentiation
Antagonized by anticholinesterase
What is the mechanism of NDPNMB?
Compet with ACh at alpha subunits at postjunctioal nicotinic receptor. Also has some action at pre-junctional receptor
What effect does Sux have on HR?
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)
Side effects from NDPNMB are ______. (rare/common)
Which NMB is associated with histamine release?
Which NMB is associated with tachycardia?
Pancuronium has a _____ autonomic margin of safety.
Name drugs that enhanece NDNMB (6)
Ganglionic blockers (trimethaphan)
How do phenytoin and other seizure meds affect NMB?
Increased metabolism, may need to use a drip
Hypokalemia and hypothermia _________ blockade
How do thermal injury/burns affect blockade (nondepolarizing)
How does magnesium affect NM blockade?
Magnesium inhibits ACh release so therefore potentiates block
What happens if you mix a steroid relaxant with a Isoquinolone relaxant?
they are synergistic. YOu can get a real long block
What if you give roc before the sux has worn off?
synergistic. always check twitches
What is the onset and duration of pancuronium?
3-5 minutes, 60-90 minutes
What are the CV effects of pancuronium?
Increased HR, MAP and CO
The dose for pancuronium is the same as_______
Clearance of pancuronium is decreased up to ___% with renal failure
What is the onset and duration of Atracurium?
3-5 minutes, 20-35 minutes
How is atracurium cleared?
Hoffman elimination and ester hydolysis
not dependent on kidney or liver
What are the side effects of atracurium
-may lead to bronchoconstriction, should avoid in asthmatics
How does metabolism of atracurium differ in peds vs elderly?
No different since it is not dependent on liver BF
What is the metabolite of atracurium and what effect does it have?
Laudanosine--CNS stimulant--probably not clinically significant
What is the dose of cisatracurium?
infusion 1-2 ug/kg/min
Does cisatracurium cause histamine release?
How is Cisatracurium metabolized?
How does pH and temperature affect hoffman degradation?
INcreased pH increases elimination
decreased body temperature decreases elimination
What is the intra op dose of vecuronium?
0.01mg/kg q 15-20 min for maintenance
INfusion: 1-2 mcg/kg/min
How is vecuronium metabolized and cleared?
predominantly metablolized and excreted by liver.
What is the RSI and maintenance dose for roc?
0.1 mg/kg maintenance
How is roc metabolized and cleared?
All is cleared in bile and kidneys
Mivacurium is a _________-acting NMBD that is no longer in production
How is mivacurium cleared?
Which NMBD would you use for renal or severe hepatic failure?
Mivacurium, cisatracurium, atracurium
Which NMDB would be the best choice for long cases?