Respiratory Care Pharmacology Chapter 18: Skeletal Muscle Relaxants (Neuromuscular Blocking Agents)

drugs that cause skeletal muscle weakness or paralysis

neuromuscular blocking agents (NMBA's)

give two other terms for neuromuscular blocking agents

-paralytics

-muscle relaxants

NMBAs produce their effect at the neuromuscular junction by interfering with what neurotransmitter?

Acetylcholine (ACh)

do NMBAs cross the blood brain barrier?

no

are NMBAs absorbed by the GI tract?

no

what major respiratory procedure do NMBAs facilitate?

endotracheal intubation

True or False: NMBAs enhance patient-ventilator synchrony

True

True or False: NMBAs often cause seizures and lockjaw

FALSE: NMBAs TERMINATE seizures and lockjaw

Do NMBAs affect the central nervous system?

no

transmission of nerve conduction in the skeletal muscle system is chemically mediated by...

Acetylcholine (ACh)

action potential occurs upon membrane ___________________

Depolarization

when membrane potential returns to baseline

repolarization

name the two major types of NMBA's

-Depolarizing agents

-Nondepolarizing agents

NMBAs that work by competitive inhibition of acetylcholine receptors

Nondepolarizing NMBAs

the blocking of acetylcholine receptors without activating them is an example of...

competitive inhibition

True or False: Nondepolarizing neuromuscular blocking agents compete against endogenous acetylcholine for the acetylcholine receptor at the neuromuscular junction

True

what agents can be used to reverse the neuromuscular blockade caused by nondepolarizing agents?

Acetylcholinesterase inhibitors

name 3 specific acetylcholinesterase inhibitors

-Neostigmine

-Edrophonium

-Pyridostigmine

which branch of the autonomic nervous system is responsible for muscle contraction?

Parasympathetic (cholinergic)

True or False: Nondepolarizing agents chemically resemble epinephrine

FALSE: Nondepolarizing agents chemically resemble ACETYLCHOLINE

how are nondepolarizing agents administered?

Parenterally via IV fluids

The level of response to nondepolarizing agents depends on....

the dose

how long is the duration of action for nondepolarizing agents?

35-60

what is the generic name for Pavulon?

Pancuronium

what is the generic name for Norcuron?

Vecuronium

what is the major nondepolarizing agent?

Rocuronium

There is only one depolarizing NMBA. Name it.

Succinylcholine (Anectine)

Which type of NMBA has a shorter onset and duration?

Depolarizing agents

what is the duration of depolarizing agents?

10-15 minutes

which agents are more ideal for intubation?

Depolarzing agents

a phase I block is characterized by...

prolonged depolarization/fasciculations

Can the paralysis caused by succinylcholine be reversed?

no

name 2 adverse side effects of succinylcholine

-Vagal response with repeated boluses

-increased intracranial/intraocular/intragastric pressure

True or False: NMBAs and analgesics are essential for endotracheal intubation

True

what vitals should be monitored during endotracheal intubation? why?

-heart rate

-blood pressure

-When increased (tachycardia, hypertension), this is indicative of pain, and the need for more analgesics

what agents are used to prevent pain during endotracheal intubation?

sedatives (analgesics, amnestics)