Nicotinic cholinergic transmission, NMBA

Question 1

Excitation contraction coupling

Answer 1

Process by which an action potential in a motor neuron leads to contraction of a muscle

Question 2

Polarized membrane

Answer 2

Positive charge on the outside, negative charge on the inside

Question 3

Steps in muscle contraction

Answer 3

Action potential at NMJ release ACH, ACH binds to nicotinic m, end plates depolarize, depol over muscle membrane happens, release of calcium ions from SR, calcium permits actin/myosin to bump uglies and cause muscle contraction, ach quickly dissociates from receptors on motor end plate, calcium take into SR causing relaxation

Question 4

Non depolarizing compete with

Answer 4

binding to nicotinic M receptors

Question 5

Order of paralysis

Answer 5

Eyes face first, then limbs, abdo and glottis. Last is respiratory muscles

Question 6

Hypotension

Answer 6

NMBA can cause hypotension due to blockade of nicotinic m receptors, also from histamine release. Can’t cross BBB

Question 7

Succs paralysis

Answer 7

4-6 minutes (at 1.5mg/kg)

Question 8

Succ degraded by

Answer 8

Pseudocholinesterase which is present in plasma

Question 9

Succ peaks

Answer 9

1 minute after administration, lasts no longer than 10 minutes

Question 10

Psuedocholinesterase

Answer 10

Can be deficient

Question 11

MH

Answer 11

Rare, potentially fatal, triggered by succ, 1:25,000 Muscle rigidity, extremely high temp (up to 43C)

Question 12

MH cause in a nutshell

Answer 12

Increased calcium from SR causing prolonged muscle rigidity

Question 13

Succ hyperK+

Answer 13

Rarely can cause hyperk+ on its own Significant hyperK+ from burns, trauma (crush injuries) rhabdo

Question 14

Succ trade name

Answer 14

Anectine

Question 15

Succ contras

Answer 15

Hypersensitivity known or suspected hyperK+, family hx of MH or pseudocholinesterase deficiency, myopathies with elevated CK

Question 16

Succ dose

Answer 16

1.5mg/kg IV/IO max of 150mg Ped 1.5-2.0mg/kg IV/IO

Question 17

Succ considerations

Answer 17

Sedation/analgesia first Withhold in difficult predicted airway Drug takes 60-90 for full effect Acute airway burns are not a cause for hyperK+

Question 18

This chart

Answer 18