Exam 5 MH

Question 1

MH is a disorder of the

Answer 1

skeletal muscle (hypermetabolic)

Question 2

Inhalation agents that trigger MH

Answer 2

Sevo
Iso
Des
halothane

Question 3

NMB that triggers NH

Answer 3

Succinycholine
(accelerates onset and increases severity of MH episode)

Question 4

States with high incidences

Answer 4

Wisconsin
Nebraska
West Virginia
Michigan

Question 5

MH genetic pattern

Answer 5

autosomal dominant
(if one parent has it, 50% change child will get it)

Question 6

What receptor is site of defect for MH

Answer 6

RYR1 (skeletal muscle)
Ryanodine receptor

Question 7

What is the ryanodine receptor role

Answer 7

Calcium release channel of SR

Question 8

MH pathophysiology

Answer 8

Uncontrolled release and regulation of calcium. Constant muscle contraction

Recycling Ca+ and contracting increases muscle metabolism 2-3 fold

Question 9

Physiologic consequences of MH (5)

Answer 9

1. increase O2 consumption
2. augments carbon dioxide production
3. augments heat production
4. Depletes ATP stores
5. Generates lactic acid

Question 10

Acidosis, hyperthermia and ATP depletion cause

Answer 10

Sarcolemma destruction: loss of K, myoglobin, creatinine kinase (to extracellular fluid)

Question 11

MH muscle defect is in

Answer 11

SKELETAL muscle (not cardiac)

Question 12

Earliest sign of MH is

Answer 12

increased ETCO2

Question 13

volatiles can cause MH as long as _____ after induction

Answer 13

6 hours

Question 14

labs and clinical events during MH

Answer 14

Apex card game

Question 15

Clincal events during MH:

Answer 15

1. ETCO2 rise
2. tacycardia, tachypnea
3. labile BP or arythmias
4. Masseter or muscle rigidity
5. Rising temp
6. Cola colored urine (myogolibinuria)
7. Mottled, cyanotic skin
8. Decreased Sa)2

Question 16

MH ABG

Answer 16

1. PACO2 > 60 mmhg
2. Base excess more negative than -8mEq/L
3. pH <7.25

Question 17

MH serum K+

Answer 17

> 6 mEq/L

Question 18

MH serum Creat Kinase

Answer 18

> 20,000

Question 19

MH Serum myoglobin

Answer 19

> 170 mcg/L

Question 20

MH Urine myoglobin

Answer 20

> 60 mcg/L

Question 21

Why is MH such a big deal?

Answer 21

Acidosis + hyperkalemia +hyperthermia = cardiac irritability, labile BP, arrhythmias, cardiac arrest

Question 22

Late MH complications (5)

Answer 22

1. cerebral edema
2. myoglobinuric renal failure
3. coagulopathy
4. hepatic dysfunction
5. pulmonary edema

Question 23

Diseases that have genetic link to MH (4)

Answer 23

1. Central core disease
2. king denborough syndrome
3. multiminicore disease
4. Evans myopathy

*apex matching game

Question 24

They key to successful MH management is

Answer 24

early recognition and prompt treatment

Question 25

MH treatment steps

Answer 25

1. Stop triggering agent 2. call for help and stop procedure 3. hyperventilate with 100% O2 at high flows 4. Dantrolene

Question 26

Dantrolene dosing

Answer 26

2.5 mg/kg every 5-10 min until symptoms abate

Question 27

At what dose of dantrolene should you consider other causes of symptoms?

Answer 27

20 mg/kg

Question 28

in MH, keep temp at

Answer 28

38 deg C

Question 29

Treat life threatening dysrhythmias with

Answer 29

1. Lidocaine 2. Procainamide NOT CALCIUM CHANNEL BLOCKERS LIKE VERAPAMIL

Question 30

Procainamide MH dose

Answer 30

200 mg IV

Question 31

Sodum bicarb dose (MH acidosis)

Answer 31

1-2 mEq/kg IV

Question 32

Hyperkalemia MH treatment

Answer 32

dextrose 25-50 g Insulin 10 units in 50 mL 50% dextorse in water

Question 33

MH urin output goal

Answer 33

2 mL/kg/hr with lasix and mannitol as needed

Question 34

Mannitol MH dose

Answer 34

0.25 mg/kg IV for up to 4 doses (may be enough in dantrolene to be effective)

Question 35

lasix dose MH

Answer 35

1mg/kg up to 4 doses

Question 36

Dantrolene MOA

Answer 36

reducing calcium efflux from SR, counteracting abnormal intracellular calcium levels

Question 37

How to prepare dantrolene

Answer 37

reconstitute 20mg vial with 60 mL sterile water for injection

Question 38

Know how to calculate how many vials you'll need

Answer 38

2.5 mg/kg up to 20 mg/kg 20 mg vials

Question 39

For a 70 kg patient, how many vials of dantrolene do you need?

Answer 39

9 vials

Question 40

Mix dantrolene with

Answer 40

sterile water, or it precipitates

Question 41

Even if symptoms stop, dantrolene should be repeated after symptoms stop at

Answer 41

1mg/kg q 4-6 hrs for 24 hrs

Question 42

Why can't you give calcium channel blockers with MH

Answer 42

causes marked hyperkalemia and cardiac depression (dilt, verapamil) use procainamde (sodum channel blocker) or lidocaine for dysrhythmias

Question 43

Ryanodex is

Answer 43

dantrolene in a more concentrated vial

Question 44

One vial of ryanodex is

Answer 44

250mg per vial

Question 45

How to reconstitiute ryanodex

Answer 45

5 mL of sterile water per vial

Question 46

Gold standard for MH diagnosis

Answer 46

caffeine halothan contracture test (CHCT)

Question 47

For susceptible patient:

Answer 47

1. place cooling mattress under 2. avoid GA and LA, use TIVA 3. avoid succs and volatiles

Question 48

Machine prep for susceptible patient:

Answer 48

1. remove vaporizers 2. change soda lime 3. change circuits 4. flush machine with O2 high and high flows 10L/min for 20-150 min 5. add charcoal filter in inspiratory limb 6. have MH cart in OR and 36 vials of dantrolene and sterile water ready 7. observe in PACU 2.5 hrs after surgery

Question 49

Trismus

Answer 49

sustained and foreceful contracture of masseter muscle (normal)

Question 50

Masseter muscle rigidity means

Answer 50

impossible to open mouth - sign of MH, STOP

Question 51

If masseter muscle rigidity occurs, patient should be addmitted:

Answer 51

24 hours ICU

Question 52

If MH criss, pt should be admitted:

Answer 52

36 hrs ICU