MH

Question 1

MH mutation genes

Answer 1

RYR 1 chr 19
CACNA1S chr 1
STAC3 chr 12

Question 2

Hypermetabolism: ATP needed for what 3 things

Answer 2

Ca release, reuptake into SR, and troponin decoupling

Question 3

MH: succ vs VA causes cell level

Answer 3

Succ sustained depolarization at nAChR. VA at ryanodine receptor, ca release from SR

Question 4

Earliest s/s MH

Answer 4

Hypercarbia, tachypnea, tachycardia

Question 5

Confirmatory lab in kids w masseter spasm after sux

Answer 5

> 20,000 CPK

Question 6

MMR: what is normal, check what, MH occurs how often

Answer 6

Mild inc masseter tone after sux w limb flaccidity. Check K and ABG. MH occurs in 20% of cases of MMR

Question 7

3 symptoms that occur w rhabdo

Answer 7

Muscle pain, myoglobinuria, arrhythmias from high K

Question 8

CPK correlates

Answer 8

In >20k well w rhabdo, less well w fever and acidosis

Question 9

Rapid v slow rhabdo

Answer 9

K dangerously high/quick in rapid, in slow its safer, K is redistributed before blood levels increase

Question 10

Sympathetic response leads to 3 things in heart/vessels

Answer 10

Inc catecholamines lead to inc HR, cutaneous vasoconstriction, inc SVR
Inc CO

Question 11

What to do in isolated MMR

Answer 11

D/c volatiles, give propofol, turn up flows, get another IV/give vol/ABG. Observe 24h if other symptoms. Maybe muscle bx

Question 12

Gold standard MH test

Answer 12

Halothane caffeine contracture test. Muscle in halothane, sustained contracture. 80% specificity

Question 13

How dantrolene works, 1/2 time

Answer 13

Reduces muscle tone and metab. Dec release of Ca from SR. Blocks external entry of Ca into sarcoplasm. Inhib ca thru ryanodine receptors. 10-15 e 1/2

Question 14

Dantrolene: doesnt potentiate effects of what

Answer 14

Non depolarizing muscle relaxants or interfere w reversal. Can cause weakness if pre existing NM disease

Question 15

DONT use dantrolene with what

Answer 15

CCB, life threatening hyperkalemia and myo depression

Question 16

How many vials need to be in facility if sux is used, what else needs to be there

Answer 16

36 minimum. Sterile water, 60 ml/vial

Question 17

Dantrolene dosage

Answer 17

2.5 mg/kg bolus, then maintenance dose 2 mg.kg q 5 min. Total 10 mg/kg. Then 1 mg/kg q6 for 72 hours

Question 18

Where we want temp. Saline bolus dose.

Answer 18

38 c. 15 ml/kg q 10 min

Question 19

Hyperkalemia treatment

Answer 19

1 ml/kg d50 glucose and 0.15 u/kg regular insulin and/or CaCl 5-10 mg/kg IV

Question 20

Monitoring how long after, recrudescence how often. Avoid what, measure what

Answer 20

36h in icu. 25%. No LR (K). Coag profile for DIC and CKs q6h

Question 21

Lab supplies needed

Answer 21

6 abg kits, Ck myoglobin, sma 19, pt/ptt, fibrinogen, fsps, CBC, LA level. Urine myoglobin level x2, urine dipstick hgb

Question 22

Muscle diseases assoc w MH 3

Not assoc w which one

Answer 22

Central core disease, king denborough syndrome, and Evans myopathy. Not: MD but can still develop rhabdo so still avoid triggering agents

Question 23

Neuroleptic malignant syndrome presentation. Who is susceptible

Answer 23

Fever, muscle rigidity, ANS instab, delirium, elev CPK. Pts on haldol, prolixin, thorazine

Question 24

Sudden cardiac arrest after sux in young males can be what

Answer 24

R/t hyperkalemia in undx myopathy. 50% mortality rate, may also have rigidity and hyperthermia

Question 25

Meds/tx for sudden unexpected cardiac arrest

Answer 25

Ca cl, hco3, insulin, glucose, hyperventilation. May need dialysis and CPB

Question 26

Report MH to who

Answer 26

North American mh registry. In CHOP in Pittsburgh. Barbara Brandon