Malignant Hyperthermia

Question 1

what is the primary ion associated with MH?

Answer 1

calcium

Question 2

patients with MH exhibit significant hyper- or hypo-metabolism?

Answer 2

hypermetabolism

Question 3

what are the triggering agents for MH?

Answer 3

succinylcholine

volatile agents

Question 4

what happens to O2 consumption during MH?

Answer 4

increases 3-5x normal

Question 5

what is the predominant sign of MH?

Answer 5

drastic sudden increase in EtCO2

Question 6

MH is often associated with what other type of disorders?

Answer 6

muscle disorders

Question 7

what is the first step of treatment when MH is suspected?

Answer 7

Stop triggering agent

Question 8

when can MH present?

Answer 8

Explosive onset during induction of anesthesia
Insidious onset during maintenance of anesthesia
Insidious onset postoperatively

Question 9

what are the early signs of MH?

Answer 9

increase CO2
increase HR
resp/metabolic acidosis
venous desaturation
electrolyte abn
Masseter Muscle Rigidity

Question 10

where does dantrolene work?

Answer 10

at the muscle

Question 11

later signs of MH include…

Answer 11

worsening of other symptoms
increase in temp
hemodynamic instability

Question 12

is muscle rigidity always present with MH?

Answer 12

NO

Question 13

T or F: MH occurs only during induction

Answer 13

FALSE

Question 14

T or F: Once treated, MH will not reoccur

Answer 14

FALSE

Question 15

what is the normal cause of death for MH patients in the first few hours?

Answer 15

Hyperkalemia –> V fib

Question 16

what is the normal cause of death for MH patients after several hours?

Answer 16

pulmonary edema
coagulopathy
acid/base abnormalities, electrolyte imbalance

Question 17

what is a common cause of death for MH patients days after original symptoms?

Answer 17

multi-organ failure, brain damage

renal decompensation

Question 18

“chipmunk cheeks” are associated with what?

Answer 18

MMR-Masseter Muscle Rigidity

Question 19

how common is masseter muscle rigidity?

Answer 19

rare (0.008%)

Question 20

what CPK is strongly associated with MH?

Answer 20

CPK >20,000

Question 21

list four diseases associated with MH

Answer 21

Central Core Disease
King-Denborough Syndrome
Hypokalemic periodic paralysis
Multiminicore Disease

Question 22

what are some other conditions that have possible connections to MH?

Answer 22

• Exertional heat stroke
• Exercise induced rhabdomyolysis
• Carnitine palmitoyl transferase deficiency
• Duchenne muscular dystrophy, Becker muscular dystrophy

Question 23

when is succinylcholine indicated?

Answer 23

difficult airway

full stomach

Question 24

Children less than 9 years of age who experience a sudden cardiac arrest after succinylcholine, in the absence of hypoxemia, should be treated for ________ first.

Answer 24

acute hyperkalemia

Question 25

what is the normal cause for an increase in temperature?

Answer 25

iatrogenic overheating

Question 26

what are some differential diagnoses for MH associated with Tachycardia (with/without fever and no rigidity)

Answer 26

hypoxia, light anesthesia, iatrogenic overheating, tourniquet, thyrotoxicosis, sepsis, pheochromocytoma, transfusion reaction, osteogenesis imperfecta, anti-cholinergic syndrome

Question 27

what are some differential diagnoses for MH associated with Tachycardia, fever and muscle rigidity?

Answer 27

``` NMS hypoxic encephalopathy ionic contrast agents in CSF amphetamine toxicity cocaine toxicity ETOH withdrawal ```

Question 28

what are the first steps of treatment for MH?

Answer 28

STOP all volatile agents and Succinylcholine CALL FOR ASSISTANCE! HYPERVENTILATE with 100% O2, flow > 10 L/min (circle system and absorbent need not be changed) Give Dantrolene

Question 29

what is the normal dose for dantrolene and how is it provided?

Answer 29

2.5mg/kg | 20 mg bottle (powder)

Question 30

what should you not give in conjunction with dantrolene?

Answer 30

Calcium Channel blockers (can cause cardiac arrest)

Question 31

what is the end goal for temperature for a MH patient?

Answer 31

Hot not normal....don't want to overshoot

Question 32

how long should dantrolene be given?

Answer 32

continue Dantrolene (1 mg/kg IV every 6 hours) x 24-36 hours

Question 33

how long should MH patients stay in ICU?

Answer 33

24-48 hours

Question 34

what is the gold-standard in MH testing?

Answer 34

Halothane-Caffeine Contracture Test

Question 35

what are the contraindications for the Halothane-Caffeine Contracture Test?

Answer 35

< 4 y/o (20kg) | < 3 mos. from the event

Question 36

what equipment concerns must be taken into consideration for patients at risk for MH?

Answer 36

``` "clean" machine - no vaporizers -flush system with fresh gas -fresh circuits MH cart near OR Standard monitors available ```

Question 37

worse out comes are associated with what two factors?

Answer 37

Muscle build and DIC (disseminated intravascular coagulopathy)