Malignant Hyperthermia

Question 1

MH Characteristics

Answer 1

sustained hypermetabolism

Inherited

abnormal handeling of intracellular Ca+

Triggered by Pharmacologic agents possibly heat/exercise

Question 2

Who gets MH

Answer 2

1 : 15,000 children

1 : 20,000 - 50,000 Adults

1 : 2,000-3,000 have trait

Question 3

Clinical manifestations of MH

Answer 3

hypercarbia

tachycardia

muscle rigidity (masterator muscle)

cyanosis

hyperthermia > 38.8 C

cola colored uring (myoglobin)

Question 4

Labs with MH

Answer 4

elevated ETCO₂

decreased Ph

Question 5

ABG will show what

Answer 5

Mixed metabolic and resp acidosis

hyperkalemia

Question 6

What receptor regulates the SR Ca+ exchange

Answer 6

RYR-1 ( ryanodine) receptor

Question 7

what happens if the Ca+ is not returned to the SR

Answer 7

sustained contraction

Question 8

Agents that will trigger a MH event

Answer 8

SUCs

volital agents

Question 9

waht agents will NOT trigger a MH event

Answer 9

NDNMB

N₂O

Propofol, ketamine, etomidate, opoids and benzos

Local anesthetics

Question 10

Treatement for MH

Answer 10

Dantrolene 2.5 mg/kg rapid IV

100% O₂

Removal of triggering agent

Core temp and Ice pack with COLD NS levages

GET HELP

Question 11

Dantrolene contains what other medication with it

Answer 11

Mannatol so your pt will diurese

Question 12

How much dantrolene do you give

Answer 12

repeat 2.5 mg/kg dose until Sx stop or max at 10 mg/kg

Question 13

Why do you not give LR to these Pts

Answer 13

they are already building up lactic acid you dont need to add to this acidosis

Question 14

Labs that need to be ordered

Answer 14

serial blood gases

coags

UA myoglobin

lactic acid

creatine kinase

Question 15

Maintance dantrolene dose

Answer 15

1mg/kg Q6hrs for 36 hrs

Question 16

why would you monitor blood glucose level

Answer 16

hypoglycemia R/Thypermetabolic state

Question 17

Metabloic acidosis TX

Answer 17

1-2 mEq sodium bicarb

Question 18

Hyperkalemia TX

Answer 18

10mEq/kg Ca+ chloride

10-50 mEq/kg Ca+ Gluconate

OR

1ml/kg of D50with 0.15 units/kg of Regular Insulin

(10 units usually)

Question 19

Can us use Ca+ channel blockers with Dantrolene

Answer 19

HELL NO you will KILL them.

Increases K+ and can cause Asystole

Question 20

Rhabdomyolysis Tx

Answer 20

get rid of the myoglobin form the kidneys with lasix and bicarb

Question 21

MH kills by

Answer 21

Acidosis

Hyperkalemia

organ failure due to hyperthermia

DIC

Renal failure due to myoglobinuria

Question 22

MH may be mimiced by

Answer 22

Fever with out muscle rigidity - thyrotoxicosis, sepsis, phenochromocytoma, iatrogenic overheating, anticholinergic syndrome

Fever with muscle symptoms - Neuroleptic maligant syndrome, Hypoxic encephalopathy, Ionic contrast agents in CSF, cocaine, amphetamines and ecstasy

Question 23

Diagnostic test for MH

Answer 23

Caffeine Halothane test (CHCT)

Question 24

Indications for CHCT

Answer 24

unexplained rabdo after surgery

MMR w rabdo

exercise induced rabdo

Question 25

What Hx in a Pt increases your concern for MH

Answer 25

any muscular dystrophy increases the chance of MH

Question 26

Central core myopathy

Answer 26

motor developement delay

lower limb muscle delay

mutation in the RYR-1

Question 27

Duchenne muscualr dystrophy

Answer 27

X linked recessive affecting males

abnormal muscle fiber function

developmental motor delay

Question 28

King Denborough Syndrome

Answer 28

dysmorphic facial features

Question 29

Heat stroke

Answer 29

hyperthermia as a trigger

Question 30

Neuroleptic Malignant syndrome

Answer 30

triggered by antipsychotic meds

Question 31

surgical Tx for pt with a HX of MH

Answer 31

dont use triggering agents

TIVA

Regional

Ketamine

propofol / opoids

watch in PACU for 4 hrs post surgery