Flashcards in Topic 21 Deck (20):
What is Malignant Hyperthermia?
an autosomally dominant disorder of skeletal muscles.
--Calcium that’s stored in skeletal muscle is released inappropriately causing muscles to contract & stiffen simultaneously
Malignant Hyperthermia causes what effects? (8)
skeletal muscle breakdown (rhabodmyolysis)
do most cases occur in adults or children?
Most cases occur in children and young adults <30 years old
--Occurs in all races & ethnicities
how long before symptoms appear?
appear within one hour (but can be delayed up to ~12 hours)
name some known chemical triggers of MH? (4)
name some things that are NOT triggers of MH? (5)
-Intravenous anesthetics (including Propofol)
-Non-depolarizing muscle relaxants
-Sedatives and Tranquilizers.
International mortality data on MH ranges from 1.4%-20.0% which appears to be based entirely on what?
the speed of MH diagnosis and therapy initiation!
name 4 SPECIFIC signs of MH
Dramatically increase CO2 production
name 4 NON-SPECIFIC signs of MH
Acidosis (both respiratory & metabolic)
what are the 3 MH Clinical presentations?
Masseter Muscle Rigidity (MMR)
Late Onset MH
(most common): muscular rigidity, extreme hyperthermia, tachycardia. Typically occurs shortly after anesthetic induction
Masseter Muscle Rigidity (MMR)=
profound jaw muscle rigidity after succinylcholine administration; may be an early sign of MH
Late Onset MH=
(uncommon): Occurs within the first hour of anesthetic termination
why is MMR a prognostic indicator? *KNOW*
Patients with a history of MMR post-anesthetic induction have a 25-30% chance of having Fulminant MH during their next anesthetic!
Why does MH occur? *KNOW*
A mutation in the ryanodine receptor gene (RYR1) in skeletal muscles affects the muscles’ ability to properly utilize calcium
Treatment of acute MH (7 steps) *KNOW COLD*
1. Immediately discontinue volatile gas anesthetics and succinylcholine administration
2. Hyperventilate with 100% oxygen
3. Give 1-2 mg/kg bicarbonate
4. Give Dantrolene at a dose of 2.5mg/kg IV push and repeat PRN
5. Cool patient
6. Treat arrhythmias but DO NOT GIVE CALCIUM CHANNEL BLOCKERS!!!
7. Monitor coagulation and electrolytes
how much dantrolene do you give to treat
2.5mg/kg IV push and repeat PRN
when you treat the arrhythmia's- what are you careful not to give?
DO NOT GIVE CALCIUM CHANNEL BLOCKERS!!!