What is malignant hyperthermia (MHS)? - ANSWER This is a complex
genetic disorder of skeletal muscle typically manifesting clinically as a
hypermetabolic crisis when a susceptible individual receives a halogenated
inhalational anesthetic agent or succinylcholine
-They have skeletal muscle receptor abnormalities that allow excessive
myoplasmic calcium to accumulate in the presence of certain anaesthetic-
triggering agents. This excessive Ca lead to sustained muscle contraction
How is malignant hyperthermia inherited? -ANSWER In an autosomal
dominant pattern
-Can arise de novo
What genes are commonly involved? -ANSWER Genes responsible for coding
proteins of the calcium channel in the sarcoplasmic reticulum are most
commonly affected: the ryanodine receptor (RYR1) and the closely associated
dihydropyridine receptor (DHP
Approximately 50 percent of known cases of MH are caused by mutations on? -
ANSWER chromosome 19 in regions that encode the hydrophilic, amino-
terminal portion of the RYR1 receptor
Who is at risk for developing MHS? - ANSWER -Patients having a history of
unexpected exertional rhabdomyolysis under conditions that are less extreme
compared to usual triggers
, -in such cases, patients with severe statin-induced myopathy may potentially be
at increased risk of carrying the RYR1 mutation
-Myopathies, particularly of the central core myopathy, due to RYR1 mutations,
are presumed to be MHS
Duchenne and Becker muscular dystrophy: What occurs when they are
administering succinylcholine? - ANSWER When exposed, they develop
rhabdomyolysis and severe hyperkalemia
to succinylcholine (and perhaps with volatile anesthetics); although this is not
MH, anesthetic considerations are similar
Other Myopathies with ryanodine receptor abnormalities that should avoid
triggering agents? - ANSWER ●Central core myopathy
●Multiminicore disease
●King-Denborough syndrome
●Native American myopathy
●Hypokalemic periodic paralysis - possible increased risk
●Any other myopathy associated with or caused by an RYR1 mutation
what is succinylcholine? - ANSWER A neuromuscular blocking agent, it is
depolarizing. Succinylcholine binds to nicotinic receptors in skeletal muscle and
causes persistent depolarization of the motor end plate. When the drug is first
administered, it produces transient muscle contractions called fasciculations.
The fasciculations are quickly followed by a sustained muscle paralysis.
Succinylcholine is used to produce muscle relaxation before, and during,
surgery and to permit intubation of the airway
Is there any screening for MHS? - ANSWER No, need good history, anesthetic
history, family and personal hx
genetic disorder of skeletal muscle typically manifesting clinically as a
hypermetabolic crisis when a susceptible individual receives a halogenated
inhalational anesthetic agent or succinylcholine
-They have skeletal muscle receptor abnormalities that allow excessive
myoplasmic calcium to accumulate in the presence of certain anaesthetic-
triggering agents. This excessive Ca lead to sustained muscle contraction
How is malignant hyperthermia inherited? -ANSWER In an autosomal
dominant pattern
-Can arise de novo
What genes are commonly involved? -ANSWER Genes responsible for coding
proteins of the calcium channel in the sarcoplasmic reticulum are most
commonly affected: the ryanodine receptor (RYR1) and the closely associated
dihydropyridine receptor (DHP
Approximately 50 percent of known cases of MH are caused by mutations on? -
ANSWER chromosome 19 in regions that encode the hydrophilic, amino-
terminal portion of the RYR1 receptor
Who is at risk for developing MHS? - ANSWER -Patients having a history of
unexpected exertional rhabdomyolysis under conditions that are less extreme
compared to usual triggers
, -in such cases, patients with severe statin-induced myopathy may potentially be
at increased risk of carrying the RYR1 mutation
-Myopathies, particularly of the central core myopathy, due to RYR1 mutations,
are presumed to be MHS
Duchenne and Becker muscular dystrophy: What occurs when they are
administering succinylcholine? - ANSWER When exposed, they develop
rhabdomyolysis and severe hyperkalemia
to succinylcholine (and perhaps with volatile anesthetics); although this is not
MH, anesthetic considerations are similar
Other Myopathies with ryanodine receptor abnormalities that should avoid
triggering agents? - ANSWER ●Central core myopathy
●Multiminicore disease
●King-Denborough syndrome
●Native American myopathy
●Hypokalemic periodic paralysis - possible increased risk
●Any other myopathy associated with or caused by an RYR1 mutation
what is succinylcholine? - ANSWER A neuromuscular blocking agent, it is
depolarizing. Succinylcholine binds to nicotinic receptors in skeletal muscle and
causes persistent depolarization of the motor end plate. When the drug is first
administered, it produces transient muscle contractions called fasciculations.
The fasciculations are quickly followed by a sustained muscle paralysis.
Succinylcholine is used to produce muscle relaxation before, and during,
surgery and to permit intubation of the airway
Is there any screening for MHS? - ANSWER No, need good history, anesthetic
history, family and personal hx
