What is Malignant Hyperthermia (MH) and what is it triggered by? -
ANSWER MH is characterised by a HYPERMETABOLIC state and
SKELETAL MUSCLE RIGIDITY
It is triggered by exposure to INHALATIONAL agents or
SUCCINYLCHOLINE in susceptible individuals
What is the pathophysiology of MH? - ANSWER Pathophysiology of MH:
- many mutations on the Ryanodine (Ryr1) and alpha 1 subunit of the Ca+
receptor
impairment of Ca+ reuptake by the sarcoplasmic reticulum upon exposure to
trigger agents
What is the incidence of MH in children and adults? - ANSWER 1 in 15,000
in children
1 in 50,000 in adults
50% of MH patients had a prior uneventful anesthetic using trigger agents
Recent studies indicate that as many as 1 in 3,000 people have the genetic
mutation that predisposes them to a MH reaction under GA
, MH should be strongly suspected when there is an unanticipated significant
increase in ______ that responds only to a very large increase in minute
ventilation - ANSWER ETCO2
What are the clinical signs of MH? - ANSWER Clinical signs of MH:
hypercarbia
tachycardia
markedly increased in minute ventilation
muscle rigidity, difficult to ventilate, increased peak pressures
skin mottling
hyperthermia, may be a late sign, d/t inc in muscle metabolism = heat
production
brown urine
DIC
What are some laboratory findings of MH? - ANSWER Laboratory findings of
MH:
inc PaCO2
inc CK
inc plasma lactate
dec PaO2
acidosis
hyperkalemia, potassium leaks out of the muscle cells
myoglobin in blood or urine - from cell death and rhabdomyolysis - precipitates
in renal tubules causes urinary obstruction and RF
ANSWER MH is characterised by a HYPERMETABOLIC state and
SKELETAL MUSCLE RIGIDITY
It is triggered by exposure to INHALATIONAL agents or
SUCCINYLCHOLINE in susceptible individuals
What is the pathophysiology of MH? - ANSWER Pathophysiology of MH:
- many mutations on the Ryanodine (Ryr1) and alpha 1 subunit of the Ca+
receptor
impairment of Ca+ reuptake by the sarcoplasmic reticulum upon exposure to
trigger agents
What is the incidence of MH in children and adults? - ANSWER 1 in 15,000
in children
1 in 50,000 in adults
50% of MH patients had a prior uneventful anesthetic using trigger agents
Recent studies indicate that as many as 1 in 3,000 people have the genetic
mutation that predisposes them to a MH reaction under GA
, MH should be strongly suspected when there is an unanticipated significant
increase in ______ that responds only to a very large increase in minute
ventilation - ANSWER ETCO2
What are the clinical signs of MH? - ANSWER Clinical signs of MH:
hypercarbia
tachycardia
markedly increased in minute ventilation
muscle rigidity, difficult to ventilate, increased peak pressures
skin mottling
hyperthermia, may be a late sign, d/t inc in muscle metabolism = heat
production
brown urine
DIC
What are some laboratory findings of MH? - ANSWER Laboratory findings of
MH:
inc PaCO2
inc CK
inc plasma lactate
dec PaO2
acidosis
hyperkalemia, potassium leaks out of the muscle cells
myoglobin in blood or urine - from cell death and rhabdomyolysis - precipitates
in renal tubules causes urinary obstruction and RF
