what is the primary ion associated with MH?
calcium
patients with MH exhibit significant hyper- or hypo-metabolism?
hypermetabolism
what are the triggering agents for MH?
succinylcholine
volatile agents
what happens to O2 consumption during MH?
increases 3-5x normal
what is the predominant sign of MH?
drastic sudden increase in EtCO2
MH is often associated with what other type of disorders?
muscle disorders
what is the first step of treatment when MH is suspected?
Stop triggering agent
when can MH present?
Explosive onset during induction of anesthesia
Insidious onset during maintenance of anesthesia
Insidious onset postoperatively
what are the early signs of MH?
increase CO2 increase HR resp/metabolic acidosis venous desaturation electrolyte abn Masseter Muscle Rigidity
where does dantrolene work?
at the muscle
later signs of MH include…
worsening of other symptoms
increase in temp
hemodynamic instability
is muscle rigidity always present with MH?
NO
T or F: MH occurs only during induction
FALSE
T or F: Once treated, MH will not reoccur
FALSE
what is the normal cause of death for MH patients in the first few hours?
Hyperkalemia –> V fib
what is the normal cause of death for MH patients after several hours?
pulmonary edema
coagulopathy
acid/base abnormalities, electrolyte imbalance
what is a common cause of death for MH patients days after original symptoms?
multi-organ failure, brain damage
renal decompensation
“chipmunk cheeks” are associated with what?
MMR-Masseter Muscle Rigidity
how common is masseter muscle rigidity?
rare (0.008%)
what CPK is strongly associated with MH?
CPK >20,000
list four diseases associated with MH
Central Core Disease
King-Denborough Syndrome
Hypokalemic periodic paralysis
Multiminicore Disease
what are some other conditions that have possible connections to MH?
- Exertional heat stroke
- Exercise induced rhabdomyolysis
- Carnitine palmitoyl transferase deficiency
- Duchenne muscular dystrophy, Becker muscular dystrophy
when is succinylcholine indicated?
difficult airway
full stomach
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.
acute hyperkalemia
what is the normal cause for an increase in temperature?
iatrogenic overheating
what are some differential diagnoses for MH associated with Tachycardia (with/without fever and no rigidity)
hypoxia, light anesthesia, iatrogenic overheating, tourniquet, thyrotoxicosis, sepsis, pheochromocytoma, transfusion reaction, osteogenesis imperfecta, anti-cholinergic syndrome
what are some differential diagnoses for MH associated with Tachycardia, fever and muscle rigidity?
NMS hypoxic encephalopathy ionic contrast agents in CSF amphetamine toxicity cocaine toxicity ETOH withdrawal
what are the first steps of treatment for MH?
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
what is the normal dose for dantrolene and how is it provided?
2.5mg/kg
20 mg bottle (powder)
what should you not give in conjunction with dantrolene?
Calcium Channel blockers (can cause cardiac arrest)
what is the end goal for temperature for a MH patient?
Hot not normal….don’t want to overshoot
how long should dantrolene be given?
continue Dantrolene (1 mg/kg IV every 6 hours) x 24-36 hours
how long should MH patients stay in ICU?
24-48 hours
what is the gold-standard in MH testing?
Halothane-Caffeine Contracture Test
what are the contraindications for the Halothane-Caffeine Contracture Test?
< 4 y/o (20kg)
< 3 mos. from the event
what equipment concerns must be taken into consideration for patients at risk for MH?
"clean" machine - no vaporizers -flush system with fresh gas -fresh circuits MH cart near OR Standard monitors available
worse out comes are associated with what two factors?
Muscle build and DIC (disseminated intravascular coagulopathy)
