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Disease Info (Science)

Etiology

Approximately 50% of patients with MH have a de novo mutation affecting calcium channels, while the other 50% have an autosomal-dominant inherited mutation.

Triggering Factors:

Inhalational agents* (sevoflurance, desflurane, isoflurane)
Succinylcholine*
Phenothiazines

Non-Triggering Factors:

Non depolarizing muscle blowing agents (rocuronium, vecuronium, cis-atracurium)
Nitrous Oxide
Ketamine
Barbiturates
Propofol
Local Anesthetics
Benzodiazepines

Pathogenesis

An episode of MH is mediated by calcium overload within the skeletal muscle cell that leads to cellular hypermetabolism, sustained muscular contraction and breakdown, anaerobic metabolism, and acidosis.

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Additional Presentation

Early

elevated end-tidal CO2*
tachycardia
tachypnea
masseter spasm
generalized muscle rigidity
mixed metabolic and respiratory acidosis
unstable BP
sweating and skin mottling

Late

hyperkalemia (> 6)
cardiac arrest
rapid rise in core body temperature
elevated CK (> 10 000)
myoglobenemia and myoglobinuria
DIC </aside>

Common DDx/Mimicker

Underlying patient conditions:
Acquired patient conditions:
Intraoperative Issues

Red flags symptoms	Other Ethology	Difference
‣, Hyper-metabolic state	hyperthyroidism, thyroid storm, pheochromocytoma, SNS stimulation + insufficient anesthesia
‣	neuroleptic malignant syndrome, myotonia, muscular dystrophies, ‣ toxicity
Increased Temperature	transfusion reaction, heat stroke, neuroleptic malignant syndrome
‣ and ‣	diabetic coma
‣	‣ toxicity

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Resource

https://www.mhaus.org/healthcare-professionals/

Can call for help:
Stanford Anesthesia Cognitive Aid Program: Cognitive Aids for Perioperative Crises