This document contains information on malignant hyperthermia susceptibility including key points about genetics, symptoms, investigations, triggers, and treatment. Malignant hyperthermia susceptibility is associated with mutations in the RYR1 gene and is inherited in an autosomal dominant pattern. Symptoms include muscle rigidity, weakness, rhabdomyolysis, and autonomic effects like tachycardia. Triggers include inhalational anesthetics and exercise in hot conditions. Treatment involves dantrolene administration, hyperventilation, bicarbonate, cooling, and avoiding calcium agents.

1. “Isn’t making a smoking section in a restaurant like making a peeing section in a
swimming pool?”
― George Carlin
MALIGNAT HYPERTHERMIA SUSEPTIBILITY
• MHS 1-6
• RYR gene
• Chromosome 19q13
• Rynodine receptor present in calcium Channel
• Autosomal domnant
C/F=
Skeletal muscle
Rigidity and weakness
Rhabdomyolysis
Muscle spasms especially affecting masseter, but can be generalised
Myalgia
Autonomic
Sympathetic overactivity
Hyperventilation
Tachycardia
Haemodynamic instability
Cardiac arrhythmia
INVESTIGATIONS
Increased oxygen consumption
Hypercapnia
Lactic acidosis
Raised creatine kinase
Hyperkalaemia
TRIGGERS
anaesthesia (inhalational agents— isoflurane, desflurane,) suxamethonium
Milder malignant hyperthermia: exercise in hot
conditions, neuroleptic drugs, alcohol, infections
TREATMENT
Dantrolene 2 mg/kg intravenously every 5 minutes to a total of 10 mg/kg
Hyperventilation with supplemental oxygen
Sodium bicarbonate
Active cooling
Discontinue anaesthesia
Maintain urine output over 2 ml/kg/hour
Avoid calcium, calcium antagonists, b-blockers
Non nobis solum nati sumus
(​Not for ourselves alone are we born​)
-Dr. Eashan Srivastava