Malignant Hyperthermia for the New Hampshire RSI Paramedic Christopher A. Fore MD, FACEP EMS Medical Director Concord Hospital

What is Malignant Hyperthermia An extremely rare autosomal dominant genetic disorder (approx 1:50,000) Hypermetabolism and extreme muscular rigidity are the hallmark findings A rare complication of depolarizing paralytic agents, especially when combined with inhaled anesthetic gases

What Actually Happens? Excessive calcium release inside muscle cells Dramatic increased muscle tone ensues Heat is released during this process Increased oxygen consumption and carbon dioxide production Uncontrolled hyperthermia and cell death

How Severe is the Reaction? Untreated, mortality is 70% Treated aggressively, the mortality can be reduced to 5% Malignant hyperthemia IS NOT an allergic reaction, and is therefore NOT treated as an allergic or anaphylaxic reaction

Will I Recognize This? Malignant hyperthermia is characterized by: –Very notable sustained muscular contractions –Hyperventilation –Hyperthermia –Flushing of the skin may occur, although cyanosis can also ensue if the condition is worsening

What Can I Do? Manage the airway –Malignant hyperthermia can cause masseter spasm (clenched jaw) and can therefore make managing the airway difficult.

What Can I Do? Cool the patient: –Cold packs –Lower the temperature of the ambulance –IV fluid boluses

What Can I Do? Identify malignant hyperthermia: –Alert receiving facility of potential malignant hyperthermia –They will need to quickly obtain dantrolene sodium to treat the patient

What Can I Do? Continue to care for the patient: –Don’t forget to treat the underlying medical/surgical process that required the use of succinyl choline administration

What Will Happen at the Hospital? Dantrolene sodium infusion will be given Aggressive cooling Support of electrolyte abnormalities and renal function ICU stabilization

Summary: Malignant Hyperthemia What Happens –Profound muscular rigidity –Hyperthermia –Tachycardia –Flushing of skin What to Do –Manage the airway –Cool the patient –Give IV fluids unless contraindicated –NOTIFY RECEIVING HOSPITAL OF CHANGE IN CONDITION