Malignant Hyperthermia Flashcards
What are triggers for MH?
Inhaled agents and succinylcholine.
First and most sensitive sign of MH?
unexplained tachycardia.
What is the most specific sign of MH?
Increasing ETCO2=hypercapnia, 2-3x normal
What labs might confirm or help treat MH?
Initial Metabolic Acidosis then a combined resp/met acidosis. Hyperkalemia. Hypercalcemia. Hyperphosphatemia. Elevated CK. Myoglobinuria. Hypoxemia/hypercarbia on blood gas.
What is the overall mortality of MH?
10% overall.
Up to 70% without dantrolene therapy.
What are the first few things to do when MH is suspected?
Stop off triggering agents.
Call for help.
What interventions can be done as soon as MH is suspected?
Hyperventilate with 100% FIO2 on BMV.
Dantrolene 2.5mg/kg repeat up to 10mg/kg.
Bicarbonate 1-2mEq/kg.
Cooling measures.
What treatment should be done first for hyperkalemia?
Dextrose and Insulin….
…Along with hyperventilation, Bicarb
What drug should be used for persistent ventricular arrhythmias?
Procainamide.
What medication must be avoided due to potential for life threatening hyperkalemia and myocardial depression?
Calcium Channel Blockers.
What can be done to prevent reoccurance of hypermetabolic state after MH?
Continued dantrolene 1mg/kg Q6hrs.
How does dantrolene work?
Directly interferes with muscle contraction by inhibiting Ca++ release from the sarcoplasmic reticulum.
What receptor does dantrolene work on?
The ryanodine receptor
What is the Gold standard preop test for MH?
Muscle biopsy with halothane-caffeine contracture test
What diseases are associated with MH?
*Duchenne's Muscular dystrophy*. King Denborough syndome. Central-core disease. Myotonia. Osteogensis imperfecta. Fukuyama. Beckers.
Does a prior uneventful general anesthetic rule out possibility for MH?
No it does not.
What are some descriptors of King Denborough Syndrome?
Myopathy, short stature, cryptochidism, pectus carinatum, lumbar lordosis, thoracic kyphosis, unusual facial characteristics
Boys <9yrs old who experience sudden cardiac arrest after succinylcholine in the absence of hypoxia are like to have what? and how should it be treated?
Subclinical Muscular Dystrophy. Treat the probably hyperkalemia first with CaCl, Bicarb.
Not related to MH, just succinylcholine.
When do symptoms of MH typically occur?
Usually develop within one hour after exposure to trigger substance.
