Malignant hyperthermia Presentation 1

MALIGNANT HYPERTHERMIA (MH)

MOCK DRILL 2017

MH BACKGROUND

A life threatening clinical syndrome of hyper An inherited autosomal dominant trait with It is triggered in
metabolism involving the skeletal muscle reduced penetrance. *Penetrance refers to the susceptible individuals primarily by the
proportion of people with a particular genetic volatile inhalation anesthetic agents and the
change (such as a mutation in a specific gene)
muscle relaxant succinylcholine
who exhibit signs and symptoms of a genetic
disorder. If some people with the mutation do

not develop features of the disorder, the
condition is said to have reduced (or
incomplete) penetrance.

A history of uneventful anesthesia with MH- The annual number of suspected MH cases
triggering agents does not rule per year in the US is 700 individuals
out a susceptibility to MH

DIAGNOSIS MH is a subclinical myopathy, Sustained elevation of
OF MH after the exposure to triggering calcium causes excessive

agents, large quantities of stimulation of aerobic
calcium are released from the and anaerobic glycolic metabolism

skeletal muscle and cause which results in respiratory and
a hypermetabolic state. metabolic acidosis, rigidity,

altered cell permeability and
hyperkalemia.

EARLY Inappropriately elevated carbon dioxide production, which is manifested as
METABOLIC raised end-tidal Co2 on capnography or as tachypnea if the patient is
SIGNS breathing spontaneously
Increased oxygen consumption
Mixed metabolic and respiratory acidosis
Profuse sweating
Mottling of skin

EARLY CARDIOVASCULAR SIGNS

Inappropriate tachycardia
Cardiac arrhythmia (especially ectopic ventricular beats and
ventricular bigemini)
Unstable arterial pressure

MUSCLE Masseter spasm if
RIGIDITY succinylcholine has been used
Generalized muscle rigidity

LATER SIGNS Hyperkalemia
OF MH Rapid increase in core body temperature
Grossly elevated blood levels of creatine phosphokinase and
myoglobin
Dark urine (myoglobinuria)
Severe cardiac arrhythmia and cardiac arrest
Disseminated intravascular coagulation

ACUTE TREATMENT FOR MH

Early diagnosis/Get help/Get Dantrolene and Cart
Notify the surgeon, stop procedure if possible
Hyperventilate the patient with 100% O2
Discontinue volatile agents and succinylcholine
Dissolve Dantrolene (Revonto), the 20 mg in each vial with 60 cc of sterile water
Infuse Dantrolene 2.5 mg/kg IV rapidly through a large-bore IV, repeat every 5 minutes until reversal of
the reaction occurs
*recommended to have 36 Dantrolene vials (containing 20mg/vial) immediately available

DANTROLENE DOSING CHART

ACUTE TREATMENT OF MH (CONTINUED)

Bicarbonate- (for metabolic acidosis) 1-2 Cooling- lavage open body cavities, apply ice Dysrhythmias respond to treatment of acidosis
mEq/kg to body surfaces, infuse cold saline and hyperkalemia

intravenously. (Cold saline is located in mini
refrigerator in MH cart).

* Do not administer calcium Hyperkalemia- treat with Check blood sugar levels, ETCO2
channel blockers, may cause hyperkalemia hyperventilation, bicarbonate, glucose/insulin, levels, blood gases, CK

calcium levels, temperature, urine output, urine
concentration, coagulation studies

Diabetic coma Drug toxicity Equipment malfunction,
increased carbon

dioxide, rebreathing,
soda lime exhausion

DIFFERENTIAL Exercise hyperthermia Freeman-Sheldon Muscular
DIAGNOSIS syndrome dystrophies (Duchene

and Becker)

Myotonia Ventilation problems

IMPORTANT 1 2
INFORMATION
If a MH crisis happens Malignant Hyperthermia
in my room: I call 711 Association of the United
and say: "MH alert in OR States (MHAUS) - 1-800-
room ___" Then call 644-9737 can be
MHAUS for assistance. consulted for assistance
with treatment

Transfer patient to ICU and Dantrolene 1mg/kg q 4-
monitor 24-48 hours 6 hours or .25mg/kg/hr by

Patient and family should be infusion for at least 24
educated about MH and hours. The half-

referred to a testing center life of Dantrolene is 6-
for a caffeine halothane 10 hours.
contracture test (CHCT)

POST-
ACUTE PHASE

Creatine kinase will peak in Monitor lab results and vital
about 8-10 hours after the signs
event and should return to

near normal levels.

Myoglobinuria should be
monitored for and

treated with fluids and
diuretics

WHAT Dantrolene- 36 vials of 20 mg dantrolene sodium/60 ml after reconstitution in sterile
MEDICATIONS water. Currently, we have to use 50cc sterile water vials.
Sodium bicarbonate (8.4%) -50 ml x 5
SHOULD BE Dextrose 50% -50 ml vials x 2
ON Calcium chloride (10%) -10 ml vials x 2
Regular insulin –100 units/ml x 1(refrigerated)
A MH CART Lidocaine*for injection (2%) -100mg/5ml or 100 mg/ 10ml in preloaded syringes (3)
Amiodarone is also accepted
Refrigerated cold saline solution- A minimum of 3,000 ml for IV cooling

Charcoal filters- two pairs of Syringes - (60ml x 5) to IV catheters- 16G, 18G, NG tubes
activated charcoal filters * dilute Dantrolene 20G, 2inch; 22G, 1

looking into obtaining inch; 24G, ¾-inch (4 each)

GENERAL Toomey irrigation syringes- Various temperature probes CVP kits Transducer kits
EQUIPMENT (60ml x 2)
ON MH
EQUIPMENT Large sterile drape Urine meter Irrigation tray Ice packs

Bucket for ice Test strips for
urine hemoglobin * not on

cart

LAB TESTING SUPPLIES Syringes for ABG x 6
ON MH CART Blood specimen tubes
Blood culture bottles
Urine collection container

REFERENCES

• Chapin, J.W., & Geibel, J. Malignant Hyperthermia. Medscape (2016).
• Emergency Therapy for Malignant Hyperthermia. Malignant Hyperthermia

Association of the United States (2005)

• http://www.mhaus.org/healthcare-professionals/professional-development