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Management of Malignant Hyperthermia Susceptible Patients and a MH Crisis (2.18)

Management of Malignant Hyperthermia Susceptible Patients and a MH Crisis (2.18) - Policies, Clinical, UWHC Clinical, Department Specific, Surgical Services, Clinical

2.18

UNIVERSITY OF WISCONSIN

POLICY & PROCEDURE

EFFECTIVE DATE

AUGUST 1990
ORIGINAL
 REVISION

FEBRUARY 2017
PAGE 1
OF 5
POLICY #

2.18
ADMINISTRATIVE MANUAL
NURSING MANUAL
OTHER Surgical Services
TITLE
MANAGEMENT OF MALIGNANT HYPERTHERMIA
SUSCEPTIBLE PATIENTS AND A MH CRISIS



I. DEFINITION

Malignant hyperthermia (MH) is a fulminant skeletal muscle hypermetabolic crisis triggered by volatile
anesthetic agents, and succinylcholine in genetically susceptible patients.

II. PURPOSE

To familiarize OR and PACU nursing staff with actions taken preoperatively for known MH susceptible
patients and in the event of a MH crisis in the operating rooms or PACU. (Note: Ask the anesthesiologist
if the patient is a susceptible MH patient.)

III. POLICY

A. The Anesthesia care team should notify the nursing team of known MH susceptible patients.
B. All known patients at risk should have this information written on the white board listing,
prominently displayed in the OR, and on the OR door (similar to signage for isolation precautions
or latex allergy).
C. Anesthesia should prepare the anesthesia machine according to their written guidelines, available
on the Anesthesiology Department website.
D. Forced air and water blankets may be placed on the OR table for patients who are known or
suspected to be susceptible to MH.
E. The MH box (red tackle box) with dantrolene may be brought to the room. The Inpatient OR MH
box is located in the Pharmaceutical Room (E7/391). The OSC MH box is stored in the OSC
Pharmacy Room (F6/206). The AFCH OR MH box is located in the Pharmaceutical Room (3311).
The MH box in the AFCH Diagnostic Pavilion is located in the Anesthesia workroom (1136). Be
sure to sign out MH box (wipe board) to location of room. The cardiac drug box may be needed or
requested by Anesthesia if the patient triggers.
F. The patient will be assessed for the specific clinical signs of MH. Presenting signs may be
tachycardia, arrhythmias, hypercapnia, metabolic acidosis, tachypnea, increased end tidal CO2;
profound muscle rigidity (including isolated masseter muscle trismus), unstable blood pressure,
cyanosis, mottling, sweating, rapid temperature increase, cola-colored urine (myoglobinuria),
rhabdomyolysis (muscle breakdown with increased serum CPK). Note: Rapid temperature increase
is not always present with MH.
G. Chilled normal saline IV solution will be available in the Inpatient OR Pharmaceutical Room
(E7/391), AFCH OR (3311) and in OSC pharmacy refrigerator (F6/206). If needed, a runner
should be sent to AFCH OR Pharmaceutical Room to retrieve chilled normal saline solutions for
AFCH Diagnostic Pavilion.

UNIVERSITY OF WISCONSIN

POLICY & PROCEDURE

EFFECTIVE DATE

AUGUST 1990
ORIGINAL
 REVISION

FEBRUARY 2017
PAGE 2
OF 5
POLICY #

2.18
ADMINISTRATIVE MANUAL
NURSING MANUAL
OTHER Surgical Services
TITLE
MANAGEMENT OF MALIGNANT HYPERTHERMIA
SUSCEPTIBLE PATIENTS AND A MH CRISIS



IV. PROCEDURE

Prior to a case for a patient known to be at risk for MH, if present, remove the anesthesia circuit, breathing
bag & C02 sampling line (dispose of them). Remove vaporizers from the machine & store them & any
succinylcholine outside the operating room. Remove the CO2 absorbent canister. Perform a 90 second flush
of the machine with high flow (>10LPM) fresh gas (air is fine).
Following the 90 second flush: install a new C02 absorbent canister. Install the charcoal filters on the
inspiratory and expiratory limbs appropriately (see the filter instructions). Attach a new anesthesia circuit,
C02 sample line & breathing bag. Prepare for TIVA.
Note:
Use fresh gas flows of no less than 3 LPM.
Replace filters during the case:
A. Every 1 hour when managing a triggered MH event.
B. Every 12 hours when managing a susceptible or known MH patient.

In the event of an actual MH crisis or trigger the same machine preparation procedure can be followed.
Further - some or all of the following steps will be instituted by the Anesthesia care team with appropriate
assistance from OR nursing staff.

A. Get help. Notify the surgeon. Call for extra OR staff, anesthesia staff, and possibly extra surgeons.
Call the Malignant Hyperthermia Association of the United States (MHAUS) Hotline: 1-800-644-
9737, as directed.
B. Get the MH Box.
C. Discontinue the triggering anesthetic agents immediately; conclude surgery as soon as possible.
1. Succinylcholine, isoflurane, desflurane, and sevoflurane are unsafe anesthetic agents for MH
susceptible patients.
2. Triggered patients are critically ill and care must focus on stabilizing their condition.
D. Hyperventilate the patient with 100% oxygen at high flows (8-10 liter/min) to compensate for
metabolic acidosis and flush volatile anesthetics from the circuit.
1. The patient has increased oxygen demands and CO2 production because of the hypermetabolic
state.

E. Place charcoal filters on the inspiratory and expiratory limbs. These are available in the MH boxes.
Alternatively, if charcoal filters are not available, flush the circuit with high fresh gas flow. Do not
waste time changing the circuit and CO2 absorbent. If time allows during a trigger, the vaporizers
can be removed. NOTE: Bag-valve-mask and tank oxygen can be used to hyperventilate the patient
during trigger episodes while the breathing circuit is being flushed.

UNIVERSITY OF WISCONSIN

POLICY & PROCEDURE

EFFECTIVE DATE

AUGUST 1990
ORIGINAL
 REVISION

FEBRUARY 2017
PAGE 3
OF 5
POLICY #

2.18
ADMINISTRATIVE MANUAL
NURSING MANUAL
OTHER Surgical Services
TITLE
MANAGEMENT OF MALIGNANT HYPERTHERMIA
SUSCEPTIBLE PATIENTS AND A MH CRISIS



1. Filter or flush volatile anesthetics out of the circuit and the patient.
F. Give 2.5 mg/kg (actual body weight) of dantrolene IV as an initial dose. Several additional doses
may be required to treat the initial episode up to a maximum cumulative dosage of 10 mg/kg.
1. The drug comes in vials containing 250 mg of dantrolene sodium and 125 mg of mannitol.
Each dantrolene vial is reconstituted with 5 mL of sterile water for injection (do not use any
other solution). Sterile water vials will be provided in each MH box. Shake the vial to
reconstitute (until an orange-colored uniform suspension is achieved). The final concentration
after reconstitution is 50 mg/mL. Draw the reconstituted solution into a syringe based on the
dose ordered and administer by rapid IV push. Solution can be administered either into the IV
catheter while an IV infusion of either NS or D5W is freely running; or into the indwelling
catheter without a freely running infusion. Flush the line afterwards. Do not dilute or transfer
the reconstituted suspension to another container to infuse the product. The mixture expires
within 6 hours of reconstitution. Continue administration until signs of MH abate. Repeat
doses every 4 - 6 hours may be needed to prevent recurrence during a severe crisis. Repeat
doses beyond the initial dose of up to 10mg/kg, if required, should be ordered in Health Link
and prepared by Central Pharmacy. Repeat dosing will generally occur in the ICU.
G. Bring cardiac arrest cart to room. Plug in defibrillator and place defibrillator pads. NOTE: Cause
of fatal rhythm event may be due to acidosis and hyperkalemia.
1. Tachycardia and other arrhythmias are often first symptoms of MH crisis.
H. Start arterial line and place additional IVs or central line. Convert all fluids to NaCl. Lines will be
essential for management requiring frequent lab draws.
I. Prepare and send serial blood gases and labs.
1. Essential lab tests (have tubes, etc. ready): ABGs and electrolytes, lactic acid, glucose (can use
glucometer), CPK, urine and serum myoglobin, baseline clotting studies.
J. Insert Foley catheter and assess initial specimen for myoglobinuria.
1. Monitor urinary output and assess for myoglobin in the urine (dark color).
2. Have specimen containers available to send additional urine specimens for myoglobin
analysis.
K. Maintain urine output: If needed, administer mannitol 0.25 g/kg IV and furosemide 1 mg/kg IV
(up to 4 doses each).
1. Increased urinary output (> 2 mL/kg/hr) will prevent myoglobin from forming casts in the
kidney with subsequent renal failure.
L. As necessary, administer Sodium Bicarbonate, 1-2 mEq/kg increments guided by arterial pH and
PCO2. A small bolus of Sodium Bicarbonate may be given prior to first lab results.
1. This is used to treat the severe metabolic acidosis and hyperkalemia of a typical MH crisis
(drives the K+ back into the cells).
M. As necessary, give regular insulin (1-10 units) and 50 mL 50% D/W. Emergency regular insulin

UNIVERSITY OF WISCONSIN

POLICY & PROCEDURE

EFFECTIVE DATE

AUGUST 1990
ORIGINAL
 REVISION

FEBRUARY 2017
PAGE 4
OF 5
POLICY #

2.18
ADMINISTRATIVE MANUAL
NURSING MANUAL
OTHER Surgical Services
TITLE
MANAGEMENT OF MALIGNANT HYPERTHERMIA
SUSCEPTIBLE PATIENTS AND A MH CRISIS



vials are stored in the Inpatient OR Pharmaceutical Room (E7/391), AFCH OR (3311) and in
OSC side A and B refrigerators (F6/206).
1. Insulin will assist in pushing the K+ into the cells. The 50% D/W provides an exogenous
energy source. The insulin and glucose may be given as a bolus or a continuous drip.
N. As necessary, give lidocaine, amiodarone, or magnesium sulfate per ACLS protocols for cardiac
dysrhythmias caused by MH.
1. Dysrhythmias are usually caused by acidosis and hyperkalemia.
2. Lidocaine or procainamide should not be given if a wide-QRS complex arrhythmia is likely
due to hyperkalemia, as this may cause asystole.
3. Calcium channel blockers use is contraindicated in an MH crisis due to drug-drug interaction
with dantrolene (leads to severe hyperkalemia).
O. Aggressive body cooling measures are not advised, especially cooling of the limbs since
peripheral vasoconstriction may slow dantrolene getting to muscle. Do not “pack” kids with ice,
beyond ice-filled gloves on the groin. Keep the room temperature comfortable for everyone.
1. Iced lavage of cavities, etc. should not distract from really important matters - getting the
dantrolene in, and treating the hyperkalemia.
P. Anesthesia can be maintained with intravenous anesthesia if the procedure must continue (TIVA,
possibly including propofol, midazolam, opioids, and non-depolarizing neuromuscular blockers
such as rocuronium, vecuronium, or cisatracurium). Help anesthesia team get more drugs and start
infusions as directed.
Q. If a patient at risk is undergoing cardiopulmonary bypass, remind the perfusionist not to use
volatile agents (give him/her the sign to put on the pump).
R. Arrange an ICU bed. Transfer patient to an ICU post-operatively for continuous monitoring as
lethal recurrences of MH may happen.
1. Call report to the ICU if the patient is transferred there directly.

S. Transport the MH box to the ICU. Monitoring must continue in the ICU.
1. NOTE: Recurrences are common and life threatening. Patients need to be closely watched for
48 hours with dantrolene immediately available.
2. NOTE: MH box must be returned promptly after patient transport to the ICU.

V. MH susceptible patients who are managed with non-triggering anesthetic agents and monitored
appropriately post-op may be discharged home after outpatient surgery at the discretion of the
attending anesthesiologist.

VI. REFERENCES


UNIVERSITY OF WISCONSIN

POLICY & PROCEDURE

EFFECTIVE DATE

AUGUST 1990
ORIGINAL
 REVISION

FEBRUARY 2017
PAGE 5
OF 5
POLICY #

2.18
ADMINISTRATIVE MANUAL
NURSING MANUAL
OTHER Surgical Services
TITLE
MANAGEMENT OF MALIGNANT HYPERTHERMIA
SUSCEPTIBLE PATIENTS AND A MH CRISIS



A. AORN Perioperative Standards and Recommended Practices 2008, pages 103-140
B. Malignant Hyperthermia “Hotline” 1-800-MH-HYPER (1-800-644-9737) -- Provides medical
professional with access to experts who specialize in MH crises 24 Hours a Day, 365 Days/Year
C. Malignant Hyperthermia Association of the United States: http://www.mhaus.org/
D. Ryanodex® [package insert]. Eagle Pharmaceuticals, Inc., Woodcliff Lake; NJ; July 2014
http://www.ryanodex.com/wp-content/uploads/2014/07/ryanodex-prescribing-information.pdf

REVIEWED BY

Surgical Services Policy and Procedure Committee 3/2017
Megan Donovan, PharmD 3/2017
Denise Dillon, MSN, Surgical Services Supervisor 3/2017
Lori Kong, RN, Surgical Services Supervisor 3/2017
Ashley Rusch, BSN, RN, CNOR, Nursing Education Coordinator 3/2017
Katharine Holley, MSN, RN, CNOR, Nursing Education Specialist 3/2017
Russ Ward, Anesthesia Clinical Engineer 3/2017
Andrew Schroeder, MD 3/2017
Aimee Becker, MD 3/2017
Deb Rusy, MD 3/2017
Richard Galgon, MD 3/2017
Scott Springman, MD 3/2017

SIGNED BY

Anne Mork, MHCDS, MS, RN 3/2017
Interim Director, Surgical Services Department