1. Malignant Hyperthermia:
Mock Code

2. ABC’s of managing MH Pre-operative:
Ask about personal and family history of MH; Adverse Anesthesia reactions (unexplained fever or death); Aware of clinical signs
Body temperature
Capnographic monitoring
Dantrolene
(MHAUS, 2009)

3. Intraoperative Primary Survey/Clinical Signs:
Awareness: suspecting MH crisis?
Airway: severe masseter spasm
Breathing: difficult to ventilate/intubate
Body rigidity after succinylcholine
Body temperature high (late sign)
Capnography: elevation of end CO2
Drugs: triggering agents
Exposure/Examine: skin color, perfusion,temperature, urine color, extremities, muscle tone
(MHAUS, 2009)

4. Emergency Treatment Ask for Help/Ask for MH cart
Breathing: hyperventilate with 100% oxygen
Cooling: blanket; fluids-15cc/kg IV 3 times; irrigate wound, stomach, & stomach; Call MH Hotline:
Dantrolene: 2.5 mg/kg IV and until signs are controlled
Check Electrolytes-**potassium
(MHAUS, 2009)

5. Secondary steps Acidosis? Monitor blood gases.
Bicarbonate? 1-2 mEq/kg guided by pH
Circulation/monitoring: arterial line, venous catheter, labs, blood gases, CBC, Coagulation tests, CK, myoglobin levels
Dysrhythmias: treat
Diuresis: output > 1 ml/kg/hr
Electrolytes: treat
Follow up: Arterial and venous blood gases; Body temperature (core); end-tidal CO2; CK, Coagulation tests; Diuresis; Electrolytes
(MHAUS,2009)

6. Post-Operative Post-Crisis Problems:
Alkalinize urine & diurese, monitor for ARF (acute myoglobinuric renal failre)
Beware hypothermic, hyperkalemic, hypervolemic overshoot
Creatine Kinase levels (CK)- severity of rhabdomylosis (watch for renal failure)
Compartment Sundrome
Elevated liver functions hours post MH
Follow CNS function
Good communication to medical specialists
(MHAUS,2009)

7. Post-Acute Phase Aware of recrudescence signs
Ask relatives about Anesthesia problems /neuromuscular disorders
Biopsy: send to center for evaluation
Contact MHAUS for information/referral
Dantrolene 1 mg/kg IV q 4-6 hrs and continued for hours
Document: submit forms to the national/international North American MH Registry:
(MHAUS, 2009)

8. Mock Code Scenario
A 40-year-old, 90 kg woman is undergoing liposuction under general anesthesia. She is intubated and receiving desflurane anesthesia. When she is turned from prone to supine, the patient feels stiff. No temperature probe is in place and she feels warm. Her heart rate is now 160 bpm and her ETCO2 is 82 despite minute ventilation of 12 L/min: Pt has Malignant Hyperthermia
(MHAUS, 2009)

9. Operating Room: When MH is suspected
Stops inhalation agents and uses non-triggering agents (Anesthesia Duty)
Hyperventilate with 100% oxygen at high flows: at least 10 L/min (Anesthesia Duty)
Circulator: notifies control desk and a MH code is called by the person in charge. Ask for additional help from PACU if needed
Anesthesia tech or assigned team member will take a replacement anesthesia machine into operating room
(Corporate Surgical Committee, 2010)

10. Operating Room
If replacement not available, the soda line and circuit are changed immediately and the system is flushed with oxygen before proceeding. (Anesthesia Duty)
Anesthesia MD in charge of crisis intervention
(Corporate Surgical Committee, 2010)

11. Roles are assigned Anesthesia Staff: Change anesthesia machine
Monitor vital signs
Administer Dantrolene and other meds to treat symtoms
Assist with cooling by providing large quantities of iced saline lavage
Place additional monitoring lines e.g. arterial line
(Corporate Surgical Committee, 2010)

12. Surgeon, Scrub, & Circulator
Assist in cooling the patient by providing iced saline lavage direct to peritoneal or thoracic cavity if open
Stop surgical procedure as soon as possible
Scrub secures the incision site (i.e. applies dressings or covers wound to protect it from disruption)
(Corporate Surgical Committee, 2010)

13. Second Circulator Assists preparing Dantrolene for administration
Each vial should be reconstituted with 60 ml of sterile water (bacteriostatic agent)
Records medication and progress of interventions
(Corporate Surgical Committee, 2010)

14. Third Circulator Assists in surface cooling of the patient as directed
Obtains additional supplies as directed
(Corporate Surgical Committee, 2010)

15. Scrub tech/Clinical Tech/RN
Immediately available to run specimens to the lab
Immediately available to assist as directed
(Corporate Surgical Committee, 2010)

16. Surgery Desk Nurse
Assigns staff to the operating room where the MH crisis is (may include help from PACU)
Notifies PACU personnel and Nursing Operations Manager
(Corporate Surgical Committee, 2010)

17. MH suspected in PACU
Primary care nurse to notify the control desk and a MH Code is to be called by the person in charge.
Additional help may be asked from the operating room/pre-op staff
Hyperventilate with 100% oxygen at high gas flows: at least 10 L/min
Charge Nurse (Team Leader) will immediately assign a staff member to get the MH cart
Anesthesia MD is in charge
(Corporate Surgical Committee, 2010)

18. Anesthesia Staff
Will administer Dantrolene and medications used to treat symptoms
Assist in cooling patient by providing large quantities of cold saline lavage
Place additional monitoring lines. E.g. arterial line
(Corporate Surgical Committee, 2010)

19. Second RN Assists preparing Dantrolene for administration
Records medications and progress of intervention
(Corporate Surgical Committee, 2010)

20. Third RN Assists in surface cooling of the patient as directed
Obtains additional supplies as directed
(Corporate Surgical Committee, 2010)

21. Debriefing of Mock Code
Using the report of the timing of the events as a guide
Each participant discusses what went right and what could be improved.
Notes are taken and used to guide future drills
(Corporate Surgical Committee, 2010)

22. Clinical Tech/RN Immediately available to run specimens to the lab
Immediately available to assist as directed
(Corporate Surgical Committee, 2010)

23. PACU Desk/ Charge Nurse
Assigns staff to the patient where the MH crisis is (may include help from OR)
Submits MH form to the national/international North American MH Registry of MHAUS
(Corporate Surgical Committee, 2010)

24. References
Corporate Surgical Committee. (2010). Malignant hyperthermia crisis intervention. Orlando Health.
The Malignant Hyperthermia Association of the United States[MHAUS]. (2009). Guide to malignant hyperthermia. Retrieved from mhaus.org