In this episode, I’ll discuss the ICU pharmacist’s role in recognizing and treating malignant hyperthermia.
Malignant hyperthermia (MH) is a rare and life-threatening reaction to anesthesia that results in an uncontrolled rise of myoplasmic calcium, leading to hyperkalemia and rhabdomyolysis. It occurs in about 1 out of 100,000 administrations of anesthesia.
MH is typically thought of as a problem that develops and is recognized in the operating room and nowhere else in the hospital. Staff education usually focused entirely on OR staff, and MH carts containing everything needed for treatment are usually only stored in the OR.
However, MH can occur an hour after anesthesia or anywhere succinylcholine has been administered, making its occurrence outside of the OR a real possibility.
Not only is succinylcholine used in the ICU, but as a recent review in the journal Critical Care Medicine highlights:
Increasing use of inhalational anesthetics in the ICU underscores the need for enhanced education on the diagnosis and management of MH to ensure optimal patient sedation care and safety.
MH is suspected when, within minutes to an hour after administering a triggering agent, the patient develops a rise in temperature, hypercarbia, and muscular rigidity.
The treatment for MH is prompt administration of dantrolene. Dantrolene is a skeletal muscle relaxant that interferes with the release of calcium ions from the sarcoplasmic reticulum. By lowering the myoplasmic calcium ion concentration, the sustained muscular contraction present in MH is ended along with the acute catabolic process.
Because the risk of mortality and morbidity increases for every 10-minute delay in giving dantrolene, I believe the main focus of the pharmacist should be obtaining and preparing the first dose of dantrolene. A secondary focus can be to get the expertise of an anesthesiologist to the bedside because it is likely that the pharmacist has the knowledge of how best to rapidly contact local anesthesiologists or the national MH hotline.
To that end, when MH is suspected outside of the OR, the pharmacist can facilitate the care of the patient by taking the following steps:
1. Obtain the MH cart from the OR or PACU and bring it to the patient’s bedside.
2. If not already done by another clinician, use your phone to notify the anesthesia department and call them to the bedside while you are in the process of obtaining the cart.
3. When the cart is at the patient’s bedside, immediately prepare an initial dose of 2.5 mg/kg dantrolene.
4. If your anesthesia provider has not arrived, contact the MHAUS hotline, the number for which can be found at mhaus.org.
After the first dose of dantrolene is administered, supportive care will likely be directed by the anesthesiologist at the bedside or on the MH hotline.
Although this information might come up once or not even at all in a pharmacist’s career, having the knowledge of the location of your MH cart and anesthesia contact information has the potential to decrease the delay to dantrolene administration and provide the best chance for a positive patient outcome should MH occur outside of the OR.
Members of my Hospital Pharmacy Academy have access to a practical training video on the treatment of malignant hyperthermia. I’ve created this material as well as 200+ practical trainings and many more resources in the Academy to help hospital pharmacists learn practical critical care and hospital pharmacy skills and translate theoretical knowledge to the bedside. To get immediate access to everything the Academy has to offer go to pharmacyjoe.com/academy to join today.
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
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