2023 FSA Podium and Poster Abstracts

P023: EMERGENT ANESTHETIC FOR PATIENT WITH MYASTHENIA GRAVIS AND HISTORY OF MALIGNANT HYPERTHERMIA
Michael S Ibrahim; University of Florida Health Jacksonville

Introduction: Both malignant hyperthermia and myasthenia gravis present the anesthesiologist with a difficult anesthetic situation.

Malignant hyperthermia has an underlying genetic basis, and genetically susceptible individuals are at risk of developing malignant hyperthermia if they are exposed to any of the potent inhalational anesthetics or succinylcholine (1). Malignant hyperthermia may prove fatal unless it is recognized in its early stages and treatment is promptly and aggressively implemented (1).

Myasthenia gravis is a disease affecting the nicotinic acetylcholine receptor of the post-synaptic membrane of the neuromuscular junction, causing muscle fatigue and weakness. The myasthenic patient can be a challenge to anesthesiologists, and the post-surgical risk of respiratory failure has always been a matter of concern (2).

Malignant hyperthermia or myasthenia gravis present for difficult anesthetics for anesthesiologists, however sparse literature is available on how manage a patient with both these conditions.

We present a case of a septic 68-year-old female with severe myasthenia gravis and known history of malignant hyperthermia requiring a general anesthetic for emergent surgery.

Methods: A literature review was performed using the PubMed database, utilizing keywords such as “myasthenia gravis”, “malignant hyperthermia”, “anesthesia”, and “rocuronium”. A thorough review of the results was conducted.

Results: After undergoing a thorough literature review, we found there was no literature commenting on a patient with both myasthenia gravis and history of malignant hyperthermia.

Patients with a history of malignant hyperthermia are must not be exposed to potent inhalation anesthetics or succinylcholine (1). The easiest way to avoid these agents is to avoid general anesthesia by substituting a regional anesthetic technique if appropriate. In situations where general anesthesia is required, strategies to avoid the triggering agents are essential (1). Potent inhalational agents can be substituted with the use of a total intravenous anesthetic technique (1).

Two techniques have been recommended for general anesthesia in the myasthenic patient. Because of the unpredictable response to succinylcholine and the marked sensitivity to nondepolarizing muscle relaxants, some anesthetists avoid muscle relaxants and depend on deep inhalational anesthesia, for tracheal intubation and maintenance of anesthesia. However, others utilize a balanced technique which includes the use of muscle relaxants, without the need for deep inhalational anesthesia with its concomitant respiratory and cardio- vascular side effects (3). In some instances, the use of an epidural/regional anesthesia makes it possible to avoid general anesthesia all together (2).

Discussion: Myasthenia gravis and malignant hyperthermia place the anesthesiologist in a difficult anesthetic position. The literature describes appropriate anesthetic management of each of these conditions independently, but is sparse in describing management of a patient that has both of these conditions. After undergoing a thorough literature review, it appears a successful way to treat both conditions could be to place an epidural and avoid a general anesthetic (1,2). However, this patient presented with significant weakness with concern for maintaining her airway, necessitating the need for a general anesthetic.

We describe a successful general anesthetic in a patient with both severe myasthenia gravis and a history of malignant hyperthermia who presented for an emergent case.