(248) Fever Fiasco! Malignant Hyperthermia Complicated by Gemella morbillorum Septic Shock

Introduction: Malignant hyperthermia (MH) is a rare genetic disorder affecting skeletal muscle calcium channels making them susceptible to volatile anesthetics and the paralytic succinylcholine. The exposure results in sustained muscle contraction leading to hyperpyrexia, hypercapnia, and rhabdomyolysis. If untreated, mortality exceeds 70%, with confusion between MH and SIRS often causing delays. We present a case of a succinylcholine-induced MH, further complicated by G. Morbillorum sepsis of unknown etiology.

Description: A 71-year-old male patient, presented with 2 days of fever and shortness of breath. Chest x-ray showed increased bilateral infiltrates. Initially, he was admitted with the presumed diagnosis of CAP and started on ceftriaxone and azithromycin after appropriate cultures were obtained. Shortly thereafter, he had worsening hypoxemia leading to emergent intubation using propofol and succinylcholine with initial end-tidal CO2 (ETCO2) of 28mmHg. He had a brief peri-intubation PEA arrest and achieved ROSC after 2 minutes. In the ICU, he had a temperature of 105.2F along with masseter rigidity and an increase in his ETCO2 to 59mmHg. MH was suspected and he was rapidly stabilized using Ryanodex and supportive care with a prompt reduction in his temperature and hypercapnia. His masseter rigidity responded quickly after the third dose of Ryanodex. Given his progressive acidosis, shock, and need for renal-replacement therapy he was transferred to a tertiary care center. Despite maximal efforts and supportive care, he succumbed to multi-organ failure within 48 hours of presentation. Blood cultures confirmed G. Morbillorum 2 hours before his death.

Discussion: Malignant hyperthermia is a rare disorder with only 700 cases annually nationwide, and a mortality rate of less than 5% with early recognition and appropriate treatment. Our patient developed MH due to succinylcholine and despite early recognition and rapid treatment of his malignant hyperthermia, he developed multi-organ failure due to septic shock from a rare pathogen. This case highlights the importance of maintaining a high degree of suspicion for MH, especially in the critical care setting where succinylcholine is used frequently, and sepsis induced fever can lead to a delay in recognition and management.