Delayed Malignant Hyperthermia After Recent Surgery

Abstract

Malignant hyperthermia is a rare reaction of extreme fever and muscle rigidity to agents used for sedation and anesthesia. Typically, the reaction is within minutes of anesthesia administration. In this case report, we will discuss a 35year-old male who had a reaction 11 hours postoperatively. CASE PRESENTATION:A 35-year-old male with a history of HIV, anemia, and alcohol abuse came to the hospital due to right hip fracture sustained during a seizure episode at home, he was also found to be in alcohol withdrawal. On day 2 early morning, he underwent total hip replacement and was extubated post-op successfully. Sevoflurane and Rocuronium were used to achieve anesthesia. Post op, patient was hemodynamically stable with hydromorphone for pain control along with dexmedetomidine for withdrawal. In the evening at 2000h, the patient became agitated with muscular rigidity. His rectal temperature was 107 F. His labs were CK-1000, K-4.4, Mg-1.2. Peripheral smear showed no hemolysis. Rectal acetaminophen and dantrolene and cool saline were administered while blood cultures drawn and empiric antibiotics were started for suspected infection. The patient responded to therapy promptly and remained afebrile throughout the night. Due to improving symptoms, empiric antibiotics were discontinued. The patient remained afebrile after 24 hours and was transferred out of the ICU.DISCUSSION: Malignant hyperthermia is a rare but life-threatening reaction to commonly used inhaled anesthetics and depolarizing muscle relaxants. It is mediated by an autosomal dominant mutation in the gene RYR1 (ryanodine receptor), heterozygous mutation for RYR1 receptor has been associated with delayed onset of malignant hyperthermia.CONCLUSIONS: Cases of malignant hyperthermia have been reported to occur as late as four days after depolarizing muscle relaxant administration. Therefore, it is important to consider malignant hyperthermia as a cause of hyperpyrexia in patients who have undergone recent surgery.