A Case Report of an Incidental Ultrasound Finding in a Suspected Malignant Hyperthermia Patient

Abstract

Malignant hyperthermia (MH) is a rare but life-threatening genetic disorder of the skeletal muscles triggered by inhalation anesthetics or succinylcholine. A 49-year-old female developed symptoms of MH shortly after a lumbar surgery. Despite being insidious, MH was diagnosed based on the clinical grading scale. We incidentally discovered fine fasciculations in extremities while inserting an ultrasound-guided arterial catheter. On receiving dantrolene, her symptoms improved within 20 minutes; a subsequent ultrasound revealed no fasciculations. Although halothane contracture testing was not available, the fasciculations that resolved with dantrolene administration in a MH suspected patient opens up a new potential avenue of diagnostics. (A&A Practice. 2022;16:e01651.) GLOSSARYABG = arterial blood gas; ALS = amyotrophic lateral sclerosis; ATP = adenosine triphosphate; BP = blood pressure; CK-MB = creatine kinase MB; CK-total = creatine kinase total; EQUATOR = Enhancing the QUAlity and Transparency Of health Research; ICU = intensive care unit; IVCT = in vitro contracture testing; MH = malignant hyperthermia; NMS = neuroleptic malignant syndrome; PACU = postanesthesia care unit; TSH = thyroid stimulating hormoneFigure. Timeline of the episode of malignant hyperthermia. ABG indicates arterial blood gas; BP , blood pressure; CK-MB, creatine kinase MB; PACU, postanesthesia care unit.