title: Acute hypomagnesaemia causing intra-operative lower limb movements in a paraplegic patient, despite full neuromuscular blockade.
abstract: Alterations in electrolyte homeostasis associated with major surgery, intravenous fluid therapy, malnutrition, and critical illness are common but usually non-specific. This case report describes the sudden onset of forceful rhythmic flexion movements in both lower limbs during scoliosis surgery in a 12-year-old paraplegic boy with spina bifida. These movements arose despite adequate depth of anaesthesia, complete neuromuscular blockade, and treatment of hypocalcaemia. They persisted post-operatively after reversal of neuromuscular blockade and emergence from anaesthesia. Hypomagnesaemia was identified and treated post-operatively which coincided with cessation of the movements. We deduce hypomagnesaemia to be the aetiology of this unusual clinical presentation. This report underscores the interdependency of Ca2+ and Mg2+ homeostasis in excitable tissues and emphasizes that abnormalities observed in each cation should not be considered independently. In the perioperative care of spinal fusion patients, hypocalcaemia is a well-recognised and understood complication.
authors.affiliation: Department of Anaesthesia, Children's Hospital of Eastern Ontario, University of Ottawa, ON, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Ozard
authors.forename: P
authors.initials: P
authors.lastname: Mossdorf
authors.forename: A
authors.initials: A
authors.lastname: Doja
authors.forename: H
authors.initials: H
authors.lastname: Writer
authors.forename: D R
authors.initials: DR
authors.lastname: Doherty
mesh_terms: D000208:Acute Disease; D000927:Anticonvulsants / Q000008:administration & dosage; D002118:Calcium / Q000097:blood; D002648:Child; D006801:Humans; D007431:Intraoperative Complications / Q000188:drug therapy*; D035002:Lower Extremity / Q000503:physiopathology*; D008274:Magnesium / Q000097:blood*; D008278:Magnesium Sulfate / Q000008:administration & dosage; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D009119:Muscle Contraction / Q000187:drug effects*; D019148:Neuromuscular Blockade / Q000379:methods*; D010264:Paraplegia / Q000150:complications*; D012600:Scoliosis / Q000601:surgery; D016135:Spinal Dysraphism / Q000150:complications
chemical_list: D000927:Anticonvulsants; D008278:Magnesium Sulfate; D008274:Magnesium; D002118:Calcium