Spinal Anesthesia using Hyperbaric Bupivacaine, in an Elderly Patient with Myasthenia Gravis undergoing Total Hip Replacement: a case analysis

Introduction: Given the rising demand for joint arthroplasty in the aging population, this report provides a clinical framework for the uncomplicated anesthetic management of patients presenting with rare neuromuscular diseases and multimorbidity. Myasthenia gravis (MG) is a rare autoimmune disorder characterised by fatigable muscle weakness and respiratory vulnerability, caused by antibodies targeting postsynaptic acetylcholine receptors.

Anaesthetic management of patients with MG presents unique challenges due to their inherent sensitivity to neuromuscular blocking agents, and the heightened risk of precipitating a myasthenic crisis. During general anesthesia, cautious drug titration, meticulous monitoring, and risk of prolonged postoperative ventilatory support or exacerbation of myasthenic symptoms are great concerns. Regional anesthetic techniques offer an alternative by minimising systemic effects on respiratory function. To the best of our knowledge, there are limited reports on anesthetic management of elderly patients with MG undergoing orthopaedic surgeries. We present a retrospective case analysis of successful anaesthetic management for an elderly patient with this rare disease.

Method: We report the case of a woman, in her 80s, with stable MG, multiple comorbidities (including hypertension and hypothyroidism), with diagnosis of osteoporosis who underwent elective total hip replacement. Perioperative multidisciplinary assessments involved consultations with neurology, cardiology, and pneumonology. Spinal anesthesia with hyperbaric bupivacaine (10 mg) and morphine (100 mcg), supplemented with midazolam, ondansetron, dexamethasone, and ephedrine were implemented. Patient consent was obtained for the case analysis.

Results: Using this anesthetic strategy, combined with multidisciplinary perioperative assessment, the patient experienced no myasthenic crisis or respiratory compromise postoperatively. The patient was discharged 7 days later with a favourable local and general evolution.

Conclusions: This report supports consideration of regional anesthesia as a safe and effective option in high-risk neuromuscular patients, highlighting its potential to optimise perioperative safety and outcomes in surgical cases involving elderly patients with myasthenia gravis.