eP705 - Epidural Anesthesia-analgesia Can Be Used for Open Laparotomy in High-risk Patients, Such as Those with Myasthenia Gravis

Purpose/Background: Myasthenia gravis (MG) is an antibody-mediated autoimmune disorder that disrupts postsynaptic acetylcholine receptors with consequent impaired cholinergic transmission. Often manifesting with fatigable weakness, bulbar symptoms, and respiratory dysfunction, MG is estimated to have an incidence of 4.1 to 30 cases per 1,000,000. Given its pathophysiology, MG patients can be challenging to manage during open abdominal surgery. Neuromuscular blocking agents are generally avoided given their unpredictable efficacy and risk of precipitating MG crisis, and reversal agents such as sugammadex are not always reliable. Regional neuraxial anesthesia can eliminate the need for these agents in such high-risk patients and has been reported previously in other thoracoabdominal surgeries, such as thymectomy, cholecystectomy, and mammaplasty. Here, we report a case of a 66-year-old male with a history of advanced MG, adrenocortical insufficiency (AI), and cardiac dysrhythmias who successfully underwent an open sigmoid colectomy and colostomy creation under epidural anesthesia-analgesia for persistent diverticulitis.Methods/Interventions: Epidural anesthesia was obtained with a 19G standard epidural catheter at the T11-12 level, 0.5% bupivacaine, lidocaine, morphine, and epinephrine. Throughout, the patient remained on spontaneous noninvasive ventilatory support via a bilevel positive airway pressure machine. While awake in lithotomy, the patient underwent an open sigmoid colectomy with end colostomy creation in the left lower quadrant.Results/Outcomes: The sigmoid colectomy was successfully carried out without any complication. Operative time was 140 min. Immediately postoperatively, the patient’s vital signs were stable with SpO2 of 99%, respirations of 22/min, pulse of 49 beats/min, and blood pressure of 92/47 mmHg. The patient initially experienced some postoperative nausea and non-bloody, non-bilious emesis that was well-managed conservatively. The remaining hospital course was unremarkable, and he was discharged home 8 days after the surgery.Conclusion/

Discussion: Given the patient's history, respiratory fragility, and prior episodes of cardiac dysrhythmias, we opted to employ epidural anesthesia to minimize perioperative complications, namely MG crisis. MG patients have an increased risk of prolonged mechanical ventilation postoperatively, and neuraxial anesthesia may compromise respiratory function if the block has a high level; in addition to the multidisciplinary coordination of care, these concerns were mitigated by maintaining noninvasive ventilatory support with careful monitoring and targeting a T11-12 level. MG patients are also unpredictably sensitive to the discontinuation of their medications (ex. pyridostigmine), so these were continued up to the time of surgery. Given his chronic steroid use and subsequent AI, the patient received a stress-dose of prednisone preoperatively. Despite the patient’s high-risk features for an open abdominal procedure, the utilization of epidural anesthesia allowed us to perform the surgery successfully with a sufficient sensory and motor block while minimizing the risk of systemic effects and respiratory compromise as well as avoiding the need for tracheal intubation and postoperative opioids for pain control. This demonstrates the efficacy and utility of regional neuraxial anesthesia-analgesia for MG and other high-risk patients undergoing open abdominal surgery.