Suspected Pseudocholinesterase Deficiency During Left Thyroid Lobectomy and Isthmusectomy: A Case Report.

Background: Pseudocholinesterase (butyrylcholinesterase) deficiency is an acquired or inherited condition in which decreased plasma levels of the pseudocholinesterase enzyme lead to an inability to metabolize the neuromuscular blocking agents succinylcholine and mivacurium, prolonging their paralytic effects. This often results in delayed extubation and additional intensive care requirements in the postoperative period.

Case Description: We describe a case of suspected pseudocholinesterase deficiency in a previously healthy 59-year-old female who underwent a left thyroid lobectomy and isthmusectomy. The patient received 120 mg of succinylcholine chloride before intubation. The patient did not meet extubation criteria following the completion of the procedure approximately two hours after receiving succinylcholine chloride. The patient was transferred to the ICU for respiratory support and for the medication to clear from the patient's system. The patient regained muscle control approximately four hours after receiving succinylcholine chloride and was extubated without complication. The patient shared post-extubation that she had a blood relative with the diagnosis of pseudocholinesterase deficiency.

Conclusion: Pseudocholinesterase deficiency is rare but can result in potentially serious complications following the administration of succinylcholine chloride, mivacurium, or ester local anesthetics due to reduced metabolism and subsequently increased pharmacodynamic effects. Given the widespread use of succinylcholine chloride as a neuromuscular blocking agent, such as in this case, providers must be aware of the presentation, pathophysiology, diagnosis, and management. Additionally, this case demonstrates the importance of thoroughly inquiring about any personal or family history of anesthetic complications during a preoperative assessment.