2024 FSA Podium and Poster Abstracts

P049: CASE REPORT: A RARE CASE OF DELAYED EMERGENCE FROM ANESTHESIA DUE TO PSEUDOCHOLINESTERASE DEFICIENCY
Gordon J Hubbell, DO; Stewart Slomowitz, MD; HCA Florida Westside/Northwest Anesthesia

Introduction/Background: There are several differential diagnoses when considering the etiology of delayed emergence from anesthesia. The purpose of this case report is to describe the clinical implications of an uncommon cause of delayed emergence known as Pseudocholinesterase Deficiency, in which a rare defect in the pseudocholinesterase enzyme, which can be genetic or acquired, decreases the metabolism of specific pharmacologic agents including the popular short acting muscle relaxant Succinylcholine. The result in this case was a drastic prolongation of neuromuscular blockade that can vary among individuals and be difficult to diagnose. Lab tests such as the “Dibucaine Number” can quantify this deficiency, although the majority of patients with this defect won’t be diagnosed until they experience a case of prolonged emergence.

Methods/Results: We report a case of delayed emergence from anesthesia due to pseudocholinesterase deficiency in a 90-year-old female undergoing a left hip arthroplasty. The patient received a PENG (Pericapsular nerve group) block preoperatively without sedation or complications and then received 100mg Succinylcholine, 100mg Propofol, and 25mcg of Fentanyl for intubation with no further administration of narcotics for the duration of the 2-hour procedure under general anesthesia with sevoflurane. At the end of the procedure the patient would not wake up despite having zero expired volatile anesthetic and had no spontaneous ventilation or reaction to stimuli or gag reflex. Lab work was sent which was grossly negative for abnormalities and the possibility of medication error was eliminated. Pseudocholinesterase deficiency began to be suspected when zero twitches were able to be elicited at multiple sites with multiple different monitors used. After an additional hour the patient was brought to the ICU ventilated and stable, and a Dibucaine Number was ordered. The patient was successfully extubated in stable condition around 6 hours after the initial administration of succinylcholine, and the dibucaine number result came back several weeks later at 41 consistent with the heterozygous atypical variety of pseudocholinesterase deficiency. Upon further investigation family members admitted to having known of an unclear familial history of a sensitivity to anesthesia.

Discussion/Conclusion: This is a rare case of prolonged neuromuscular blockade in which a patient received only 100 mg of the depolarizing neuromuscular blocking agent succinylcholine which resulted in prolonged paralysis lasting approximately 6 hours. The diagnosis was confirmed using twitch monitoring and the dibucaine number lab test. This case demonstrates the clinical significance of this rare deficiency and the stepwise process of narrowing down our differential diagnosis in order to proceed with the proper standard of care.