Prolonged neuromuscular block associated with cholinesterase deficiency.

RATIONALE: Hereditary genetic mutations may cause congenital cholinesterase deficiency. When succinylcholine and mivacurium are applied on cholinesterase-deficient patients during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication. PATIENT CONCERNS: A previously healthy 30-year-old female presented prolonged spontaneous breathing recovery after general anesthesia. DIAGNOSES: After the patient's postoperative spontaneous breathing recovery delayed, the plasma cholinesterase was found to be 27 U/L, which was far below the normal level (4000 U/L to 13500 U/L). This patient had no disease that can cause plasma cholinesterase deficiency and was therefore diagnosed as congenital cholinesterase deficiency. INTERVENTIONS AND OUTCOMES: The patient was sent to the intensive care unit (ICU) intubated for mechanical ventilator support, and on the next day the tracheal tube was removed without any complications when her spontaneous respiration resumed. LESSONS: Cholinesterase is an enzyme secreted by the liver involved in many physiological processes in human body. Plasma cholinesterase commonly contains acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). When succinylcholine and mivacurium are applied on patients with cholinesterase-deficiency during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication. Lately, new evidences have suggested that hereditary genetic mutations may be responsible for congenital cholinesterase deficiency.