[Prolonged phase II neuromuscular blockade following succinylcholine administration].

Area of Science:

• Anesthesiology and Pharmacology
• Clinical Biochemistry and Genetics

Background:

• Succinylcholine is a common muscle relaxant used in anesthesia, typically causing a short-acting Phase I neuromuscular block.
• Genetic variations in plasma butyrylcholinesterase activity can lead to atypical drug metabolism and prolonged neuromuscular blockade.
• Phase II neuromuscular block, a less common response to succinylcholine, can be prolonged in individuals with enzyme deficiencies.

Observation:

• A patient receiving a single dose of succinylcholine experienced an unusually long duration of neuromuscular blockade.
• The patient exhibited characteristics of a Phase II neuromuscular block, which persisted for six hours.
• This prolonged blockade was attributed to genetically determined abnormal plasma butyrylcholinesterase activity.

Findings:

• The case highlights a rare instance of a six-hour prolonged Phase II neuromuscular block following a single succinylcholine dose.
• Abnormal plasma butyrylcholinesterase activity was identified as the underlying cause of the extended blockade.
• The necessity of vigilant neuromuscular monitoring in patients receiving succinylcholine is underscored.

Implications:

• This case emphasizes the importance of recognizing and managing rare adverse drug reactions in clinical practice.
• Routine monitoring for neuromuscular blockade is crucial for patient safety, especially when administering succinylcholine.
• Understanding genetic variations in drug-metabolizing enzymes is vital for personalized anesthetic care and preventing prolonged paralysis.