There was a uworld Q on this. The duration of action of Succinylcholine is determined by its metabolism by plasma cholinesterase. Some people are homozygous for an abnormal plasma cholinesterase, aka "pseudocholinesterase" or "butyrylcholinesterase" (BCHE). People with a homozygous BCHE mutation have delayed metabolism of succinylcholine, mivacurium, heroin, and cocaine.
In these patients, paralysis from succinylcholine can last for hours and you have to maintain them on mechanical ventilation until they can breath on their own
Also, I think what is key is to realize that injuring CN X ('intraoperative CN X injury') does not lead to diaphragm paralysis, only phrenic nerve injury would do that.
Furthermore, the other options ('idiosyncratic rxn to sevoflurane' and 'ryanodine receptor defect') are for malignant hyperthermia, NOT unable to breath spontaneously.
Might be a dumb question but... Can patients normally breathin on their own if givne succinylcholine?
submitted by โhaliburton(225)
https://ghr.nlm.nih.gov/condition/pseudocholinesterase-deficiency
"People with pseudocholinesterase deficiency may not be able to move or breathe on their own for a few hours after [fast-acting drugs, such as succinylcholine and mivacurium] are administered.