title: Influence of plasma cholinesterase activity on recovery from mivacurium-induced neuromuscular blockade in phenotypically normal patients.
abstract: The significance of plasma cholinesterase (pChe) activity for the duration of action of mivacurium in phenotypically normal patients was evaluated in 35 patients during neurolept anaesthesia. The response to train-of-four nerve stimulation was recorded using a Myograph 2000. Ten patients with normal pChe (Group I) and five patients with decreased pChe activity (Group 2) were given a small test dose of mivacurium 0.03 mg kg-1. Mivacurium 0.1 mg kg-1 was administered following spontaneous recovery from the first dose. The mean suppression of the height of the first (T1) of the train-of-four responses following mivacurium 0.03 mg kg-1 patients with normal and decreased enzyme activity was 40% and 56%, respectively, and the mean T1 suppression after mivacurium 0.1 mg kg-1 was 100% in both groups. The times to different levels of twitch height recovery following the 0.1 mg kg-1 dose did not differ between the two groups of patients. Another 20 patients with normal or decreased pChe activity (Group 3) were given mivacurium 0.2 mg kg-1. In this group the time to maximum block was 1.4 min (1.0-4.0) mean (range) and the time to reappearance of the T1 response was 15.0 min (7.4-22.7) (range). An inverse relationship was found between the patients' pChe activity and the time to first response. It is concluded that mivacurium is short-acting in patients with normal pChe phenotype and normal to low-normal pChe activity. No patient with very low pChe activity was included in the study. A prolonged response to mivacurium may, however, be expected in these patients.
authors.affiliation: Department of Anaesthesia, Glostrup Hospital, University of Copenhagen, Denmark.
authors.forename: D
authors.initials: D
authors.lastname: Ostergaard
authors.forename: F S
authors.initials: FS
authors.lastname: Jensen
authors.forename: E
authors.initials: E
authors.lastname: Jensen
authors.forename: L T
authors.initials: LT
authors.lastname: Skovgaard
authors.forename: J
authors.initials: J
authors.lastname: Viby-Mogensen
mesh_terms: D000762:Anesthesia Recovery Period; D002802:Cholinesterases / Q000097:blood* / Q000235:genetics; D003992:Dibucaine; D004558:Electric Stimulation; D005483:Flushing / Q000139:chemically induced; D006801:Humans; D007262:Infusions, Intravenous; D007546:Isoquinolines / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000077590:Mivacurium; D009119:Muscle Contraction / Q000187:drug effects; D009388:Neostigmine / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010641:Phenotype; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors; D014459:Ulnar Nerve / Q000187:drug effects
chemical_list: D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D009388:Neostigmine; D000077590:Mivacurium; D002802:Cholinesterases; D003992:Dibucaine