title: Hypothermic cardiopulmonary bypass influences the concentration-response relationship and the biodisposition of rocuronium.
abstract: In 10 patients scheduled for elective coronary artery bypass grafting under midazolam-sufentanil anaesthesia, the influence of hypothermia on the plasma concentration-response and biodisposition of rocuronium were investigated. Neuromuscular function was monitored mechanomyographically. Plasma and urine concentrations of rocuronium were determined by high performance liquid chromatography. Hypothermic cardiopulmonary bypass prolonged the duration of action of maintenance doses and altered the plasma concentration-response relationship. The elimination and distribution half-lives, following the last maintenance dose after rewarming, and the urinary excretion of rocuronium were similar to values obtained during normothermia. A diminished hepatic uptake and storage in the liver of rocuronium during hypothermia may explain the more pronounced prolongation of the duration compared to that of other steroidal neuromuscular blocking agents.
authors.affiliation: Research Group for Experimental Anesthesiology and Clinical Pharmacology, University Hospital, Groningen, The Netherlands.
authors.forename: N J
authors.initials: NJ
authors.lastname: Smeulers
authors.forename: J M
authors.initials: JM
authors.lastname: Wierda
authors.forename: L
authors.initials: L
authors.lastname: van den Broek
authors.forename: R C
authors.initials: RC
authors.lastname: Gallandat Huet
authors.forename: P J
authors.initials: PJ
authors.lastname: Hennis
mesh_terms: D000759:Adjuvants, Anesthesia; D000328:Adult; D000368:Aged; D000732:Androstanols / Q000493:pharmacokinetics*; D000758:Anesthesia; D002315:Cardiopulmonary Bypass; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006207:Half-Life; D006801:Humans; D007036:Hypothermia, Induced; D008874:Midazolam; D008875:Middle Aged; D009126:Muscle Relaxation / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000493:pharmacokinetics*; D000077123:Rocuronium; D017409:Sufentanil
chemical_list: D000759:Adjuvants, Anesthesia; D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D017409:Sufentanil; D008874:Midazolam; D000077123:Rocuronium