Intubating conditions and blockade after mivacurium, rocuronium and their combination in young and elderly adults.
OBJECTIVE
Mivacurium-rocuronium combinations have been demonstrated to be more potent than either drug given alone. Combinations were compared with mivacurium and rocuronium, with respect to onset, intubating conditions, and duration of action in young and elderly adults.


METHODS
Fentanyl-propofol-N2O-isoflurane anesthesia was given to ASA I and II adults aged 18-65 yr (45 patients) and over 66 yr (45 patients). In this blinded randomized study, we compared accelerographic adductor pollicis response and visual assessment of response to facial nerve stimulation after 0.25 mg x kg(-1) mivacurium, 0.6 mg x kg(-1) rocuronium, and a combination of 0.08 mg kg(-1) mivacurium plus 0.2 mg x kg(-1) rocuronium. Intubating conditions at 2.5 min were rated as excellent, good, fair or poor.


RESULTS
Onset times were similar for all drugs regimens and for both age groups (204-276 sec at the thumb; 142-196 sec at the eye) (P<0.05 between muscles). Intubating conditions were similar in all groups, and rated good or excellent, except in two subjects. In young patients duration to 25% recovery was longer (P<0.05) for rocuronium (mean +/- SD) (39+/-11 min) than for either mivacurium (23+/-6 min), or the combination (27+/-7 min). Duration was prolonged in the elderly for rocuronium (54+/-17 min), and the combination (35+/-11 min), but not for mivacurium (24+/-6 min).


CONCLUSIONS
Mivacurium-rocuronium combinations yield onset times and intubating conditions similar to either parent agent with only two thirds as much total drug. Duration for such a mixture is similar to that of mivacurium in young adults and slightly prolonged in the elderly.
Motamed
C
C
Department of Anaesthesia, Hôtel-Dieu, Centre Hospitalier de l'Université de Montréal, Québec, Canada.
Donati
F
F
D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D000732:Androstanols / Q000008:administration & dosage*; D000762:Anesthesia Recovery Period; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D016009:Chi-Square Distribution; D004338:Drug Combinations; D005154:Facial Nerve / Q000187:drug effects; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D007546:Isoquinolines / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D000077590:Mivacurium; D009119:Muscle Contraction / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D000077123:Rocuronium; D016037:Single-Blind Method; D013933:Thumb / Q000294:innervation; D013997:Time Factors
D000732:Androstanols; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D004338:Drug Combinations; D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium; D000077123:Rocuronium