[Clinical effect of mivacurium in morbidly obese patients].
OBJECTIVE
To compare the clinical effect of mivacurium in morbidly obese and normal-weight patients.


METHODS
Ten morbidly obese patients (body mass index >40) and 10 normal-weight patients (body mass index, 21-24) with normal plasma cholinesterase levels. Anesthesia was provided with propofol and remifentanil in continuous infusion and a mixture of oxygen and nitrous oxide. Mivacurium was administered at a dose based on the patient's weight (0.15 mg x kg(-1)). The neuromuscular block was monitored by train-of-four (TOF) acceleromyography after stimulation of the cubital nerve at the forearm. We measured the onset time (time from administration of the muscle relaxant to 95% twitch depression), duration of block (times from dosing to 5% recovery after the first twitch [T1] of a TOF stimulus and to a TOF ratio of 80%), and the recovery indices (time between 25% and 75% recovery after T1 and between recovery of TOF ratios of 25% and 80%). Groups were compared with the Student t test.


RESULTS
Mean (SD) onset time was similar in the 2 groups (normal weight 2.73 [1] minutes vs morbidly obese 1.91 [0.6] minutes). Other measures of duration and recovery were also similar in the 2 groups, respectively: duration of dose-T1 5%, 12.23 (2.1) vs 11.45 (3) minutes; dose-TOF ratio 80%, 24.71 (4.6) vs 24.81 (5) minutes); recovery index T1 25%-75%, 6.45 (2) vs 5.56 (1) minutes; recovery of TOF ratio T1 25%-80%, 9 (2) vs 10.11 (2) minutes.


CONCLUSIONS
We found no differences in the clinical effect of mivacurium between morbidly obese and normal-weight patients when doses were based on real weight.
Barrio
J
J
Servicio de Anestesiología, Hospital Arnau de Vilanova, Valencia. jabama16@hotmail.com
San Miguel
G
G
Molina
I
I
Asensio
I
I
Gramuntell
F
F
García
V
V
D000328:Adult; D001835:Body Weight; D005260:Female; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D000077590:Mivacurium; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D009767:Obesity, Morbid / Q000601:surgery*; D013997:Time Factors
D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D000077590:Mivacurium