BJA Advance Access originally published online on September 23, 2005
British Journal of Anaesthesia 2005 95(6):769-772; doi:10.1093/bja/aei249
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CLINICAL PRACTICE |
Onset and duration of mivacurium-induced neuromuscular block in patients with Duchenne muscular dystrophy
,1,11 Department of Anaesthesiology and 2 Department of Orthopaedics, Friedrich-Alexander University, Erlangen-Nuremberg, Erlangen, Germany
* Corresponding author: Department of Anaesthesiology, Friedrich-Alexander Universität, Erlangen-Nuremberg, Krankenhausstrasse 12, D-91054 Erlangen, Germany. E-mail: hubert.schmitt{at}kfa.imed.uni-erlangen.de
Background. To determine the response to mivacurium, we prospectively studied onset time and complete spontaneous recovery from mivacurium-induced neuromuscular block in patients with Duchenne muscular dystrophy (DMD).
Methods. Twelve boys with DMD, age 5–14 yr, seven of them wheelchair-bound, ASA II–III, and 12 age- and sex-matched controls (ASA I) were enrolled in the study. Anaesthesia was induced with fentanyl 2–3 µg kg–1 and propofol 3–4 mg kg–1 titrated to effect, and maintained by continuous i.v. infusion of propofol 8–12 mg kg–1 and remifentanil as required. The lungs were ventilated with oxygen in air. Neuromuscular transmission was assessed by acceleromyography using train-of-four (TOF) stimulation every 15 s. After baseline readings, a single dose of mivacurium 0.2 mg kg–1 was given. The following variables were recorded: (i) lag time; (ii) onset time; (iii) peak effect; (iv) recovery of first twitch from the TOF response to 10, 25 and 90% (T10, T25, T90) relative to baseline; (v) recovery index (time between 25 and 75% recovery of first twitch); and (vi) recovery time (time between 25% recovery of first twitch and recovery of TOF ratio to 90%). For comparison between the groups the Mann–Whitney U-test was applied.
Results. There were no differences between the groups in lag time, onset time and peak effect. However, all recorded recovery indices were significantly (P<0.05) prolonged in the DMD group. The median (range) for time points T10, T25 and T90 in the DMD and control group was 12.0 (8–16) vs 8.4 (5–15) min, 14.1 (9–20) vs 10.5 (7–17) min and 26.9 (15–40) vs 15.9 (12–23) min, respectively. The recovery index and recovery time were similarly prolonged in the DMD group.
Conclusions. These results support the assumption that mivacurium-induced neuromuscular block is prolonged in patients with DMD.
This study was presented at the Annual Meeting of the American Society of Anaesthesiologists, Las Vegas, October 2004.
These authors contributed equally to this work.