Background: The aim of this study was to investigate the effect and safety of pyridostigmine for the reversal of a neuromuscular block (NMB) in patients with Duchenne muscular dystrophy (DMD). In patients with DMD recovery from a rocuronium-induced NMB is markedly delayed.
Methods: Fourteen DMD patients (aged between 11 and 19 years) scheduled for elective scoliosis repair were studied. Following tracheal intubation without muscle relaxant, all patients received a single dose of rocuronium 0.6 mg.kg(-1). NMB was monitored by acceleromyography at the adductor pollicis muscle. When the first twitch height (T1) of the train-of-four (TOF) had recovered to 25% seven patients received either pyridostigmine 0.1 mg.kg(-1) (the anticholinergic drug with a long duration of action) or saline in a blinded manner. The times to attain TOF ratio of 0.9 were recorded. For comparison the Mann-Whitney U-test was used.
Results: Recovery to TOF ratio of 0.9 was significantly (P < 0.05) accelerated by pyridostigmine [84 (median), 57-141(range)] compared with controls (148, 84-243 min). The recovery time (time between T1 of 25% and TOF of 90%) was also significantly (P < 0.01) shortened by pyridostigmine (15, 8-49 vs 76, 43-144 min, respectively). Time to recovery of T(1) to 90% was not different between the groups (108, 63-134 vs 169. 61-208 min, respectively).
Conclusions: Pyridostigmine 0.1 mg.kg(-1) effectively reversed a rocuronium-induced NMB in DMD patients.