title: Rocuronium 0.3 mg x kg-1 (ED95) induces a normal peak effect but an altered time course of neuromuscular block in patients with Duchenne's muscular dystrophy.
abstract: BACKGROUND
  In patients with Duchenne's muscular dystrophy (DMD) recovery from neuromuscular block is delayed. It has been assumed that this is because of a higher potency of muscle relaxants in this patient cohort. We determined the peak effect, and the time course of action of rocuronium 0.3 mg x kg(-1) (ED(95)) in DMD patients.
  
  
  METHODS
  Twenty-four patients (12 with DMD and 12 controls; aged 10-18 years) were studied. All patients were anesthetized with propofol and fentanyl/remifentanil. Neuromuscular transmission was monitored by acceleromyography. After induction all patients received a single dose of rocuronium 0.3 mg x kg(-1). The complete time course of action as onset, peak effect and spontaneous recovery was recorded.
  
  
  RESULTS
  The onset time (s) to maximum block was significantly (P < 0.01) prolonged in DMD patients (median: 315; range: 120-465) compared with controls (195, 75-270). The peak effect (% twitch depression relative to baseline) was not different between the groups (DMD: 59-100; controls: 28-100). In the DMD group, recovery was significantly (P < 0.01) delayed compared with controls at all recorded time points. The clinical duration (min) was 40.3 (22-89) in the DMD group vs 9.8 (6-17) in the control group (P < 0.01).
  
  
  CONCLUSIONS
  The similar peak effect in both groups does not confirm the thesis of rocuronium having a higher potency in DMD patients. The documented very long recovery after the ED(95) of rocuronium emphasizes the need for careful assessment of neuromuscular function in DMD patients.
authors.affiliation: Department of Anaesthesiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Tino
authors.initials: T
authors.lastname: Muenster
authors.forename: Joachim
authors.initials: J
authors.lastname: Schmidt
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wick
authors.forename: Juergen
authors.initials: J
authors.lastname: Forst
authors.forename: Hubert J
authors.initials: HJ
authors.lastname: Schmitt
mesh_terms: D000293:Adolescent; D000732:Androstanols / Q000008:administration & dosage / Q000494:pharmacology*; D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous; D019162:Anesthetics, Combined; D016022:Case-Control Studies; D002648:Child; D004305:Dose-Response Relationship, Drug; D005283:Fentanyl; D006801:Humans; D008297:Male; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology*; D009213:Myography; D019148:Neuromuscular Blockade; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000503:physiopathology; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage / Q000494:pharmacology*; D010880:Piperidines; D015742:Propofol; D000077208:Remifentanil; D000077123:Rocuronium; D013997:Time Factors
chemical_list: D000732:Androstanols; D019162:Anesthetics, Combined; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines; D000077208:Remifentanil; D005283:Fentanyl; D000077123:Rocuronium; D015742:Propofol