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

• Published in: Pediatric anesthesia 2006-08, Vol.16 (8), p.840-845
• Main Authors: Muenster, Tino, Schmidt, Joachim, Wick, Stefanie, Forst, Juergen, Schmitt, Hubert J
• Format: Article
• Language: English
• Subjects: Adolescent; Androstanols - administration & dosage; Androstanols - pharmacology; Anesthesia Recovery Period; Anesthesia, Intravenous; Anesthetics, Combined; Case-Control Studies; Child; Dose-Response Relationship, Drug; Fentanyl; Humans; Male; Muscular Dystrophy, Duchenne - physiopathology; Myography; Neuromuscular Blockade; Neuromuscular Junction - drug effects; Neuromuscular Junction - physiopathology; Neuromuscular Nondepolarizing Agents - administration & dosage; Neuromuscular Nondepolarizing Agents - pharmacology; Piperidines; Propofol; Time Factors
• ISSN: 1155-5645

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. 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. 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). 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.