Onset and effectiveness of rocuronium for rapid onset of paralysis in patients with major burns: priming or large bolus.
BACKGROUND
Burn injury leads to resistance to the effects of non-depolarizing muscle relaxants. We tested the hypothesis that a larger bolus dose is as effective as priming for rapid onset of paralysis after burns.


METHODS
Ninety adults, aged 18-59 yr with 40 (2)% [mean (SE)] burn and 30 (2) days after injury, received rocuronium as a priming dose followed by bolus (0.06+0.94 mg kg(-1)), or single bolus of either 1.0 or 1.5 mg kg(-1). Sixty-one non-burned, receiving 1.0 mg kg(-1) as a primed (0.06+0.94 mg kg(-1)) or full bolus dose, served as controls. Acceleromyography measured the onset times.


RESULTS
Priming when compared with 1.0 mg kg(-1) bolus in burned patients shortened the time to first appearance of twitch depression (30 vs 45 s, P<0.05) and time to maximum twitch inhibition (135 vs 210 s, P<0.05). The onset times between priming and higher bolus dose (1.5 mg kg(-1)) were not different (30 vs 30 s for first twitch depression and 135 vs 135 s for maximal depression, respectively). The onset times in controls, however, were significantly (P<0.05) faster than burns both for priming and for full bolus (15 and 15 s, respectively, for first twitch depression and 75 and 75 s for maximal depression). Priming caused respiratory distress in 10% of patients in both groups. Intubating conditions in burns were significantly better with 1.5 mg kg(-1) than with priming or full 1.0 mg kg(-1) bolus.


CONCLUSIONS
A dose of 1.5 mg kg(-1) not only produces an initial onset of paralysis as early as 30 s, which we speculate could be a reasonable onset time for relief of laryngospasm, but also has an onset as fast as priming with superior intubating conditions and no respiratory side-effects.
Han
T-H
TH
The Department of Anesthesia, 5937 JPP, Roy J. and Lucille A. Carver College of Medicine, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242, USA. anthony-han@uiowa.edu
Martyn
J A J
JA
D000328:Adult; D000368:Aged; D000732:Androstanols / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D002056:Burns / Q000503:physiopathology* / Q000601:surgery; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade / Q000009:adverse effects; D009469:Neuromuscular Junction / Q000187:drug effects / Q000503:physiopathology; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000139:chemically induced; D000077123:Rocuronium; D013997:Time Factors; D055815:Young Adult
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium