rocuronium and Burns

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.. 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.. 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.. 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.

Topics: Adult; Aged; Androstanols; Burns; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Intubation, Intratracheal; Male; Middle Aged; Neuromuscular Blockade; Neuromuscular Junction; Neuromuscular Nondepolarizing Agents; Prospective Studies; Respiratory Insufficiency; Rocuronium; Time Factors; Young Adult

Rocuronium, which has a short onset time and is free of hyperkalemic effects, could be considered for rapid-sequence induction of anesthesia in patients with burns. In this study, we assessed the neuromuscular pharmacodynamics of rocuronium in patients with major burns. Adults aged 18-59 yr who had a major burn injury (n = 56) and a control group of 44 nonburned patients were included. Rocuronium was used at 3 times (0.9 mg/kg) or 4 times (1.2 mg/kg) the 95% effective dose. Anesthesia consisted of propofol and fentanyl with nitrous oxide and oxygen. Neuromuscular block was monitored with an acceleromyograph by using train-of-four stimulation. The onset time to 95% neuromuscular block was prolonged in burned compared with nonburned patients (115 +/- 58 s versus 68 +/- 16 s for 0.9 mg/kg; 86 +/- 20 s versus 57 +/- 11 s for 1.2 mg/kg). Dose escalation shortened the onset time, prolonged the duration of action, and improved intubating conditions in burned patients. All recovery profiles were significantly shorter in burned versus nonburned groups with both doses. Resistance to the neuromuscular effects of rocuronium was partially overcome by increasing the dose. A dose up to 1.2 mg/kg provides good tracheal intubating conditions after major burns.

Topics: Adolescent; Adult; Androstanols; Anesthesia Recovery Period; Anesthesia, General; Burns; Dose-Response Relationship, Drug; Female; Humans; Intubation, Intratracheal; Male; Middle Aged; Monitoring, Intraoperative; Neuromuscular Blockade; Neuromuscular Nondepolarizing Agents; Prospective Studies; Rocuronium