Comparison of four strategies to reduce the pain associated with intravenous administration of rocuronium

Background. I.V. rocuronium produces intense discomfort at thesite of injection in conscious patients. Four strategies toreduce or prevent this discomfort were studied. Methods. Two hundred and fifty adult patients, ASA I–III,were randomized into five groups of 50 patients in a blinded,prospective study. The control group received rocuronium 10 mgalone. For the remaining four groups, rocuronium 10 mgwas mixed with sodium bicarbonate 8.4% 2 ml, fentanyl 100 µg,lidocaine 2% or normal saline. The pH and osmolality of allmixtures were measured. Patient data were analysed using ordinallogistic regression. Osmolality and pH data were analysed usingthe Kruskal–Wallis test with Dunn’s multiple comparisontest. Results. When compared with rocuronium alone, only the additionof saline failed to significantly reduce the pain reported bypatients. The addition of fentanyl reduced the complaint ofpain by 1.9 times (P<0.049) and the addition of lidocaine2% reduced it by 3.6 times (P<0.0001). Sodium bicarbonate8.4% reduced the reporting of pain by 18.4 times (P<0.0001). Conclusions. Sodium bicarbonate 8.4%, when added to rocuronium,markedly reduces the experience of pain during the i.v. administrationof a small dose of rocuronium. Br J Anaesth 2003; 90: 377–9