Comparison of two rocuronium bromide doses in adult and elderly patients who underwent laparoscopic surgery

Background The aim of our study was to evaluate the effects of two different doses of rocuronium bromide (0.5 mg/kg and 0.9 mg/kg) on the length of neuromuscular block, on the haemodynamic stability and on the side effects in patients of different ages. Methods We recruited 80 patients who underwent laparoscopic surgery (cholecystectomy, appendicectomy, varicocelectomy) belonging to ASA I–II classes and divided them into four groups: • 20 adults (A0.5) who received rocuronium bromide 0.5 mg/kg • 20 elderly patients (E0.5) who received rocuronium bromide 0.5 mg/kg • 20 adults (A0.9) who received rocuronium bromide 0.9 mg/kg • 20 elderly patients (E0.9) who received rocuronium bromide 0.9 mg/kg Intubation conditions, continuous monitoring of HR, NIBP, SpO2, EtCO2 were recorded. Onset time, REC 25%, TOF-ratio 0.70 were analysed by TOF-WATCH. Nerve-evoked muscle tension and neuromuscular paralysis extension were expressed by strength of contraction of adductor pollicis, in response to a direct stimulation of the ulnar nerve (TOF). Results The results showed that in elderly patients the effect of rocuronium bromide, at two different doses, was similar. Significant differences regarding the onset time was found among the groups showing that with the same dose of rocuronium bromide, the onset time was prolonged in elderly patients compared to adult patients. Moreover, increasing the dose, the onset time was reduced in both groups (p < 0.05). Forty per cent of adult group A0.5 showed excellent intubation conditions versus 60% of A0.9 (p < 0.05); elderly patients did not show any significant difference in the intubation procedure after different doses of rocuronium bromide. Conclusions The results from the four groups showed that in elderly patients 0.5 mg/kg of rocuronium bromide resulted in a good recovery, while 0.9 mg/kg increased the recovery time. Moreover, in adults the high dose was more effective because it reduced the number of injections and post-operative recovery time. Introduction Rocuronium, a derivative of vecuronium, is a non-depolarising myorelaxant. It has the fastest onset as compared to all nondepolarising neuromuscular blockers, with an intermediate duration of action and minimal haemodynamic effects and histamine release. There are several studies in the literature on rocuronium for fast and safe tracheal intubation (similar to succinylcholine). The action mechanism, metabolism and side effects for nondepolarising myorelaxants, like other drugs, occur not only for the properties of the molecule, but also for the characteristics of the patient. Therefore, it is important to consider anatomic and physiologic characteristics of the subject treated with the drug and all the changes due to age, sex and disease in order to better determine the right dose. Age is one of the most important factors. In fact, with ageing there is a reduction of two pharmacokinetic parameters: plasmatic clearance (Cp) and apparent distribution volume (Vd). Many previous studies have shown that anatomic and physiologic conditions of the elderly significantly influenced the pharmacodynamic of administered molecules. For this reason,