Intravenous lidocaine suppresses dexamethasone-induced perineal pruritus during anesthesia induction: a randomized...

Previous studies have found that intravenous dexamethasone may produce perineal pruritus in some patients when administered as premedicant in the preoperative period. This randomized controlled, double-blind study evaluated the efficacy of pretreatment of lidocaine on the incidence and severity of dexamethasone-induced perineal pruritus. 400 patients were enrolled in this study and allocated randomly into four groups (n=100, in each). Then, patients received intravenously anesthesia induction as the following sequence of medications: injecting 0.9% sodium chloride (placebo) 10 mL in group I, lidocaine 0.5mg/kg in group II, lidocaine 1mg/kg in group III, and lidocaine 1.5mg/kg in group IV, 1 minute later, injecting 10mg dexamethasone in all groups. The severity of perineal pruritus was graded based on the VAS as none (VAS 0), mild (VAS 1-3), moderate (4-6), or severe (VAS 7 to 10), and recorded the occurrence, the severity and the duration of perineal pruritus. Occurrence of perineal pruritus was significantly reduced in group III and group IV (8%, 9% vs 40% and 33% in Groups I and II, respectively, p<0.05). The incidence of perineal pruritus of females was higher than males in groups I and II (P<0.05). The duration of perineal pruritus was shorter in group IV compared to groups I, II and III (p<0.05). We conclude that pretreatment 1mg/kg or 1.5mg/kg lidocaine may effectively reduce the incidence of perineal pruritus.