Comparative Evaluation of Volatile Anaesthetic Agents for Attenuation of Venous Cannulation Pain: A Prospective, Randomized Controlled Study.

Abstract

Topical application of volatile anaesthetic agents has been found to attenuate the response to a mechanical stimulus; however, this effect of volatile anaesthetic on perception of pain during venous cannulation is not known. To compare the efficacy of topically administered volatile anaesthetic agents for attenuating venous cannulation pain. This prospective, randomized, placebo controlled and double blind study was conducted on 120 patients, aged 20-60years. They were of American Society of Anaesthesiologists (ASA) I or II physical status, of either sex, planned for elective surgeries. These patients were randomized into 4 groups, of 30 each. Equipotent doses of halothane (1ml), isoflurane (1.5ml), sevoflurane (2.7ml) and sterile water (2.5ml; Control) were topically administered on the volar surface of forearm wrapped with cotton and aluminium foil; venous cannulation was performed with 18G intravenous cannula after 30 min. These patients were assessed for the incidence and severity of pain upon venous cannulation {visual analog scale (VAS), 0-100mm; 0 = no pain and 100 = worst imaginable pain}. Data were analysed by one-way ANOVA, Chi-square test and Kruskal-Wallis test. The p<0.05 was considered as significant. A significant reduction in the incidence of venous cannulation pain was observed in the halothane (79%) group as compared to control (100%; p<0.05), isoflurane (100%; p<0.05) and sevoflurane (100%; p<0.05) groups. The severity of venous cannulation pain as assessed by median (interquartile range, Q1-Q3). VAS scores was reduced in the halothane {10 (10-20); p<0.001}, isoflurane {20 (10-30); p<0.001} and sevoflurane {20 (20-30); p<0.001} groups as compared to the control group {40 (30-40)}; VAS score in the halothane group was significantly less as compared to isoflurane (p<0.05) and sevoflurane (p<0.05) groups. Topical application of halothane is most effective in reducing incidence and severity of venous cannulation pain; however, topical application of isoflurane and sevoflurane decreases only the severity of venous cannulation pain.