Topical amethocaine (Ametop™) is superior to EMLA for intravenous cannulation

Abstract

Purpose: A eutectic mixture of local anesthetics (EMLA) is commonly used to provide topical anesthesia for intravenous (iv) cannulation. One of its side effects is vasoconstriction, which may render cannulation more difficult. A gel formulation of amethocaine (Ametop") is now commercially available. The aim of this study was to compare EMLA and Ametop TM with regard to the degree of topical anesthesia afforded, the incidence of vasoconstriction and the ease of iv cannulation. Methods: Thirty two ASAI adult volunteers had a # 16 gauge iv cannula inserted on two separate occasions using EMLA and Ametop TM applied in a double blind fashion for topical anesthesia. Parameters that were recorded after each cannulation included visual analogue pain scores (VAPS), the presence of vasoconstriction and the ease of cannulation, graded as: I = easy, 2 = moderately difficult, 3 = difficult and 4 = failed. Results: The mean VAPS + SD after cannulation with Ametop'~ M was 12 + 9.9 and with EMLA was 25.3 -+ 16.6 (P = 0.002). Vasoconstriction occurred after EMLA application on 17 occasions and twice after Ametop TM (P = 0.001). The grade of difficulty of cannulation was 1.44 _+ 0.88 following EMLA and 1.06 _+ 0.25 with Ametop TM (P = 0.023). Conclusions: Intravenous cannulation was less painful following application of Ametof" than EMLA. In addition, Ametop TM caused less vasoconstriction and facilitated easier cannulation. Its use as a topical anesthetic agent is recommended, especially when iv access may be problematic.Objectif : Un m~lange eutectique d'anesth&iques Iocaux (MEAL) est souvent utilis6 pour I'anesth6sie topique Iors d'une canulation intraveineuse (iv). La vasoconstriction, qui est I'un des effets secondaires du MEAL, peut compliquer la mise en place d'une canule. Une pr&entation en gel d'am&hocaine (Ametop TM) est maintenant offerte dans le commerce. Le but de la pr&ente 6tude &ait de comparer le MEAL et I'Ametop TM en regard du degrE d'anesth&ie topique foumi, de rincidence de la vasoconstriction et de la facilitE de la canulation iv. M&hode : On a ins&E, en deux occasions s6par&s chez 32 volontaires adultes d'&at physique ASA I, une canule iv de calibre 16 en utilisant en double aveugle le MEAL et Ametop TM pour rEaliser ranesth6sie topique. Apr& chaque canulation, on a enregistr6 les param&res suivants : les scores de douleur ~ I'&helle visuelle analogue (EVA), la presence de vasoconstriction et la facilit6 de canulation notEe I = facile, 2 = mod&Ement difficile, 3 --di~cile et 4 = impossible. l~uJ.tats : Les scores moyens ~ I'E--VA + I'&art type ont ~t~ de 12 -9,9 ~ la suite de la canulation avec Ametop TM Met de 25,3 _+ 16,6 apr& le MEAL (P = 0,002). La vasoconstriction est survenue en 17 occasions apr& I'application du MEAL et deux fois plus souvent apr& Ametop TM (P --0,00 I). Le degr6 de difficult6 de canulation a 6t6 de 1,44 _+ 0,88 apr& le MEAL et de 1,06 +_ 0,25 apr& Ametop TM (P = 0,023). Conclusion : La canulation intraveineuse est moins douloureuse apr& I'application d'Ametop TM que celle du MEAL. D...

Topical Anesthetics for Dermal Instrumentation: A Systematic Review of Randomized, Controlled Trials

“…Speirs et al 21 found topical tetracaine to provide greater analgesia than EMLA, but the difference in visual analogue scale scores was not statistically significant. The remaining 3 trials 22,44,45 concluded that topical tetracaine provides significantly greater anesthesia than EMLA.…”

“…The study involved 100 adults undergoing radial artery puncture and found comparable efficacy between the 2 forms of anesthesia. Four other randomized, controlled trials compared either tetracaine 4% gel 21,44,45 or tetracaine 5% cream 22 with EMLA cream. The procedure in each trial was intravenous cannulation.…”

Comparison of Ice and Lidocaine- Prilocaine Cream Mixture in the Reduction of Pain During Peripheral Intravenous Cannulation in Emergency Department Patients

“…Damar yolu açma öncesi lokal ilaç uygulamanın dezavantajları ise yan etki ihtimali ve ek maliyettir. Lidokain+prilokain kremin önce vazokonstrüksiyon, uygulamanın 180. dakikası sonrası ise vazodilatasyona neden olduğu bilinmektedir (12)(13)(14)(15). Bu durum girişimin başarısızlıkla sonuçlanabileceğini düşündürmekle birlikte çalışmalarda iv kanülasyonu güçleştirdiği saptanmamıştır.…”

The use of topical anaesthesia during repair of minor lacerations in Departments of Emergency Medicine: A literature review

“…Browne et al (1999) compared the superiority of ametop in relation to EMLA for its use in intravenous cannulation. This study found that intravenous cannulation was less painful following the application of ametop in comparison to EMLA.…”