EMLA Application Exceeding Two Hours Improves Pediatric Emergency Department Venipuncture Success

Abstract

The purpose of this study was to determine whether placing Eutectic Mixture of Local Anesthetics (EMLA) at emergency department (ED) triage improves venipuncture success. Emergency department triage nurses prospectively identified patients aged 0–18 years assessed to have 50% or greater chance of needing venipuncture while in the emergency department. Identified patients received EMLA or no intervention according to randomized 24-h blocks. Data were collected on need for venipuncture, venipuncture success (defined as obtaining access in one attempt), and duration and success of EMLA application (defined as EMLA occluded between 1 and 5 h). Parents' satisfaction and perception of pain were assessed with a 5-item scale. Consent was obtained from 267 out of 287 patients, in whom 111 of 154 venipunctures were successful (72%). EMLA (n = 100) and no-intervention (n = 167) groups did not differ by age or dehydration-related illnesses. Nurses flagged patients more often on days when EMLA was not applied (χ² = 37.8, df2, p < 0.0001), but with lower specificity of needing venipuncture (48.5% no-intervention venipuncture rate vs. 73% venipuncture rate with EMLA (χ² = 14.4, df2, p = 0.0001). Of the 73 EMLA patients undergoing venipuncture, 2 removed EMLA at unknown times; 2 had application duration longer than 5 h, and nurses chose non-EMLA venipuncture sites for 8. Punctures through EMLA sites with appropriate duration were successful in 51/61 (84%) versus 58/89 (65%) in untreated skin (p = 0.01, odds ratio (OR) = 2.8; 95% confidence interval (CI) [1.3, 6.2]). Success in intention-to-treat groups did not differ (OR = 1.8, 95% CI [0.87, 3.7]). Improved venipuncture success was seen linearly with increased application duration (p = 0.018). Parents perceived less pain with punctures through EMLA sites (p = 0.006). Venipuncture through an EMLA site reduced pain and improved success. Rates improved with increasing application duration. Barriers to triage EMLA placement should be evaluated. Application longer than 2 h should be studied further as a means to improve success. EMLA was supplied as a part of the Investigator-sponsored study program of AstraZeneca.