Eutectic Mixture of Local Anesthesia Cream Can Reduce Both the Radial Pain and Sympathetic Response During Transradial Coronary Angiography

Background and Objectives: Radial artery spasm is one of the most common complications of transradial coronary angiography (TRA): the radial artery is prone to cathecholamine-induced contraction and radial pain during TRA could increase the sympathetic tone. The object of this study was to evaluate whether the eutectic mixture of local anesthesia (EMLA) cream, in addition to lidocaine infiltration, could reduce the sympathetic response by reducing radial pain during TRA. Subjects and Methods: Seventy-six patients were randomized 1 : 1 to either EMLA or control groups. Radial pain was measured by the visual analogue scale (VAS) and the verbal rating scale (VRS-4). Sympathetic response, including systolic (SBP) and diastolic blood pressure (DBP), pulse rate (PR), stroke volume (SV) and total peripheral resistance (TPR), was measured by photoplethysmography. Results: Radial pain measured during lidocaine infiltration was significantly lower in the EMLA group (VAS: 3.1 vs. 4.0, p=0.04; VRS-4: 2.0 vs. 2.2, p=0.03) and the sympathetic response was significantly blunted in the EMLA group from baseline to lidocaine infiltration (${\Delta}SBP,\;mm\;Hg:\;5\;vs.\;13,\;p<0.01;\;{\Delta}DBP,\;mm\;Hg:\;2\;vs.\;7,\;p=0.03;\;{\Delta}PR,\;beat/min:\;2\;vs.\;8,\;p<0.01,\;{\Delta}SV,\;mL:\;3\;vs.\;21,\;p<0.01;\;{\Delta}TPR,\;mm\;Hg\;\cdot\;L/min$: 1.0 vs. 5.9, p<0.01). Conclusion: In patients undergoing TRA, the EMLA cream, in addition to lidocaine infiltration, effectively reduces the radial pain and thereby the sympathetic response, during lidocaine infiltration.