Lidocaine Reduces Pain and Anxiety From Peripheral IV Cannula Insertion

      Injected buffered lidocaine or lidocaine cream can reduce the pain and anxiety associated with intravenous cannula insertion, according to study findings reported in the August issue of the Annals of Emergency Medicine. Between the two, injected lidocaine is more effective in alleviating pain.         Many patients who present to the emergency department require placement of a peripheral IV line, which frequently causes pain and anxiety, Dr. Candace McNaughton, from Vanderbilt University, Nashville, Tennessee, and colleagues note.        Most IV placements in the ER are done without local anesthesia, the researchers point out. This may be due to "time constraints, difficulty with their application, perceived ineffectiveness, a belief that use of local anesthesia makes it more difficult to place IVs, or a belief by healthcare providers that the pain of IV insertion is insignificant."      Research has shown that both the pain and anxiety of IV insertion can be reduced by pretreatment with local anesthetics, but the best method was unclear. Anesthetic creams are often used to reduce pain during IV insertion. However, in a busy ER setting, their usefulness is limited due to their delayed onset of action, the authors note. By contrast, injected anesthetics have a more rapid onset, but require an additional needle stick.      In a randomized, crossover study, Dr. McNaughton's team compared pin and anxiety in 70 medical students or nurses who had IVs placed after pretreatment with injected buffered lidocaine, lidocaine cream, or no analgesia. A 10-point numeric rating scale was used to assess pain, anxiety, and treatment preference immediately following IV insertion.      The median pain scores with lidocaine cream and injected, buffered lidocaine were 3 and 1, respectively. Without analgesia, the pain was much worse with a median score of 7. Similarly, the median anxiety score with both lidocaine treatments was 2 compared with a score of 4 without analgesia. The pretreatment method had no bearing on the likelihood of success, the report indicates, and most of the IV placement attempts were successful.      When surveyed, 70% of the subjects indicated that they would always request injected, buffered lidocaine for themselves and for their patients undergoing IV insertion. Lidocaine cream was the preferred treatment for 26% of subjects and no analgesia for 4%. Ann Emerg Med. 2009;54:214-220. News Author: Anthony J. Brown, MD CME Author: Laurie Barclay, MD