Background: It has been suggested that saline with benzyl alcohol preservative has anesthetic properties when injected intradermally. We compared the pain associated with intravenous line (i.v.) placement in patients who received intradermal lidocaine, intradermal saline + benzyl alcohol preservative, or no anesthesia.
Methods: We performed a prospective randomized clinical trial in a convenience sample of children over 6.8 years old seen in the emergency department of a large, urban children's hospital. Children received either intradermal saline with 0.9% benzyl alcohol preservative, intradermal lidocaine, or no anesthesia prior to i.v. placement. The patient recorded the pain of the entire procedure on a visual analog scale. In the two groups that received an intradermal injection, the patient also recorded the pain of the first and second injection on a similar scale.
Results: Ninety-nine children were studied, 33 in each group. Pain scores were not normally distributed. The median pain scores in millimeters for the entire procedure were 41.0 (interquartile range, 11 to 62) in the nonanesthetic group, 9.0 (interquartile range 3 to 37) in the saline with benzyl alcohol group, and 10.0 (interquartile range, 4 to 32) in the lidocaine group (P = 0.006 for saline vs nonanesthetic, P = 0.04 for lidocaine vs nonanesthetic, P = 0.57 for saline vs lidocaine). There was no difference between groups with regard to baseline anxiety, demographic characteristics, size of i.v. inserted, number of i.v. attempts, or pain upon intradermal injection.
Conclusion: Saline with benzyl alcohol and 1% lidocaine are equally effective as intradermal anesthetics for i.v. line placement in children, and are both more effective than no anesthesia.