Comparison of 4 analgesic agents for venipuncture.

This study compared pain on application, pain on venipuncture, cost, and convenience of 4 analgesic agents used for venipuncture. A convenience sample of 280 preoperative subjects was assigned randomly to 1 of 4 groups. Group 1 received 2.5% lidocaine--2.5% prilocaine cream (LPC) topically, Group 2 received dichlorotetrafluoroethane spray (DCTF), Group 3 received 0.5% lidocaine subcutaneously, and group 4 received normal saline with 0.9% benzyl alcohol (BA) subcutaneously. A 7-point verbal descriptor scale measured pain on application, and a 100-mm visual analogue scale measured pain on venipuncture. Cost was measured and compared on unit-dose basis. Convenience was measured with a questionnaire survey completed by the investigators. There was no significant difference (P < .05) among the groups for age, sex, ASA physical status, or difficulty of venipuncture. There was a significant difference in pain on application for all 4 agents (P < .05). The DCTF had the highest pain on application score (1.7 +/- 0.1), while the LPC had no pain on application (0.0 +/- 0). Lidocaine had a higher pain on application score (1.08 +/- 0.1) than the BA (0.52 +/- 0.1) but a lower score than DCTF. Lidocaine (1.3 +/- 0.3) was significantly less painful (P < .05) on venipuncture than LPC (2.18 +/- 0.3) and DCTF (2.5 +/- 0.3) but was not significantly different than BA (1.92 +/- 0.3). (All scores are given as mean +/- SEM.) There was a significant difference in cost and convenience among the 4 agents, with BA and lidocaine being the least expensive analgesic agents. Lidocaine, DCTF, and BA were equally convenient to use, while LPC was the least convenient, (P < .05). Lidocaine had low pain on venipuncture and low cost and convenience of use, but it was less than ideal in terms of pain on application. The BA had all the qualities of an ideal analgesic agent for venipuncture in this sample and should be considered as an analgesic agent for venipuncture.