Comparison of Analgesic Effect of Local Anesthetic Injection for Pain Relief During Peripheral Venous Insertion in Adult Surgical Patients: A Prospective Observational Study.

Purpose: Intradermal injection of local anesthetic has been reported to have greater analgesic effect for peripheral venous catheter (PVC) insertion than topical application in adult surgical patients. However, the injection of local anesthetic itself is a painful procedure compared to topical application. We compared the analgesic effect of a lidocaine-prilocaine patch with intradermal injection of 2 % lidocaine on pain intensity at the time of analgesia and PVC insertion as assessed by a visual analog scale (VAS) in adult patients.

Design: A prospective observational study.

Methods: After institutional review board (IRB) approval, we studied 70 patients scheduled for surgery and expected to have peripheral venous cannulation in the operating room. Patients who presented in the operating room with a topical anesthetic patch were assigned to the patch group, and patients who presented without a topical anesthetic patch were assigned to the injection group. The injection group received a 2 % lidocaine injection with a 26-gauge (G) needle just before PVC insertion by anesthetists. The patch group received a lidocaine-prilocaine patch on the dorsal hand 1 to 2 hours before the scheduled surgery time by ward nurses. The primary endpoints were pain using the VAS score at the time of PVC insertion and pain associated with the local anesthetic procedure.

Findings: The patch group included 34 patients (21 male, 13 female, age 61 [median], interquartile range [IQR] 45 to 69), and the intradermal injection group included 31 patients (22 male, 9 female, age 60 [median], IQR 52 to 73). All patients analyzed had a 20-G catheter in the dorsal hand. The median VAS score for PVC insertion was 4 in the intradermal injection group (IQR 0 to 14) and 2 in the patch group (IQR 0 to 16) (P = .707). Median VAS scores for the local anesthetic procedure were 16 in the intradermal injection group (IQR 10 to 32) and 0 in the patch group (IQR 0 to 0) (P < .001).

Conclusions: We found no difference in the pain intensity for PVC insertion between topical application of local anesthetic by lidocaine-prilocaine patch and intradermal injection of 2 % lidocaine. VAS scores for anesthetic application were significantly lower in the patch group. The lidocaine-prilocaine patch provided analgesia equivalent to intradermal injection with 2 % lidocaine for PVC but without the pain associated with injection of local anesthetic.