A Double-Blind Randomized Controlled Trial Showing the Analgesic and Anesthetic Properties of Lidocaine E to Be Equivalent to Those of Ropivicaine and Bupivacaine in Carpal Tunnel Release Surgery

Abstract

In a three-phase trial, the anesthetic properties of lidocaine, bupivacaine and ropivicaine were compared in carpal tunnel release surgery. In phase I, two groups of 25 sequential patients were injected with either lidocaine plain 2% or lidocaine 2% with adrenaline 1:100,000 (E), as the local anesthetic for outpatient carpal tunnel release surgery. Subjective injection pain, postoperative pain at 2 h increments and the number of analgesic pills taken were recorded. During the first postoperative hours, outcome measures were superior in the lidocaine E group. In phase II, a double-blind randomized design compared 42 patients injected with either lidocaine E or a combination of lidocaine E and bupivacaine. Postoperative pain scores and analgesic pills taken were compared using nonparametric statistical tests. During the first 4 h there was a slight benefit in the duration of the anesthetic and fewer pain pills were used in the bupivacaine group. Phase III was a randomized double-blind comparison of ropivicaine and lidocaine E 2% in 72 patients. There was a slight decrease in pain scores and fewer analgesic pills required during the first 6 h in the ropivicaine group. Lidocaine plain 2% provided significantly inferior analgesic and anesthetic properties compared with lidocaine E 2%, bupivacaine or ropivicaine. Sequential randomized comparisons between lidocaine E and bupivacaine and ropivicaine showed clinical equivalence. The present study showed lidocaine E 2% to be a satisfactory and comparatively cost-effective anesthetic for outpatient carpal tunnel surgery.