Bicarbonate Addition to Lidocaine-Epinephrine in Surgery Under WALANT

Distal upper limb and distal lower limb surgery performed under local anesthesia using the WALANT technique (Wide Awake Local Anesthesia No Tourniquet) has become standard practice in ambulatory orthopedic surgery. Current infiltration mixtures used by orthopedic surgeons include lidocaine-epinephrine with the addition of 8.4% bicarbonate to reduce injection-related pain and improve analgesia duration. However, the clinical benefit of bicarbonate addition remains insufficiently supported by evidence and may increase preparation complexity and risk, including potential solution crystallization.

The aim of the ROPIWA-2 trial is to investigate whether omission of bicarbonate from the local infiltration mixture is noninferior to bicarbonate addition with respect to early postoperative quality of recovery on postoperative day 1. We hypothesize that removing bicarbonate does not impair postoperative quality of recovery after ambulatory hand and foot surgery under WALANT. Expected benefits include confirmation of a simpler, ready-to-use anesthetic solution that is easier and safer to use, without reducing patient comfort or recovery. The expected risks are those normally associated with this type of procedure.