Pain Relief Durations of Different Concentrations of Lidocaine in Wide Awake Hand Surgery: A Prospective Randomised Clinical Trial.

Objective: This study aims to determine the minimal concentration of lidocaine to provide adequate analgesia in wide awake local anaesthesia no tourniquet (WALANT) hand surgeries comparing 3 dilutions of tumescent lidocaine with epinephrine solution.

Study Design: A randomised control trial. Place and Duration of the Study: The study was held at the Plastic Surgery Department of Mayo Hospital, Lahore, from September 2020 to March 2021.

Methodology: Inclusion criteria were post-traumatic hand contractures and tendon and nerve injuries. The patients were randomised to 3 groups of 30 each: Group A (0.1% lidocaine), Group B (0.2% lidocaine), and Group C (0.3% lidocaine). The dilution of adrenaline also remained constant at 1:200,000. Pain was measured using the Visual Analogue Scale. The three groups were compared for demographics and the total duration of analgesia in minutes.

Results: All groups showed adequate pain relief during surgery with no cases requiring conversion to general anaesthesia. The highest total duration of analgesia was seen in the 0.3% group (805.3±195.2 minutes), followed by the 0.2% group (500.4±87.2 minutes) and 0.1% group (381.3±31.6 minutes) (p<0.05). No patient developed any signs of lidocaine toxicity. A low Lidocaine concentration of 0.1% was effective in providing analgesia during surgery though increasing the lidocaine concentration to 0.3% would result in greater post-operative analgesic time without increasing toxicity.

Conclusion: Adequate analgesia was recorded with all 3 lidocaine concentrations. The greatest pain-free duration was however observed in the  0.3% lidocaine group.

Key Words: Wide awake local anaesthesia no tourniquet (WALANT), Lidocaine concentrations, Hand surgery, Analgesia, Adverse effects.