Efficacy and safety of digital nerve block for pain management during sharp debridement of digital ulcers in systemic sclerosis: A prospective observational study

Abstract

Introduction: Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis and vascular abnormalities, often leading to the development of digital ulcers (DUs). DUs are painful and debilitating, significantly impacting patients' quality of life. Effective pain management during debridement is crucial, yet there is no consensus on the optimal approach. This study evaluates the efficacy and safety of digital nerve block (DNB) using lidocaine and mepivacaine for pain control during sharp debridement of DUs in SSc patients.

Methods: This prospective observational study was conducted from September 2023 to May 2024 at the Rheumatology Operating Unit, University of Verona. Patients were randomized to receive either 1 mL of 2% lidocaine or 2% mepivacaine for DNB. Pain levels were assessed using a categorical grading scale during the injection and debridement. The outcomes were pain control and performance of lidocaine versus mepivacaine.

Results: The cohort developed 46 ulcers. The pain was abolished in almost all patients. Lidocaine achieved faster anaesthesia (127.92 ± 34.32 s) compared with mepivacaine (252.65 ± 49.89 s, p < 0.001). Mepivacaine resulted in less pain during injection (p = 0.006). No significant difference in pain levels during debridement was observed between the two anaesthetics. Three mild adverse effects (Raynaud's phenomenon) were reported. All procedures were completed successfully, and 35 ulcers healed with a mean time of 6.1 ± 7.77 weeks.

Conclusions: DNB with mepivacaine provides effective pain control during DU debridement in SSc patients, with lower injection site pain and comparable efficacy to lidocaine. The procedure is safe, well-tolerated and facilitates successful ulcer healing. Further studies with larger cohorts are warranted to confirm these findings.

Keywords: Systemic sclerosis; anaesthetic; debridement; digital nerve block; digital ulcer.

Figure 1.

(a) The normal nerve branches of the median nerve are depicted in their innervation of the palmar and, partially, the dorsal aspect of the finger. The digital nerves can be reliably localized by palpation of the anatomical landmarks, without the need for ultrasound guidance. The digital nerves, veins and arteries run together in a neurovascular bundle that splits at the level of the metacarpal joint, approximately 1 cm below the interdigital space. The operator palpates this point to localize the injection site, which corresponds to the theoretical position represented by the red dots (b). The operator injects 1 mL of either 2% lidocaine or 2% mepivacaine on each side of the metacarpal head, for a total of 2 mL per digit. This dosage equates to 20 mg of the local anaesthetic. The injections are performed on the palmar side to cover the entire digital innervation territory and ensure complete anaesthesia of the fingertip (c). Created in BioRender. Idolazzi, L. (2024) BioRender.com/n22t546