Abstract

Introduction: Refractory chronic pain remains a major challenge in clinical practice. At the Erasme Pain Clinic, intravenous ketamine infusions, alone or combined with an adjuvant analgesic, are proposed in selected complex cases. The primary objective of this retrospective study was to describe the patient management procedure between 2010 and 2024.

Methods: We retrospectively reviewed the records of 89 adult patients. Collected data included demographic characteristics, pre- and post-cycle pharmacotherapy, infusion composition, trajectories of clinical scores (Visual Analogue Scale [VAS], DN4), and reported adverse effects. Results are presented descriptively.

Results: The cohort comprised 74% women, with a mean age of 50 years. The median interval between the first consultation and the first infusion was 92 weeks. Overall, 75% of patients continued treatment, and 70% reported improvement rated as moderate to very good. The most frequent adverse effects were fatigue (33%), nausea (13%), dizziness (19%), and pain exacerbation (18%). Resting pain intensity (VAS) decreased from a median of 7 to 6 after the cycle (p < 0.001). The median number of concomitant medications decreased from 4 to 3 (p = 0.013).

Conclusion: This study underscores substantial heterogeneity in practices and in patient profiles treated with intravenous ketamine infusions, with or without lidocaine. Despite encouraging trends, the findings should be interpreted cautiously. A standardised protocol and prospective follow-up are warranted to optimise this management.