Background: Infusions with lidocaine or ketamine have been separately established in the treatment of chronic pain. This study aims to retrospectively evaluate the effect of combined infusions of lidocaine and ketamine. Materials & methods: Patient records were screened for receipt of combined ambulatory infusions of lidocaine and ketamine from 2012 through 2021. A scoring system was designed to assess pain response retrospectively. Results: A total of 319 patients were included. Median pain reduction in days was 10.00 (interquartile range: 13.25). Side effects were limited to the acute phase of infusions. A total of 41.4% of patients who received concomitant pain medication reported a dose reduction. Conclusion: Our data support combined infusions as a safe therapy option, with good short-, medium- and long-term reductions in pain and great heterogeneity in treatment response. Clinical trial registration: ClinicalTrials.gov (NCT05103319).
Keywords: chronic pain; infusion therapy; ketamine; lidocaine; pain reduction.
What is this study about? This study examined data of patients with chronic pain who received an infusion at our hospital with two drugs, lidocaine and ketamine, in an effort to reduce pain. We examined the records of 319 patients and a total of 2995 infusion protocols to gather our data. We wanted to know how much and for how long pain was reduced by these infusions. Additionally, we tried to identify the specific features of patients who profited the most during our infusions. We also had a look at the side effects of the infusions and wanted to know if patients could reduce their daily pain medication intake when receiving infusions. What were the results? On average, people had less pain for 10 days after the infusions. Women seemed to benefit more than men. Otherwise, we were unable to identify specific features that predicted how much a patient would benefit. Side effects occurred only during the infusions and for a short period afterward. In addition, 41.4% of patients who took pain medication daily were able to reduce their intake. What do the results mean? These results support our clinical experience that infusions with lidocaine and ketamine are safe and can contribute to reduced pain in patients with chronic pain, at least in the short term, and for some patients even longer.