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Effect of Intravenous Low-dose S-ketamine on Pain in Patients with Complex Regional Pain Syndrome: A Retrospective Cohort Study

Overview
Journal Pain Pract
Specialties Neurology
Psychiatry
Date 2021 Jul 7
PMID 34233070
Citations 5
Authors
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Abstract

Objective: The objective of this study was to assess the effectiveness of a low-dose intravenous S-ketamine treatment on refractory pain in patients with Complex Regional Pain Syndrome (CRPS).

Methods: In this retrospective study, patients with CRPS who received intravenous S-ketamine from March 2010 to April 2019 were included. According to our inpatient protocol, S-ketamine dose was increased until pain reduction was achieved or side effects were observed. Maximum dose was 14 mg/h and treatment duration was 7 days. Primary outcome parameters were pain scores (Numeric Rating Scale) at baseline (T0), end of infusion (T1), and approximately 4 weeks postinfusion (T2). Patients were categorized as responder/nonresponder at T1 and T2. Patients were considered a responder in case there was pain score reduction of greater than or equal to 2 points or if treatment was reported as successful.

Results: Forty-eight patients were included. Mean disease duration was 5 years (interquartile range [IQR] = 6 years). Median pain score significantly decreased from 8 (IQR = 2) at T0 to 6 (IQR = 4) at T1 (p < 0.001). At T1, 62% of the patients were responders. At T2, 48% of the patients remained a responder. A significant proportion of the responders at T1 turned into nonresponders at T2 (p = 0.03).

Conclusion: In a group of patients with CRPS with refractory pain, low-dose intravenous S-ketamine treatment resulted in effective pain relief during infusion. Although a significant proportion of initial responders became nonresponders at follow-up, half of the patients were still a responder at ~ 4 weeks postinfusion. Further research is needed to investigate mechanisms responsible for pain relief by S-ketamine infusions and to ascertain possible predictors of response to the treatment.

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References
1.
De Kock M, Loix S, Lavandhomme P . Ketamine and peripheral inflammation. CNS Neurosci Ther. 2013; 19(6):403-10. PMC: 6493703. DOI: 10.1111/cns.12104. View

2.
Perez R, Zollinger P, Dijkstra P, Thomassen-Hilgersom I, Zuurmond W, Rosenbrand K . Evidence based guidelines for complex regional pain syndrome type 1. BMC Neurol. 2010; 10:20. PMC: 2861029. DOI: 10.1186/1471-2377-10-20. View

3.
Harden R, Bruehl S, Stanton-Hicks M, Wilson P . Proposed new diagnostic criteria for complex regional pain syndrome. Pain Med. 2007; 8(4):326-31. DOI: 10.1111/j.1526-4637.2006.00169.x. View

4.
Woolf C, Decosterd I . Implications of recent advances in the understanding of pain pathophysiology for the assessment of pain in patients. Pain. 1999; Suppl 6:S141-S147. DOI: 10.1016/S0304-3959(99)00148-7. View

5.
Bartel D . MicroRNAs: target recognition and regulatory functions. Cell. 2009; 136(2):215-33. PMC: 3794896. DOI: 10.1016/j.cell.2009.01.002. View