A rapid positive influence of S-ketamine on the anxiety of patients in palliative care: a retrospective pilot study

• DOI: 10.1186/s12904-019-0499-1
• Publication Date: 2020-01-03T15:03:16Z
• Authors: Eduard Falk; Daniel Schlieper; Patrick van Caster; Matthias J. Lutte...; Jacqueline Schwartz; Joachim Cordes; Ina Grau; Peter Kienbaum; Martin Neukirchen
• Keywords: Adult; Male; Analysis of Variance; Depression; Esketamine; Palliative Care; RC952-1245; Pilot Projects; Psychological distress; Anxiety; Middle Aged; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Special situations and conditions; Anti-Anxiety Agents; Humans; Female; Ketamine; S-ketamine; Research Article; Aged; Retrospective Studies

Abstract Background Patients in palliative care need rapid-acting pharmacological options for psychological distress. N-methyl-D-aspartate antagonist ketamine is known to have a fast onset of anti-depressant and anxiolytic action. Its S-enantiomer S-ketamine (or esketamine) is an analgesic used as a routine treatment for refractory pain as an intravenous infusion (0.25 mg/kg over 45 min). This study investigates whether S-ketamine pain therapy has a positive impact on psychological distress caused by anxiety and depression in palliative care.

Methods Patient routine data from a palliative care unit of a tertiary care hospital were used in a retrospective analysis after positive ethics approval. Eight patients, who received analgesic S-ketamine treatment, were compared to a control group matched by gender and age. The main analysis was conducted using three-way mixed MANOVA followed by two-way mixed ANOVA. Target variables were the values for anxiety and depression in the state-trait anxiety-depression inventory STADI. The predictor variables were the time of measurement before (T1) and after (T2) S-ketamine application and group membership.

Results Comparison of the S-ketamine group (n = 8; 4 male, 4 female; average age 52 years) with the control group (n = 8; 3 male, 5 female; average age 55 years) revealed a significant multivariate effect on anxiety and depression F(1, 14) = 4.78; p = 0.046; r = 0.50. The univariate comparisons showed a significant reduction of the anxiety scores from T1 to T2 in the S-ketamine group compared to the control group F(1, 14) = 10.14; p = 0.007; r = 0.65. With regard to depression, there was no significant reduction from T1 to T2 in the group comparison F(1, 14) = 1.60; p = 0.23; r = 0.32. No long-lasting effects on pain were found.

Conclusions Our findings show that psychological distress of patients in palliative care may improve after a single administration of S-ketamine, which mainly alleviates anxiety in those patients. Limitations of this study arise from non-randomization, retrospective analysis and low sample size. Therefore, further prospective and ideally randomized studies are necessary.