Scientific Poster Session III: Resident and Fellows Research-in-Progress

Abstract

Research Question or Hypothesis: For patients treated for refractory pain with oral ketamine, what is the impact of escalating doses on pain scores?

Study Design: Retrospective chart review

Methods: This is a retrospective study reviewing the medications records of patients from July 1, 2018, through June 20, 2022. Patients were included if prescribed ketamine in addition to scheduled opioids, able to communicate pain scores, and not pregnant. Patients were stratified into five groups. Group 1 prior to ketamine initiation, group 2 total daily ketamine dose < 50 mg/day, group 3 total daily ketamine dose 50 mg – 99 mg, group 4 total daily ketamine dose 100 mg – 149 mg, and group 5 total daily ketamine dose = 150 mg. Primary outcome of interest is changes in daily mean pain scores with escalating doses of ketamine. Secondary outcomes are comparing pain scores between each ketamine grouping, morphine milliequivalent (MME) daily changes, and safety outcomes.

Results: 30 of the 46 screened were included. The mean age was 53 years old, 53% were male, and admission from cancer pain (90%) with an average ketamine usage of 5 days. Patients in Groups 2 (16%),3(20%),4(14%) and 5(20%) had clinically relevant changes to pain scores (=2). Quantitative MME changes occurred in Group 2 (-3427), Group 3 (-1551), Group 4 (+246) and Group 5 (+77). Safety events occurred in 13% of patients with 4 patients reporting psychiatric adverse events and 1 experienced movement disorder.

Conclusion: Overall ketamine was well tolerated and can be used to reduce opioid utilization in patients with acute pain. Doses >100mg/day was not as beneficial to patients numerically than doses <100mg.

Presenting Author

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