Parenteral ketamine as an analgesic adjuvant for severe pain: development and retrospective audit of a protocol for a palliative care unit

Abstract

Background: Ketamine is an effective analgesic agent for treating a variety of neuropathic and cancer pain syndromes. Recent studies indicate that ketamine may have a particular role in the management of patients with neuropathic and/or pain syndromes that are poorly responsive to opioids.

Objective: To develop, implement, and subsequently assess a protocol designed to maximize the analgesic effect of ketamine while minimizing its side effects.

Design: A retrospective chart audit of 16 patients who had used the ketamine protocol over a 12-month period. Criteria for assessing the effectiveness of ketamine were defined.

Results: Ketamine was an effective, well-tolerated analgesic adjuvant for 11 of 16 patients with previously uncontrolled pain. Pain scores were reduced by at least 4 of 10 in 15 of the 16 patients. Median opioid dose reduction on starting ketamine was 25%.

Conclusion: The audit confirmed the safety and effectiveness of ketamine as an analgesic adjuvant for patients with severe pain. Baseline opioid dose reduction and prophylactic use of haloperidol or benzodiazepine were effective in minimizing psychotomimetic side effects.