Article Text
Abstract
Background Ketamine is a potential adjuvant analgesic in palliative care patients with refractory pain. Regional guidance from 2012 recommends a ‘burst’ regimen with rapidly escalating doses over 5 days via continuous subcutaneous infusion (CSCI).
Aim To identify current evidence for ketamine as an analgesic in palliative care in order to update regional guidance.
Methods A systematic review of the literature was performed in April 2021 using electronic searches of Medline, Embase, Cinahl and Cochrane. Studies were assessed against agreed criteria by at least two independent reviewers. In parallel a case-note audit of palliative patients treated with ketamine was completed across multiple settings between August – October 2021 examining current practice against the 2012 standards and guidance.
Results The case-note audit of 77 patients revealed 48.5% received burst ketamine, 27.9% oral ketamine and 23.5% lower-dose CSCI ketamine. In the literature review ten studies were accepted after full text review: two randomised controlled trials (RCT), seven observational studies and the 2017 Cochrane review ‘Ketamine as an adjuvant to opioids for cancer pain’. All included studies focused on cancer pain and were of mixed methods and quality with mixed results. A 2012 RCT of burst ketamine in 185 patients did not show any benefit over placebo and demonstrated an increased rate of adverse events. Concern over the possible lack of clinical benefit with potential for harm with a burst regimen was also highlighted in the 2017 Cochrane review.
Conclusions Burst regimens of ketamine are widely used in the region. Current evidence in this area is limited, but no longer supports recommending burst regimens with rapidly escalating doses. These findings have been presented regionally and will inform the update of the new guideline. This process highlights the regenerative potential of regional audit networks in helping to keep clinical practice up to date, evidence-based and consistent.