A single infusion of intravenous ketamine improves pain relief in patients with critical limb ischaemia: results of a double blind randomised controlled trial.
We report the first double blind randomised controlled trial of regular opioids and an infusion of low dose (0.6 mg/kg) intravenous ketamine compared with opioids and placebo in patients with allodynia, hyperalgesia and hyperpathia secondary to critical limb ischaemia. Thirty-five patients completed the study, 18 received regular opioids plus ketamine, while 17 received regular opioids plus placebo. Using the Brief Pain Inventory, the % pain relief that the patients in the ketamine group attributed to their medication improved significantly from 50% immediately pre-infusion to 65% 24 h post-infusion and 69% 5 days post infusion. Over the same period, the pain relief achieved by the placebo group rose from 58% pre-infusion to 56% 24 h post infusion and then 50% relief 5 days later. This was statistically significant (P<0.05) using both the t-test and the Wilcoxon Rank Sum test. The ketamine group also showed a statistically significant difference 24 h post infusion of the effect of pain on their general activity (P=0.03) and on their enjoyment of life (P=0.004). This study shows that combining a single infusion of low dose ketamine with regular opioid analgesia can result in a significant improvement in pain relief for this patient group.
Mitchell
Alison C
AC
Department of Palliative Medicine, Beatson Oncology Centre, Western Infirmary, Glasgow, Scotland G11 6NT, UK The Edinburgh Cancer Centre, Western General Hospital, Edinburgh, UK.
Fallon
Marie T
MT
D000368:Aged; D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000008:administration & dosage; D001007:Anxiety / Q000188:drug therapy; D003863:Depression / Q000188:drug therapy; D004311:Double-Blind Method; D005121:Extremities; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007511:Ischemia / Q000150:complications*; D007649:Ketamine / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome
D000700:Analgesics; D000701:Analgesics, Opioid; D007649:Ketamine