Salas, S., Frasca, M., Planchet-Barraud, B., Burucoa, B., Pascal, M., Lapiana, J.M., … Baumstarck, K. (2012). Ketamine analgesic effect by continuous intravenous infusion in refractory cancer pain: Considerations about the clinical research in palliative care. Journal of Palliative Medicine, 15(3), 287–293.

DOI Link

Study Purpose

To assess the efficacy of continuous IV infusion of ketamine in patients suffering from opiate-refractory cancer pain admitted to palliative care units

Intervention Characteristics/Basic Study Process

Patients were computer randomized to either IV morphine plus ketamine or morphine plus placebo. Morphine could be titrated by 50% once daily. Evaluations were performed at baseline, 2 hours, 24 hours, and 48 hours after initiation of infusion. Ketamine was given at continuous infusion of 0.5mg/kg per day and increased to 1mg/kg per day if pain score did not improve after 24 hours.

Sample Characteristics

  • The sample consisted of 20 patients (11 experimental and 9 control) with a mean age of 60.3 years.
  • The sample was 70% male and 30% female.
  • Key disease characteristics were  not included.

Setting

This was a multisite study conducted in France.

Phase of Care and Clinical Applications

  • Patients were in the end-of-life phase of care.
  • The study has clinical applicability to end of life and palliative care.

Study Design

This was a randomized, double blind, placebo-controlled study.

Measurement Instruments/Methods

  • Pain was rated using a Numeric Pain Intensity Scale from 0–10.
  • The Edmonton Symptom Assessment Scale and Patient Treatment Satisfaction Scale were used.
  • Daily morphine dose was recorded.
  • The Epworth Sleepiness Scale (ESS) was used to record daytime sleepiness.

Results

Pain did not significantly differ between the two groups. No significant differences were found in morphine changes, ESS scores, or satisfaction scores between the two groups.

Conclusions

The combination of morphine and ketamine did not improve pain or decrease opioid requirements.

Limitations

  • The sample size was small, with fewer than 30 patients.
  • Ketamine doses were not titrated, and only one dose was trialed. A dose finding trial is needed.

Nursing Implications

Although ketamine did not improve pain scores in patients with opiate refractory pain, further studies are needed because of study limitations.