In terms of pain relief, the ketamine-based regimen was not determined to be superior to the morphine-based regimen. Nevertheless, ketamine therapy was related to a considerable decrease in cumulative opioid dose.
Sickle cell disease (SCD) is an inherited hematologic illness in which deoxygenated hemoglobin polymerizes, causing red blood cells to assume a sickle-like shape. These abnormally shaped, stiff cells cause vaso-occlusion in the microcirculation, which leads to tissue ischemia. Moreover, red blood cell membrane destruction causes persistent hemolytic anemia.
This prospective, randomized, double-blind, parallel-group, pragmatic, controlled trial was published in Academic Emergency Medicine. A total of 278 patients with SCD who presented with acute sickle vaso-occlusive crisis were included and placed in ketamine and morphine groups. Participants were randomly assigned to receive a 30-minute infusion of a single dose of either ketamine or morphine.
The primary outcome was the mean difference in the numerical pain rating scale (NPRS) score over 2 hours. NPRS was monitored every 30 minutes for a maximum of 180 minutes. Cumulative dosage of opioids was a secondary outcome. The mean (±SD) NPRS scores over 2 hours were 5.7 (±2.13) and 5.6 (±1.90) in the ketamine and morphine groups, respectively.
The ketamine group received considerably lower cumulative doses of morphine than the morphine group during their ED stay (mean SD = 4.5 ± 4.6 mg vs. 8.5 ± 7.55 mg). Moreover, 6.3% of participants in the ketamine group and 2.2% of participants in the morphine group experienced adverse drug effects.
In this RCT, the ketamine-based regimen was not found to be superior to the morphine-based regimen in terms of pain reduction. However, ketamine therapy substantially reduced the cumulative opioid dose. Other outcomes, including adverse events and hemodynamic indicators, were not significantly different between the two groups. The NPRS score improved in both groups, indicating a clinically significant reduction in pain; however, the ketamine-based regimen was not superior to morphine alone.
This study concluded that early administration of ketamine to sickle cell disease patients experiencing vaso-occlusive crises was associated with a strong analgesic effect, reduced cumulative morphine dosages, and no notable safety issues. Future research should investigate the efficacy and safety of recurrent ketamine doses or continuous infusion for adults with sickle vaso-occlusive crisis and the effects of ketamine and opioids compared to opioids alone.
Reference:
Alshahrani, M. S., AlSulaibikh, A. H., ElTahan, M. R., AlFaraj, S. Z., Asonto, L. P., AlMulhim, A. A., . . . Alhazzani, W. (2022). Ketamine administration for acute painful sickle cell crisis: A randomized controlled trial. Academic Emergency Medicine, 29(2), 150-158. doi:10.1111/acem.14382
