No abstract

Results: During enrollment, one subject was observed to have a severe dysphoric reaction and the study was temporarily suspended. An interim analysis was performed to identify serious complications. For the ketamine group, none were deemed "very concerning" but four patient reactions were considered "mildly concerning." Seventeen patients were randomized, but one received an unblinded dose of ketamine with seven patients receiving ketamine and ten receiving placebo. The mean pain score at 0 minutes did not differ between placebo and ketamine [7.3 versus 6.9; mean difference: 0.4 (95% CI: -1.7, 2.5)], but it differed significantly at 30 minutes [7.7 versus 3.7; mean difference: -3.9 (95% CI: -6.4, -1.5)]. As expected, this difference decreased at 60 minutes [6.8 versus 4.9; mean difference: -1.9, 0.3)]. Total morphine did not differ between placebo and ketamine [9.0 versus 10.3 mg; mean difference: 1.3 (95% CI: -4.5, 7.1)].Conclusion: Preliminary analysis suggests a clinically significant decrease in pain score at 30 minutes for those patients who received ketamine in combination with morphine as compared to morphine alone. As ketamine was metabolized, the substantial improvement in pain score was somewhat diminished at 60 minutes. Despite the lower pain scores, there was no appreciable difference between groups in the amount of morphine they received. Although none of the side effects of ketamine were considered "very concerning," four of the seven subjects who received ketamine had a "mildly concerning" yet significant adverse effect.