Primary and secondary outcomes
postoperative cognitive dysfunction, postoperative delirium, postoperative cognitive dysfunction*OR, cognitive dysfunction, pain, Delirium
REGRESSION, SECONDARY
The incidence of postoperative delirium was lower (p = 0.001) in the dexmedetomidine group compared to the ketamine and placebo groups. Delirium occurred in one patient (5%) in the dexmedetomidine group, two patients (10%) in the ketamine group, and 15 patients (75%) in the placebo group (Table 
Primary and secondary outcomes
Multivariable logistic regression analysis of the independent predictors of postoperative deliriumOR = Odds Ratio; CI, Confidence IntervalThe incidence of postoperative cognitive dysfunction was lower (p = 0.006) in the dexmedetomidine group compared to the ketamine and placebo groups. No patients reported cognitive dysfunction in the dexmedetomidine group compared to two patients (10%) in the ketamine group and seven patients (35%) in the placebo group (Table 
Multivariable logistic regression analysis of the independent predictors of postoperative cognitive dysfunction*OR = Odds Ratio; CI, Confidence IntervalPostoperative pain scores were lower in the ketamine group (0.00 ± 0.0, 0.00 ± 0.0) at 30 and 60 min after surgery compared to the placebo (1.1 ± 0.2, p < 0.001; 2.3 ± 0.1, p < 0.001) and dexmedetomidine (0.7 ± 0.2, p = 0.001; 1.8 ± 0.2, p < 0.001) groups. However, the dexmedetomidine group had lower VAS scores (1.30 ± 0.2; 1.75 ± 0.1) than the placebo group (2.20 ± 0.1, p < 0.001; 2.30 ± 0.2, p = 0.022) at 60 min and 4 h after surgery (Fig. 
VAS score differences among the studied groups over timeThe length of hospital stay was shorter in the placebo group than in the dexmedetomidine (p = 0.034) and ketamine (p = 0.016) groups. In contrast, there was no significant difference in the length of hospital stay between the ketamine and dexmedetomidine groups (p = 0.757) (Table 