Figure 2. Changes in peripheral oxygen saturation (SpO₂). Data are shown as mean DA: dexmedetomidine- alfentanil, KA: ketamine-alfentanil. T0: baseline, T1, T5, and T15: 1, 5 and 15 min after drug infusion in both groups, T recov: at the recovery ward, T2h, and T6h: 2 and 6 hours after infusion.