Fig. 1

Mean ± standard deviation of plasma concentration (ng mL⁻¹) of ketamine (graph A) e fentanyl (graph B) obtained from fourteen dogs undergoing unilateral mastectomy treated for 8 h with ketamine (GK: bolus 0.5 mg kg⁻¹; CRI 20 µg kg⁻¹ min⁻¹ in intra- and postoperative periods), fentanyl (GF: bolus 5 µg kg⁻¹; intraoperative CRI 5 µg kg⁻¹ h⁻¹ and postoperative CRI 2 µg kg⁻¹ h⁻¹), or combination of ketamine-fentanyl (GKF: aforementioned doses) in intra- and postoperative periods