The Effect of Intraoperative Dexmedetomidine-Ketamine Infusion on the Patients Undergoing Radical Mastectomy: Randomized Controlled Study

This prospective randomized controlled study will be carried out on 70 female patients who will be presented for radical mastectomy in the general surgery department in Tanta university hospitals over three month duration and 6 months follow up that starts immediately after obtaining ethical committee approval, an informed written consent will be obtained from all the participants, all patients data will be confidential and will be used for the current study only.

-Inclusion criteria: Female patients aged 50-70 years, ASA class I-III, and presented for elective radical mastectomy.

• Exclusion criteria: Patients refused to participate. Patients with known or suspected or known allergy to the used medication. Patients with preoperative chronic pain, Patients received preoperative opioids or gabapentoids. Patients with major cardiac, renal, respiratory, or hepatic disease. Uncooperative patients. Obese patients with BMI >36

Anesthetic technique Once the patients will arrive to the operating room, intravascular access will be established, fluid preload will be started, and basic monitor will be attached. An assistant anesthetist will help in preparation of a 50 ml syringe connected to a syringe pump that will contain normal saline or a mixture of 100 ug dexmedetomidine and 50 mg ketamine.

Anesthesia will be induced by fentanyl 1 ug/kg, propofol 1.5 mg/kg, and cis-atracurium 0.15 mg/kg to facilitate tracheal intubation. After endotracheal intubation, the patients will be connected to a mechanical ventilator with its parameters adjusted to maintain etCo2 32-36 mmHg. Anesthesia will be maintained by isoflurane 1% MAC in mixture of oxygen:air 1:1 with the use of low flow (1 ml/min). The patients will be randomly allocated into two equal groups by the aid of computer-generated software of randomization: -