The Efficacy of Adding Dexmedetomidine Perineurally to Bupivacaine in Ultrasound Guided Fascia Iliaca Block Versus Intravenously Infused Dexmedetomidine on Hemodynamic Stability Intraoperatively and Postoperative Analgesia Following Hip Arthroscopy

This study is a randomized controlled trial at Ain Shams university hospital, Cairo, Egypt. The study will include 88 patients (44 patients) in each group planned for undergoing hip arthroscopy under general anesthesia, will be randomly assigned into one of the following two groups using computer generated codes and opaque sealed envelopes:

All patients will range from ASA I or II, planned for elective hip arthroscopy, aging from 18 to 65 years, body weight renge from 70- 80 Kg of both sexes.

Patients will receive 0.03 mg/kg intravenous (IV) midazolam as a preanesthetic medication, and 1 mg Granisetron as a postoperative nausea and vomiting (PONV) prophylaxis after application of routine monitoring (electrocardiogram, non-invasive blood pressure monitoring and oxygen saturation (SPO2)).

A standard anaesthetic technique will be followed. After preoxygenation for three minutes, anaesthesia will be induced with: propofol 2-3 mg/kg, fentanyl 1µg/kg. Atracuirium besilate 0.5 mg/kg will be used to provide muscle relaxation. All patients will be mechanically ventilated with a tidal volume of 8 ml/kg. 1-2 minimum alveolar concentration (MAC) of isoflurane mixed with oxygen (50%) and air (50%) will be used for maintenance of anesthesia.

GROUP A will receive Dexmedetomidine in dose of of 0.5μg/ kg/hour It elicits a biphasic blood pressure response: a short hypertensive phase followed by hypotension. It is expected that the decreased blood pressure and heart rate, will happen with ongoing therapy within 15 minutes, mediated by central α2A-AR, that decrease the release of noradrenaline from the sympathetic nervous system (10) And that is the reason we will start Dexmedetomidine infusion just after intubation.