Enhanced recovery after ear, nose and throat surgery is based on multimodal and multidisciplinary perioperative interventions to decrease postoperative pain. Functional endoscopic sinus surgery is a surgical management for chronic rhinosinusitis. Although a common procedure, there is a lack of knowledge about perioperative pain and specific pain management after such a procedure. Most of recommendations given in guidelines for postoperative pain management in nasal surgery and sinus surgery are subsumed under head and neck surgery. Head and neck surgery is a wide field covering widely variable surgical procedures. So, postoperative pain management guidelines may not meet the requirements for pain management during and after endoscopic sinus surgery.

Various medications have been used to improve the surgical field and postoperative pain including intravenous clonidine, dexmedetomidine, lidocaine, and magnesium.

Lidocaine has been used considering its analgesic, immuno-modulating, and anti-inflammatory properties. The opioid sparing effect of lidocaine is supported by a high level of evidence. The effectiveness of lidocaine infusion in obtaining reduction of postoperative pain, gastrointestinal recovery time, postoperative nausea and vomiting, and shortening the hospital length of stay, was demonstrated principally in major gastro-intestinal surgery.

Magnesium sulfate is a good option in multimodal analgesia, as it stabilizes the cell membrane and intracytoplasmic organelles by mediating the activation of Na+-K+ ATPase and Ca++ ATPase enzymes, which have an important role in transmembrane ion exchange during the depolarization and repolarization phases. Moreover, magnesium inhibits the release of norepinephrine by blocking the N-type Ca++ channels at nerve endings.

Many studies were designed to prove the role of the analgesic effect of lidocaine and magnesium infusion. However, this is the first randomized controlled study to assess the effect of lidocaine infusion versus magnesium sulphate infusion on decreasing total fentanyl requirements in patients undergoing functional endoscopic sinus surgery.

This randomized controlled trial was designed to compare the efficacy of lidocaine hydrochloride infusion versus magnesium sulphate infusion in controlling perioperative pain in patients undergoing functional endoscopic sinus surgery.

Inclusion Criteria:

• Age from 21 to 60 years.
• Both genders.
• American society of Anesthesiologist (ASA) physical status I-II
• Scheduled for functional endoscopic sinus surgery under general anesthesia.

Exclusion Criteria:

• Patients with prolonged QT interval.
• Patients with renal disease.
• Patients with a history of allergy to lidocaine or magnesium sulfate.
• American Society of Anesthesiologists class higher than II.
• Patient refusal