Comparative Study between Magnesium Sulfate and Lidocaine for Controlled Hypotension during Functional Endoscopic Sinus Surgery: A Randomized Controlled Study

BACKGROUND: Intraoperative bleeding impairs surgical field visibility during functional endoscopic sinus surgery (FESS); several methods have been used to decrease blood loss and improve surgical field, one of them is usage of hypotensive anesthetic agents. AIM: We intended to compare magnesium sulfate with lidocaine, regarding their efficiency in inducing controlled hypotension and providing a better surgical field exposure during FESS and the influence of their usage on extubation time. SETTINGS AND DESIGN: This study design was a prospective randomized controlled double-blinded clinical study. PATIENTS AND METHODS: Eighty adult patients with patients' physical status ASA Classes I and II, aged 20–50 years scheduled for FESS were randomly divided into two study groups; each group contains 40 patients: Group L received lidocaine 2 mg/kg/h with maximum of 200 mg/h starting at induction of anesthesia and continuing until the end of surgery and Group M received an iv bolus of magnesium sulfate 50mg/kg in a total of 100ml saline over 10 min followed by infusion of 15mg/kg/h until the end of surgery; patients were observed for the quality of the surgical field, blood loss, and extubation time. STATISTICAL ANALYSIS USED: Student's t-test or Mann–Whitney's U, Chi-square, or Fisher's exact tests were used. RESULTS: Group L showed a significant decrease in blood loss (P = 0.01), better surgical field clarity (P = 0.002), and shorter extubation time (P = 0.001) than Group M, but there was no statistically significant difference between the two study groups as regards hemodynamics. CONCLUSION: We concluded that both magnesium sulfate and lidocaine successfully induced controlled hypotension in patients undergoing FEES, but lidocaine provided better surgical field clarity and shorter extubation time.