A Randomized, Controlled Research Comparing between Lidocaine and Magnesium Sulfate for Induced Hypotension during Middle Ear Surgery

Abstract

Background: Controlled hypotension is a strategy to minimize blood loss and improving operative field visibility. The aim of the study is to see the effectiveness and safety of lidocaine and magnesium as hypotensive drugs during middle ear surgery. Patients and methods: This study was conducted on 75 participants, ASA I or II planned for middle ear operation, participants were divided randomly into 3 groups. Lidocaine group (group L) received bolus of 1 mg/kg IV lidocaine then 2 mg/kg/h infusion of lidocaine. Magnesium group (group M) received a 15 mg/kg/h infusion after receiving an IV 35 mg/kg bolus in 150ml saline within 15 minutes. Control (group C) was infused with normal saline 10 mg/kg/h. Results: Lidocaine group offers better surgical field exposure with better surgeon's satisfaction than magnesium and control groups. There was insignificant variation among investigated groups regarding mean arterial pressure (MAP) immediately post induction. Intraoperative MAP revealed insignificant variations among lidocaine and magnesium groups but substantial differences between both and control group. Regarding heart rate (HR) there was insignificant variation among investigated groups at baseline and after induction however there was significant decrease in HR from baseline post intubation and all the study time. Lidocaine group's intraoperative blood loss was less than other two groups, patients in magnesium and control groups needed more fentanyl doses. The operating time, emergent and recovery time was substantially shorter in the lidocaine group than magnesium and control groups. Conclusion: During middle ear operations, lidocaine has superior results due to significant reduction in operative field bleeding, optimal field exposure, and shorter procedure times than magnesium and control groups.