Comparing the Effects of Lidocaine/Paracetamol and Midazolam/Fentanyl as a Premedication on Pain Intensity and Hemodynamic Changes in Patients Undergoing Cataract Surgery With Topical Anesthesia: A Randomized Double-blinded Pilot Study

Background: Several supplementary approaches have been used to increase the patient’s comfort during phacoemulsification under topical anesthesia. Objective: This study aimed to compare the effects of lidocaine/paracetamol (LP) and midazolam/fentanyl (MF) administration on pain intensity and hemodynamic changes in patients undergoing cataract surgery using phacoemulsification. Methods: This study was designed and implemented as a pilot randomized double-blinded clinical trial. A total number of 80 patients with cataracts scheduled for phacoemulsification were randomly assigned to two groups (40 subjects in each group) to receive lidocaine at a dose of 1.5 mg/kg and then infused with 1 g of paracetamol in 100 cc of normal saline (LP group) or midazolam 0.2 mg/kg and fentanyl 1.5 µg/kg (MF group). Hemodynamic parameters and sedation scores were measured before, 5, and 15 minutes after surgery, and then during recovery. Furthermore, pain (VAS), patient-surgeon satisfaction, propofol, and opioid consumption were all assessed. Findings: The sedation scores during recovery in the LP group were significantly lower (P= 0.04) than those in the MF group. Respiratory depression was also significantly lower (P<0.001) in the LP group compared to that infused by MF. According to other findings, no significant difference was observed between both study groups. Conclusion: The use of lidocaine-paracetamol as a supplementary approach for patients undergoing cataract surgery under topical anesthesia can cause better sedation scores with lower respiratory depression compared to the use of midazolam-fentanyl.