Variation in induction dose and time of propofol on administering inhaled nitrous oxide during induction A prospective randomized controlled study

In this study, patients will undergo a comprehensive preoperative assessment, including detailed history taking, physical examination, and routine investigations. An intravenous line will be established, and IV fluids will be administered. The general anesthesia procedure will be explained, and informed consent will be obtained. Patients will be instructed to fast overnight and will receive Tab. Anxit 0.5mg the night before surgery to reduce anxiety. Upon entering the operating theatre, multipara monitors will be attached to record baseline vital signs, including heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and oxygen saturation (SpO2). Premedication will include Glycopyrrolate 0.2mg and Fentanyl 2mcg/kg, followed by 3 minutes of preoxygenation with 100% oxygen. Patients will be randomly assigned to one of two groups. Group A will receive a 70% nitrous oxide and 30% oxygen mixture via a Bain’s Circuit, alongside a propofol infusion at 30mg/min (3ml/min). Group B will receive 100% oxygen via a Bain’s Circuit with the same propofol infusion rate. Propofol infusion will be adjusted until the patient reaches an apneic state, with induction time recorded from the start of infusion to apnea and the total dose administered noted. Following this, succinylcholine (2mg/kg) will be administered for intubation with a cuffed endotracheal tube. Anesthesia will be maintained with a mixture of O2, N2O, and other inhalational agents. Hemodynamic parameters will be monitored and recorded at various intervals: preoperatively (T1), before propofol infusion (T2), and at 1-minute intervals up to 4 minutes after starting propofol infusion (T3-T6), at apneic state (T7), before intubation (T8), and after intubation (T9).