In group A:

• The researcher, who supervised the anesthesia, explained the concept of the study to all patients before induction, and then a tourniquet was placed around the dominant arm of the patients after placing a cotton bandage; to be inflated to 200mmHg or 40 mmHg above the systolic blood pressure of the patient; immediately before administration of the muscle relaxant later on.
• Patients received inhalation induction using sevoflurane 8% and fentanyl 2 µg/kg was administered intravenously. After loss of consciousness, and BIS value of 50 or less, the tourniquet cuff was inflated then atracurium 0.5 mg/kg was given intravenously and sevoflurane reduced to 2%, then laryngoscopy and intubation were done when action of neuromuscular blocker (NMB) was confirmed by the disappearance of T3,T4. During this time, mask assisted ventilation with 100% oxygen was used to achieve normocapnia

In group B:

• The researcher, who supervised the anesthesia, explained the concept of the study to all patients before induction, and then a tourniquet was placed around the dominant arm of the patients after placing a cotton bandage; to be inflated to 200mmHg or 40 mmHg above the systolic blood pressure of the patient; immediately before administration of the muscle relaxant later on.
• In group B: propofol 1.5 mg/kg and fentanyl 2 µg/kg were administered intravenously. After loss of consciousness, and BIS value of 50 or less, the tourniquet cuff was inflated and then atracurium 0.5 mg/kg was given intravenously. Propofol infusion 6 mg/kg/hr was started, until action of neuromuscular blocker (NMB) was confirmed by disappearance of T3,T4, then laryngoscopy and intubation were done. The used dosing regimen is according to previous guidelines [8] [9].No inhalational agent was used. Mask assisted ventilation was used to achieve normocapnia.

IFT response, hemodynamics and BIS value were recorded during intubation period. Then the data acquisition was stopped and the isolated forearm cuff deflated. IFT values were noted by two independent observers

Score is from zero to 5 Increasing score means increasing risk of awareness especially if >3 The primary outcome was IFT response was recorded at laryngoscopy and intubation to identify awareness at this stressful timepoint.

Value from 100 to zero. 100 means fully awake We aim to be with in 40-60 intraoperatively to decrease risk of awareness

BIS values were recorded at the following timings:

• Baseline
• After induction and muscle relaxation,
• During laryngoscopy,
• After successful intubation
• After 20 minutes from skin incision
• After 40 minutes from skin incision