All included patients were fasted for 8 hours and did not receive any analgesics 6 hours before surgery. The VAS was trained for all participants. Patients were placed in the study groups after entering the operating room based on the described randomization method. Neither the patient nor the assessor was aware of the study group.
In the operating room, 200 mL of normal saline was infused before induction of spinal anesthesia, and the pain intensity was assessed with the VAS. Vital signs were also checked. Spinal anesthesia was induced using a Quinke needle G26 at the injection rate of 0.2 mL/s. Immediately after injection, patients were positioned in the Trendelenburg position, and after 30 seconds, their anesthesia level was checked every 30 seconds by the Pin Prick test. After anesthesia reached the L1 level, patients were returned to the supine position, and their ability to move their healthy foot was evaluated; then, they received 2 mg of midazolam. A tourniquet was applied, and all patients were oxygenated during surgery with a mask at a rate of 4–6 L/min.
Vital signs were checked every 5 minutes during the first 15 minutes. Patients with over 20% drop in blood pressure and a heart rate of <50 received inotrope. Those with nausea received atropine or androsterone. Shivering during surgery was treated with 25 mg of pethidine or androsterone.
The onset of anesthesia is as follows: the time interval between induction of anesthesia and anesthesia at L1 and the time interval between anesthesia at L1 and anesthesia at two levels below were measured.
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