Preparation of NS
The case-assigned anesthesiologist opened the envelope and prepared the allocated amount of NS before the study participants entered the operating suites. The amount of NS was calculated based on the patient’s TBW. The smallest possible syringe size was chosen to draw NS. The anesthesiologists were able to select either a slip-tip 2.5 mL syringe, slip-tip 5 mL syringe, or luer-lock 10 mL syringe (Terumo®, Tokyo, Japan).