General anesthesia procedure
STERILE, INFILTRATION, INFILTRATING
After 3 minutes of preoxygenation, anesthesia was induced with an injection of 3 μg/kg of Fentanyl followed by 3 mg/kg of Propofol; and with intubation using a silicone wire-reinforced tracheal tube with 0.2 mg/kg Cisatracurium. Anesthesia was maintained using isoflurane with a minimum alveolar concentration (MAC) of 1% in a 50% oxygen/air mixture. A 0.03 mg/kg Cisatracurium bolus was administered every 40 min, and a Fentanyl bolus of 0.1 μg/kg was injected whenever there was an increase of 20% of the base values in heart rate or systolic arterial blood pressure.Before surgery, an anesthesiologist, not involved in the study, prepared an unlabeled sterile syringe using 10 ml of ketamine (2 m/kg) or 10 ml of a saline solution. After wound closure, the infiltration was performed by a blinded surgeon. The needle was introduced to a depth of 0.5 cm, an aspiration was then performed to avoid an intravascular injection followed by infiltrating the wound. The content of the syringe was used for homogenous infiltration of the subcutaneous wound sides by the surgeon.