2.5 Analgesia protocol, evaluation of pain, and sensorial block
Another blinded anesthesiologist (AIU) conducted pain assessments at 0.5 h postoperatively using the 11-point Numerical Rating Scale (NRS), which ranges from ‘0’ (meaning ‘no pain’) to‘10’ (meaning ‘worst pain imaginable’). Within 24 hours after operation, the patient received intravenous injection of tramadol 1-2 mg/kg to relieve pain in the surgical ward until the NRS pain score was ≤3 in accordance with hospital policy. The patients were sent to the surgical ward at the end of the 0.5 h. In the surgical ward, patients were assessed again 0.5, 1, 3, 6, 12, 18, and 24 hours postoperatively. If the postoperative NRS was greater than 3 points, tramadol 1–2 mg/kg was administered i.v., and then pain was evaluated after 30 minutes.