Outcome measures
delirium, postoperative cognitive dysfunction, Postoperative pain, pain
SECONDARY
The primary endpoint was the incidence of delirium within three days after surgery. Patients were examined for delirium twice a day (after 6.00 a.m. and again after 6.00 p.m.). The secondary outcomes included postoperative cognitive dysfunction, duration of surgery (measured from incision to wound closure), duration of anesthesia (measured from anesthesia induction to anesthetic drug discontinuation), time to extubation (measured from anesthetic drug discontinuation to extubation), and the total doses of fentanyl used during the operation. Postoperative pain was assessed by the Visual Analog Scale (VAS) (0 = no pain, 10 = most severe pain) at the 30th minute (t1), 1st hour (t2), 4th hour (t3), 12th hour (t4), and 24th hour (t5) after surgery. The time to first postoperative request for analgesia (nalbuphine 0.05 mg/kg) when VAS was ≥ 3 was recorded, and the total nalbuphine consumption in the first 24 h was calculated.