Postoperative data collection
nausea, Postoperative pain, vomiting, pain, dizziness
ADVERSE EVENTS
Postoperative pain at rest was assessed using the VAS (ranging from 0 to 10, 0 = no pain, 10 = the worst imaginable pain). Patients received 0.1 μg/kg of sufentanil administered by an anesthesiologist to achieve a VAS score ≤ 3 before discharge from the post-anesthesia care unit. If the VAS score > 3, 0.1 μg/kg sufentanil was given repeatedly in intervals of at least 15 min until the VAS score ≤ 3. Postoperative visits were performed by a nurse anesthetist who was independent of the research process. Additional analgesic drugs (primarily intravenous morphine) were given by surgeon whenever the VAS score was > 3 after pressing the PCIA pump frequently. The S-ketamine consumption of PCIA, first postoperative flatus time of patients, VAS scores at 24 h and 48 h after surgery, the additional requirement of analgesic drugs, and sufentanil consumption of PCIA in the first postoperative 24 h were recorded from the time when the patient was discharged from the post-anesthesia care unit. All adverse events such as dizziness, nausea, and vomiting were documented.