General anesthesia was induced with midazolam 0.1 mg∙kg-1, propofol 2 mg∙kg-1, and cisatracurium 0.15 mg∙kg-1. The patients were intubated with a left-sided double-lumen tube in adequate size and positioned laterally. Anesthesia was maintained with 1 minimum alveolar concentration (MAC) sevoflurane. The patients awoke from anesthesia in a post-anesthesia care unit, and were extubated after the administration of adequate doses of atropine and neostigmine as required. After surgery, if a patient complained of pain then she/he was given i.v. oxycodone by an anesthetist before commencing the patient controlled analgesia (PCA). This dose was titrated to achieve adequate analgesia. Each patient then commenced PCA. The PCA solution was oxycodone (1mgml-1) and the PCA was programmed to allow a self-administered bolus dose of 1mg oxycodone with a lockout time of 5 min. Additionally, patients were given 1 g intravenous paracetamol every 6 h and 100mg of intravenous ketoprofen every 12 h.

General anesthesia was induced with midazolam 0.1 mg∙kg-1, propofol 2 mg∙kg-1, and cisatracurium 0.15 mg∙kg-1. The patients were intubated with a left-sided double-lumen tube in adequate size and positioned laterally. Anesthesia was maintained with 1 minimum alveolar concentration (MAC) sevoflurane. The patients awoke from anesthesia in a post-anesthesia care unit, and were extubated after the administration of adequate doses of atropine and neostigmine as required. After surgery, if a patient complained of pain then she/he was given i.v. oxycodone by an anesthetist before commencing the patient controlled analgesia (PCA). This dose was titrated to achieve adequate analgesia. Each patient then commenced PCA. The PCA solution was oxycodone (1mgml-1) and the PCA was programmed to allow a self-administered bolus dose of 1mg oxycodone with a lockout time of 5 min. Additionally, patients were given 1 g intravenous paracetamol every 6 h and 100mg of intravenous ketoprofen every 12 h.

Intraoperatively, fentanyl in fractional doses of 1-3 µg∙kg-1 were applied if the heart rate (HR; Heart Rate) or mean blood pressure (MBP; Mean Blood Pressure) increased by more than 20% above the baseline value obtained just before surgery commencement.

During general anesthesia the pain-related stress was assessed using a method of skin conductance fluctuations. The measurement was based on changes in skin conductance that arise under the influence of a pain stimulus.

Intraoperative usage of opioids was noted.

Non-invasive arterial blood pressure was recorded every 5 minutes during operation.

Heart rate was recorded every 5 minutes during operation.

Overall analgesia satisfaction was recorded at 24 and 48 postoperative hours with Likert scale. The points in Likert scale were assigned as below:

1. Very satisfied.
2. Satisfied.
3. Neither satisfied nor dissatisfied.
4. Dissatisfied.
5. Very dissatisfied.