The aim of this study is to investigate the relationship of preoperative Neutrophil/Lymphocyte Ratio (NLR) with postoperative pain and the effect of preoperative NLR level on timing of epidural analgesia in thoracotomy.

The study was conducted prospectively in 60 patients aged 18-75 years, ASA I-III, who underwent thoracotomy. The patients were divided into 2 groups as NLR level above 2 (Group A) (n:32) and NLR level below 2 (Group B) (n:28). Each group was divided into subgroups with equal numbers of Prempative analgesia group and control group. Local anesthetic was administered to the preemptive analgesia group (Group P) 20 minutes before the surgical incision through the epidural catheter, and to the control group (Group K) 20 minutes before the patient was awakened from the epidural catheter. NRS levels and additional analgesia needs were recorded at 2, 4, 8, 12 and 24 hours postoperatively.

Inclusion Criteria:

• Patient graded as American Society of Anesthesiologist (ASA) physical status, I, II or III
• Patient subjected to thoracotomy operation

Exclusion Criteria:

Patient having morbid obesity,

• Patient having renal failure,
• Patient having hepatic failure,
• Patient having neuropsychiatric disease,
• Patient allergy to the study drugs

A total of 60 female and male patients aged 18-75 years, in the ASA I-III risk group, who will undergo elective thoracotomy