Despite significant advances in perioperative care, major complications continue to be seen in patients undergoing major surgery. Enhanced recovery after surgery (ERAS) protocols are perioperative care practices designed to reduce perioperative complications, maintain preoperative organ function, and provide early recovery by reducing the psychological and physiological response to major surgery and the intense stress response that develops following surgery. In this context, ERAS protocols have been established for many surgical procedures. One is the thoracic ERAS (ERATS) protocol applied to thoracic surgery, and the evidence for ERATS is increasing; literature data support the application of ERATS. However, there are limited studies on the application of ERAS protocols to thoracic surgery, and more studies are needed to develop ERATS protocols.

Postoperative complications may be reduced in patients who are treated with the ERAS protocol, their length of hospital stay (LOS) may be shortened, and patients may regain their initial functions faster. Objectively, a marker indicating whether the ERAS protocol can be implemented effectively has not yet been demonstrated. Reducing postoperative inflammation is thought to reduce LOS. Based on this, the investigators think that the early recovery seen in patients who undergo ERAS is due to the effect of ERAS protocols on the inflammatory process. Therefore, laboratory parameters such as C-reactive protein (CRP), white blood cell count, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocytes ratio (LMR) may differ in patients who have undergone the ERAS protocol compared to patients who have not. These parameters have been evaluated comprehensively in studies as inflammatory parameters. In addition, clinical studies indicate that the C-reactive protein to albumin ratio (CAR) can be used as inflammatory and prognostic markers. Also, the investigators hypothesized that inflammatory parameters used in routine clinical follow-up may be effective in evaluating the clinical consequences of ERATS protocols. In this study, the investigators aimed to evaluate the effects of the ERATS protocol on postoperative inflammatory parameters and investigate whether these parameters have a role in evaluating the effectiveness of the ERATS protocol.

Inclusion Criteria:

• Patients between 18-80 years of
• Patients underwent elective thoracic surgery,
• American Society of Anesthesiologists (ASA) I-II-III
• Body mass index (BMI) between 18.5-35 kg/m2

Exclusion Criteria:

• Patients with systemic inflammatory diseases
• Patients with a history of anti-inflammatory and anti-allergic drugs,
• Patients with a history of corticosteroid usage,
• Patients who had received intraoperative blood product transfusions,
• Patients who had previously undergone thoracic surgery,
• Patients with missing data

The study included patients between 18-80 years of age who had undergone elective thoracic surgery, whose physical condition was I-II-III according to the ASA, and whose BMI was between 18.5-35 kg/m2.