The aim of this study is to evaluate the predictive value of albumine, C-reactive protein (CRP), procalcitonin, and lactates in terms of surgical stress and postoperative complications. These biomarkers will be measured from the day before surgery until postoperative day four in patients undergoing major surgery. Major surgery was defined as esophagus, gastric, liver, pancreas, endocrine, retroperitoneal, or colorectal procedures including an organ resection for benign or malignant disease and lasting more than 2 hours.

This prospective study was conducted at the Department for Visceral Surgery at the University Hospital of Lausanne Switzerland (CHUV) between February and December 2015 (NCT02356484). The study was approved by the Institutional Review Board (No. 367/15), and all patients provided written consent prior to surgery. Inclusion criteria were age >18 years, and elective major abdominal surgery-defined as an operative procedure with anticipated duration ≥2 hours.17 Perioperative care closely adhered to recently published enhanced recovery guidelines (http://erassociety.org.loopiadns.com/guidelines/list-of-guidelines). Standardised fluid administration was followed by advanced haemodynamic monitoring to avoid intraoperative fluid overload. According to the clinical care pathway, intravenous fluid was typically discontinued the morning after surgery.

Biological markers Serum levels of albumin, CRP, PCT and lactate (LCT) were perioperatively measured in a fasting state, Following standardised institutional guidelines. Blood samples were drawn the day before surgery, the day of surgery (4-6 hours after the end of the operation) and on the first, second and third postoperative day. As Baseline values tend to show large variations especially for albumin,4 10 we considered that a dynamic value (difference between two time-points) might be more informative than a snapshot value. Several values based on preoperative and postoperative concentrations were thus calculated for each marker (ie, Δ Max: maximal difference between the preoperative and postoperative values; Δ POD 0: difference of concentration on POD -1 and POD 0; Δ POD 1: difference of concentration on POD-1 and POD 1).

Inclusion Criteria:

• Patients over 18 years old
• Patients undergoing esophagus, gastric, liver, pancreas, endocrine, retroperitoneal, or colorectal surgery
• Operation time more than 2 hours
• Operation including an organ resection for benign or malignant disease

Exclusion Criteria:

• Immunosuppressive therapy
• Cognitive impairment or language comprehension problems
• Absence of the consent form prior to first blood sample

Patients undergoing major surgery (esophagus, gastric, liver, pancreas, endocrine, retroperitoneal, or colorectal surgery)