Table 1 Eligibility criteria

· Undergoing major abdominal surgery, predominantly pancreatic surgery (pancreatectomy), for any reason

· Require careful postoperative monitoring of blood glucose levels

· Expected to be under intensive care for ≥ 8 h after surgery

· Insertion of a multi-lumen central venous catheter for medical reasons (e.g., anaesthesia and operative purposes)

· Aged 18–80 years

· Able to understand the design and possible consequences of the clinical study

In addition, all patients must meet the following criteria, or will not be included in the study:

· Successful central venous cannulisations with a multi-lumen catheter

· One lumen is not needed for medical purposes, such as perioperative fluid therapy or medication administration

Patients fulfilling any of the following criteria will be excluded from the study:

· History of thrombosis, embolism, or vascular obliteration

· Bleeding disorders (e.g., thrombocytosis)

· Acute or chronic cardiac failure

· Acute or chronic kidney failure (i.e., patients on renal replacement therapy)

· Evidence of postoperative hyperhydration (pulmonary vascular congestion)

· Acquired immune deficiency syndrome

· Receiving immunosuppressive therapy

· Signs or symptoms of acute or chronic infection

· No perioperative antibiotic prophylaxis (with mezlocillin 4 g and metronidazole 500 mg, for example)

· No perioperative prophylaxis to prevent venous thromboembolism (e.g., unfractionated or fractioned/low-molecular weight heparin)

· The amount of flushing medium administered is > 500 mL

· Pregnancy or lactation

· Participation in other clinical studies and observation period of competing studies, respectively