Goal Directed Fluid Therapy Compared to Liberal Fluid Therapy in Patients Subjected to Colorectal Surgery

Intraoperative fluid management for major abdominal and intestinal surgeries is quite important in terms of postoperative organ perfusion and complications. Many complications such as acute renal failure, hypotension, arrhythmia, and anastomosis leak may occur secondary to intraoperative hypovolemia whereas hypervolemia may cause pulmonary edema, postoperative pneumonia, prolonged mechanical ventilation, delayed wound healing, edema in the gastrointestinal system (GIS), and decreased GIS motility.

In the perioperative period, fluid therapy and gastrointestinal function may complement each other or complicate it. If fluid therapy is not optimal, it may cause delayed gastrointestinal function and avoid early oral intake. If gastrointestinal dysfunction develops in the perioperative period, it may lead to fluid and electrolyte loss and metabolic problems. Thus, the intraoperative fluid management of the patient is very important.

Accurate assessment of a patient's volume status is an important goal for the anesthetist in the operating theatre to achieve hemodynamic stability and adequate tissue oxygenation. Different intraoperative fluid management protocols are in use for this purpose. The most common one is conventional fluid management (CFM). Fluid replacement is managed according to clinical assessment and heart rate (HR), arterial blood pressure (ABP) and central venous pressure (CVP) monitorization.

While goal-directed fluid therapy (GDFT) is a perioperative strategy, where fluid administration targets continuously-measured hemodynamic variables, such as cardiac output, stroke volume, stroke volume variation, pulse pressure variation and other factors to guide intravenous and inotropic therapy, with the aim of maximizing tissue perfusion and oxygen delivery.

Cardiac output is assessed by static indices or dynamic indices. Static indices of cardiac preload such as central venous pressure (CVP) and pulmonary artery wedge pressure are of little help for decisions regarding volume replacement. Dynamic variables such as pulse pressure variation (PPV) and stroke volume variation (SVV) are increasingly used to detect the cyclic fluctuation of the arterial pressure wave in the mechanically ventilated patient in order to predict fluid responsiveness.