Abstract
Perioperative fluid management is a critical aspect of surgical care, containing the preoperative, intraoperative, and postoperative phases. Management of patients without individualisation, utilizing established standard protocols, may lead to undesirable events such as hypovolaemia and hypervolaemia during both intraoperative and postoperative periods. Insufficient fluid administration can result in peripheral vasoconstriction, leading to decreased oxygen delivery, impaired tissue perfusion, and dysfunction of vital peripheral organs. Conversely, excessive fluid administration may cause increased vascular permeability due to glycocalyx damage, tissue oedema, impaired tissue perfusion, local inflammation, delayed wound healing, wound infection, and anastomotic leaks. The pursuit of an optimal fluid regimen that prevents volume overload while maximizing tissue perfusion has led to the adoption of individualized, targeted fluid replacement therapies, supported by advancing technology. In this approach, basic physiological variables related to cardiac output or global oxygen distribution are measured. In optimized fluid management, fluid replacement is adjusted according to targeted physiological variables in a continuously re-evaluated process. These physiological variables can be assessed using different methods, from simple tests to complex devices that evaluate the patient’s tissue perfusion and cardiac output. Developments in recent years have drawn attention to the future of non-invasive or less invasive cardiac output measurement devices, as well as the utilization of ultrasonographic cardiac output measurements.