Update in Perioperative Fluid Management

Abstract

Perioperative fluid therapy has a direct bearing on the outcome, and it should be tailored to the needs of the patient. The goal is to maintain the effective circulatory volume while avoiding interstitial fluid overload whenever possible. In the practice of anesthesia, routine monitoring of physiological parameters (blood pressure, urine output ….etc) is often used to guide fluid therapy. However these parameters can't predict rapid changes or volume responsiveness. Hence hemodynamic parameters (SVV,PPV,PLR…and others) are used and appear to be superior to static parameters like CVP and PCWP in prediction of volume responsiveness. Current data suggest that perioperative fluid restriction yields positive post-operative outcome in most elective cases with the exception of minor procedures where liberal strategy may be applied. A predefined strategy to fluid management may be inadequate for high risk patients or those who have long been hospitalized before surgery in whom hypovolemia is suspected. For those patients, modified goal directed therapy (GDT) proved to enhance outcome by ensuring adequate tissue perfusion at all times perioperatively using - mostly-colloid boluses. Due its obvious advantages, most studies showing benefit with goal directed approach have used Esophageal Doppler Monitoring (EDM) to guide fluid therapy. For minimal to moderately invasive surgical procedures, It's advised to use balanced crystalloid solution (eg. Ringer lactate). For major surgical procedures with significant fluid shift and hemodynamic labilityits preferred to combine crystalloids and colloids to limit fluid administration. Colloids also proved to enhance microcirculatory blood flow and give good results as a coload in neuroaxial anesthesia. Finally, as important as the choice of fluid, is the timing and rate of administration in the perioperative period.