Goal Directed Fluid Therapy in Patient Undergoing Major Abdominal Surgery

Abstract

Any operation represents trauma. Physiological response to surgery is known as “stress response”. The surgical stress response is believed to be a necessary and beneficial response. However, exaggerated activation of various components of the surgical stress response due to many factors during major operations especially inappropriate fluid administration can result in hemodynamic instability, and metabolic derangement leading to multiple organ failure and mortality (Gary et al., 2013). Hypovolemia post major surgery is common, unrecognized and potentially avoidable.Standard monitoring methods of fluid management have failed. Historically, intravenous fluid administration to treat hypovolaemia has been guided by measurements of pulse rate, arterial pressure and central venous pressure. However, this approach seems to lack sensitivity and specificity in identifying volume deficit, leading to both inadequate and excessive fluid administration (Miller et al., 2014). Modern monitoring systems measure hemodynamic variables that are the best predictors of fluid responsiveness, such as stroke volume (SV), stroke volume variation (SVV), pulse pressure variation (PPV), these advanced hemodynamic parameters may indicate hypovlemia before a change in heart rate or blood pressure (Kungys et al., 2009). Perioperative goal-directed therapy (PGDT) aims at optimization of intravascular fluid volume in order to optimize cardiac output (Stroke Volume), in order to optimize tissue perfusion and oxygen delivery to the tissues. It uses a non or minimally invasive measurement of SV or SVV to monitor the response to fluid challenge. Patient who respond to fluid challenge with an increase in SV more than 10 % are considered fluid responsive and may benefit from more fluid challenges . Euvolemic patients will not exhibit a change in SV more than 10 % and not likely to benefit (Michard, 2005). Goal-directed therapy can be used alone or as a part of enhanced recovery after surgery (ERAS) pathway. Accurate hemodynamic monitoring of CO, SV and SVV allows physicians to provide fluid as needed, in appropriate amounts, and optimal timing resulting in reduction of postoperative complications, days of hospital stay and subsequent mortality, especially in high risk surgical patients (Powell et al., 2011).