Stroke volume variation as a predictor of intravascular volume depression and possible hypotension during the early postoperative period after esophagectomy.

BACKGROUND: Perioperative hypotension during esophagectomy results from hypovolemia caused by a shift of extracellular fluid from the intravascular to the extravascular compartment. Fluid management is often difficult to gauge during major surgery because there are no reliable indicators of fluid status, and some patients still experience cardiorespiratory instability. In this retrospective study, we evaluated stroke volume variation (SVV), calculated by using a new arterial pressure-based cardiac output measurement device, as a predictor for fluid responsiveness after esophageal surgery.
METHODS: Eighteen patients undergoing esophagectomy with extended radical lymphadenectomy were monitored by the FloTrac sensor/Vigileo monitor system during the perioperative and immediate postoperative period. Fluid responsiveness was assessed and compared with concurrent SVV and central venous pressure (CVP) values, and routine hemodynamic variables.
RESULTS: Eleven of 18 patients needed additional volume loading within the first 10 postoperative hours as a result of hypotension. The maximum SVV value of fluid resuscitated patients was >15% in all cases, whereas six of seven patients without postoperative hypotension had maximum SVV values of <15%. The correlation between SVV and the development of hypotension was statistically significant (P = 0.0012). From the linear correlation analysis of hemodynamic variables influenced by additional fluid loading, SVV was significantly correlated to cardiac output (r = 0.638; P = 0.049), whereas CVP was not (P > 0.05).
CONCLUSION: We conclude that SVV, as displayed on the Vigileo monitor, is an accurate predictor of intravascular hypovolemia and is a useful indicator for assessing the appropriateness and timing of applying fluid for improving circulatory stability during the perioperative period after esophagectomy.