title: Stroke volume variation as a predictor of intravascular volume depression and possible hypotension during the early postoperative period after esophagectomy.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Surgical Division, Hakodate Goryoukaku Hospital, Hakodate City, Hokkaido, Japan. neo-coba@mub.biglobe.ne.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Koh
authors.forename: Takashi
authors.initials: T
authors.lastname: Irinoda
authors.forename: Eiji
authors.initials: E
authors.lastname: Meguro
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Hayakawa
authors.forename: Akinori
authors.initials: A
authors.lastname: Takagane
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000601:surgery*; D002496:Central Venous Pressure; D004938:Esophageal Neoplasms / Q000601:surgery*; D016629:Esophagectomy / Q000009:adverse effects*; D006439:Hemodynamics; D006801:Humans; D007022:Hypotension / Q000175:diagnosis* / Q000209:etiology; D020896:Hypovolemia / Q000175:diagnosis* / Q000209:etiology; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation; D011184:Postoperative Period; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013318:Stroke Volume