title: Correlation between IVC dimensions and volume status on CT scan.
abstract: BACKGROUND
  End points of resuscitation in trauma patients are difficult to define. The size of the inferior vena cava (IVC) on CT scan may accurately indicate volume status and guide resuscitation efforts. Our hypothesis was that IVC "flatness" on CT scan reflects volume status in hemodynamically normal trauma patients.
  
  
  METHODS
  The study population was drawn from a database of trauma patients who had abdominal CT scans and lactate levels drawn on arrival. Lactate was chosen as a marker of volume status since hypotensive patients were unlikely to undergo CT. Anteroposterior (AP) and transverse (TV) diameters of the IVC were measured at the suprarenal and infrarenal locations. A flatness index was calculated for each location (TV ÷ AP) and this value was correlated with heart rate, blood pressure, and lactate.
  
  
  RESULTS
  There was no difference in IVC flatness at the suprarenal or infrarenal position for patients with an elevated lactate compared with those with a normal lactate: 1.54 ± 0.18 versus 1.43 ± 0.08 (P = 0.2) suprarenal and 1.54 ± 0.46 versus 1.68 ± 0.58 (P = 0.4) infrarenal. IVC flatness at the suprarenal location weakly correlated with blood pressure (r = -0.29). IVC flatness did not correlate with blood pressure at the infrarenal location (r = -0.1). IVC flatness did not correlate with heart rate (P > 0.3) or age (P > 0.2).
  
  
  CONCLUSIONS
  These results did not demonstrate a correlation between IVC flatness and the markers of intravascular volume of heart rate, blood pressure, or lactate. IVC flatness on CT scan is not a valid indicator of volume status in hemodynamically normal trauma patients.
authors.affiliation: Department of Surgery, UCSF East Bay, Alameda County Medical Center, Oakland, California 94602, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Miraflor
authors.forename: Louise
authors.initials: L
authors.lastname: Yeung
authors.forename: Aaron
authors.initials: A
authors.lastname: Strumwasser
authors.forename: Javid
authors.initials: J
authors.lastname: Sadjadi
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Victorino
mesh_terms: D000328:Adult; D000368:Aged; D001810:Blood Volume; D001811:Blood Volume Determination / Q000379:methods*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012151:Resuscitation / Q000379:methods; D012771:Shock, Hemorrhagic / Q000000981:diagnostic imaging* / Q000628:therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*; D015599:Trauma Severity Indices; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging*; D014947:Wounds and Injuries / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D019344:Lactic Acid