title: Functional intravascular volume deficit in patients before surgery.
abstract: BACKGROUND
  Stroke volume (SV) maximization with a colloid infusion, referred to as individualized goal-directed therapy, improves outcome in high-risk surgery. The fraction of patients who need intravascular volume to establish a maximal SV has, however, not been evaluated, and there are only limited data on the volume required to establish a maximal SV before the start of surgery. Therefore, we estimated the occurrence and size of the potential functional intravascular volume deficit in surgical patients.
  
  
  METHODS
  Patients scheduled for mastectomy (n=20), open radical prostatectomy (n=20), or open major abdominal surgery (n=20) were anaesthetized, and before the start of surgery, a 200 ml colloid fluid challenge was provided and repeated if a >or=10% increment in SV estimated by oesophageal Doppler was established. The volume needed for SV maximization defined the intravascular volume deficit.
  
  
  RESULTS
  Forty-two (70%) of the patients needed volume to establish a maximal SV. For the patients needing volume, the required amount was median 200 ml (range 200-600 ml), with no significant difference between the three groups of patients. The required volume was >or=400 ml in nine patients (15%).
  
  
  CONCLUSIONS
  The majority of anaesthetized patients present with a functional intravascular volume deficit before surgery. Although the deficit in general was minor, a fraction of patients presented with a deficit that may be of clinical relevance, emphasizing the importance of the individual approach of goal-directed fluid therapy.
authors.affiliation: Department of Anaesthesia, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. morten.bundgaard-nielsen@rh.regionh.dk
authors.forename: M
authors.initials: M
authors.lastname: Bundgaard-Nielsen
authors.forename: C C
authors.initials: CC
authors.lastname: Jørgensen
authors.forename: N H
authors.initials: NH
authors.lastname: Secher
authors.forename: H
authors.initials: H
authors.lastname: Kehlet
mesh_terms: D000368:Aged; D000465:Algorithms; D000768:Anesthesia, General; D001810:Blood Volume / Q000502:physiology*; D015992:Body Mass Index; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D020896:Hypovolemia / Q000150:complications*; D008297:Male; D008408:Mastectomy; D008875:Middle Aged; D057234:Preoperative Period; D011468:Prostatectomy; D012306:Risk; D013318:Stroke Volume / Q000502:physiology