title: Stroke volume variation to guide fluid therapy: is it suitable for high-risk surgical patients? A terminated randomized controlled trial.
abstract: BACKGROUND
  Perioperative goal-directed fluid therapy (GDFT) may improve outcome after high-risk surgery. Minimal invasive measurement of stroke volume variation (SVV) has been recommended to guide fluid therapy. We intended to study how perioperative GDFT with arterial-based continuous SVV monitoring influences postoperative complications in a high-risk surgical population.
  
  
  METHODS
  From February 1st 2012, all ASA 3 and 4 patients undergoing abdominal surgery in two university hospitals were assessed for randomization into a control group or GDFT group. An arterial-line cardiac output monitor was used to measure SVV, and fluid was given after an algorithm in the intervention group. Restrictions of the method excluded patients undergoing laparoscopic surgery, patients with atrial fibrillation and patients with severe mitral/aortal stenosis. To detect a decrease in number of complication from 40 % in the control group to 20 % in the GDFT group, n = 164 patients were needed (power 80 %, alpha 0.05, two-sided test). To include the needed amount of patients, the study was estimated to last for 2 years.
  
  
  RESULTS
  After 1 year, 30 patients were included and the study was halted due to slow inclusion rate. Of 732 high-risk patients scheduled for abdominal surgery, 391 were screened for randomization. Of those, n = 249 (64 %) were excluded because a laparoscopic technique was preferred and n = 95 (24 %) due to atrial fibrillation.
  
  
  CONCLUSIONS
  Our study was stopped due to a slow inclusion rate. Methodological restrictions of the arterial-line cardiac output monitor excluded the majority of patients. This leaves the question if this method is appropriate to guide fluid therapy in high-risk surgical patients.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT01473446.
authors.affiliation: Department of Clinical Medicine, University of Bergen, 5020 Bergen, Norway ; Department of Anaesthesia and Intensive Care, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Ib
authors.initials: I
authors.lastname: Jammer
authors.affiliation: Department of Anesthesiology and Intensive Care, Oulu University Hospital, PL 21, 90029 Oulu, Finland.
authors.forename: Mari
authors.initials: M
authors.lastname: Tuovila
authors.affiliation: Department of Anaesthesia and Intensive Care, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Atle
authors.initials: A
authors.lastname: Ulvik