title: Randomized controlled trial of stroke volume optimization during elective major abdominal surgery in patients stratified by aerobic fitness.
abstract: BACKGROUND
  The benefits of stroke volume optimization during surgery are unclear, with recent data not replicating the positive effects of earlier studies.
  
  
  METHODS
  This was a randomized controlled trial of standard fluid therapy with or without supplementary blinded intraoperative stroke volume optimization in 220 patients having major elective rectal resection or cystectomy with ileal conduit. All patients were treated using a contemporary enhanced recovery pathway. Interventional fluid challenges used Gelofusine (B Braun, Germany), guided by stoke volume variability measured by LiDCOrapid (LiDCO, UK). Participants were stratified by aerobic fitness (characterized by preoperative cardiopulmonary exercise test), surgical specialty, and intended surgical approach (open or laparoscopic). The primary outcome was the prevalence of moderate or severe complications on day 5 after surgery, defined using the postoperative morbidity survey (POMS) criteria.
  
  
  RESULTS
  Patients received ∼13 ml kg(-1) h(-1) of i.v. fluids during surgery. The intervention group received an additional mean (sd) 956 (896) ml Gelofusine. There were no statistically significant differences between groups in any primary or secondary end point. A positive POMS on postoperative day 5 was noted in 54 of 111 control subjects (48.6%) and 55 of 109 participants in the intervention group [50.5%; adjusted odds ratio 0.90 (95% confidence interval 0.52-1.57), P=0.717]. Mean (sd) hospital length of stay was 9.6 (6.8) days in the control group and 11.8 (11.5) days in the intervention group (adjusted difference -2.1 (-4.6 to 0.3) days, P=0.091). There was no statistical interaction between stroke volume optimization and aerobic fitness in terms of rate of complications or length of stay.
  
  
  CONCLUSIONS
  Algorithm-driven stroke volume optimization is of no benefit when superimposed on a liberal baseline fluid regimen in patients having elective major abdominal surgery, when stratified to minimize differences in fitness and surgical approach between groups.
  
  
  BACKGROUND
  ISRCTN21597243.
authors.affiliation: Department of Surgery, Derriford Hospital, Plymouth, UK Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: C W
authors.initials: CW
authors.lastname: Lai
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK.
authors.forename: T
authors.initials: T
authors.lastname: Starkie
authors.affiliation: Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: S
authors.initials: S
authors.lastname: Creanor
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Struthers
authors.affiliation: Department of Anaesthesia, Torbay Hospital, Torquay, UK.
authors.forename: D
authors.initials: D
authors.lastname: Portch
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK.
authors.forename: P D
authors.initials: PD
authors.lastname: Erasmus
authors.affiliation: Department of Surgery, Derriford Hospital, Plymouth, UK.
authors.forename: N
authors.initials: N
authors.lastname: Mellor
authors.affiliation: Department of Surgery, Derriford Hospital, Plymouth, UK.
authors.forename: K B
authors.initials: KB
authors.lastname: Hosie
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK.
authors.forename: J R
authors.initials: JR
authors.lastname: Sneyd
authors.affiliation: Department of Anaesthesia, Derriford Hospital, Plymouth, UK Plymouth University Peninsula Schools of Medicine and Dentistry, Plymouth, UK gary.minto@nhs.net.
authors.forename: G
authors.initials: G
authors.lastname: Minto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003107:Colorectal Surgery; D004311:Double-Blind Method; D017558:Elective Surgical Procedures; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010809:Physical Fitness / Q000502:physiology*; D011183:Postoperative Complications / Q000453:epidemiology; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology*; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
keywords: colorectal surgery; exercise test; fluid therapy; haemodynamics; postoperative complications