title: Intraoperative perfusion management impacts postoperative outcomes: an analysis of 682 autologous breast reconstruction patients.
abstract: BACKGROUND
  Anesthetic management remains an understudied aspect of free autologous breast reconstruction. This study aims to critically examine intraoperative anesthetic management as it relates to free flap perfusion and its effect on major complications.
  
  
  METHODS
  A retrospective cohort study was performed examining all abdominally based free autologous breast reconstructions from 2005 to 2011 at a single institution. Analysis focused on perioperative care and specifically fluid administration, urine output (UOP), vasopressor administration, and case duration. Outcomes included major intraoperative and postoperative complications. A post-hoc analysis was performed to determine anesthetic factors associated with thrombotic events.
  
  
  RESULTS
  Overall, 682 patients (1033 flaps) were included. Patients with low UOP had lower rates of intraoperative fluid infusion rates/kg (p=0.0001), Estimated Blood Loss (EBL) (p=0.006) and pressor administration (p=0.03), but no significant differences were noted in intraoperative thrombotic events according to UOP. However, the below normal UOP cohort demonstrated a significant increased rate of delayed postoperative thromboses (p=0.03). A post hoc analysis of postoperative thrombotic events revealed that low rates of fluid resuscitation (OR=3.01, p=0.04) and low intraoperative UOP (OR=3.67, p=0.04) were independently associated with delayed thrombosis. A sub-analysis demonstrated that patients with ≥2 comorbidities and below normal UOP were at particular risk (any delayed thrombotic event OR=4.3, p=0.03; any delayed venous thrombosis OR=9.1, p=0.03).
  
  
  CONCLUSIONS
  This study demonstrates that intraoperative fluid under-resuscitation may place patients at increased risk for postoperative flap thrombosis, and low UOP is an important metric whereby intraoperative resuscitation should be gauged. Patients with comorbid conditions and below normal intraoperative UOP should be monitored particularly closely for delayed thrombotic events.
  
  
  METHODS
  Prognostic/risk category, level II.
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. Electronic address: jonas.nelson@uphs.upenn.edu.
authors.forename: Jonas A
authors.initials: JA
authors.lastname: Nelson
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Fischer
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Ritwik
authors.initials: R
authors.lastname: Grover
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Mirzabeigi
authors.affiliation: Lankenau Medical Center Anesthesiology, Wynnewood, PA, USA.
authors.forename: Priscilla
authors.initials: P
authors.lastname: Nelson
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Ari M
authors.initials: AM
authors.lastname: Wes
authors.affiliation: Division of Plastic Surgery, Yale New-Haven Hospital, New Haven, CT, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Au
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Serletti
authors.affiliation: Division of Plastic Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Liza C
authors.initials: LC
authors.lastname: Wu
mesh_terms: D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D005440:Fluid Therapy / Q000706:statistics & numerical data; D058752:Free Tissue Flaps / Q000098:blood supply*; D006084:Graft Rejection; D006801:Humans; D007430:Intraoperative Care; D016462:Mammaplasty; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011183:Postoperative Complications; D012151:Resuscitation; D012189:Retrospective Studies; D013927:Thrombosis / Q000453:epidemiology*; D014556:Urine; D059349:Urine Specimen Collection
keywords: Anesthesia; Complications; Fluid resuscitation; Free flap breast reconstruction; Thrombosis; Urine output