title: Predicting the Need for Intra-operative Large Volume Blood Transfusions During Thoraco-abdominal Aortic Aneurysm Repair.
abstract: OBJECTIVE
  Thoraco-abdominal aortic aneurysm (TAAA) repair is a complex procedure performed in patients at high cardiovascular risk. High volume intra-operative bleeding is often recorded, and the amount of intra-operative blood product transfusion is associated with relevant morbidity and mortality. The aim of the study was to identify pre-operative predictors of intra-operative large volume blood transfusions (LVBT) to stratify patients pre-operatively.
  
  
  METHODS
  This was a retrospective analysis of prospectively collected data of all patients who underwent open TAAA surgery at San Raffaele Scientific Institute from January 2009 to December 2015. Intra-operative red blood cell (RBC) transfusions were administered to maintain a hematocrit of at least 30%. A LVBT was defined as a transfusion of at least four RBC units, corresponding to 1000 mL.
  
  
  RESULTS
  The study population included 428 patients: 260 (61%) received fewer than 4 RBC units, and 168 (39%) were transfused with at least 4 RBC units. In patients who underwent LVBT, higher mortality was observed after surgery (p=.003), longer intensive care unit admission (p=.004), and longer mechanical ventilation compared with less transfused patients (p=.0002). The patients who received fewer units were administered a higher dose of heparin during the surgical operation compared with patients of the LVBT group: 3400±1100 vs. 2900±1300 IU (international units) (p=.0004). Pre-operative chronic renal failure (OR 1.8), the pre-operative haemoglobin value (OR 0.8), and the need for urgent or emergent surgery (OR 3.15) were independent predictors of LVBT on multivariate analysis.
  
  
  CONCLUSIONS
  The identification of patients at risk of intra-operative LVBT during TAAA surgery is critical as these patients experience a worse outcome. Nevertheless, only few independent predictors are available for clinical practice.
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pieri
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Nardelli
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: De Luca
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Landoni
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Frassoni
authors.affiliation: Department of Vascular Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Melissano
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Zangrillo
authors.affiliation: Department of Vascular Surgery, IRCCS San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Chiesa
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milan, Italy. Electronic address: monaco.fabrizio@hsr.it.
authors.forename: F
authors.initials: F
authors.lastname: Monaco
mesh_terms: D000368:Aged; D017545:Aortic Aneurysm, Thoracic / Q000401:mortality / Q000601:surgery*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D016009:Chi-Square Distribution; D016208:Databases, Factual; D017707:Erythrocyte Transfusion / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006400:Hematocrit; D006801:Humans; D007558:Italy; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000209:etiology; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality
keywords: Large volume blood transfusion; Mortality; Open TAAA repair; Risk predictors