title: The utility of preoperative level of erythrocytosis in the prediction of postoperative blood loss and 30-day mortality in patients with tetralogy of fallot.
abstract: BACKGROUND
  Postoperative major bleeding is a relatively common complication of patients undergoing corrective surgery of tetralogy of Fallot (TOF). Life-threatening blood losses can lead to aggressive transfusions or reoperation. Little is known about the risk factors associated with a bleeding tendency in TOF patients. This study aimed to establish predictive models for postoperative blood loss and mortality in TOF patients.
  
  
  METHODS
  We conducted a retrospective observational study involving patients with TOF who were posted for corrective cardiac surgery in a single hospital between 2010 and 2015. Hospital records including sociodemographic, pre- and intra-operative characteristics were extracted. Postoperative blood loss (within 24 and 48 h) and 30-day mortality were the primary and secondary outcomes, respectively. Multivariate linear and logistic regression models were used to identify determinants of outcomes.
  
  
  RESULTS
  A total of 60 patients were included in this study. The median age was 1 year (interquartile range = 0.62-5) and the male to female ratio of 1.7:1. Mean postoperative blood loss within 24 h was 283 ± 212 mL. In multivariate linear regression, preoperative hematocrit (β = 6.63, P = 0.042) and duration of intraoperative oxygenator with CPB (β = 5.16, P = 0.025) were significantly correlated with postoperative blood loss within 24 h. After adjusting for sociodemographic, intra- and post-operative characteristics, preoperative hematocrit (odds ratio [OR] = 1.10, 95% confidence interval [CI] = 1.01-1.21), and postoperative red blood cell transfusions (OR = 3.88, 95% CI = 1.16-12.9) showed statistically significant association with 30-day mortality. The area under the receiver operating characteristic curve of the multivariable model was 0.863.
  
  
  CONCLUSIONS
  Preoperative levels of erythrocytosis appear to predict postoperative blood loss and short-term mortality in TOF patients undergoing corrective surgery.
authors.affiliation: Department of Anesthesiology, Hospital Universitario del Valle, Cali, Colombia.
authors.forename: Jhon Harold
authors.initials: JH
authors.lastname: Guevara
authors.affiliation: Department of Anesthesiology, Hospital Universitario del Valle; Faculty of Health, School of Medicine, Universidad del Valle, Hospital Universitario del Valle, Cali, Colombia.
authors.forename: Andres
authors.initials: A
authors.lastname: Zorrilla-Vaca
authors.affiliation: Department of Anesthesiology, Centro Medico Imbanaco, Cali, Colombia.
authors.forename: Gloria C
authors.initials: GC
authors.lastname: Silva-Gordillo
mesh_terms: D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011086:Polycythemia / Q000097:blood / Q000401:mortality*; D019106:Postoperative Hemorrhage / Q000401:mortality*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013771:Tetralogy of Fallot / Q000401:mortality* / Q000601:surgery*