title: Interleukin-6 levels in serum and lung lavage fluid of children undergoing open heart surgery correlate with postoperative morbidity.
abstract: OBJECTIVE
  To evaluate the relationship of perioperative levels of interleukin 6 (IL-6) in serum and bronchoalveolar fluid with morbidity and mortality in children undergoing cardiopulmonary bypass (CPB).
  
  
  METHODS
  Prospective, noninterventional study.
  
  
  METHODS
  Operating room and pediatric intensive care unit (PICU) of a university hospital.
  
  
  METHODS
  None.
  
  
  RESULTS
  IL-6 levels were measured in serum and lung lavage fluid obtained before, during, and after CPB using the B9.9 bioassay. Alveolar epithelial lining fluid (AELF) volume was calculated using the urea correction method. Mean intraoperative AELF IL-6 levels increased fourfold compared to preoperative levels, and mean serum IL-6 levels increased fivefold after CPB. Mean intraoperative AELF IL-6 levels correlated with intraoperative blood transfusion (r2 = 0.18; p = 0.049) and duration of inotropic support (r2 = 0.29; p = 0.009), mechanical ventilation (r2 = 0.24; p = 0.019), and PICU stay (r2 = 0.29; p = 0.008). Mean serum IL-6 levels 2 h after CPB correlated with intraoperative blood transfusion (r2 = 0.3;p = 0.007), and with Pediatric Risk of Mortality score on postoperative day 3 (r2 = 0.24; p = 0.022), and were higher in patients with massive fluid retention (p = 0.014) and in nonsurvivors (p = 0.003).
  
  
  CONCLUSIONS
  Serum and alveolar IL-6 levels increase after CPB, and correlate with postoperative morbidity. Serum IL-6 levels also correlate with mortality. They may be useful in assessing the severity of the systemic inflammatory response after CPB.
authors.affiliation: Division of Pediatric Critical Care and Pulmonary Medicine, Georgetown University Children's Medical Center, Washington, DC 20007, USA. Hauserg@gunet.georgetown.edu
authors.forename: G J
authors.initials: GJ
authors.lastname: Hauser
authors.forename: J
authors.initials: J
authors.lastname: Ben-Ari
authors.forename: M P
authors.initials: MP
authors.lastname: Colvin
authors.forename: H J
authors.initials: HJ
authors.lastname: Dalton
authors.forename: J H
authors.initials: JH
authors.lastname: Hertzog
authors.forename: M
authors.initials: M
authors.lastname: Bearb
authors.forename: R A
authors.initials: RA
authors.lastname: Hopkins
authors.forename: S M
authors.initials: SM
authors.lastname: Walker
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001681:Biological Assay / Q000379:methods / Q000706:statistics & numerical data; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002315:Cardiopulmonary Bypass / Q000401:mortality / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D006330:Heart Defects, Congenital / Q000378:metabolism / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000032:analysis*; D007432:Intraoperative Period; D011183:Postoperative Complications / Q000453:epidemiology / Q000378:metabolism*; D011184:Postoperative Period; D011446:Prospective Studies; D017741:Survivors / Q000706:statistics & numerical data; D018746:Systemic Inflammatory Response Syndrome / Q000453:epidemiology / Q000378:metabolism*
chemical_list: D015850:Interleukin-6