title: Inflammatory response to cardiac bypass in ewe fetuses: effects of steroid administration or continuous hemodiafiltration.
abstract: OBJECTIVE
  We sought to investigate the effectiveness of glucocorticoid administration or continuous venovenous hemodiafiltration on endothelin and corticotropin-releasing factor release or clearance during prolonged fetal cardiac bypass and on the overall performance of fetuses.
  
  
  METHODS
  Circulating endothelin 1, 2, and 3 and corticotropin-releasing factor levels were measured in fetal ewes during a 60-minute cardiac bypass period performed with an inline axial flow pump. Blood samples were collected before, during, and 90 minutes after cardiac bypass. Animals were divided into 4 groups. The betamethasone group (n = 6) received maternal treatment with 12 mg of betamethasone 1 and 2 days before the experiment. The methylprednisolone group (n = 5) received fetal treatment with 40 mg/kg intravenous methylprednisolone at the beginning of cardiac bypass. The continuous venovenous hemodiafiltration group (n = 4) underwent continuous venovenous hemodiafiltration with a 0.3-m(2) polysulfone filter during cardiac bypass. The final group was the control group (n = 4).
  
  
  RESULTS
  Maternal steroid pretreatment failed to decrease endothelin or corticotropin-releasing factor production when compared with levels in the control animals. Fetal treatment with methylprednisolone produced a significant decrease in endothelin 2 production during cardiac bypass (P <.02) and endothelin 1 production at the end of the experiment (P <.02). Continuous venovenous hemodiafiltration blocked completely the increase of endothelin and corticotropin-releasing factor levels during cardiac bypass (P <.02), which was maintained 90 minutes after cardiac bypass. Acid-base balance was preserved during cardiac bypass by the continuous venovenous hemodiafiltration but worsened after disconnection of the extracorporeal circuit, whereas animals treated with methylprednisolone had better pH, Paco(2), and bicarbonate levels by the end of the experiment. The overall tolerance of the procedure was better in the continuous venovenous hemodiafiltration group during cardiac bypass and in the methylprednisolone group at the end of the experiment.
  
  
  CONCLUSIONS
  Continuous venovenous hemodiafiltration provides sustained stability of endothelin levels during fetal cardiac bypass. This technique might help, in association with fetal steroid treatment, to contain the inflammatory response leading to postbypass placental dysfunction.
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Ospedale Bambino Gesu', Rome, Italy. carotti@opbg.net
authors.forename: Adriano
authors.initials: A
authors.lastname: Carotti
authors.forename: Francesco
authors.initials: F
authors.lastname: Emma
authors.forename: Stefano
authors.initials: S
authors.lastname: Picca
authors.forename: Enrico
authors.initials: E
authors.lastname: Iannace
authors.forename: Sonia B
authors.initials: SB
authors.lastname: Albanese
authors.forename: Mauro
authors.initials: M
authors.lastname: Grigioni
authors.forename: Francesco
authors.initials: F
authors.lastname: Meo
authors.forename: Mario
authors.initials: M
authors.lastname: Sciarra
authors.forename: Roberto M
authors.initials: RM
authors.lastname: Di Donato
mesh_terms: D000136:Acid-Base Equilibrium; D000818:Animals; D001623:Betamethasone / Q000008:administration & dosage; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D016232:Endothelins / Q000097:blood*; D005112:Extracorporeal Circulation; D005260:Female; D005333:Fetus / Q000601:surgery*; D005938:Glucocorticoids / Q000008:administration & dosage*; D017583:Hemodiafiltration; D008775:Methylprednisolone / Q000008:administration & dosage; D011247:Pregnancy; D012756:Sheep
chemical_list: D016232:Endothelins; D005938:Glucocorticoids; D003346:Corticotropin-Releasing Hormone; D001623:Betamethasone; D008775:Methylprednisolone