title: Effects of intravenous administration of polymyxin B in neonatal foals with experimental endotoxemia.
abstract: OBJECTIVE
  To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia.
  
  
  METHODS
  Prospective experimental study.
  
  
  METHODS
  14 healthy neonatal foals.
  
  
  METHODS
  Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 μg/kg [0.23 μg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) solution. Subsequent doses of polymyxin B or saline solution were administered IV at 8 and 16 hours. Blood was collected at various time points, and outcome variables, including heart rate, respiratory rate, rectal temperature, attitude score, WBC count, neutrophil count, lymphocyte count, monocyte count, platelet count, Hct, blood lactate concentration, blood glucose concentration, serum tumor necrosis factor-α concentration, and plasma thromboxane B2 concentration, were measured. Urine was collected prior to and after experimentation to determine whether nephrotoxicosis was associated with treatment.
  
  
  RESULTS
  The treatment group had significantly lower blood lactate concentration and serum tumor necrosis factor-α and plasma thromboxane B2 concentrations and had higher blood glucose concentrations and better attitude scores, compared with the control group, at various time points during the study. No other significant differences and no evidence of overt nephrotoxicosis were detected.
  
  
  CONCLUSIONS
  Administration of polymyxin B IV in healthy neonatal foals challenged with lipopolysaccharide attenuated some clinical and serum biochemical derangements associated with endotoxemia.
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA. dwong@iastate.edu
authors.forename: David M
authors.initials: DM
authors.lastname: Wong
authors.forename: Brett A
authors.initials: BA
authors.lastname: Sponseller
authors.forename: Cody J
authors.initials: CJ
authors.lastname: Alcott
authors.forename: Prince N
authors.initials: PN
authors.lastname: Agbedanu
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Walter H
authors.initials: WH
authors.lastname: Hsu
mesh_terms: D061605:Administration, Intravenous; D000818:Animals; D000831:Animals, Newborn; D019446:Endotoxemia / Q000139:chemically induced / Q000188:drug therapy / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008070:Lipopolysaccharides / Q000633:toxicity*; D008297:Male; D011112:Polymyxin B / Q000008:administration & dosage / Q000627:therapeutic use*; D013929:Thromboxane B2 / Q000097:blood; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D013929:Thromboxane B2; D011112:Polymyxin B