title: Analysis of particulate contaminations of infusion solutions in a pediatric intensive care unit.
abstract: OBJECTIVE
  To examine the physical properties and chemical composition of particles captured by in-line microfilters in critically ill children, and to investigate the inflammatory and cytotoxic effects of particles on endothelial cells (HUVEC) and macrophages in vitro.
  
  
  METHODS
  Prospective, observational study of microfilters following their use in the pediatric intensive care unit. In vitro model utilizing cytokine assays to investigate the effects of particles on human endothelial cells and murine macrophages.
  
  
  RESULTS
  Twenty filter membranes from nine patients and five controls were examined by electron microscopy (EM) and energy dispersion spectroscopy (EDX). The average number of particles found on the surface of the used membranes was 550 cm(2). EDX analysis confirmed silicon as a major particle constituent. Half of the filter membranes showed conglomerates containing an unaccountable number of smaller particles. In vitro, glass particles were used to mimic the high silicon content particles. HUVEC and murine macrophages were exposed to different contents of particles, and cytokine levels were assayed to assess their immune response. Levels of interleukin-1beta, interleukin-6, interleukin-8, and tumor necrosis factor alpha were suppressed.
  
  
  CONCLUSIONS
  Particle contamination of infusion solutions exists despite a stringent infusion regiment. The number and composition of particles depends on the complexity of the applied admixtures. Beyond possible physical effects, the suppression of macrophage and endothelial cell cytokine secretion in vitro suggests that microparticle infusion in vivo may have immune-modulating effects. Further clinical trials are necessary to determine whether particle retention by in-line filtration has an influence on the outcome of intensive care patients.
authors.affiliation: Department of Pediatric Cardiology and Intensive Care Medicine, Hannover Medical School, Hannover, Germany. Thomasjack@gmx.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Jack
authors.forename: Bernadette E
authors.initials: BE
authors.lastname: Brent
authors.forename: Martin
authors.initials: M
authors.lastname: Boehne
authors.forename: Meike
authors.initials: M
authors.lastname: Müller
authors.forename: Katherina
authors.initials: K
authors.lastname: Sewald
authors.forename: Armin
authors.initials: A
authors.lastname: Braun
authors.forename: Armin
authors.initials: A
authors.lastname: Wessel
authors.forename: Michael
authors.initials: M
authors.lastname: Sasse
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D016638:Critical Illness; D016207:Cytokines / Q000737:chemistry*; D004340:Drug Contamination; D004797:Enzyme-Linked Immunosorbent Assay; D005374:Filtration / Q000295:instrumentation*; D006801:Humans; D007262:Infusions, Intravenous; D015278:Intensive Care Units, Pediatric; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008854:Microscopy, Electron; D010316:Particle Size; D019999:Pharmaceutical Solutions / Q000737:chemistry*; D011446:Prospective Studies; D013052:Spectrometry, X-Ray Emission; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D016207:Cytokines; D019999:Pharmaceutical Solutions