title: Effects of pentafraction and hetastarch plasma expansion on lung and soft tissue transvascular fluid filtration.
abstract: BACKGROUND
  Hetastarch and pentafraction are high molecular weight starch solutions designed to augment plasma oncotic pressure. Although clinical utilization of hetastarch has been limited by reported coagulation abnormalities, pentafraction is a newer derivative that appears to have few adverse hemostatic effects. We examined the ability of pentafraction to modulate lung and soft tissue transvascular fluid filtration under hypoproteinemic conditions compared with hetastarch and Ringer's lactate (LR).
  
  
  METHODS
  Awake, protein-depleted sheep (n = 19) were prepared with lung and soft tissue lymph fistulas, and comparable infusions of 5% pentafraction (n = 6), 6% hetastarch (n = 6), or LR (n = 7) were administered. Plasma and lymph samples were collected during 24-hour period to determine changes in protein concentrations, plasma-to-lymph oncotic gradients, and lung (QL) and soft tissue (QS) lymph flows.
  
  
  RESULTS
  QL and QS rose nearly twofold after protein depletion alone. LR infusion increased QL and QS to 8.7 +/- 1.7 and 3.1 +/- 0.6 times normoproteinemic baseline, respectively (p < 0.05). In contrast, hetastarch and pentafraction infusion limited the increase in QL to 4.2 +/- 1.1 and 4.0 +/- 0.8 times normoproteinemic baseline, respectively (p < 0.05 versus LR) and did not significantly increase QS. Hetastarch and pentafraction infusions increase plasma oncotic pressure by nearly 6 mm Hg, which significantly widened the plasma-to-lymph oncotic pressure gradients above preinfusion baseline by 4.7 +/- 0.7 and 3.4 +/- 0.4 mm Hg in lung and 4.6 +/- 0.7 and 3.2 +/- 0.4 mm Hg in soft tissue, respectively (p < 0.05).
  
  
  CONCLUSIONS
  Both hetastarch and pentafraction limit transvascular fluid filtration under hypoproteinemic conditions by augmenting plasma oncotic pressure and the plasma-to-lymph oncotic pressure gradient. Because of fewer adverse hemostatic effects pentafraction may be an improvement over current therapies in critical care fluid management.
authors.affiliation: Department of Surgery, University of Wisconsin Hospital and Clinics, Madison 53792.
authors.forename: G A
authors.initials: GA
authors.lastname: Myers
authors.forename: R L
authors.initials: RL
authors.lastname: Conhaim
authors.forename: D J
authors.initials: DJ
authors.lastname: Rosenfeld
authors.forename: B A
authors.initials: BA
authors.lastname: Harms
mesh_terms: D000818:Animals; D003238:Connective Tissue / Q000098:blood supply*; D006439:Hemodynamics / Q000187:drug effects*; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D008168:Lung / Q000098:blood supply*; D008196:Lymph / Q000502:physiology; D008970:Molecular Weight; D010949:Plasma / Q000502:physiology; D011312:Pressure; D011506:Proteins / Q000378:metabolism; D012756:Sheep
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D011506:Proteins