title: Evaluating abdominal oedema during experimental sepsis using an isotope technique.
abstract: OBJECTIVE
  Abdominal oedema is common in sepsis. A technique for the study of such oedema may guide in the fluid regime of these patients.
  
  
  METHODS
  We modified a double-isotope technique to evaluate abdominal organ oedema and fluid extravasation in 24 healthy or endotoxin-exposed ('septic') piglets. Two different markers were used: red blood cells (RBC) labelled with Technetium-99m ((99m)Tc) and Transferrin labelled with Indium111 ((111)In). Images were acquired on a dual-head gamma camera. Microscopic evaluation of tissue biopsies was performed to compare data with the isotope technique.
  
  
  RESULTS
  No (99m)Tc activity was measured in the plasma fraction in blood sampled after labelling. Similarly, after molecular size gel chromatography, (111)In activity was exclusively found in the high molecular fraction of the plasma. Extravasation of transferrin, indicating the degree of abdominal oedema, was 4·06 times higher in the LPS group compared to the healthy controls (P<0·0001). Abdominal free fluid, studied in 3 animals, had as high (111)In activity as in plasma, but no (99m)Tc activity. Intestinal lymphatic vessel size was higher in LPS (3·7 ± 1·1 μm) compared to control animals (0·6 + 0·2 μm; P<0·001) and oedema correlated to villus diameter (R(2) = 0·918) and lymphatic diameter (R(2) = 0·758). A correlation between a normalized index of oedema formation (NI) and intra-abdominal pressure (IAP) was also found: NI = 0·46*IAP-3·3 (R(2) = 0·56).
  
  
  CONCLUSIONS
  The technique enables almost continuous recording of abdominal oedema formation and may be a valuable tool in experimental research, with the potential to be applied in the clinic.
authors.affiliation: Hedenstierna Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Marco
authors.initials: M
authors.lastname: Lattuada
authors.forename: Enn
authors.initials: E
authors.lastname: Maripuu
authors.forename: Carl Hard af
authors.initials: CH
authors.lastname: Segerstad
authors.forename: Hans
authors.initials: H
authors.lastname: Lundqvist
authors.forename: Göran
authors.initials: G
authors.lastname: Hedenstierna
mesh_terms: D000005:Abdomen; D000818:Animals; D001706:Biopsy; D002199:Capillary Permeability; D004195:Disease Models, Animal; D004487:Edema / Q000097:blood / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D004731:Endotoxins; D004912:Erythrocytes / Q000378:metabolism; D007205:Indium Radioisotopes / Q000097:blood / Q000493:pharmacokinetics; D042601:Lymphatic Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D008991:Monitoring, Physiologic / Q000379:methods*; D011485:Protein Binding; D011877:Radionuclide Imaging; D018805:Sepsis / Q000097:blood / Q000139:chemically induced / Q000150:complications*; D013552:Swine; D013667:Technetium / Q000097:blood / Q000493:pharmacokinetics; D014168:Transferrin / Q000378:metabolism
chemical_list: D004731:Endotoxins; D007205:Indium Radioisotopes; D014168:Transferrin; C044101:endotoxin, Escherichia coli; D013667:Technetium