OBJECTIVEIn major burn wounds of more than 15% total burn surface area mediator-associated reactions lead to capillary leak resulting in critical condition. Little is known about the efficiency of protein substitution. We quantified and qualified the systemic and local protein loss in burn patients during protein substitution, comparing fresh frozen plasma and the human serum protein solution Biseko.METHODSIn 40 patients suffering from second-degree burn wounds with the total burn surface area between 20% and 60%, immediately after admission a defined wound surface area was enclosed with in a wound chamber. Wound fluid and serum samples were collected in 8 hour intervals for 2 days. Samples were analyzed for total protein, albumin, immunoglobulins -A, -G, -M, clotting parameters, c-reactive protein, and white blood cells. Protein substitution started 24 hour posttrauma. In a randomized pattern, patients received equal volumes of fresh frozen plasma or Biseko.RESULTSTotal protein and albumin accumulated in high concentrations in wound fluid. With beginning of fresh frozen plasma substitution on day 2 posttrauma, serum total protein (1.7 g-3.9 g) and albumin (1.3 g-3.4 g) concentrations increased. Substitution of Biseko resulted in a stronger increase (serum total protein 1.8 g to 4.5 g, albumin 0.9 g to 3.4 g). Wound fluid concentrations revealed similar change patterns. Immunoglobulins showed higher serum levels in the Biseko group. C-reactive protein and white blood cell values indicated a lower immunological reaction in the Biseko group.CONCLUSIONSSubstitution of human protein solutions such as Biseko can result in significantly higher serum protein and albumin concentrations as well as lower infection parameters. Higher serum immunoglobulins could help to decrease potential immunodeficiency.