[Influence of parenteral nutrition on phospholipid metabolism in the rat lung in the posttraumatic period].

Most experimental studies in the field of parenteral nutrition following trauma are aimed at a reduction of catabolism and therefore an improvement of the N-balance. The aim of this study was to investigate the influence of PN on PHL composition in the posttraumatic lung, especially in the surfactant fraction. We compared a carbohydrate - amino acid formula with a formula containing carbohydrate - amino acid - lipid. Polytrauma was performed by single femur fracture plus laparotomy with eventeration of the intestines for 30 minutes and hypovolemia (2 ml/100 g bw). After an adaption phase with reduced caloric supply, full caloric support was given from the 4th to the 14th day (100 Kcal/kg bw/day). The following metabolic parameters were used: N-balance; phospholipid total, -classes, -molecular species and fatty acid pattern of lecithin in lung tissue and lavage (using special HPLC and GC techniques). There were small differences between the groups using standard metabolic parameters (such as nitrogen balance). In contrast, we found significantly altered phospholipid patterns in the lung. With lipid emulsion there was an increased fraction of saturated lecithins (mainly dipalmitoyl phosphatidylcholine). From our data we conclude that it is possible to influence surfactant phospholipid composition by parenteral nutrition through the use of lipid emulsion. This might be useful for posttraumatic lung treatment.