[Perioperative anemia and erythropoiesis]. / Perioperative Anämie und Erythropoese.

50 consecutive patients with hip arthroplasty had acute normovolaemic haemodilution and intra- and postoperative autotransfusion using Autotrans, Dideco GmbH. 18 of 50 patients received homologous blood products additionally to autotransfusion (Hb less than 8 g/dl, hemodynamic instability). There was no evidence for coagulation disorders, hypoxia or hypovolaemia during the whole investigation period (until the 10th p.o. day) though in some cases haemoglobin-levels less than 7 g% were accepted. No variations of erythropoietin levels could be observed postoperatively, suggesting that acute anaemia alone does not affect erythropoiesis. Reticulocytes, however, increased significantly from the 4th postoperative day. There was no correlation between number of reticulocytes and erythropoietin levels. Lactate levels stayed within normal range during the whole investigation period thus indicating normal microcirculation. The present data demonstrate that postoperative anaemia can be tolerated even in elder patients if intravascular volume is kept constant (normovolaemia). In accordance with recent literature the course of erythropoietin levels seemed to prove that there was no functional reduction in oxygen-availability.

[Effect of particle size and emulsifier on pharmacokinetic values of a parenterally administered fat emulsion]. / Uber den Einfluss von Teilchengrösse und Emulgator auf pharmakokinetische Kenndaten einer parenteral applizierten Fettemulsion.

To evaluate pharmacokinetic data during parenteral application of a fat emulsion a controlled study in healthy volunteers was performed. Another aim of the study was to investigate whether these kinetics could be changed by modification of the emulsion. For this purpose, 10 male medical students--free of any metabolic disorders--received modified batches of one fat emulsion (Lipovenös), differing with respect to particle size or emulsifier. The emulsions were applied using a pump-controlled continuous infusion technique. The dosage was calculated according to body weight: 0.1 g/kg B.W./h. There was a 7-10 day interval between one application and the following study period, again using the same volunteers. Thus every volunteer served as his own control. Routine laboratory parameters as well as parameters relating to fat metabolism were measured. While routine laboratory parameters were not statistically different between the groups, pharmacokinetic data showed differences according to the batches used. Highest triglyceride and free fatty acid levels i.s. were present after application of the emulsion with low medium particle size, while lowest levels were found after increasing the particle size to 380 nm. In addition, it could be documented that an increase in medium particle size resulted in higher elimination rate, transfer and pool size. The modified emulsifier led to an additional increase of these effects, thus inducing beneficial metabolic profiles. The results of the present investigation might perhaps enable us to adjust the profile of future fat emulsions, with the aim of optimizing or restoring metabolic hemostasis.

[Modified neuroleptanalgesia with buprenorphine]. / Modifizierte Neuroleptanalgesie mit Buprenorphin.

A modification of neuroleptanalgesia by substituting fentanyl with buprenorphine is presented. Both anaesthesia techniques could be applied alternatively. We did not recognize any significant difference between the two groups concerning haemodynamics, the secretion of the so called stress hormones (antidiuretic hormone, cortisol) as well as the postoperative respiratory depression. The long lasting analgesia, which could be achieved by buprenorphine, can be advantageous in certain surgical interventions. The lack of a potent antagonist for buprenorphine in addition to its longer half-life for--not being of advantage in any anaesthesia--is discussed.