[Modern aspects of enteral and parenteral feeding of newly operated patients]

In a decisive degree the modern trophotherapy further the decrease of the lethality from operation and of the rate of postoperative complications. In the differential indication between parenteral and enteral nutrition at present an international change takes place. The early enteral nutrition after operative interventions of medium severity is a real alternative to the parenteral nutrition. Therapy concepts for the balanced nutrition of newly operated patients are presented. The intake of nutrition via small intestine is less dangerous than via veins and is clearly more economical.

A modified D-xylose absorption test

A modified D-xylose-test is described which enables intestinal absorption to be assessed independently of renal and hepatic function. The speed of appearance of the peak of D-xylose-concentration in plasma after an oral administrated dose and the extent of absorption in the small intestine as a time-function, were analysed by graphic-mathematical evaluation of the kinetics of plasma D-xylose concentration after oral and intravenous administration. Small intestinal functional integrity was assessed in 172 normal individuals (aged from 3 to 96 years), also in 9 patients with coeliac disease. The speed and the extent of D-xylose absorption were significantly reduced in all cases of untreated coeliac disease and during relapse. There were no differences between normal individuals and treated patients. Experience over many years indicates that the modified D-xylose-test is a simple, reliable and inexpensive standard method for detecting changes in intestinal absorption.

[The thyrotropic function of the hypophysis and peripheral thyroid hormones after removal of bland and autonomous nodular goiters]

Bilateral subtotal resection or enucleation or unilateral resection was performed in 60 patients (36 with bland nodular goitre, 24 with autonomic adenoma). The thyrotropic pituitary activity and the peripheral thyroid function were examined in all patients preoperatively and followed up for 12 months postoperatively. The results show that all patients with bilaterally resected bland nodular goitre require postoperative administration of thyroid hormone, since enhanced thyrotropic activity is seen not later than three months after surgery. Since thyrotropic function remains normal in unilaterally operated nodular goitre, thyroid hormone administration does not appear generally necessary. In patients with autonomic adenoma there is postoperatively variability of function, independent of the surgical method employed. In view of possible functional recompensation, final decision on the administration of thyroid hormones should not be made before the end of the sixth postoperative month. These results can be considered as guidelines for a differentiated postoperative management.

[Small intestinal absorption in cancer patients--basis for enteral feeding therapy in oncology]

A deteriorating nutritional condition combined with the loss of body mass is one of the most noticeable symptoms of cancer. In order to answer the question to what extent absorption disorders in the small intestine are responsible for the malnutrition which develops, we studied 54 oncologic patients using modified D-xylose absorption tests. After the oral and intravenous administration of 10 g D-xylose at different times, the degree of absorption dependent on time was determined on the basis of a biophysical model. When accompanied by general nonspecific tumor symptoms, the frequency of absorption restrictions was increased. An established relation was found between the extent of small intestinal absorption, on the one hand, and the degree of spreading (staging) and the degree of histological differentiation of the carcinoma, on the other hand. Enteral absorption disorders represent a partial cause for the development of malnutrition in cancer patients and must be viewed as a result of a metabolic situation which is distinctly catabolic.

[Protein turnover in liver failure--determination using the stable isotope 15N]

The 15N-tracer technique gives new opportunities to medical research for investigation of normal and pathological nitrogen metabolism. Analysis of 15N kinetic data derived from total nitrogen excretion in the urine allows to calculate quantitatively certain parameters of protein synthesis and protein metabolism. At the same time analysis of serum samples will allow measurement of 15N-nitrogen incorporation into particular protein or non-protein fractions of the plasma. In the study reported here patients with different liver parenchyme lesions (acute hepatitis, chronic active hepatitis, biliary obstruction, cirrhosis of the liver, hepatic coma) were investigated with a standardized 15N-tracer method developed by us. It could be shown, that protein turnover in patients with liver insufficiency is significantly decreased as compared to healthy persons. Decrease of protein synthesis is associated with a still more pronounced decrease of protein catabolism. There are significant differences in dynamics of 15N in patients with hepatic coma as compared to other patients with liver parenchyme disease without portal encephalopathy. Nevertheless, even in hepatic coma 15N incorporation into plasma proteins can be shown. Differences in the 15N elimination kinetics of the non-protein pool between patients with chronic active hepatitis, biliary obstruction and hepatic coma could be found.

[Importance of the modern hospital diet in medical practice]

Hospital diet is an essential part of modern therapy in all medical departments. It comprises both the so-called normal diets which are prepared according to modern nutritional knowledge, dietetic foods and the various forms of artificial nutrition (nutrient-defined and chemically defined diets, parenteral and combined nutrition, i.e. enteral and parenteral nutrition). The integration of nutritional therapeutic problems into the treatment of patients requires optimal scientific and practical forms of organisation of nutrition in the clinic. For that purpose, cooperation of clinical, technical, economic and pedagogic divisions is of prime importance. The organisation of patient nutrition in the St. Georg District Hospital in Leipzig is described as a feasible model.

[Protein synthesis following experimental injuries in the pig as disease model. Comparison of infusion solutions with various amino acid patterns]

This study compares the effect of two amino acid solutions on protein metabolism after injury by measuring nitrogen balance, 15N-elimination, total body protein synthesis and utilisation of administered nitrogen in an experimental study using pigs. Protein synthesis and nitrogen utilisation were determined using a 15N-tracer technique with recourse to mathematical model concepts. The non-surgical control animals had a lower urinary nitrogen excretion, a more favourable nitrogen balance, a higher 15N-retention, greater total body protein synthesis and utilisation of the infused amino acids during infusion of an amino acid solution with a standard amino acid pattern (A) than the operated animals (solution B). Comparison of the post-operative data shows that if solution A is compared with solution B whose amino acid content takes account of changes in plasma amino acid metabolism following trauma, solution B yields the better results in respect of 15N-retention as well as total body protein synthesis and nitrogen utilisation.

[Standardized 15N-tracer method for the assessment of protein metabolism in clinical practice]

A standardized 15N tracer method is described for the assessment of the nitrogen and protein metabolism in healthy and pathological changed organism. The method represents an isotope technical procedure for the application in the clinical research and practice. The single parts of this routine method are: --the clinical preparation of the patient/proband by means of a standardized nutritional regime, --the tracer administration (single dose) and the sampling (urine, blood), --the 15N-tracer technique (sample chemistry, emissions-spectrometric isotope analysis), --the mathematical evaluation of 15N tracer data.

Protein synthesis after experimental injury in pigs. A comparison of infusion solutions with different amino acid patterns

This study compared the effect of three amino acid solutions on protein metabolism after injury by measuring plasma amino acid pattern, nitrogen balance, total body protein synthesis and utilisation of administered nitrogen in an experimental protocol using pigs. Protein synthesis and nitrogen utilisation were determined using a 15N-tracer technique with recourse to mathematical model concepts. Control animals which had not undergone surgery had a lower urinary nitrogen excretion, a more favourable nitrogen balance, greater total body protein synthesis and utilisation of the infused amino acids during the infusion of an amino acid solution with a standard pattern of amino acids (A) than the operated animals infused with either solution A or two other test amino acid solutions B and C. Comparison of the post-operative data showed that if solution A is compared with solution (B) whose amino acid content takes account of changes in plasma amino acids following trauma and a solution (C) which contains a high fraction of branched chain amino acids, solution (B) yields the best results in respect of total body protein synthesis and nitrogen utilisation.

[General practice of nutrition diagnosis]

Important condition for a parenteral, enteral or parenteral-enteral nutrition, especially in patients before extended operations of during conservative therapy, is an exact nutritional assessment before beginning of this therapy. By means of biochemical examinations (visceral proteins), anthropometric measurements (body mass, triceps skinfold, arm muscle circumference, creatinine index) and immunological methods (total lymphocyte count in the blood, skin testing with test antigens) it is possible to classify nutritional conditions in severity and kind of malnutrition. By evaluating the digestive and resorptive capacity it is possible to determine the way of application.

[Hepatic coma - experimental study with swine (part 1)]

An acute coma hepaticum was produced in 8 pigs by means of one intraperitoneal dose of thioacetamide. Distinct changes in the behaviour of the animals, changes of the biochemical parameters inclusively the enzyme pattern with a typical lesion pattern of the liver parenchyma and a displacement of the plasma amino acids were shown. All pathological changes in comparison with the normal animal characterize the liver insufficiency after 24 hours as a comatose state. This acute toxic model serves as the base for investigations within the physiology of nutrition about parenteral feeding of L-amino acid mixtures in coma hepaticum. The nearly exclusive hepatotropic lesion degree of thioacetamide is suitable as an experimental model for this purpose.

[Enteral resorption in the immediate postoperative phase following selective proximal vagotomy]

The postoperative absorption of the small intestine after selective proximal vagotomy was found out by means of the modified D-xylose absorption test in 23 patients on operating day, and on 1st, 5th, 8th, 9th and, 10th postoperative day. The constant of the adsorption speed was reduced on the operating day and decreased further to the 4th postoperative day. Afterwards the preoperative value was obtained approximately. The temporal state of the relative maximum of the curve of serum concentration (the moment tm) occurred in the same time interval. The tm-value obtained the preoperative value approximately. The dimensions of the absorption in the small intestine was reduced by 36% on the operating day, by 20,5% on the 1st postoperative day, and by 10% on the 4th postoperative day on the arithmetical average. The influence of the gastric emptying after SPV and of gastro-intestinal hormones on the process of absorption was discussed.

[Parenteral nutrition - present status and modern trends]

In the present paper practical references for the use of aimed balanced nutrition, particularly of parenteral nutrition, in surgery are given. The complete and total parenteral nutrition is an intervening therapeutic form for the patient. Before the beginning of the nutrition a possibly comprehensive diagnosis of the condition of the nutrition with the help of the state of nutrition is necessary, the volume of which will be depend on the existing diagnostic possibilities of an institution. Moreover, the success and the effectivity of the parenteral nutrition depend on the optimum composition of the nutrient and on a good nutritional technique as well as on an optimum control of the course of nutrition. Taking into consideration the high use for the improvement of the results of treatment a considerable expenditure must be put up with. This means a very strong indication.

Insulin secretion in maturity-onset-diabetes. Function of isolated islets

An impaired insulin response to glucose is a characteristic finding in maturity onset diabetes (MOD). To clarify whether the decreased insulin response in vivo is related to a primary defect of the beta-cells, isolated islets of MOD - obtained by intraoperative biopsy - were examined for their insulin content, biosynthesis and release. The in vitro experiments showed that despite a missing or significantly reduced insulin response in vivo the isolated beta-cells of the same patients had a normal insulin content, a normal or even high biosynthesis, and insulin release could be induced by glucose. These results suggest that the primary defect in MoD cannot be related to an intrinsic failure of the beta-cells to response to glucose; extrapancreatic factors seem to influence their reaction to glucose. These factors may be of a higher level in those patients or the reaction of the beta-cells is more inhibited by the same concentrations in diabetic patients.

[Postoperative small intestinal absorption after cholecystectomy]

The postoperative resorption in the small intestine after cholecystectomie was found out by means of the modified D-xylose resorption test on the 2-th, 4-th, 6-th an 8-th postoperative day for 14 patients. The velocity and the dimension of the enteral resorption of D-xylose was lower in the immediate postoperative phase. The dimension of the D-xylose resorption was normalized on 4. p. o. day and obtained the preoperative starting-value on the 8-th postoperative day. The myoelectrical activity of the small intestine normalized in a shorter time after cholecystectomy than the enteral resorption. A formal parallelism consists between the normalisation of the motoric activity of the stomach and the xylose-resorption in the immidiate postoperative phase. For the small intestine resorption in the postoperative phase completely clarified and required further investigations. The influences of electrolyte displacement and disturbances of the microcirculation in the postoperative period in the small intestine resorption were discussed.

[Intestinal absorption in the short-bowel syndrome]

An extreme diminution of the absorption surface by resection or exclusion of the small intestine leads to the clinical picture of the short-intestine-syndrome. The absorption effect of the proximal small intestine can be exactly established with the help of the modified D-xylose-test. On the basis of three typical examples the high evidence of this functional test can be demonstrated. The pathophysiological principles of the intestinal adaptation after by-pass-operations and resections of the small intestine are discussed.

Zur Verwertung von Aminosäuren-Infusionslösungen beim Gesunden und bei Patienten im Streß, untersucht an ¹⁵N-Glyzin

Unter Anwendung des stabilen Isotops ¹⁵N wurde die Verwertung von Aminosäureninfusionslösung bei Gesunden und bei Patienten im Streß (Zustand nach Cholezystektomie) untersucht. Die Ergebnisse beziehen sich auf Infusionsgeschwindigkeit, Dosierung, Infusionslösung und Glyzin als Tracersubstanz. Es konnte nachgewiesen werden, daß Aminosäuren auch im Streß zur Eiweißsynthese herangezogen werden, wenn auch in geringerem Maße als bei Probanden in ausgeglichenem Stoffwechselzustand. Vom infundierten ¹⁵N verblieben 72 bis 77 % bei ausgeglichener Bilanz und 56 bis 58 % bei kataboler Stoffwechsellage im Organismus. Die Harnstoffbildung lief im Streß verstärkt und beschleunigt ab. Die gefundenen Werte passen gut zu den Resultaten früherer Zufuhr-Bilanz-Versuche an Patienten in verschiedenen Streßlagen. Sie gestatten Aussagen über die Effektivität der parenteralen Aminosäurenzufuhr im Streß.