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Biomedical subjects

A Leutenegger

Publications and source records attributed to A Leutenegger.

89 records · Page 5Linked to original sources

Glucagon, insulin, cortisol, and growth hormone levels following major surgery: their relationship to glucose and free fatty acid elevations.

Circulating hormone and substrate levels were measured in 7 patients at regular intervals before, during and after pulmonary surgery. During surgery, cortisol and growth hormone were significantly elevated, pancreatic glucagon was unchanged and insulin was depressed. One and two days after surgery, growth hormone had almost returned to preoperative fasting values, but cortisol, insulin and glucagon levels were significantly increased. The mean insulin:glucagon molar ratio declined from a preoperative fasting value of 3.2 +/- 0.5 (+/- SEM) to 1.7 +/- 0.4 during operation but was within normal limits 1 and 2 days after surgery due to a parallel rise and fall in plasma insulin and glucagon. Plasma glucose was elevated both during operation and for several days thereafter, whereas free fatty acid levels were increased only during operation. Thus, there was no consistent relation between insulin:glucagon ratio or any of the hormone levels and the observed elevations in plasma glucose and free fatty acids. It is concluded that neither any of the hormones assayed nor the insulin:glucagon ratio was the primary determinant of plasma glucose and free fatty acid responses to surgery. Rather, fuel homeostasis appeared to result from the combined effects of glucagon, insulin, growth hormone, cortisol and adrenergic activity.

Adult↗

[Parenteral hyperalimentation (author's transl)].

Intravenous hyperalimentation allows complete nutrition and anabolism in patients who cannot be fed by the oral route. However, several complications have been reported, e.g. septicaemia and hyperglycaemina. In 51 intensive-care patients receiving hyperalimentation, 18% were found to be hyperglycaemic in spite of insulin administration. Hyperglycaemia was frequently associated with stress. In 8 patients undergoing major surgery, which was chosen as a stress model, decreased insulin and increased glucagon, growth hormone and cortisone levels were observed. These findings could explain stress-induced glucose intolerance. In a further experiment, 8 intensive-care patients were given alternative intravenous feedings with either 600g of a mixture of glucose, fructose and xylitol in a ration of 1:2:1 or 600g glucose per day. During both regimens insulin administration was required in 4 patients, but the insulin dosage was lower with the mixture. Plasma glucose during glucose infusion was 205+/-25mg/100ml(M+/-SEM) and the sum of plasma glucose, fructose and xylitol during infusion of the mixture was 176+/-33mg/100ml, the difference being of borderline significance (p less than 0.05). The advantages and disadvantages of infusable substrates are summarized on the basis of the available literature and it is concluded that, in general, glucose is preferable. However, if hyperglycaemia is difficult to control, partial replacement of glucose by glucose substitutes or fat emulsions may be advantageous. A routine infusion programme for central venous feeding is suggested. Causes and prevention of side-effects are reviewed. In many patients receiving central venous nutrition less hazardous and less expensive methods could be used such as nasogastric tube feeding, elemental diet or peripheral venous nutrition.

Blood Glucose↗

[Elementary diet as an alternative to parenteral feeding in severe gastrointestinal diseases].

21 patients with gastroenterological disease and indication for the use of intravenous nutrition received an elemental diet (ED) for 5-44 days. In 6 out of 8 patients with exacerbation of Crohn's disease remissions were achieved, apart from 3 persistent fistulas. In 5 out of 9 cases with various primary diseases and postoperative intestinal fistulas, spontaneous healing was observed. Furthermore, 2 patients with ulcerative colitis, 1 with radiation enteritis and 1 with pancreatitis were treated with ED. On ED, hemoglobin increased from 11.3 +/- 0.4 (m +/- SEM) to 12.0 +/- 0.5 g% (p less than 0.01) and serum albumin from 2.7 +/- 0.1 to 3.4 +/- 0.1 g% (p less than 0.001). Nitrogen requirements were studied in 11 patients receiving various quantities of ED. Nitrogen balance was found to be in equilibrium or positive in 7 patients, and negative in 4. In one patient with severe ulcerative colitis, fecal nitrogen losses were higher than urinary nitrogen losses. The unpleasant taste of ED resulting from free amino acids limited the ED supply in 3 patients and led to premature ending of ED administration in 3 other patients. In such cases ED may be given by nasogastric tube feeding. From the results presented it appears that ED is indicated in Crohn's disease and intestinal fistulas. However, the results obtained require confirmation by further observations and comparison with an intravenously fed control group.

Adolescent↗

Comparison of glucose and fructose tolerance before and after starvation.

Glucose and fructose were studied in eight healthy volunteers who fasted twice for 4 days. Before and after the fasts each subject received a 4-hr glucose or fructose infusion providing 0.5 g/kg/hr. Glucose infusion during starvation resulted in a mean maximal plasma glucose rise of 401 +/- 21 mg/100 ml (+/- SEM) as compared to 119 +/- 10 mg/100 ml before starvation. Insulin/glucose ratios were lower than normal in fasted subjects. Fructose infusion during fasting produced a maximal plasma glucose rise of 91 +/- 9 mg/100 ml as opposed to 5+/-1 mg/100 ml before starvation. During fructose infusion in the fasted state, plasma fructose levels were higher than control and the rise in blood lactate and pyruvate was delayed, but finally lactate concentrations were above control values. The antiketotic effects of intravenous glucose and fructose were similar during fasting but fructose was significantly less potent in reducing free fatty acid levels. After starvation, urinary carbohydrate losses during glucose infusion were 5 times higher than those observed during fructose infusion. Thus, fructose utillization was less impaired during fasting than was glucose utilization, although fasting induced abnormalities in both glucose and fructose metabolism.

Adult↗

Postoperative tolerance to glucose and sugar substitutes.

In 51 surgical intensive-care patients, who were given 400 to 650 g glucose per day i.v., 18% of arterial blood sugar values were found to be above 250 mg/100 m1 in spite of frequent insulin administration. In 8 lobectomized patients increased plasma levels of pancreatic glucagon, cortisol, and growth hormone were observed which may in part explain postoperative glucose intolerance. In addition previous carbohydrate deprivation was found to impair glucose tolerance. Several measures are suggested to reduce the incidence of hyperglycemia during i.v. glucose feeding. In a further study 24 cholecystectomized or vagotomized patients received in alternate sequence either a combination of glucose (G), fructose (F) and xylitol (X), the G/F/X-ratio being 1/2/1, or glucose alone for 5 days. The infusion rate was 1.42 g carbohydrate/kg/24 hrs. On operation day and was increased by the same amount every day up to 7.14 g/kg/24 hrs. Tolerance was good in both groups but urinary losses of infused substrates were higher in the group receiving the GFX-combination. It is concluded that after surgery of intermediate magnitude the GFX-combination offers no advantage over glucose alone. However, in severely ill patients, where glucose intolerance is more pronounced, further carefully monitored studies with sugar substitutes appear of interest.

Adult↗