Fatty acid composition of platelet membrane lipids after administration of two different fat emulsions in critically ill patients.

OBJECTIVE: To determine the effects on platelet membrane fatty acid composition following administration of two different fat emulsions. DESIGN: Prospective, randomized, double-blind study. SETTING: Intensive care unit in a university-affiliated hospital. PATIENTS: 12 adult critically ill patients in need of total parenteral nutrition. INTERVENTIONS: Patients were treated with total parenteral nutrition (TPN) for 7 days, receiving for fat intake either a long-chain triglyceride (20% LCT) emulsion (group 1, n=6) or a medium-chain triglyceride-LCT (20% MCT/LCT) emulsion (group 2, n=6). MEASUREMENTS AND RESULTS: High-performance liquid chromatography of membrane fatty acids was carried out before and after 7 days of TPN. In the LCT group, an increase in C18:2n-6 and a decrease in caprylic acid and docosahexaenoic acid, which resulted in a decreased ratio of n-3/n-6 fatty acid content, was observed. In the MCT/LCT group, a reduced percentage of palmitoleic acid and arachidonic acid was shown. CONCLUSIONS: The observed changes in fatty acid composition are in agreement with the lipid composition of the fat emulsions used. Because the C18:2n-6/C18:3n-3 ratio in both emulsions is close (approximately 9.0), the observed changes in the fatty acid composition of platelets may not be relevant for platelet function.

Bibliographic information retrieval in the field of artificial nutrition.

The enormous amount of data available for clinical and research purposes has made information searching a complex task. We have designed a study to determine which bibliographic databases provide appropriate information for the field of artificial nutrition. Of the 149 databases consulted in the preliminary search, 15 were found to contain an appreciable number of titles related to our field. As a general result, we found that MEDLINE had the largest number of titles but other databases oriented toward more specific topics contained references that were unique to them. The results show that an exhaustive search for any topic concerning artificial nutrition must be done on MEDLINE, EMBASE and Current Contents (75% productivity). These can be complemented with others according to their specialization in the subject to be treated. To obtain productivity over 75%, from five to seven databases must be consulted, according to the item under study.

[The assessment of nutritional status in patients over 60 with arteriopathy]. / Valoración del estado nutricional en pacientes mayores de 60 años afectos de arteriopatía.

The nutritional status of patients older than 60 years affected by arteriopathy, who were admitted in a scheduled manner to a Vascular Surgery Department, have been studied. The nutritional status was evaluated upon admittance to the hospital and again upon release from the same, to determine whether this changes during the hospital stay. A total of 93 patients (80 men males and 13 females), with a mean age of 71 years, who were admitted to the hospital during a one year period, were studied prospectively. Among the present risk factors, active smokers or ex-smokers (83.87%), diabetics (32.25%), and the consumption of more than 40 g of alcohol/day (21.5%), should be noted. Upon admittance to the hospital, 43.5% of the studied cases presented mild malnutrition. During the hospital stay, which lasted 26.4 +/- 13.8 days, the nutritional status of these patients was ot modified. It should be noted that the delayed type sensitivity skin tests showed anergy in all cases, which suggests that this parameter is not a good nutritional marker for individuals over 60. Finally, we observe that the lean body mass index did not correlate with the rest of the anthropometric parameters used, which could indicate that age affects the lean body mass more than it does the other body components.

Effect of two lipid emulsions on platelet function.

OBJECTIVE: To examine the effect of two lipid emulsions administered with total parenteral nutrition (TPN) on platelet aggregation and activation and the production of eicosanoids in nonseptic critically ill patients. DESIGN: Prospective, randomized, unblinded, non-crossover study. SETTING: ICU of a general teaching hospital. PATIENTS: 23 adult, critically ill, nonseptic patients, who were in need of TPN for at least 7 days. INTERVENTIONS: The patients were randomly distributed into 2 groups each of which received TPN with a different essential fatty acid content. The 2 lipid emulsions, Intralipid 20% (long-chain triglycerides) and Lipofundin MCT/LCT 20% (10% each of long- and medium-chain triglycerides) provided 43% of the nonprotein caloric requirements calculated for each patient. Parameters demonstrating platelet function (plasma beta-thromboglobulin, platelet factor 4, platelet aggregation, 6-keto-PGF1 alpha) were assessed before starting TPN and after 4 and 7 days of initiation. RESULTS: Before beginning lipid perfusion, platelet activation evaluated by beta TG and PF4 levels was notable, 6-keto-PGF1 alpha production was elevated and no hyperaggregation of platelets was observed in patients. The studies of platelet function at 4 and 7 days of TPN did not show significant changes with respect to the basal data or between the 2 groups. CONCLUSIONS: Our results indicate that platelet function was not affected by either of the 2 lipid emulsions administered to patients during the study period.

[The nutrition of liver transplant patients in an intensive medicine service comparing the years 1989 and 1992]. / Nutrición de los enfermos trasplantados hepáticos en un Servicio de Medicina Intensiva, comparando los años 1989 y 1992.

We examined the possible changes undergone in the form of feeding post liver-transplant patients admitted to our Intensive Care Unit (ICU), comparing 1989 and 1992. As biological nutritional parameters, we reviewed blood lymphocyte values and albumin prior to the transplant, immediately after, seven days following and on discharge from the ICU. In the two periods studied, we assessed the features of the nutritional support received by these patients (type and chronology). We found that, in 1992, parenteral nutrition (in significant form, p = 0.04) and oral diet (as trend, p = 0.06) was initiated earlier than in 1989. We noted a tendency to change the overall nutritional pattern, with an increase seen in 1992 in oral diet and a reduction in parenteral nutritional when compared to the 1989 period. In 1992, 24% of patients received oral diet as a first nutrition as against none in 1989. These data must be correlated with the time in the Intensive Medicine Service and the tendency to reduce mortality, even though transplant patients in 1992 were significantly older than in 1989, while their selection and the base pathology altered the pattern of these patients.

[Carbohydrate and lipid metabolism in the cancer patient]. / Metabolismo de los hidratos de carbono y lípidos en el paciente canceroso.

The role of nutrition in cancer patients is highly important, not just in preventing development of the cancer but also in avoiding greater weight loss accompanying the cancerous cachexia in the evolution of the cancer. The different ways of treating cancer also involve increased deterioration of the nutritional state. To design a correct nutritional strategy for these patients, it is fundamental to understand the anomalies present at the metabolic level, including those affecting the cancer carrying host and those observed in the tumor itself. The results of various studies carried out on animals and neoplastic subjects using predominantly glucose as the non-protein calorie source suggest a stimulating effect on tumor growth. On the other hand, it appears that there is, at the level of the tumor, an inability to correctly oxidize fatty acids. Enhanced knowledge of the different alterations to carbohydrate and fat metabolism found in cancer patients might aid in a better grasp and design of a nutritional strategy aimed at reducing morbidity and mortality in these patients and improving their quality of life.

[The effect of 2 lipid emulsions on platelet function]. / Influencia de dos emulsiones lipídicas en la función plaquetaria.

We examined the effect on platelet aggregation and activation and the production of eicosanoids in nonseptic critical patients of two lipidic emulsions administered with total parenteral nutrition. The two lipidic emulsions, Intralipid (20% of long chain triglycerides) and Lipofundina (10% each of long and medium-chain triglycerides), of differing essential fat acid content, provided 43% of the non-protein calorific requirements calculated for each patient. There were no other variables in the parenteral nutrition administered: the patients were distributed in two groups on a randomized basis according to the type of lipids received. We assessed the parameters demonstrating platelet function before parenteral nutrition, and after 4 and 7 days of such nutrition. Throughout the study, platelet aggregability was seen not to differ significantly from normal, even though the activation parameters controlled, beta TG and PF4, were from the outset significantly higher than normal; the thromboxane B2 averages calculated remained high, with wide individual variability, while averages for 6-keto-PGF1 alpha [correction of 0], which were initially high, showed a tendency (not statistically significant) to drop after 4 and 7 days nutrition. We did not observe that the administration of LCT or MTC/LCT led to changes in platelet aggregation and/or activation in the patients studied.

[Parenteral nutrition: a utilization study in a general hospital]. / Nutrición parenteral: estudio de utilización en un hospital general.

A follow-up of 116 patients initiating parenteral nutrition was performed from December 1990 to March 1991 (average of 18 patients on parenteral nutrition per day, which accounted for a prevalence of 2% compared to total patients admitted), in order to determine a series of characteristics related to the use of parenteral nutrition in our hospital, by means of obtaining concrete, updated information. With regard to the patients, it was observed that 37% of these were suffering from chronic ailments, with more or less incapacitating pathologies. The nutritional state prior to parenteral nutrition was normal in 53% of cases, and the most common reasons for admittance to hospital were neoplasias (27%) and digestive pathology (18%). 42% of the patients were admitted to the ICU and 34% to General Surgery. Indication for parenteral nutrition was intestinal pathology in 23% of cases, followed by pancreatic pathology in 16% of cases and pathology of the oesophagus in 10%; in 45% of cases, it was commenced during the postoperative period. With regard to the composition of the parenteral nutrition, we should mention the use of polyols instead of glucose in 80% of diabetic patients and 75% of patients with pancreatitis, the widespread use of mixture of 50% medium and long chain triglycerides and the use of amino acid solutions with 20% branched chain in most patients, both in situations of stress and maintenance.

[Nutritional support in liver transplantation]. / Soporte nutricional en el trasplante hepático.

Given the malnutrition present in patients suffering from advanced hepatic illness, as well as the implications of this in the post-hepatic transplant period, a study was made of various biochemical parameters (prealbumin, retinol-bound protein, zinc, magnesium, cholesterol and amino acid pattern) as indicators of the nutritional condition of a series of 15 patients who underwent hepatic transplants and required total parenteral nutrition (TPN) during the first 10 post-transplant days. Before the transplants were carried out, all the patients studied showed a decrease in all evaluated parameters. Ten days after the transplant, and having been fed parenterally during this time, the different parameters corrected themselves, with the exception of cholesterol. TPN, administered with enrichment of branched amino acids by 35%, practically normalized the plasma amino acid pattern.

[Somatostatin and/or total parenteral nutrition for the treatment of intestinal fistulas]. / Somatostatina y/o nutrición parenteral total en el tratamiento de las fístulas intestinales.

61 patients with postoperative enterocutaneous fistulas of the small intestine, were admitted to the Intensive Care Unit from 1983 to 1989 and divided in two groups. Group A (n = 46) was treated with Total Parenteral Nutrition (TPN), while B (n = 15) received a combination of TPN and Somatostatin. The reduction of fistula output was significantly greater in group B. Spontaneous closure was observed in 30.4% of the cases in group A and in 53.3% in group B. A significant difference in the time taken to close the fistula between group A and B (29.7 +/- 18 versus 11.1 +/- 1.6 days) was observed.

[The use of immunologic parameters to assess the effectiveness of parenteral nutrition. Preliminary study]. / Utilización de parámetros inmunológicos para valorar la eficacia de la nutrición parenteral. Estudio preliminar.

Malnutrition leads to cellular and humoral immunological response disorders. A study protocol on malnourished patients has been designed in order to assess immune response mechanisms that may be altered due to malnutrition and may or may not recover once normal metabolic conditions have been restored prior to starting the patient on parenteral feeding and control. The immune response was assessed especially regarding immunoglobulin, lymphocyte subsets and mitogen response levels. It is important to know the different malnutrition-related immunologic disorders, disorders secondary to diseases that hinder correct oral feeding, and immunologic tests may be used to assess nutritional parameters. The malnourished patients included in this trial has to be free of any other immunologic or neoplastic disease, and not receive immune response suppression therapy. The trial patients showed lower total and relative CD3 and CD4 lymphocyte values at the onset of the study, although the former lymphocyte subset recuperated sooner at the expense of increasing CD8 lymphocytes, while CD4 lymphocytes still remained low after 15 days of parenteral nutrition. Immunoglobulin levels remained within normal limits. The mitogen response capacity, which was sensibly low at the beginning, recuperated in 50% of the cases treated with parenteral nutrition. This parameters may be used as an index to assess the nutritional status of these patients. The cases studies allowed us to conclude that there was a decrease in CD4 cells and mitogen response in malnourished patients. After 15 days of parenteral nutrition, the cells did not recuperate but their function measured in terms of phytohemagglutinin, was normal in 50% of the cases.

Influence of the qualitative caloric composition of enteral diets on liver protein synthesis in normal and operated rats.

Protein synthesis L-(l-14C) leucine in liver was studied. Normal (n = 40) and operated (n = 40) Sprague-Dawley rats with an initial body weight of 161.18 +/- 12 g were divided into four groups (n = 10), respectively. Each group, subjected to the same conditions of temperature, light, noise and movement received a different commercial formula for human enteral nutrition and water for 8 days (normal rats) and six days (operated rats). All rats received the same caloric and protein intake per ml (l kcal; 6-7.10(-3) g protein), with no statistically significant differences among groups. The differences in diets were merely qualitative. The tolerance to all diets was similar, with rats attaining the expected weight. Losses of protein, alpha aminic nitrogen, total fat and non sterified fatty acid in faeces were negligible. In normal rats, different results in liver protein synthesis were obtained. No mass/synthesis rate correlation was found. Under these conditions it would appear that these results are due to the different diets used. In operated rats, a significantly different liver protein synthesis per gram of body weight was obtained, but not per gram of organ weight. These results suggest that the influence of the qualitative caloric intake, in the stress phase, is less than in the normal state.

Valuation of protein metabolism and albumin in patients submitted to peripheral parenteral nutrition (PPN).

A protein breakdown study was carried out in ten post-operative patients, 24 hours after operation and after five days of peripheral parenteral nutrition; five of these patients were in a good nutritive condition (group A) and five were suffering from malnutrition and were critically ill (group B). Results indicate that the administration of amino-acids achieved a decrease in the degree of protein breakdown in the two groups under study, and also it was observed that better use was made of the nitrogen administered, particularly by the liver when the nitrogenous supply is completed with carbohydrates such as glucose. The difference obtained in values between the oxidized leucine and the leucine administered suggests that there is an endogenous donor pool, and the differences existing between breakdown and leucine oxidation values indicate that in group A, nourished solely with amino-acids, breakdown is lesser and oxidation greater than in group B, nourished with amino-acids and glucose, which suggests that there is more stimulation to re-use the amino-acids in this group.