Role of nutrition in the management of malnutrition and immune dysfunction of trauma

Bacterial dissemination and metabolic changes in rats induced by endotoxemia following intestinal E. coli overgrowth are reduced by ornithine alpha-ketoglutarate administration

The efficacy of ornithine alpha-ketoglutarate (OKG) in preventing bacterial translocation and dissemination, metabolic disorders and changes in mucosal enzyme activities was assessed in a model of bacterial translocation in rats. Antibiotic decontamination was performed 4 d before intragastric inoculation with an Escherichia coli strain (10(10) bacteria/kg body). Two days later, the rats were given either a lipopolysaccharide (LPS) 0127:B8 or a saline injection and were deprived of food for 24 h. Enteral nutrition, [Osmolite, 880 kJ/(kg. d)] supplemented with either OKG (LPS + OKG) or glycine (Saline + Gly or LPS + Gly), was then given for 2 d. Urinary total nitrogen losses and 3-methylhistidine excretion were determined daily. On killing at d 3, bacterial translocation to the mesenteric lymph nodes (MLN) and dissemination to the spleen and liver were evaluated, jejunal mucosa enzyme activities were assayed and tissue free amino acids in muscles were measured. Endotoxin induced translocation from the gut lumen to the MLN in all groups, whereas dissemination occurred only in LPS-treated rats. OKG significantly reduced dissemination of the bacteria in the spleen. 3-Methylhistidine excretion was greater in the LPS + Gly group (+25%, P: < 0.05) than in either the LPS + OKG or Saline + Gly group. The group fed the OKG-enriched diet had higher muscular glutamine, ornithine and arginine concentrations than did the Gly-supplemented groups (P: < 0.05). Intestinal sucrase and aminopeptidase activities were higher in the LPS + OKG group than in the LPS + Gly group (-30%, P: < 0.05). OKG supplementation limits bacterial dissemination and metabolic changes after injury in rats and thus may be useful in the prevention of gut-derived sepsis in critically ill patients.

Bacterial dissemination, rather than translocation, mediates hypermetabolic response in endotoxemic rats

OBJECTIVE

To study the pathogenesis of the host response during bacterial translocation, a rat model was designed for prolonged follow-up after injury.

DESIGN

A prospective, controlled animal study.

SETTING

Animal laboratory.

SUBJECTS

Young male Wistar rats.

INTERVENTIONS

Antibiotic decontamination of rats was performed 4 days before intragastric inoculation with a selected Escherichia coli strain (10(10) bacteria/kg of body weight). Two days later, the rats received a lipopolysaccharide injection or not (control group) and were observed for 3 days. They were then killed. A reference group (pair-fed healthy animals) was studied in parallel.

MEASUREMENTS AND MAIN RESULTS

During observations, urinary total nitrogen loss and 3-methylhistidine excretion were determined daily. When the rats were killed, mesenteric lymph nodes (MLNs), spleen, and liver were aseptically removed and cultured. Colonies identified as translocated E. coli were counted in each organ. Intracellular amino acid free pools were measured in extensor digitorum longus and anterior tibialis. Endotoxin induces bacterial translocation of bacteria from gut lumen to MLNs (100% vs. 59% in the lipopolysaccharide-untreated control group; p < .05) and dissemination to spleen and liver (65% and 45% of positive cultures after endotoxemia, respectively, vs. 6% and 12% in the control groups). No translocation occurred in the reference group. Evidence for the hypermetabolic response was seen in lipopolysaccharide-treated and infected rats, but protein catabolism was more closely related to the occurrence of bacterial dissemination to spleen and liver than to translocation alone (e.g., the cumulative 3-methylhistidine excretion during the observation period was 4.07+/-0.18 micromol in uninfected rats, 4.48+/-0.29 in rats with positive MLN cultures alone and 6.17+/-0.30 in MLN, spleen, or liver infected rats; 1 vs. 2, NS; 3 vs. 1, and 3 vs. 2, p < .05).

CONCLUSIONS

Gut barrier failure is associated with a deep excessive catabolic response in the host. The mechanism by which the metabolic state affects the resistance to infection apparently involves amino acid metabolism.

Early postoperative enteral immunonutrition: clinical outcome and cost-comparison analysis in surgical patients

OBJECTIVE

To determine if early postoperative feeding of patients with upper gastrointestinal malignancy, using an enteral diet supplemented with arginine, dietary nucleotides, and omega-3 fatty acids (IMPACT, Sandoz Nutrition, Bern, Switzerland) results in an improved clinical outcome, i.e., reduced infectious and wound complications and decreased treatment costs when compared with an isocaloric, isonitrogenous control diet.

DESIGN

A prospective, randomized, placebo-controlled, double-blind, multicenter trial of the clinical outcome and a retrospective cost-comparison analysis.

SETTING

Surgical intensive care units in three different German university hospitals.

PATIENTS

Of 164 patients enrolled in the study, 154 patients were eligible for analysis. They were admitted to the intensive care unit after upper gastrointestinal surgery for cancer and they received an enteral diet via needle catheter jejunostomy. Infectious complications were defined as sepsis or systemic inflammatory response syndrome, pneumonia, urinary tract infection, central venous catheter sepsis, wound infection, and anastomotic leakage. The complication events were prospectively divided into two groups: early (postoperative days 1 to 5) and late (after the fifth postoperative day) postoperative complications. The treatment costs of each complication were analyzed and compared in both groups.

INTERVENTIONS

Patients were randomized to receive either the immunonutritional diet (n = 77) or an isocaloric and isonitrogenous placebo diet (n = 77). Enteral feeding was initiated 12 to 24 hrs after surgery, starting with 20 mL/hr and advanced to a target volume of 80 mL/hr by postoperative day 5.

MEASUREMENTS AND MAIN RESULTS

Clinical examination and adverse gastrointestinal symptoms were recorded on a daily basis. Both groups tolerated early enteral feeding well, and the rate of tube feeding-related complications was low. Postoperative complications occurred in 17 patients in the immunonutrition group vs. 24 patients in the control group (NS). Further, in the early phase (postoperative day 1 to 5), complications occurred to a similar extent in both groups (12 patients in the immunonutritional group vs. 11 patients in the control group). However, in the late phase (after postoperative day 5), considerably fewer patients in the experimental diet group experienced complications compared with the control group (5 vs. 13, p < .05). In addition, the frequency rate of complicating events were recorded in each group. In the experimental diet group, a total of 22 complicating events were recorded vs. a total of 32 events in the placebo diet group (NS). However, the occurrence of late complicating events, i.e., complicating events after the fifth postoperative day, was significantly reduced in the immunonutrition group when compared with the control group (8 vs. 17 events, p < .05). The total costs for the treatment of the complications were 83,563 German marks in the experimental diet group vs. 122,430 German marks in the control group, resulting in a cost-reduction of 38,867 German marks. (At the end of December 1995, the conversion rate from German marks to U.S. dollars was 1.4365 German marks to $1.00.)

CONCLUSIONS

Early enteral feeding with an arginine, dietary nucleotides, and omega-3 fatty acids supplemented diet, as well as an isonitrogenous, isocaloric control diet (placebo) were well tolerated in patients who underwent upper gastrointestinal surgery. In patients who received the supplemented diet, a significant reduction in the frequency rate of late postoperative infectious and wound complications was observed. Thereby, the treatment costs were substantially reduced in the immunonutrition group as compared with the control group.

A prospective, randomized trial of intravenous fat emulsion administration in trauma victims requiring total parenteral nutrition

OBJECTIVE

Intravenous fat infusions are a standard component of total parenteral nutrition (TPN). We studied the effects of withholding fat infusions in trauma patients requiring TPN.

DESIGN

Polytrauma patients receiving TPN were randomized to receive a standard fat emulsion dose (L) or to have fat infusions withheld (NL) for the first 10 days of TPN. The two groups received the same amino acid and carbohydrate dose (isonitrogenous, nonisocaloric).

MATERIALS AND METHODS

Clinical outcome parameters were measured. T-cell function was assessed by measuring lymphokine activated killer and natural killer cell activity.

MEASUREMENTS AND MAIN RESULTS

Demographics including Injury Severity Score (27 +/- 8; 30 +/- 9) and APACHE II scores (23 +/- 6; 22 +/- 5) were similar for the L (n = 30) and NL (n = 27) groups, respectively. Differences (p < 0.05) were found in length of hospitalization (L = 39 +/- 24; NL = 27 +/- 16), intensive care unit length of stay (L = 29 +/- 22; NL = 18 +/- 12), and days on mechanical ventilation (L = 27 +/- 21; NL = 15 +/- 12). The L group had a higher number of infections (72 in 30) than the NL group (39 in 27) and T-cell function was depressed in this group.

CONCLUSIONS

Intravenous fat emulsion infusions during the early postinjury period increased susceptibility to infection, prolonged pulmonary failure, and delayed recovery in critically injured patients. It is not clear whether the improved outcome in the NL group was directly related to withholding the fat infusions or due to the hypocaloric nutritional regimen (underfeeding) these patients received.

Immune responses during recovery from protein-energy malnutrition

Protein-energy malnutrition (PEM) is a worldwide problem. Infants and children from developing countries and elderly people from all around the world are the two main groups suffering from PEM. PEM induces profound immunodeficiency, characterized mainly by decreased cell-mediated immunity, and also by decreased humoral and non-specific immunity. Non-specific immune deficiency is of particular importance for defences against infections and its decrease in PEM may further deteriorate nutritional and immune status, pushing patients into a vicious and dramatic circle. Refeeding such patients and the restoration of their nutritional status lead to improvement in all immune responses: a strong association between the evolution of these two responses is always observed during refeeding. The need for specific nutrients to restore immune functions during refeeding of PEM patient has been extensively studied in the past years. This review describes the pathophysiological mechanisms of immune consequences of PEM and of immune restoration with refeeding, and in addition focuses upon some nutrients of particular importance, namely glutamine, zinc and vitamin E. Particular attention is directed at the elderly patients with PEM, a growing population for which the importance of undernutrition on prognosis is not yet fully recognized.

Program characteristics of home-delivered meals programs for persons with HIV and AIDS

The nutritional status of persons with HIV and AIDS [PWAs] is constantly challenged throughout the progression of the illness. Home-delivered meals programs for PWAs are rapidly developing across the country to address this problem among the growing population of people with HIV infection and AIDS. This study examined client socio-demographic characteristics (sex, age, ethnicity), types of services offered by these programs, organizational and financial criteria, and characteristics of survey respondents. Data for this study was obtained from 15 of the 17 known home-delivered meals programs for PWAs in the United States through an original, cross-sectional survey instrument conducted by telephone interview between March 1994 and May 1994. Results from this study show an increase in the number of minority populations who participate in these programs (36% African-American and 12% Hispanic vs. 51% Caucasian), as well as women (17.2%) and children (7%). Geographic location was an important determinant for program eligibility. The number of meals served weekly varied greatly (from 510 to 12,600 per week). Other significant services included nutrition counselling, newsletters, and holiday-basket programs. Enhancing service-delivery systems was one of the more prevalent "high-priority" concerns cited, especially with regard to food quality and safety. These results show that these programs are catering increasingly to minority populations, women and children, and that they are expanding their services to meet the growing needs of their client populations. These findings suggest that there is a greater need for meals and other home-based services for persons living with HIV and AIDS.

The value and limitations of L-arginine infusion on glomerular and tubular function in the ischemic/reperfused kidney

PURPOSE

The nitric oxide precursor, L-arginine, has been shown to have a salutary effect on ischemia and reperfusion injury in skeletal muscle, skin, and intestines. Because L-arginine also increases renal blood flow, glomerular filtration, and urine flow in experimental animals with normal renal function, we postulated that L-arginine may also improve renal function after renal ischemic injury.

METHODS

Eighteen adult New Zealand white rabbits weighing 3 to 3.5 kg were subjected to bilateral normothermic renal ischemia by clamping both renal pedicles for 1 hour followed by 2 hours of reperfusion. The animals were randomized into three groups: group I (control, n = 6) received no additional treatment; group II (pretreatment, n = 6) received systemic intravenous L-arginine at 150 mg/kg over 20 minutes before induction of ischemia; group III (posttreatment, n = 6) received systemic intravenous L-arginine at 150 mg/kg over 20 minutes from the onset of reperfusion. Urine flow, creatinine clearance (CCR), fractional excretion of sodium (FENa), and renal failure index (RFI) were calculated before ischemia and 2 hours after reperfusion, by use of standard formulas. The changes of the various renal parameters were compared among the three groups.

RESULTS

Bilateral normothermic renal ischemia for 1 hour produced a significant deterioration of glomerular filtration as evidenced by a CCR decrease from 11.1 +/- 1.8 to 2.49 +/- 0.9 ml/min (p < 0.01), FENa increase from 2.9% +/- 1.0% to 20.8% +/- 1.5% (p < 0.01) and RFI increase from 4.0 +/- 1.3 to 28.8 +/- 2.6 (p < 0.01). Pretreatment with L-arginine (group II) minimized the deleterious effects caused by ischemia on glomerular filtration (CCR of 2.49 +/- 0.9 ml/min in group I vs 4.95 +/- 2.5 ml/min in group II, p < 0.05) and tubular function (FENa of 20.8% +/- 1.5% in group I vs 13.0% +/- 5.6% in group II and RFI of 28.8 +/- 2.6 in group I vs 18.6 +/- 8.0 in group II, p < 0.05). Infusion of L-arginine at the onset of reperfusion (group III) produced a significant diuretic effect (urine flow from 32.6 +/- 13.4 ml/hr in group I to 63.3 +/- 18.8 ml/hr in group III, p < 0.05) and also minimized glomerular damage (CCR from 2.49 +/- 0.9 ml/min in group I to 4.80 +/- 1.2 ml/min in group III, p < 0.05); however, no beneficial effect was observed on tubular function.

CONCLUSION

Induction of nitric oxide production by systemic L-arginine infusion can best preserve glomerular and tubular function in the ischemic/reperfused kidney when given before the ischemic insult.

Early enteral administration of a formula (Impact) supplemented with arginine, nucleotides, and fish oil in intensive care unit patients: results of a multicenter, prospective, randomized, clinical trial

OBJECTIVE

To determine if early enteral feeding, in an intensive care unit (ICU) patient population, using a formula supplemented with arginine, dietary nucleotides, and fish oil (Impact), results in a shorter hospital stay and a reduced frequency of infectious complications, when compared with feeding a common use enteral formula (Osmolite.HN).

DESIGN

A prospective, randomized, double-blind, multicenter trial.

SETTING

ICUs in eight different hospitals.

PATIENTS

Of 326 patients enrolled in the study, 296 patients were eligible for analysis. They were admitted to the ICU after an event such as trauma, surgery, or sepsis, and met a risk assessment screen (Acute Physiology and Chronic Health Evaluation II [APACHE II] score of > or = 10, or a Therapeutic Intervention Scoring System score of > or = 20) and study eligibility requirements. Patients were stratified by age (< 60 or > or = 60 yrs of age) and disease (septic or systemic inflammatory response syndrome).

INTERVENTIONS

Patients were enrolled and full-strength tube feedings were initiated within 48 hrs of the study entry event. Enteral feedings were advanced to a target volume of 60 mL/hr by 96 hrs of the event. One hundred sixty-eight patients were randomized to receive the experimental formula, and 158 patients were randomized to receive the common use control formula.

MEASUREMENTS AND MAIN RESULTS

Both groups tolerated early enteral feeding well, and the frequency of tube feeding-related complications was low. There were no significant differences in nitrogen balance between groups on study days 4 and 7. Patients receiving the experimental formula had a significant (p = .0001) increase in plasma arginine and ornithine concentrations by study day 7. Plasma fatty acid profiles demonstrated higher concentrations of linoleic acid (p < .01) in the patients receiving the common use formula and higher concentrations of eicosapentaenoic and docosahexaenoic acid (p < .01) in the patients receiving the experimental formula. The mortality rate was not different between the groups and was significantly (p < .001) lower than predicted by the admission severity scores in both feeding groups. In patients who received at least 821 mL/day of the experimental formula, the hospital median length of stay was reduced by 8 days (p < .05). In patients stratified as septic, the median length of hospital stay was reduced by 10 days (p < .05), along with a major reduction in the frequency of acquired infections (p < .01) in the patients who received the experimental formula. In the septic subgroup fed at least 821 mL/day, the median length of stay was reduced by 11.5 days, along with a major reduction in acquired infections (both p < .05) in the patients who received the experimental formula.

CONCLUSIONS

Early enteral feeding of the experimental formula was safe and well tolerated in ICU patients. In patients who received the experimental formula, particularly if they were septic on admission to the study, a substantial reduction in hospital length of stay was observed, along with a significant reduction in the frequency of acquired infections.