***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Objective To evaluate the potential clinical , metabolic , and economic advantages of enteral nutrition over total parenteral nutrition . Design Prospect i ve , r and omized clinical trial . Setting Department of surgery in a university hospital . Patients Two hundred and fifty-seven patients with cancer of the stomach ( n = 121 ) , pancreas ( n = 110 ) , or esophagus ( n = 26 ) were r and omized to receive postoperative total parenteral nutrition ( TPN group , n = 131 ) or early enteral nutrition ( EEN group , n = 126 ) . The nutritional goal was 25 kcal/kg/day . The two nutritional formulas were isocaloric and isonitrogenous , and they were continued until oral intake was at least 800 kcal/day . Measurements Morbidity , mortality , length of hospital stay , and treatment costs were evaluated in all patients . In 40 consecutive patients , selected nutritional , immunologic and inflammatory variables were studied . Moreover , intestinal oxygen tension was evaluated by micropolarographic implantable probes . Main Results The nutritional goal was reached in 100/126 ( 79.3 % ) patients in the EEN group and in 128/131 ( 97.7 % ) patients in the TPN group ( p < .001 ) . In the EEN group , hyperglycemia ( serum glucose , > 200 mg/dL ) was observed in 4.7 % of the patients vs. 9.1 % in the TPN group ( p = NS ) . Alteration of serum electrolyte levels was 3.9 % in the EEN group vs. 13.7 % in the TPN group ( p < .01 ) . No significant difference was found in nutritional , immunologic , and inflammatory variables between the two groups . The overall complication rate was similar ( 40.4 % for TPN vs. 35.7 % , for EEN;p = .52 ) . No difference was detected for either infectious or noninfectious complications , length of hospital stay , and mortality . From postoperative day 5 , intestinal oxygen tension recovered faster in the EEN group than in the TPN group ( 43 ± 5 mm Hg vs. 31 ± 4 mm Hg at day 7;p < .001 ) . EEN was four-fold less expensive than TPN ( $ 25 vs. $ 90.60/day , respectively ) . Conclusion EEN represents a rational alternative to TPN in patients who undergo upper gastrointestinal tract surgery for cancer and who clinical ly require postoperative artificial nutrition Objectives : To investigate direct postoperative outcome and plasma amino acid concentrations in a study comparing early enteral nutrition versus early parenteral nutrition after major rectal surgery . Previously , it was shown that a low plasma glutamine concentration represents poor prognosis in ICU patients . Design : A preplanned sub study of a previous prospect i ve , r and omized , open-label , single-centre study , comparing early enteral nutrition versus early parenteral nutrition in patients at high risk of postoperative ileus after surgery for locally advanced or locally recurrent rectal cancer . Early enteral nutrition reduced postoperative ileus , anastomotic leakage , and hospital stay . Setting : Tertiary referral centre for locally advanced and recurrent rectal cancer . Patients : A total of 123 patients with locally advanced or recurrent rectal carcinoma requiring major rectal surgery . Interventions : Patients were r and omized ( ALEA web-based external r and omization ) preoperatively into two groups : early enteral nutrition ( early enteral nutrition , intervention ) by nasojejunal tube ( n = 61 ) or early parenteral nutrition ( early parenteral nutrition , control ) by jugular vein catheter ( n = 62 ) . Eight hours after the surgical procedure artificial nutrition was started in hemodynamically stable patients , stimulating oral intake in both groups . Blood sample s were collected to measure plasma glutamine , citrulline , and arginine concentrations using a vali date d ultra performance liquid chromatography-t and em mass spectrometric method . Measurements and Main Results : Baseline concentrations were comparable for both groups . Directly after rectal surgery , a decrease in plasma amino acids was observed . Plasma glutamine concentrations were higher in the parenteral group than in the enteral group on postoperative day 1 ( p = 0.027 ) and day 5 ( p = 0.008 ) . Arginine concentrations were also significantly increased in the parenteral group at day 1 ( p < 0.001 ) and day 5 ( p = 0.001 ) . Conclusions : Lower plasma glutamine and arginine concentrations were measured in the enteral group , whereas a better clinical outcome was observed . We conclude that plasma amino acids do not provide a causal explanation for the observed beneficial effects of early enteral feeding after major rectal surgery Gut malnutrition in patients with persistent hypermetabolism is hypothesized to be an important factor in postseptic multiple organ failure syndrome ( MOFS ) . The hypothesis was made that enteral nutrition ( EN ) started at the onset of hypermetabolism could reduce the incidence of MOFS . Sixty-six patients with persistent hypermetabolism 4 to 6 days after onset of sepsis were prospect ively r and omized to receive either parenteral nutrition ( PN ) or enteral nutrition ( EN ) at 1.5 gm protein/kg/day and 30 nonprotein calories/kg/day ; the EN and TPN were of the same composition . There was no reduction in either the incidence of MOFS or mortality attributable to the route of nutrition administration . The PN group tended to have better visceral protein support ; the EN group had more gut complications . When analyzed , the type of formula given did have an effect on the nutritional outcome but not on the mortality rate . A formula with a nonprotein-calorie-to-nitrogen ratio of 100:1 was associated with more nitrogen retention , higher levels of visceral proteins , and better gut tolerance . The route of nutrition administration does not seem to affect the incidence of postseptic MOFS or mortality when hypermetabolism is already present and when commercially available nutritional formulas are used . The relationships among the route of nutrition , the type of enteral formula , and the disease process of hypermetabolism and MOFS appear to be complex and require much more investigation before the role of the gut and enteral nutrition can be defined OBJECTIVE To develop a model of established respiratory immunity against Pseudomonas aeruginosa pneumonia and to investigate the effects of route and type of nutrition on this immunity . SUMMARY BACKGROUND DATA Diet influences the ability of gut-associated lymphoid tissue ( GALT ) to maintain mucosal immunity . Complex enteral diets and chow maintain normal GALT population s against established IgA-mediated antiviral respiratory immunity . Both intravenous and intragastric total parenteral nutrition ( TPN ) produce GALT atrophy , but only intragastric TPN preserves established antiviral immunity . The authors hypothesized that both GALT-depleting diets ( intragastric and intravenous TPN ) would impair immunity against bacterial pneumonia . METHODS P. aeruginosa was administered intratracheally to determine the mortality rate at increasing doses , and liposomes containing P. aeruginosa antigens were used to generate effective respiratory immunization . In the final experiment , mice received liposomes containing P. aeruginosa antigens to establish immunity and then were r and omized to chow , complex enteral diets , intragastric TPN , or intravenous TPN . After 5 days of diet , mice received live intratracheal P. aeruginosa , and the death rate was recorded at 24 and 48 hours . RESULTS The LD50 and LD100 were 9 x 10(7 ) and 12 x 10(7 ) , respectively . Immunization reduced the mortality rate from 66 % to 12 % . This immunization was maintained in mice fed chow or a complex enteral diet and was lost in animals receiving intravenous TPN . Intragastric TPN partially preserved this respiratory immunity . CONCLUSIONS Protection against bacterial pneumonia can be induced by prior antigenic immunization . This protection is lost with intravenous TPN , partially preserved with a chemically defined enteral diet , and completely preserved with chow or complex enteral diets . Both route and type of nutrition influence antibacterial respiratory tract immunity Abstract Purpose We assessed the effects of early goal -directed nutrition ( EGDN ) vs. st and ard nutritional care in adult intensive care unit ( ICU ) patients . Methods We r and omised acutely admitted , mechanically ventilated ICU patients expected to stay longer than 3 days in the ICU . In the EGDN group we estimated nutritional requirements by indirect calorimetry and 24-h urinary urea aim ing at covering 100 % of requirements from the first full trial day using enteral and parenteral nutrition . In the st and ard of care group we aim ed at providing 25 kcal/kg/day by enteral nutrition . If this was not met by day 7 , patients were supplemented with parenteral nutrition . The primary outcome was physical component summary ( PCS ) score of SF-36 at 6 months . We performed multiple imputation for data of the non-responders . Results We r and omised 203 patients and included 199 in the intention-to-treat analyses ; baseline variables were reasonably balanced between the two groups . The EGDN group had less negative energy ( p < 0.001 ) and protein ( p < 0.001 ) balances in the ICU as compared to the st and ard of care group . The PCS score at 6 months did not differ between the two groups ( mean difference 0.0 , 95 % CI −5.9 to 5.8 , p = 0.99 ) ; neither did mortality , rates of organ failures , serious adverse reactions or infections in the ICU , length of ICU or hospital stay , or days alive without life support at 90 days . Conclusions EGDN did not appear to affect physical quality of life at 6 months or other important outcomes as compared to st and ard nutrition care in acutely admitted , mechanically ventilated , adult ICU patients . Clinical trials.gov identifier no. NCT01372176 We measured energy expenditure ( MREE ) and nitrogen excretion ( UUN ) in patients with severe head injury r and omized to early parenteral ( TPN , n = 21 ) or jejunal ( ENT , n = 27 ) feeding  with identical formulations . The MREE rose to 2400 + /- 531 kcal/day in both groups and remained at 135 % + /- 26 % to 146 % + /- 42 % of predicted energy expenditure over 4 weeks . Nitrogen excretion peaked the second week at 33.4 + /- 10 ( TPN ) and 31.2 + /- 7.5 ( ENT ) g N/day . Both routes were equally effective at meeting nutritional goals ( 1.2 x MREE , 2.5 g protein/kg/day intake , stabilized albumin and transferrin levels ) . Infections were equally frequent : 1.86 episodes/TPN patient versus 1.89 episodes/ENT patient . While patient charges were much greater for TPN , the hospital costs were similar for TPN and ENT support regimens . These findings show that patients with head injuries are hypermetabolic for weeks , that only 27 % are capable of spontaneously eating nutritional requirements by discharge , and that either TPN or ENT support is equally effective when prescribed according to individual measurements of MREE and nitrogen excretion Background Nutrition is one of the fundamentals of care provided to critically ill adults . The volume of enteral nutrition received , however , is often much less than prescribed due to multiple functional and process issues . To deliver the prescribed volume and correct the energy deficit associated with enteral nutrition alone , parenteral nutrition can be used in combination ( termed “ supplemental parenteral nutrition ” ) , but benefits of this method have not been firmly established . A multi-centre , r and omised , clinical trial is currently underway to determine if prescribed energy requirements can be provided to critically ill patients by using a supplemental parenteral nutrition strategy in the critically ill . Methods / design This prospect i ve , multi-centre , r and omised , stratified , parallel-group , controlled , phase II trial aims to determine whether a supplemental parenteral nutrition strategy will reliably and safely increase energy intake when compared to usual care . The study will be conducted for 100 critically ill adults with at least one organ system failure and evidence of insufficient enteral intake from six intensive care units in Australia and New Zeal and . Enrolled patients will be allocated to either a supplemental parenteral nutrition strategy for 7 days post r and omisation or to usual care with enteral nutrition . The primary outcome will be the average energy amount delivered from nutrition therapy over the first 7 days of the study period . Secondary outcomes include protein delivery for 7 days post r and omisation ; total energy and protein delivery , antibiotic use and organ failure rates ( up to 28 days ) ; duration of ventilation , length of intensive care unit and hospital stay . At both intensive care unit and hospital discharge strength and health-related quality of life assessment s will be undertaken . Study participants will be followed up for health-related quality of life , re source utilisation and survival at 90 and 180 days post r and omisation ( unless death occurs first ) . Discussion This trial aims to determine if provision of a supplemental parenteral nutrition strategy to critically ill adults will increase energy intake compared to usual care in Australia and New Zeal and . 
    Output:
    
AUTHORS ' CONCLUSIONS We found insufficient evidence to determine whether EN is better or worse than PN , or than combined EN and PN for mortality in hospital , at 90 days and at 180 days , and on the number of ventilator-free days and adverse events .
We found fewer deaths at 30 days when studies gave combined EN and PN , and reduced sepsis for EN rather than PN .