Missing effect of glutamine supplementation on the surgical outcome after pancreaticoduodenectomy for periampullary tumors: a prospective, randomized, double-blind, controlled clinical trial

Postoperative nutritional support after pancreaticoduodenectomy in adults

BACKGROUND

Resection of the head of the pancreas is most commonly done by a pancreaticoduodenectomy, known as a Whipple procedure. The most common indication for pancreaticoduodenectomy is malignancy, but can include benign tumours and chronic pancreatitis. Complete surgical resection, with negative margins, provides the best prospect of long-term survival. Pancreaticoduodenectomy involves specific and unique alterations to the digestive system and maintaining nutritional status (optimising outcomes and achieving resumption of a normal diet) in patients with cancer after major surgery is a challenge. Malnutrition is a risk factor following pancreaticoduodenectomy, due to the magnitude of the operation and the frequency of complications. Postoperatively, patients are fed either orally, enterally or parenterally. Oral intake may start with fluids and then progress to solid food, or may be ad libitum. Enteral feeding may be via a nasojejunal tube or feeding tube jejunostomy. Parenteral nutrition can be delivered via a central or peripheral intravenous line, and may provide full nutrition (TPN) or partial nutrition (supplemental PN).

OBJECTIVES

To assess the effects of postoperative nutritional support strategies on complications and recovery in adults after pancreaticoduodenectomy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS and CINAHL (from inception to October 2022), ongoing trials registers and other internet databases. We searched previous systematic reviews, relevant publications on the same topic and the references of included studies.

SELECTION CRITERIA

Randomised controlled trials of postoperative nutritional interventions in an inpatient setting for patients undergoing pancreaticoduodenectomy. We specifically looked for studies comparing route or timing rather than nutritional content.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, judged the risk of bias and extracted data. Studies requiring translation were assessed for inclusion, risk of bias and data extraction by an external translator and another author. We used GRADE to evaluate the certainty of the evidence.

MAIN RESULTS

We included 17 studies (1897 participants). Of these, eight studies could be included in a meta-analysis. The route, timing and target of nutritional support varied widely between studies. Enteral feeding (jejunostomy, nasojejunal or gastrojejunostomy) was used in at least 13 studies (one study did not specify the method of enteral route), parenteral nutrition (PN) was used in at least 10 studies (two studies had a control of 'surgeon's preference' and no further details were given) and oral intake was used in seven studies. Overall, the evidence presented in this review is of low to very low certainty. Four studies compared jejunostomy feeding with total parenteral nutrition. When we pooled these four studies, the evidence demonstrated that jejunostomy likely results in a reduced length of hospital stay (mean difference (MD) -1.61 days, 95% confidence interval (CI) -2.31 to -0.92; 3 studies, 316 participants; moderate-certainty evidence). The evidence suggested that there may be no difference in postoperative pancreatic fistula (risk ratio (RR) 0.77, 95% CI 0.41 to 1.47; 4 studies, 346 participants; low-certainty evidence) and that there may be no difference in delayed gastric emptying (RR 0.38, 95% CI 0.04 to 3.50; 2 studies, 270 participants; very low-certainty evidence) or post pancreatectomy haemorrhage (RR 0.36, 95% CI 0.06 to 2.29; 2 studies, 270 participants; very low-certainty evidence), but the evidence is uncertain. There were no data for major and minor complications defined by the Clavien-Dindo classification. Two studies compared nasojejunal feeding with total parenteral nutrition. When the two studies were pooled, the evidence suggested that there may be little to no difference between nasojejunal feeding and TPN in the length of hospital stay (MD 1.07 days, 95% CI -2.64 to 4.79; 2 studies, 242 participants; low-certainty evidence), delayed gastric emptying (RR 1.26, 95% CI 0.83 to 1.91; 2 studies, 242 participants; low-certainty evidence) or post pancreatectomy haemorrhage (RR 1.00, 95% CI 0.62 to 1.62; 2 studies, 242 participants; low-certainty evidence). TPN may slightly improve rates of clinically relevant postoperative pancreatic fistula (RR 2.13, 95% CI 1.21 to 3.74; 2 studies, 242 participants; low-certainty evidence). One study reported on major complications (RR 1.27, 95% CI 0.83 to 1.94; very low-certainty evidence) and minor complications (RR 1.01, 95% CI 0.68 to 1.50; 204 participants; very low-certainty evidence) defined by the Clavien-Dindo classification and there may be little to no difference in effect, but the evidence is uncertain. Two studies compared jejunostomy feeding with oral intake. Of note, one of the studies used a modified surgical technique as part of the intervention. We pooled these studies and found that there may be little to no difference in the length of hospital stay (MD -1.99 days, 95% CI -4.90 to 0.91; 2 studies, 301 participants; very low-certainty evidence) or delayed gastric emptying (RR 0.98, 95% CI 0.33 to 2.88; 2 studies, 307 participants; very low-certainty evidence). One study reported on major complications (RR 1.01, 95% CI 0.44 to 2.34; 247 participants; very low-certainty evidence) and minor complications (RR 0.83, 95% CI 0.59 to 1.15; 247 participants; very low-certainty evidence) defined by the Clavien-Dindo classification, postoperative pancreatic fistula (RR 0.86, 95% CI 0.30 to 2.50; 247 participants; very low-certainty evidence) and post pancreatectomy haemorrhage (RR 2.02, 95% CI 0.52 to 7.88; 247 participants; very low-certainty evidence) and there may be little to no difference in effect on these outcomes, but the evidence is uncertain. No difference in mortality was detected in any of the analyses (Clavien-Dindo Grade V) (very low-certainty evidence).

AUTHORS' CONCLUSIONS

When compared with parenteral nutrition, enteral nutrition by jejunostomy likely results in a decreased length of hospital stay and may lead to no difference in the incidence of postoperative complications. When compared with parenteral nutrition, enteral feeding by nasojejunal tube may result in no difference in the incidence of postoperative complications or length of hospital stay. When compared with oral nutrition, enteral nutrition by jejunostomy feeding may result in no difference in the incidence of postoperative complications or length of hospital stay, but the evidence is very uncertain. Further high-quality research is required and there are several ongoing studies. Given the number of different nutritional interventions available in the postoperative setting, a network meta-analysis would be more appropriate in future.

Impact of perioperative immunonutrition on postoperative outcomes in pancreaticoduodenectomy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This systematic review and meta-analysis aimed to evaluate the impact of perioperative immunonutrition on postoperative outcomes in patients undergoing pancreaticoduodenectomy (PD).

METHODS

Conducted a comprehensive search in PubMed, Embase, Cochrane Library, Medline, and Web of Science databases to identify all randomized controlled trials (RCTs) on the topic of immunonutrition and PD. Subsequently screened literature, extracted data, and assessed the risk of bias in the included studies, and finally conducted a meta-analysis using RevMan 5.3 software.

RESULTS

The analysis included a total of 10 RCTs with 574 patients, among whom 288 were in the immunonutrition group and 283 in the control group. The meta-analysis revealed a significantly lower incidence of postoperative infection-related complications (OR = 0.45; 95% CI: 0.27-0.74; P = 0.002) and severe postoperative complications (OR = 0.61; 95% CI: 0.38-0.98; P = 0.04) in the immunonutrition group compared to the control group. Additionally, patients in the immunonutrition group had a significantly shorter length of hospital stay (MD= -1.87; 95%CI -3.29 - -0.44; P = 0.01). However, the analysis revealed no statistically significant difference in the overall complication rate between the two groups (P = 0.67). Furthermore, the incidence of specific complications and perioperative mortality rates also did not demonstrate any statistically significant differences (all P > 0.05).

CONCLUSIONS

Perioperative immunonutrition in PD patients can reduce postoperative infection-related complications, but more high-quality RCTs are needed for further validation.

Pharmaconutrition: Which substrates?

With the term "pharmaconutrition" or "immunonutrition" is intended the use of specific nutritional substrates having the ability of modulating specific mechanisms involved in several immune and inflammatory pathways. To achieve these goals, these substrates have to be administered with over physiologic dose. Glutamine and omega-3 polyunsaturated fatty acids, used as single substrate, did not show clear clinical advantages on solid endpoints such as postoperative complications. Despite several multiple substrate enteral feeds are available on the market, very few of them have been tested in randomized clinical trial to prove efficacy. The most extensive investigated formulation is a combination of arginine, omega-3 fatty acids, ribonucleic acid with or without glutamine. Several meta-analyses of randomized clinical trials have been conducted to compare the effects of enteral immunonutrition with control diets on post-surgical morbidity. The results consistently showed that the use of enteral multiple substrate formulas significantly reduced infectious complications and duration of hospitalization. In a more contemporary view, pharmaconutrition should be tested more accurately in the contest of enhanced recovery programs, during neoadjuvant chemotherapy, and in the prehabilitation setting.

Value of immunonutrition in patients undergoing pancreatic resection: a trial sequential meta-analysis

BACKGROUND

The benefits of immunonutrition (IM) in patients who underwent pancreatic surgery are unclear.

METHODS

A meta-analysis of randomized clinical trials (RCTs) comparing IM with standard nutrition (SN) in pancreatic surgery was carried out. A random-effects trial sequential meta-analysis was made, reporting Risk Ratio (RR), mean difference (MD), and required information size (RIS). If RIS was reached, false negative (type II error) and positive results (type I error) could be excluded. The endpoints were morbidity, mortality, infectious complication, postoperative pancreatic fistula (POPF) rates, and length of stay (LOS).

RESULTS

The meta-analysis includes 6 RCTs and 477 patients. Morbidity (RR 0.77; 0.26 to 2.25), mortality (RR 0.90; 0.76 to 1.07), and POPF rates were similar. The RISs were 17,316, 7,417, and 464,006, suggesting a type II error. Infectious complications were lower in the IM group, with a RR of 0.54 (0.36-0.79; 95 CI). The LOS was shorter in IM (MD -0.3 days; -0.6 to -0.1). For both, the RISs were reached, excluding type I error.

CONCLUSION

The IM can reduce infectious complications and LOS The small differences in mortality, morbidity, and POPF make it impossible to exclude type II error due to large RISs.

Preoperative Glutamine Supplementation in Gastric Cancer-Thrombocyte Phagocytic Activity and Early Postoperative Outcomes

BACKGROUND

The aim of this study was to determine the phagocytic activity of thrombocytes in patients with gastric cancer and to assess the effect of oral and parenteral preoperative glutamine-based immunonutrition on nutritional status, thrombocyte phagocytic activity, and early postoperative outcomes.

METHODS

Patients suffering from invasive gastric cancer had been treated with preoperative immunonutrition with glutamine, and they were compared to patients without nutritional treatment. Nutritional status, percentage of weight loss, and BMI were assessed. Levels of total protein, albumin, cholesterol, triglycerides, platelets, and their phagocytic ability were measured twice. Postsurgical complications were assessed via the Clavien-Dindo classification.

RESULTS

Group I consisted of 20 patients with an oral glutamine-10 g daily. Group II had 38 patients who received intravenous glutamine, 1.5 mL per kg body weight of Dipeptiven. Group III consisted of 25 patients who did not receive preoperative immunonutrition. In total, 47% of patients in Group I, 54% of patients in Group II, and 33% of patients in Group III were malnourished. In Group I, the percentage of phagocytizing platelet (%PhP) was 1.1 preoperatively and 1.2 postoperatively. The phagocytic index (PhI) was 1.0 and 1.1. In Group II, %PhP was 1.1 and 1.2 and PhI was 1.0 and 1.1. In Group III, the %PhP was 1.0 and 1.2 and PhI was 1.0 and 1.1. An increase in triglyceride level was observed in both immunonutrition groups. There was a decline in total protein and albumin level in Group II. In Group III, there was a decline in total protein, albumin, and cholesterol level. The total platelet count and PhI were increased in both immunonutrition groups. There was also a rise in %PhP in Group II. In Group III, there was a rise in blood platelet level, %PhP, and PhI. The complication rates were 53% in Group I, 29% in Group II, and 40% in Group III.

CONCLUSIONS

In invasive gastric cancer, laboratory nutritional parameters are significantly reduced, causing malnutrition in 44.7% of patients. Oral glutamine supplementation inhibited the postoperative decline in protein metabolism parameters; however, this did not affect the reduction in the percentage of postoperative complications. Glutamine used preoperatively significantly reduced the percentage of serious surgical complications, regardless of the way it was supplemented. Patients with invasive gastric cancer have a significant decrease in platelet phagocytic activity. The administered preoperative parenteral nutrition and the surgical procedure itself influenced the improvement of the phagocytic activity of blood platelets. Glutamine did not have this effect, regardless of the route of administration.

Nutrition as prevention for improved cancer health outcomes: a systematic literature review

BACKGROUND

Among adults with cancer, malnutrition is associated with decreased treatment completion, more treatment harms and use of health care, and worse short-term survival. To inform the National Institutes of Health Pathways to Prevention workshop, "Nutrition as Prevention for Improved Cancer Health Outcomes," this systematic review examined the evidence for the effectiveness of providing nutrition interventions before or during cancer therapy to improve outcomes of cancer treatment.

METHODS

We identified randomized controlled trials enrolling at least 50 participants published from 2000 through July 2022. We provide a detailed evidence map for included studies and grouped studies by broad intervention and cancer types. We conducted risk of bias (RoB) and qualitative descriptions of outcomes for intervention and cancer types with a larger volume of literature.

RESULTS

From 9798 unique references, 206 randomized controlled trials from 219 publications met the inclusion criteria. Studies primarily focused on nonvitamin or mineral dietary supplements, nutrition support, and route or timing of inpatient nutrition interventions for gastrointestinal or head and neck cancers. Most studies evaluated changes in body weight or composition, adverse events from cancer treatment, length of hospital stay, or quality of life. Few studies were conducted within the United States. Among intervention and cancer types with a high volume of literature (n = 114), 49% (n = 56) were assessed as high RoB. Higher-quality studies (low or medium RoB) reported mixed results on the effect of nutrition interventions across cancer and treatment-related outcomes.

CONCLUSIONS

Methodological limitations of nutrition intervention studies surrounding cancer treatment impair translation of findings into clinical practice or guidelines.

The Effect of immunonutrition in patients undergoing pancreaticoduodenectomy: a systematic review and meta-analysis

BACKGROUND

Pancreaticoduodenectomy (PD) is a complex and traumatic abdominal surgery with a high risk of postoperative complications. Nutritional support, including immunonutrition (IMN) with added glutamine, arginine, and ω-3 polyunsaturated fatty acids, can improve patients' prognosis by regulating postoperative inflammatory response. However, the effects of IMN on PD patients' outcomes require further investigation.

METHODS

PMC, EMbase, web of science databases were used to search literatures related to IMN and PD. Data such as length of hospital stay, infectious complications, non-infectious complications, postoperative pancreatic fistula (POPF), delayed gastric emptying (DGE), mortality, systemic inflammatory response syndrome (SIRS) duration, IL-6, and C-reactive protein (CRP) were extracted, and meta-analyses were performed on these data to study their pooled results, heterogeneity, and publication bias.

RESULTS

This meta-analysis involved 10 studies and a total of 572 patients. The results showed that the use of IMN significantly reduced the length of hospital stay for PD patients (MD = -2.31; 95% CI = -4.43, -0.18; P = 0.03) with low heterogeneity. Additionally, the incidence of infectious complications was significantly reduced (MD = 0.42; 95% CI = 0.18, 1.00, P = 0.05), with low heterogeneity after excluding one study. However, there was no significant impact on non-infectious complications, the incidence of POPF and DGE, mortality rates, duration of SIRS, levels of IL-6 and CRP.

CONCLUSION

The use of IMN has been shown to significantly shorten hospital stays and decrease the frequency of infectious complications in PD patients. Early implementation of IMN is recommended for those undergoing PD. However, further research is needed to fully assess the impact of IMN on PD patients through larger and higher-quality studies.

Immunonutrition and prehabilitation in pancreatic cancer surgery: A new concept in the era of ERAS® and neoadjuvant treatment

Pancreatic cancer (PC) is an aggressive disease, with a growing incidence, and a poor prognosis. Neoadjuvant treatments in PC are highly recommended in borderline resectable and recently in upfront resectable PC. PC is characterized by exocrine insufficiency and nutritional imbalance, leading to malnutrition/sarcopenia. The concept of malnutrition in PC is multifaceted, as the cancer-related alterations create an interplay with adverse effects of anticancer treatments. All these critical factors have a negative impact on the postoperative and oncological outcomes. A series of actions and programs can be implemented to improve resectable and borderline resectable PC in terms of postoperative complications, oncological outcomes and patients' quality of life. A timely nutritional evaluation and the implementation of appropriate evidence-based nutritional interventions in onco-surgical patients should be considered of importance to improve preoperative physical fitness. Unfortunately, nutritional care and its optimization are often neglected in real-world clinical practice. Currently available studies and ERAS® guidelines mostly support the use of pre- or perioperative medical nutrition, including immunonutrition, in order to decrease the rate of postoperative infections and length of hospital stay. Further data also suggest that medical nutrition should be considered proactively in PC patients, to possibly prevent severe malnutrition and its consequences on disease and treatment outcomes. This narrative review summarizes the most recent data related to the role of prehabilitation, ERAS® program, medical nutrition, and the timing of intervention on clinical outcomes of upfront resectable and borderline PC, and their potential implementation within the timeframe of neoadjuvant treatments.

Nutritional Interventions in Pancreatic Cancer: A Systematic Review

(1) Background: Pancreatic cancer (PaCa) is directly related to malnutrition, cachexia and weight loss. Nutritional interventions (NI) are used in addition to standard therapy. The aim of this systematic review is to provide an overview of the types of NI and their effects. (2) Methods: We included RCTs with at least one intervention group receiving an NI and compared them with a control group with no NI, placebo or alternative treatment on cachexia, malnutrition or weight loss in patients with PaCa. Any available literature until 12 August 2021 was searched in the Pubmed and Cochrane databases. RCTs were sorted according to NI (parenteral nutrition, enteral nutrition, dietary supplements and mixed or special forms). (3) Results: Finally, 26 studies with a total of 2720 patients were included. The potential for bias was mostly moderate to high. Parenteral nutrition is associated with a higher incidence of complications. Enteral nutrition is associated with shorter length of stay in hospital, lower rate and development of complications, positive effects on cytokine rates and lower weight loss. Dietary supplements enriched with omega-3 fatty acids lead to higher body weight and lean body mass. (4) Conclusions: Enteral nutrition and dietary supplements with omega-3 fatty acids should be preferred in nutritional therapy of PaCa patients.

The Role of Immunonutrition in Patients Undergoing Pancreaticoduodenectomy

Pancreaticoduodenectomy (PD) is one of the most difficult and complex surgical procedures in abdominal surgery. Malnutrition and immune dysfunction in patients with pancreatic cancer (PC) may lead to a higher risk of postoperative infectious complications. Although immunonutrition (IN) is recommended for enhanced recovery after surgery (ERAS) in patients undergoing PD for 5-7 days perioperatively, its role in patients undergoing pancreatectomy is still unclear and controversial. It is known that the proper surgical technique is very important in order to reduce a risk of postoperative complications, such as a pancreatic fistula, and to improve disease-free survival in patients following PD. However, it has been proven that IN decreases the risk of infectious complications, and shortens hospital stays in patients undergoing PD. This is a result of the impact on altered inflammatory responses in patients with cancer. Both enteral and parenteral, as well as preoperative and postoperative IN, using various nutrients, such as glutamine, arginine, omega-3 fatty acids and nucleotides, is administered. The most frequently used preoperative oral supplementation is recommended. The aim of this paper is to present the indications and benefits of IN in patients undergoing PD.

The Impact of Perioperative Glutamine-supplemented Parenteral Nutrition on Outcomes of Patients Undergoing Abdominal Surgery: A Meta-analysis of Randomized Clinical Trials

The objective of this study was to evaluate the impact of perioperative glutamine-supplemented parenteral nutrition (GLN-PN) on clinical outcomes in patients undergoing abdominal surgery. MEDLINE, EMBASE, and the Cochrane Controlled Clinical Trials Register were searched to retrieve the eligible studies. Eligible studies were randomized controlled trials (RCTs) that compared the effect of GLN-PN and standard PN on clinical outcomes in patients undergoing abdominal surgery. Clinical outcomes of interest were postoperative mortality, length of hospital stay, morbidity of infectious complication, and cumulative nitrogen balance. Statistical analysis was conducted by RevMan 5.0 software from the Cochrane Collaboration. Sixteen RCTs with 773 patients were included in this meta-analysis. The results showed a significant decrease in the infectious complication rates of patients undergoing abdominal surgery receiving GLN-PN (risk ratio [RR], 0.48; 95% confidence interval [CI], 0.32 to 0.72; P = 0.0004). The overall effect indicated glutamine significantly reduced the length of hospital stay in the form of alanyl-glutamine (weighted mean difference [WMD], -3.17; 95% CI, -5.51 to -0.82; P = 0.008) and in the form of glycyl-glutamine (WMD, -3.40; 95% CI, -5.82 to -0.97; P = 0.006). A positive effect in improving postoperative cumulative nitrogen balance was observed between groups (WMD, 7.40; 95% CI, 3.16 to 11.63; P = 0.0006), but no mortality (RR, 1.52; 95% CI, 0.21 to 11.9; P = 0.68). Perioperative GLN-PN is effective and safe to shorten the length of hospital stay, reduce the morbidity of postoperative infectious complications, and improve nitrogen balance in patients undergoing abdominal surgery.

Immunonutrition vs Standard Nutrition for Cancer Patients: A Systematic Review and Meta-Analysis (Part 1)

The aim of this study was to determine the efficacy of immunonutrition vs standard nutrition in cancer patients treated with surgery. Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, EBSCOhost, and Web of Science were searched. Sixty-one randomized controlled trials were included. Immunonutrition was associated with a significantly reduced risk of postoperative infectious complications (risk ratio [RR] 0.71 [95% CI, 0.64-0.79]), including a reduced risk of wound infection (RR 0.72 [95% CI, 0.60-0.87]), respiratory tract infection (RR 0.70 [95% CI, 0.59-0.84]), and urinary tract infection (RR 0.69 [95% CI, 0.51-0.94]) as well as a decreased risk of anastomotic leakage (RR 0.70 [95% CI, 0.53-0.91]) and a reduced hospital stay (MD -2.12 days [95% CI -2.72 to -1.52]). No differences were found between the 2 groups with regard to sepsis or all-cause mortality. Subgroup analyses revealed that receiving arginine + nucleotides + ω-3 fatty acids and receiving enteral immunonutrition reduced the rates of wound infection and respiratory tract infection. The application of immunonutrition at 25-30 kcal/kg/d for 5-7 days reduced the rate of respiratory tract infection. Perioperative immunonutrition reduced the rate of wound infection. For malnourished patients, immunonutrition shortened the hospitalization time. Therefore, immunonutrition reduces postoperative infection complications and shortens hospital stays but does not reduce all-cause mortality. Patients who are malnourished before surgery who receive arginine + nucleotides + ω-3 fatty acids (25-30 kcal/kg/d) via the gastrointestinal tract during the perioperative period (5-7 days) may show better clinical efficacy.

Current evidence of nutritional therapy in pancreatoduodenectomy: Systematic review of randomized controlled trials

AIM

Evidence of nutritional therapies in pancreatoduodenectomy (PD) has been shown. However, few studies focus on the association between different nutritional therapies and outcomes. The aim of this review was to summarize the current evidence of nutritional therapies such as enteral nutrition (EN), immunonutrition, and synbiotics on postoperative outcomes after PD.

METHODS

A systematic literature search of Embase, Medline Ovid, and Cochrane CENTRAL was done to summarize the available evidence, including randomized controlled trials, meta-analyses and reviews, regarding nutritional therapy in PD.

RESULTS

A total of 20 randomized controlled trials were included in this review. Safety and tolerability of EN in PD was shown. Giving postoperative EN can shorten length of stay compared to parenteral nutrition; however, the effect of EN on postoperative complications remains controversial. Postoperative EN should be given only on selective indications rather than routinely used, and preoperative EN is indicated only in patients with severe malnutrition. Giving preoperative immunonutrition is considered to reduce the incidence of infectious complications; however, evidence level is moderate and recommendation grade is weak. The beneficial effect of perioperative synbiotics on postoperative infectious complications is limited. Furthermore, the effectiveness of other nutritional supplements remains unclear.

CONCLUSION

Recently, evidence of enhanced recovery after surgery (ERAS) in PD has been increasing. Early oral intake with systematic nutritional support is an important aspect of the ERAS concept. Future well-designed studies should investigate the impact of systematic nutritional therapies on outcomes following PD.

Efficacy of enteral glutamine supplementation in patients with severe and predicted severe acute pancreatitis- A randomized controlled trial

BACKGROUND

In severe acute pancreatitis (AP), intravenous glutamine has been shown to reduce the rate of complications, hospital stay, and mortality. In the present randomized trial, we aimed to evaluate the effect of enteral glutamine supplementation on clinical outcomes, gut permeability, systemic inflammation, oxidative stress, and plasma glutamine levels in patients with severe and predicted severe AP.

METHODS

Patients with AP admitted within 72 h of onset of symptoms were included. The primary outcome measure was development of infected pancreatic and peri-pancreatic necrosis and in-hospital mortality. High-sensitivity C-reactive protein (HS-CRP) and interleukin-6 (IL-6) were evaluated as markers of inflammation; plasma thiobarbituric acid reactive substances (TBARS) and activities of serum superoxide dismutase and glutathione peroxidase were determined to evaluate oxidative stress; serum polyethylene glycol (PEG) was tested for intestinal permeability; subjective global assessment (SGA) was used for nutritional assessment, and an improvement in organ function was measured by the Modified Marshall score. Intention-to-treat analysis was used. A p-value of < 0.05 was considered statistically significant.

RESULTS

After power calculation, we enrolled 18 patients in the glutamine and 22 in the control arm. There was no significant improvement in the development of infected necrosis and in-hospital mortality between the groups. Improvement in Modified Marshall score was observed in a higher proportion of patients receiving glutamine (15 [83.3%] vs. 12 [54.5%]; p = 0.05). Plasma glutamine levels improved more in glutamine-treated group (432.72 ± 307.83 vs. 618.06 ± 543.29 μM/L; p = 0.004), while it was lower in controls (576.90 ± 477.97 vs. 528.20 ± 410.45 μM/L; p = 0.003). PEG level was lower after glutamine supplementation (39.91 ± 11.97 vs. 32.30 ± 7.39 ng/mL; p = 0.02). Statistically significant reduction in IL-6 concentration was observed in the glutamine group at the end of treatment (87.44 ± 7.1 vs. 63.42 ± 33.7 μM/L; p = 0.02).

CONCLUSIONS

Despite absence of improvement in infected necrosis and in-hospital mortality, enteral glutamine supplementation showed improvement in gut permeability, oxidative stress, and a trend towards improvement in organ function as depicted by improvement in the Modified Marshall score.

TRIAL REGISTRATION

NCT01503320.

Meta-analysis of immunonutrition in major abdominal surgery

Background

The objective of this study was to evaluate the potential benefits of immunonutrition in major abdominal surgery with special regard to subgroups and influence of bias.

Methods

A systematic literature search from January 1985 to July 2015 was performed in MEDLINE, Embase and CENTRAL. Only RCTs investigating immunonutrition in major abdominal surgery were included. Outcomes evaluated were mortality, overall complications, infectious complications and length of hospital stay. The influence of different domains of bias was evaluated in sensitivity analyses. Evidence was rated according to the GRADE Working Group grading of evidence.

Results

A total of 83 RCTs with 7116 patients were included. Mortality was not altered by immunonutrition. Taking all trials into account, immunonutrition reduced overall complications (odds ratio (OR) 0·79, 95 per cent c.i. 0·66 to 0·94; P = 0·01), infectious complications (OR 0·58, 0·51 to 0·66; P &lt; 0·001) and shortened hospital stay (mean difference –1·79 (95 per cent c.i. –2·39 to –1·19) days; P &lt; 0·001) compared with control groups. However, these effects vanished after excluding trials at high and unclear risk of bias. Publication bias seemed to be present for infectious complications (P = 0·002). Non-industry-funded trials reported no positive effects for overall complications (OR 1·13, 0·88 to 1·46; P = 0·34), whereas those funded by industry reported large effects (OR 0·66, 0·48 to 0·91; P = 0·01).

Conclusion

Immunonutrition after major abdominal surgery did not seem to alter mortality (GRADE: high quality of evidence). Immunonutrition reduced overall complications, infectious complications and shortened hospital stay (GRADE: low to moderate). The existence of bias lowers confidence in the evidence (GRADE approach).

Efficacy and Safety of Glutamine-supplemented Parenteral Nutrition in Surgical ICU Patients: An American Multicenter Randomized Controlled Trial

OBJECTIVE

To determine whether glutamine (GLN)-supplemented parenteral nutrition (PN) improves clinical outcomes in surgical intensive care unit (SICU) patients.

SUMMARY BACKGROUND DATA

GLN requirements may increase with critical illness. GLN-supplemented PN may improve clinical outcomes in SICU patients.

METHODS

A parallel-group, multicenter, double-blind, randomized, controlled clinical trial in 150 adults after gastrointestinal, vascular, or cardiac surgery requiring PN and SICU care. Patients were without significant renal or hepatic failure or shock at entry. All received isonitrogenous, isocaloric PN [1.5 g/kg/d amino acids (AAs) and energy at 1.3× estimated basal energy expenditure]. Controls (n = 75) received standard GLN-free PN (STD-PN); the GLN group (n = 75) received PN containing alanyl-GLN dipeptide (0.5 g/kg/d), proportionally replacing AA in PN (GLN-PN). Enteral nutrition (EN) was advanced and PN weaned as indicated. Hospital mortality and infections were primary endpoints.

RESULTS

Baseline characteristics, days on study PN and daily macronutrient intakes via PN and EN, were similar between groups. There were 11 hospital deaths (14.7%) in the GLN-PN group and 13 deaths in the STD-PN group (17.3%; difference, -2.6%; 95% confidence interval, -14.6% to 9.3%; P = 0.66). The 6-month cumulative mortality was 31.4% in the GLN-PN group and 29.7% in the STD-PN group (P = 0.88). Incident bloodstream infection rate was 9.6 and 8.4 per 1000 hospital days in the GLN-PN and STD-PN groups, respectively (P = 0.73). Other clinical outcomes and adverse events were similar.

CONCLUSIONS

PN supplemented with GLN dipeptide was safe, but did not alter clinical outcomes among SICU patients.

Effect of glutamine dipeptide supplementation on primary outcomes for elective major surgery: systematic review and meta-analysis

To evaluate if glutamine (GLN) supplementation may affect primary outcomes in patients undergoing major elective abdominal operations, we performed a systematic literature review of randomized clinical trials (RCTs) published from 1983 to 2013 and comparing intravenous glutamine dipeptide supplementation to no supplementation in elective surgical abdominal procedures. A meta-analysis for each outcome (overall and infectious morbidity and length of stay) of interest was carried out. The effect size was estimated by the risk ratio (RR) or by the weighted mean difference (WMD). Nineteen RCTs were identified with a total of 1243 patients (640 receiving GLN and 603 controls). In general, the studies were underpowered and of medium or low quality. GLN supplementation did not affect overall morbidity (RR = 0.84, 95% CI 0.51 to 1.36; p = 0.473) and infectious morbidity (RR = 0.64; 95% CI = 0.38 to 1.07; p = 0.087). Patients treated with glutamine had a significant reduction in length of hospital stay (WMD = -2.67; 95% CI = -3.83 to -1.50; p < 0.0001). In conclusion, GLN supplementation appears to reduce hospital stay without affecting the rate of complications. The positive effect of GLN on time of hospitalization is difficult to interpret due to the lack of significant effects on surgery-related morbidity.

Clinical evidence for pharmaconutrition in major elective surgery

In recent years, standard nutrition preparations have been modified by adding specific nutrients, such as arginine, ω-3 fatty acids, glutamine, and others, which have been shown to upregulate host immune response, modulate inflammatory response, and improve protein synthesis after surgery. Most randomized trials and several meta-analyses have shown that perioperative administration of enteral arginine, ω-3 fatty acids, and nucleotides (immunonutrition) reduced infection rate and length of hospital stay in patients with upper and lower gastrointestinal (GI) cancer. The most pronounced benefits of immunonutrition were found in subgroups of high-risk and malnourished patients. Promising but not conclusive results have been found in non-GI surgery, especially in head and neck surgery and in cardiac surgery, but larger trials are required before recommending immunonutrition as a routine practice. Conflicting results on the real benefit of parenteral glutamine supplementation in patients undergoing elective major surgery have been published. In conclusion, enteral diets supplemented with specific nutrients significantly improved short-term outcome in patients with cancer undergoing elective GI surgery. Future research should investigate a molecular signaling pathway and identify specific mechanisms of action of immune-enhancing substrates.

Novel nutritional substrates in surgery

Pharmaco-nutrients have beneficial effects on protective and immunological mechanisms in patients undergoing surgery, which are important for recovery after injury and in combating infectious agents. The aim of this review article was to outline the potential of the administration of nutritional substrates to surgical patients and the underlying mechanisms that make them particularly important in peri-operative care. Surgery causes a stress response, which has catabolic effects on the body's substrate stores. The amino acid glutamine is a stimulating agent for immune cells. It activates protective mechanisms through its role as a precursor for antioxidants and it improves the barrier function of the gut. Arginine also enhances the function of the immune system, since it is the substrate for T-lymphocytes. Furthermore, n-3 PUFA stabilise surgery-induced hyper-inflammation. Taurine is another substrate that may counteract the negative effects of surgical injury on acid–base balance and osmotic balance. These pharmaco-nutrients rapidly become deficient under the influence of surgical stress. Supplementation of these nutrients in surgical patients may restore their protective and immune-enhancing actions and improve clinical outcome. Moreover, pre-operative fasting is still common practice in the Western world, although fasting has a negative effect on the patient's condition and the recovery after surgery. This may be counteracted by a simple intervention such as administering a carbohydrate-rich supplement just before surgery. In conclusion, there are various nutritional substrates that may be of great value in improving the condition of the surgical patient, which may be beneficial for post-operative recovery.

Systematic review of five feeding routes after pancreatoduodenectomy

BACKGROUND

Current European guidelines recommend routine enteral feeding after pancreato-duodenectomy (PD), whereas American guidelines do not. The aim of this study was to determine the optimal feeding route after PD.

METHODS

A systematic search was performed in PubMed, Embase and the Cochrane Library. Included were studies on feeding routes after PD that reported length of hospital stay (primary outcome).

RESULTS

Of 442 articles screened, 15 studies with 3474 patients were included. Data on five feeding routes were extracted: oral diet (2210 patients), enteral nutrition via either a nasojejunal tube (NJT, 165), gastrojejunostomy tube (GJT, 52) or jejunostomy tube (JT, 623), and total parenteral nutrition (TPN, 424). Mean(s.d.) length of hospital stay was shortest in the oral diet and GJT groups (15(14) and 15(11) days respectively), followed by 19(12) days in the JT, 20(15) days in the TPN and 25(11) days in the NJT group. Normal oral intake was established most quickly in the oral diet group (mean 6(5) days), followed by 8(9) days in the NJT group. The incidence of delayed gastric emptying varied from 6 per cent (3 of 52 patients) in the GJT group to 23.2 per cent (43 of 185) in the JT group, but definitions varied widely. The overall morbidity rate ranged from 43.8 per cent (81 of 185) in the JT group to 75 per cent (24 of 32) in the GJT group. The overall mortality rate ranged from 1.8 per cent (3 of 165) in the NJT group to 5.4 per cent (23 of 424) in the TPN group.

CONCLUSION

There is no evidence to support routine enteral or parenteral feeding after PD. An oral diet may be considered as the preferred routine feeding strategy after PD.

A systematic literature review and meta-analysis of randomized clinical trials of parenteral glutamine supplementation

BACKGROUND & AIMS

Glutamine supplementation has been associated with reduced mortality, infections and hospital length of stay in critically ill patients and patients undergoing major surgery. We carried out a meta-analysis to examine randomized clinical trial (RCT)-based evidence of these effects.

METHODS

Based on a systematic database search, RCTs published since 1990 were included if they evaluated the effect of parenteral glutamine supplementation against a background of parenteral nutrition. Enteral (tube) feeding in a proportion of patients was allowable. Information on RCT methodology, quality and outcomes was extracted. Random effects meta-analysis followed the DerSimonian-Laird approach.

RESULTS

Forty RCTs were eligible for meta-analysis. Parenteral glutamine supplementation was associated with a non-significant 11% reduction in short-term mortality (RR = 0.89; 95% CI, 0.77-1.04). Infections were significantly reduced (RR = 0.83; 95% CI, 0.72-0.95) and length of stay was 2.35 days shorter (95% CI, -3.68 to -1.02) in the glutamine arms. Meta-analysis results were strongly influenced by one recent trial. An element of publication bias could not be excluded.

CONCLUSION

Parenteral glutamine supplementation in severely ill patients may reduce infections, length of stay and mortality, but substantial uncertainty remains. Unlike previous meta-analyses, we could not demonstrate a significant reduction in mortality.

Effect of glutamine-supplemented parenteral nutrition on mortality in critically ill patients

Glutamine is recognized as a critical amino acid involved in immunity, intestinal health, and nitrogen transport between organs. Prior to the pivotal study by Griffiths and colleagues in 1997, no clinical trials had demonstrated a positive effect from glutamine supplementation on improving long-term survival in critically ill intensive care unit patients receiving parenteral nutrition. Subsequent investigations have confirmed these findings, but further data are needed to determine the optimal dose and timing of glutamine as well as the form of glutamine (ie, free vs dipeptide) that produces the most significant improvement in outcome parameters.

The impact of glutamine dipeptide-supplemented parenteral nutrition on outcomes of surgical patients: a meta-analysis of randomized clinical trials

OBJECTIVE

To evaluate the impact of glutamine dipeptide-supplemented parenteral nutrition (GLN-PN) on clinical outcomes in surgical patients.

METHODS

MEDLINE, EMBASE, Web of Science, and the Cochrane Controlled Clinical Trials Register were searched to retrieve the eligible studies. The studies were included if they were randomized controlled trials that evaluated the effect of GLN-PN and standard PN on clinical outcomes of surgical patients. Clinical outcomes of interest were postoperative morbidity of infectious complication, mortality, length of hospital stay, and cost. Statistical analysis was conducted by RevMan 4.2 software from the Cochrane Collaboration.

RESULTS

Fourteen randomized controlled trials (RCTs) (N = 587) were included in this meta-analysis. The results showed that glutamine dipeptide significantly reduced the length of hospital stay by around 4 days in the form of alanyl-glutamine (weighted mean difference [WMD] = -3.84; 95% confidence interval [CI] -5.40, -2.28; z = 4.82; P < .001) and about 5 days in the form of glycyl-glutamine (WMD = -5.40; 95% CI -8.46, -2.33; z = 3.45; P < .001). The overall effect indicated a significant decrease in the infectious complication rates of surgical patients receiving GLN-PN (risk ratio = 0.69; 95% CI 0.50, 0.95; z = 2.26; P = .02).

CONCLUSION

GLN-PN was beneficial to postoperative patients by shortening the length of hospital stay and reducing the morbidity of postoperative infectious complications.

Amino acid composition in parenteral nutrition: what is the evidence?

PURPOSE OF REVIEW

Complete parenteral nutrition solutions contain mixed amino acid products providing all nine essential amino acids and a varying composition of nonessential amino acids. Relatively little rigorous comparative efficacy research on altered parenteral nutrition amino acid composition has been published in recent years.

RECENT FINDINGS

Limited data from randomized, double-blind, adequately powered clinical trials to define optimal doses of total or individual amino acids in parenteral nutrition are available. An exception is the growing number of studies on the efficacy of glutamine supplementation of parenteral nutrition or given as a single parenteral agent. Parenteral glutamine appears to confer benefit in selected patients; however, additional data to define optimal glutamine dosing and the patient subgroups who may most benefit from this amino acid are needed. Although some promising studies have been published, little data are available in the current era of nutrition support on the clinical efficacy of altered doses of arginine, branched chain amino acids, cysteine, or taurine supplementation of parenteral nutrition.

SUMMARY

Despite routine use of parenteral nutrition, surprisingly little clinical efficacy data are available to guide total or specific amino acid dosing in adult and pediatric patients requiring this therapy. This warrants increased attention by the research community and funding agencies to better define optimal amino acid administration strategies in patient subgroups requiring parenteral nutrition.

Perioperative intravenous glutamine supplemetation in major abdominal surgery for cancer: a randomized multicenter trial

OBJECTIVE

To investigate whether perioperative intravenous glutamine supplementation may affect surgical morbidity.

SUMMARY BACKGROUND DATA

Small-sized randomized trials showed a trend toward a reduction of postoperative infections in surgical patients receiving glutamine.

METHODS

: A randomized, multicentre trial was carried out in 428 subjects who were candidates for elective major gastrointestinal surgery. Inclusion criteria were: documented gastrointestinal cancer, weight loss <10% in previous 6 months, and age >18 years. Patients received either intravenous infusion of L-alanine-L-glutamine dipeptide (0.40 g/kg/d; equal to 0.25 g of free glutamine) (Ala-Glu group, n = 212), or no supplementation (control group, n = 216). Glutamine infusion began the day before operation and continued postoperatively for at least 5 days. No postoperative artificial nutrition was allowed unless patients could not adequately eat by day 7. Postoperative morbidity was assessed by independent observers according to a priori definition.

RESULTS

Patients were homogenous for baseline and surgical characteristics. Mean percent of weight loss was 1.4 (2.7) in controls and 1.4 (2.4) in Ala-Glu group. Overall postoperative complication rate was 34.9% (74/212) in Ala-Glu and 32.9% (71/216) in control group (P = 0.65). Infectious morbidity was 19.3% (41/212) in Ala-Glu group and 17.1% (37/216) in controls (P = 0.55). The rate of major complications was 7.5% (16/212) in Ala-Glu group and 7.9% (17/216) in controls (P = 0.90). Mean length of hospitalization was 10.2 days (4.8) in Ala-Glu group versus 9.9 days (3.9) in controls (P = 0.90). The rate of patients requiring postoperative artificial nutrition was 13.2% (28/212) in Ala-Glu group and 12.0% (26/216) in controls (P = 0.71).

CONCLUSIONS

Perioperative glutamine does not affect outcome in well-nourished GI cancer patients.

Feeding patients following pancreaticoduodenectomy: a UK national survey

INTRODUCTION

Providing nutrition for patients following pancreaticoduodenectomy (PD) is vital but can be challenging. Due to the lack of UK national guidelines for the provision of nutrition and nutritional pre-operative assessment regarding PD, a national survey was conducted.

PATIENTS AND METHODS

A questionnaire was sent to the Department of Nutrition and Dietetics at each of the 31 specialist pancreatic centres listed with the Pancreatic Society of Great Britain and Ireland. Questions were asked regarding the nutritional assessment and treatment of patients undergoing classical PD and pylorus-preserving PD (PPPD) resections.

RESULTS

Twenty-two centres responded to the questionnaire. With regard to PD and PPPD, 82% routinely feed patients following resection, 32% have a regimen for staring feeds, 18% carry out pre-operative nutritional assessment, five centres have funding for an hepatobiliary dietition, and only four centres have a specialist hepatobiliary dietition employed. There was no consensus regarding the type or route of feeding, and at least one centre reported using parenteral nutrition exclusively.

CONCLUSIONS

Very few centres in the UK have funding for a hepatobiliary dietition. Hence pre-operative nutritional assessment in patients undergoing PD and PPPD does not receive much input. Although the importance of postoperative feeding in these patients is appreciated in all major units, there is no consensus with regards to feeding regimens. The authors hope this observational study will address these issues with this important message and stimulate further study in this area.