Immunosupression and infection after major surgery: a nutritional deficiency

Perioperative Nutritional Considerations in Colon and Rectal Surgery

Malnutrition is common in surgical patients and is associated with substantially increased morbidity and mortality. Dedicated assessment of nutritional status is advised by major nutrition and surgical societies. Assessment may utilize comprehensive and validated nutritional assessment tools or targeted history, physical examination with accompanying serologic markers to identify nutritional risk preoperatively. Emergent surgery in malnourished patients should proceed as the clinical situation dictates with consideration of ostomy or primary anastomosis with proximal fecal diversion to mitigate postoperative infectious complications. Nonemergent surgery should be delayed to facilitate nutritional optimization via oral nutritional supplementation preferably and total parenteral nutrition if necessary for at least 7 to 14 days. Exclusive enteral nutrition may be considered to optimize nutritional status and inflammation in patients with Crohn's disease. Immunonutrition use in the preoperative setting is not supported by evidence. Perioperative and postoperative immunonutrition may be of benefit but requires dedicated study in the contemporary era. Close attention to preoperative nutritional status and optimization represents a critical opportunity to improve outcomes in patients undergoing colorectal surgery.

Postoperative systemic inflammatory dysregulation and corticosteroids: a narrative review

In some patients, the inflammatory-immune response to surgical injury progresses to a harmful, dysregulated state. We posit that postoperative systemic inflammatory dysregulation forms part of a pathophysiological response to surgical injury that places patients at increased risk of complications and subsequently prolongs hospital stay. In this narrative review, we have outlined the evolution, measurement and prediction of postoperative systemic inflammatory dysregulation, distinguishing it from a healthy and self-limiting host response. We reviewed the actions of glucocorticoids and the potential for heterogeneous responses to peri-operative corticosteroid supplementation. We have then appraised the evidence highlighting the safety of corticosteroid supplementation, and the potential benefits of high/repeated doses to reduce the risks of major complications and death. Finally, we addressed how clinical trials in the future should target patients at higher risk of peri-operative inflammatory complications, whereby corticosteroid regimes should be tailored to modify not only the a priori risk, but also further adjusted in response to markers of an evolving pathophysiological response.

Inflammatory Response, Immunosuppression and Arginase Activity after Cardiac Surgery Using Cardiopulmonary Bypass

Background: Major surgeries suppress patients’ cellular immunity for several days, but the mechanisms underlying this T-cell dysfunction are not well understood. A decreased L-Arginine (L-Arg) level may inhibit T-cell function. Arginase 1 (Arg 1) is induced after traumatic injury, leading to molecular changes in T cells, including decreased expression of cell surface T-cell receptors (TCRs) and a loss in CD3ζ chain expression. In this study, we examined the temporal patterns of CD3ζ expression and Arg 1 activity in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Methods: We determined the CD3ζ chain expression; the Arg 1 activity; and the leukocyte, neutrophil and lymphocyte levels of patients on the day before surgery and at 24, 48 and 72 h after surgery. Results: Fifty adult patients scheduled for elective cardiac surgery with CPB were eligible for enrolment. Arginase activity was significantly increased between the day before surgery and at 24, 48 and 72 h after surgery (p < 0.01), and CD3ζ expression was significantly decreased between the day before surgery and at 24, 48 and 72 h after surgery (p < 0.001). We observed significant leukocytosis, neutrophilia and lymphopenia after surgery. Conclusions: The decreased CD3ζ chain expression could be due to the increased Arg 1 activity secondary to the activation of neutrophils in cardiac surgery under CPB. These findings could explain the limited immune-system-mediated organ damage resulting from systemic inflammatory response to major cardiac surgery with CPB.

Attitudes towards Enhanced Recovery after Surgery (ERAS) interventions in colorectal surgery: nationwide survey of Australia and New Zealand colorectal surgeons

BACKGROUND

Whilst Enhanced Recovery after Surgery (ERAS) has been widely accepted in the international colorectal surgery community, there remains significant variations in ERAS programme implementations, compliance rates and best practice recommendations in international guidelines.

METHODS

A questionnaire was distributed to colorectal surgeons from Australia and New Zealand after ethics approval. It evaluated specialist attitudes towards the effectiveness of specific ERAS interventions in improving short term outcomes after colorectal surgery. The data were analysed using a rating scale and graded response model in item response theory (IRT) on Stata MP, version 15 (StataCorp LP, College Station, TX).

RESULTS

Of 300 colorectal surgeons, 95 (31.7%) participated in the survey. Of eighteen ERAS interventions, this study identified eight strategies as most effective in improving ERAS programmes alongside early oral feeding and mobilisation. These included pre-operative iron infusion for anaemic patients (IRT score = 7.82 [95% CI: 6.01-9.16]), minimally invasive surgery (IRT score = 7.77 [95% CI: 5.96-9.07]), early in-dwelling catheter removal (IRT score = 7.69 [95% CI: 5.83-9.01]), pre-operative smoking cessation (IRT score = 7.68 [95% CI: 5.49-9.18]), pre-operative counselling (IRT score = 7.44 [95% CI: 5.58-8.88]), avoiding drains in colon surgery (IRT score = 7.37 [95% CI: 5.17-8.95]), avoiding nasogastric tubes (IRT score = 7.29 [95% CI: 5.32-8.8]) and early drain removal in rectal surgery (IRT score = 5.64 [95% CI: 3.49-7.66]).

CONCLUSIONS

This survey has demonstrated the current attitudes of colorectal surgeons from Australia and New Zealand regarding ERAS interventions. Eight of the interventions assessed in this study including pre-operative iron infusion for anaemic patients, minimally invasive surgery, early in-dwelling catheter removal, pre-operative smoking cessation, pre-operative counselling, avoidance of drains in colon surgery, avoiding nasogastric tubes and early drain removal in rectal surgery should be considered an important part of colorectal ERAS programmes.

Measuring the human immune response to surgery: multiomics for the prediction of postoperative outcomes

PURPOSE OF REVIEW

Postoperative complications including infections, cognitive impairment, and protracted recovery occur in one-third of the 300 million surgeries performed annually worldwide. Complications cause personal suffering along with a significant economic burden on our healthcare system. However, the accurate prediction of postoperative complications and patient-targeted interventions for their prevention remain as major clinical challenges.

RECENT FINDINGS

Although multifactorial in origin, the dysregulation of immunological mechanisms that occur in response to surgical trauma is a key determinant of postoperative complications. Prior research, primarily focusing on inflammatory plasma markers, has provided important clues regarding their pathogenesis. However, the recent advent of high-content, single-cell transcriptomic, and proteomic technologies has considerably improved our ability to characterize the immune response to surgery, thereby providing new means to understand the immunological basis of postoperative complications and to identify prognostic biological signatures.

SUMMARY

The comprehensive and single-cell characterization of the human immune response to surgery has significantly advanced our ability to predict the risk of postoperative complications. Multiomic modeling of patients' immune states holds promise for the discovery of preoperative predictive biomarkers, ultimately providing patients and surgeons with actionable information to improve surgical outcomes. Although recent studies have generated a wealth of knowledge, laying the foundation for a single-cell atlas of the human immune response to surgery, larger-scale multiomic studies are required to derive robust, scalable, and sufficiently powerful models to accurately predict the risk of postoperative complications in individual patients.

Is simultaneous panniculectomy an ideal approach to repair a ventral hernia: a general surgeon's experience

BACKGROUND

The number of Australian patients undergoing ventral hernia repair has seen a significant increase in the last twenty years. With the obesity epidemic, the general surgeon is frequently seeing patients with hernias and significant abdominal aprons and is being asked to address this at the time of the hernia repair. This can be performed utilising a general surgery and plastic surgery team, but there may be some advantages to general surgeon being able incorporate this into their practice. We present our approach to patients undergoing ventral hernia repair and simultaneous panniculectomy (VHR + PAN) by a single general surgeon.

METHODS

Data were analysed from a single surgeon's experience performing VHR + PAN at the same operation. Data were collected prospectively from 2009 to 2020. 146 cases of patients undergoing VHR + PAN were identified and included in this study.

RESULTS

The mean age of patients undergoing VHR + PAN was 58 years. The mean BMI was 35, with 59% of patients losing weight loss prior to surgery. 66% of patients had a hernia repair with biosynthetic mesh and 91% of patients had retro-rectus or pre-peritoneal mesh approach to the repair. 42% of patients had a post-operative complication with 80.6% of these being related to surgical-site occurrences. Other complications included gastrointestinal (14%), respiratory (13%) and venous thromboembolism, such as a deep vein thrombus or pulmonary embolism (6%). There were 2 deaths in the series (1.3%). The hernia recurrence rate was 6%.

CONCLUSION

Simultaneous PAN is possible in patients with an abdominal apron who are undergoing VHR, with an acceptable risk of SSOs and other complications. This technique provides excellent exposure and with appropriate training is well within the remit of the general surgeon. This may save further operative management in the future and can offer patients improved self-esteem, mobility, and independence. Patient optimisation is key, paying careful attention to pre-operative weight loss, diabetic control, smoking cessation and respiratory function. VHR + PAN is an important technique that should be in the repertoire of all abdominal wall reconstruction units.

Effect of Preoperative Immunonutrition on Postoperative Major Morbidity after Cytoreductive Surgery and HIPEC in Patients with Peritoneal Metastasis

The effect of preoperative immunonutrition intake on postoperative major complications in patients following cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) was assessed. The accuracy of C-Reactive Protein (CRP) for detecting postoperative complications was also analyzed. Patients treated within a peritoneal carcinomatosis program in which a complete or optimal cytoreduction was achieved were retrospectively analyzed. They were divided into two groups based on whether preoperative immunonutrition (IMN) or not (non-IMN) were administered. Clinical and surgical variables and postoperative complications were gathered. Predictive values of major morbidity of CRP during the first 3 postoperative days (POD) were also evaluated. A total of 107 patients were included, 48 belonging to the IMN group and 59 to the non-IMN group. In multivariate analysis immunonutrition (OR 0.247; 95%CI 0.071-0.859; p = 0.028), and the number of visceral resections (OR 1.947; 95%CI 1.086-3.488; p = 0.025) emerged as independent factors associated with postoperative major morbidity. CRP values above 103 mg/L yielded a negative predictive value of 84%. Preoperative intake of immunonutrition was associated with a decrease of postoperative major morbidity and might be recommended to patients with peritoneal carcinomatosis following CRS. Measuring CRP levels during the 3 first postoperative days is useful to rule out major morbidity.

The clinical impact of malnutrition on the postoperative outcomes of patients undergoing colorectal resection surgery for colon or rectal cancer: Propensity score matched analysis of 2011-2017 US hospitals

BACKGROUND & AIMS

Malnutrition can be prevalently found in patients with significant-to-advanced colorectal cancer, who potential require colorectal resection procedures; to accurately describe the postoperative risks, we used a propensity-score matched comparison of national database to analyze the effects of malnutrition on post-colectomy outcomes.

METHODS

2011-2017 National inpatient Sample was used to isolate inpatient ceases of colorectal resection procedures, which were stratified using malnutrition into malnutrition-present cohort and malnutrition-absent controls; the controls were propensity-score matched with the study cohort using 1:1 ratio and compared to the following endpoints: mortality, length of stay, costs, postoperative complications.

RESULTS

After matching, there were 11357 with and without malnutrition who underwent colorectal resection surgery; in comparison, malnourished patients had higher rates of in-hospital mortality (6.14 vs 3.22% p < 0.001, OR 1.96 95%CI 1.73-2.23), length of stay (15.4 vs 9.61d p < 0.001), costs ($163, 962 vs $102,709 p < 0.001), and were more likely to be discharged to non-routine discharges, including short term hospitals, skilled nursing facilities, and home healthcare. In terms of complications, malnourished patients had higher bleeding (2.87 vs 1.68% p < 0.001, OR 1.73 95%CI 1.44-2.07), wound complications (4.31 vs 1.34% p < 0.001, OR 3.32 95%CI 2.76-3.99), infection (6 vs 2.62% p < 0.001, OR 2.38 95%CI 2.07-2.73), and postoperative respiratory failure (7.27 vs 3.37% p < 0.001, OR 2.25 95%CI 1.99-2.54).

CONCLUSION

This study demonstrates the presence of malnutrition to be associated with adverse postoperative outcomes including mortality and complications in patients undergoing colorectal resection surgery for colon cancer.

Preoperative Immunonutrition vs. Standard Dietary Advice in Normo-Nourished Patients Undergoing Fast-Track Laparoscopic Colorectal Surgery

Immunonutrition (IN) appears to reduce infective complications and in-hospital length of stay (LOS) after major gastrointestinal surgery, but its use in normo-nourished patients is still controversial. The primary aim of this comparative observational study was to evaluate if pre-operative IN reduces in-hospital stay in patients undergoing laparoscopic colorectal resection for cancer under an enhanced recovery after surgery (ERAS) program. The influence of IN on time to first bowel movements, time to full oral diet tolerance, number and type of complications, reasons of prolonged LOS and readmission rate was evaluated as secondary outcome. Patients undergoing ERAS laparoscopic colorectal resection between December 2016 and December 2019 were reviewed. Patients who have received preoperative IN (group A) were compared to those receiving standard dietary advice (group B). Mean in-hospital LOS was significantly shorter in patients receiving preoperative IN than standard dietary advice (4.85 ± 2.25 days vs. 6.06 ± 3.95 days; p < 0.0492). No differences in secondary outcomes were observed. Preoperative IN associated with ERAS protocol in normo-nourished patients undergoing laparoscopic colorectal cancer resection seems to reduce LOS.

Role of arginine deiminase in thymic atrophy during experimental Streptococcus pyogenes infection

Expression of gene of arginine deiminase (AD) allows adaptation of Streptococcus pyogenes to adverse environmental conditions. AD activity can lead to L-arginine deficiency in the host cells' microenvironment. Bioavailability of L-arginine is an important factor regulating the functions of the immune cells in mammals. By introducing a mutation into S pyogenes M46-16, we obtained a strain with inactivated arcA/sagp gene (M49-16 delArcA), deficient in AD. This allowed elucidating the function of AD in pathogenesis of streptococcal infection. The virulence of the parental and mutant strains was examined in a murine model of subcutaneous streptococcal infection. L-arginine concentration in the plasma of mice infected with S pyogenes M49-16 delArcA remained unchanged in course of the entire experiment. At the same time mice infected with S pyogenes M49-16 demonstrated gradual diminution of L-arginine concentration in the blood plasma, which might be due to the activity of streptococcal AD. Mice infected with S pyogenes M49-16 delArcA demonstrated less intensive bacterial growth in the primary foci and less pronounced bacterial dissemination as compared with animals infected with the parental strain S pyogenes M46-16. Similarly, thymus involution, alterations in apoptosis, thymocyte subsets and Treg cells differentiation were less pronounced in mice infected with S pyogenes M49-16 delArcA than in those infected with the parental strain. The results obtained showed that S pyogenes M49-16 delArcA, unable to produce AD, had reduced virulence in comparison with the parental S pyogenes M49-16 strain. AD is an important factor for the realization of the pathogenic potential of streptococci.

The Potential for Cancer Immunotherapy in Targeting Surgery-Induced Natural Killer Cell Dysfunction

Natural Killer (NK) cells are granular lymphocytes of the innate immune system that are able to recognize and kill tumor cells without undergoing clonal selection. Discovered over 40 years ago, they have since been recognized to possess both cytotoxic and cytokine-producing effector functions. Following trauma, NK cells are suppressed and their effector functions are impaired. This is especially important for cancer patients undergoing the removal of solid tumors, as surgery has shown to contribute to the development of metastasis and cancer recurrence postoperatively. We have recently shown that NK cells are critical mediators in the formation of metastasis after surgery. While research into the mechanism(s) responsible for NK cell dysfunction is ongoing, knowledge of these mechanisms will pave the way for perioperative therapeutics with the potential to improve cancer outcomes by reversing NK cell dysfunction. This review will discuss mechanisms of suppression in the postoperative environment, including hypercoagulability, suppressive soluble factors, the expansion of suppressive cell populations, and how this affects NK cell biology, including modulation of cell surface receptors, the potential for anergy, and immunosuppressive NK cell functions. This review will also outline potential immunotherapies to reverse postoperative NK dysfunction, with the goal of preventing surgery-induced metastasis.

Perioperative Nutritional Optimization in Spine Surgery

Nutritional optimization in patients undergoing spine surgery is important as improved surgical outcomes and decreased rates of complications have been noted in optimized patients. With the increasingly high numbers of elderly patient and patients with metabolic comorbidities undergoing spine procedures, perioperative nutritional status should be enhanced for the best possible surgical outcomes. Methods of optimization include preoperative screening with Nutritional Risk Score or other scoring systems, looking for changes in body mass index, detecting sarcopenia, and screening for metabolic abnormalities. Assessment of blood glucose, electrolytes, cholesterol, vitamin levels, visceral proteins, and lean body mass must be done preoperatively and close monitoring should be continued postoperatively. Albumin helps to determine the health status of patients before surgery and prealbumin as a predictor of surgical outcomes is being investigated. Malnourished patients should be given balanced diets replenishing key nutrient deficits, glucose should be maintained with sliding scale insulin or continuous infusions and immunonutrition may be implemented. Postoperatively, patients should initiate a diet as soon as possible to decrease overall length of stay and complication rates, facilitating return to normal activities.

Perioperative Immunonutrition Modulates Inflammatory Response after Radical Cystectomy: Results of a Pilot Randomized Controlled Clinical Trial

PURPOSE

Poor preoperative nutritional status is associated with a higher complication rate after radical cystectomy in patients with bladder cancer. Given the short interval between diagnosis and radical cystectomy, we compared the effect of short-term specialized immunonutrition to that of a standard oral nutritional supplement on the acute inflammatory response and arginine status in patients treated with radical cystectomy.

MATERIALS AND METHODS

In this prospective, randomized study in 29 men 14 received specialized immunonutrition and 15 received oral nutritional supplement. Each group drank 3 cartons per day for 5 days before and 5 days after radical cystectomy. The Th1-Th2 balance, plasma interleukin-6 and plasma amino acids were measured at baseline, intraoperatively and on postoperative days 2, 14 and 30. Body composition was measured by dual energy x-ray absorptiometry at baseline and on postoperative days 14 and 30. Differences in outcomes were assessed using the generalized linear mixed model.

RESULTS

In the specialized immunonutrition group there was a 54.3% average increase in the Th1-Th2 balance according to the tumor necrosis factor-α-to-interleukin-13 ratio from baseline to intraoperative day, representing a shift toward a Th1 response. In the oral nutritional supplement group the Th1-Th2 balance decreased 4.8%. The change in the Th1-Th2 balance between the specialized immunonutrition and oral nutritional supplement groups significantly differed (p <0.027). Plasma interleukin-6 was 42.8% lower in the specialized immunonutrition group compared to the oral nutritional supplement group on postoperative day 2 (p = 0.020). In the specialized immunonutrition group plasma arginine was maintained from baseline to postoperative day 2 and yet the oral nutritional supplement group showed a 26.3% reduction from baseline to postoperative day 2 (p = 0.0003). The change in appendicular muscle loss between the groups was not statistically significant.

CONCLUSIONS

Th1-to-Th2 ratios, peak interleukin-6 levels and plasma arginine suggest that consuming specialized immunonutrition counteracts the disrupted T-helper balance, lowers the inflammatory response and prevents arginine depletion due to radical cystectomy.

Dysfunctional Natural Killer Cells in the Aftermath of Cancer Surgery

The physiological changes that occur immediately following cancer surgeries initiate a chain of events that ultimately result in a short pro-, followed by a prolonged anti-, inflammatory period. Natural Killer (NK) cells are severely affected during this period in the recovering cancer patient. NK cells play a crucial role in anti-tumour immunity because of their innate ability to differentiate between malignant versus normal cells. Therefore, an opportunity arises in the aftermath of cancer surgery for residual cancer cells, including distant metastases, to gain a foothold in the absence of NK cell surveillance. Here, we describe the post-operative environment and how the release of sympathetic stress-related factors (e.g., cortisol, prostaglandins, catecholamines), anti-inflammatory cytokines (e.g., IL-6, TGF-β), and myeloid derived suppressor cells, mediate NK cell dysfunction. A snapshot of current and recently completed clinical trials specifically addressing NK cell dysfunction post-surgery is also discussed. In collecting and summarizing results from these different aspects of the surgical stress response, a comprehensive view of the NK cell suppressive effects of surgery is presented. Peri-operative therapies to mitigate NK cell suppression in the post-operative period could improve curative outcomes following cancer surgery.

Deep Immune Profiling of an Arginine-Enriched Nutritional Intervention in Patients Undergoing Surgery

Application of high-content immune profiling technologies has enormous potential to advance medicine. Whether these technologies reveal pertinent biology when implemented in interventional clinical trials is an important question. The beneficial effects of preoperative arginine-enriched dietary supplements (AES) are highly context specific, as they reduce infection rates in elective surgery, but possibly increase morbidity in critically ill patients. This study combined single-cell mass cytometry with the multiplex analysis of relevant plasma cytokines to comprehensively profile the immune-modifying effects of this much-debated intervention in patients undergoing surgery. An elastic net algorithm applied to the high-dimensional mass cytometry dataset identified a cross-validated model consisting of 20 interrelated immune features that separated patients assigned to AES from controls. The model revealed wide-ranging effects of AES on innate and adaptive immune compartments. Notably, AES increased STAT1 and STAT3 signaling responses in lymphoid cell subsets after surgery, consistent with enhanced adaptive mechanisms that may protect against postsurgical infection. Unexpectedly, AES also increased ERK and P38 MAPK signaling responses in monocytic myeloid-derived suppressor cells, which was paired with their pronounced expansion. These results provide novel mechanistic arguments as to why AES may exert context-specific beneficial or adverse effects in patients with critical illness. This study lays out an analytical framework to distill high-dimensional datasets gathered in an interventional clinical trial into a fairly simple model that converges with known biology and provides insight into novel and clinically relevant cellular mechanisms.

Effects of arginine-based immunonutrition on inpatient total costs and hospitalization outcomes for patients undergoing colorectal surgery

OBJECTIVE

The aim of this study was to assess the effects of an arginine-based immunonutrition intervention for patients undergoing elective colorectal surgery on postsurgical utilization and cost outcomes.

METHODS

This analysis was based on data from two Washington State databases: Surgical Care and Outcomes Assessment Program (SCOAP) linked to the Comprehensive Hospital Abstract Reporting System (CHARS). The sample (N=722) comprises adult patients who underwent elective colorectal surgery with anastomosis in a Washington State hospital that participated in the Strong for Surgery (S4S) initiative between January 1, 2012, and December 31, 2013. A generalized linear model was used to predict the outcomes, adjusting for demographic characteristics and patient health conditions within a multivariate regression framework.

RESULTS

Findings from this study demonstrated significantly fewer readmissions and hospital days for the intervention group during the 180 d after index hospitalization. Clinical benefits included decreased risk for infections and venous thromboembolism. There was a similar pattern toward lower total costs in the immunonutrition patient group; however, these were not statistically different compared with the control group at any time point. Savings in the immunonutrition group were substantial-mean total costs per patient were less by ∼$2500 at index hospitalization, $3500 less through 30 d of follow-up, and $5300 less over 180 d compared with the control group.

CONCLUSION

These findings suggest that arginine-based immunonutrition should be thoroughly evaluated for incorporation into clinical practice for patients undergoing elective surgery. Moreover, there is a need to assess the effects of the intervention in other hospitals both within and outside Washington.

Preoperative Immunonutrition and Elective Colorectal Resection Outcomes

BACKGROUND

Randomized controlled trials demonstrate the efficacy of arginine-enriched nutritional supplements (immunonutrition) in reducing complications after surgery. The effectiveness of preoperative immunonutrition has not been evaluated in a community setting.

OBJECTIVE

This study aims to determine whether immunonutrition before elective colorectal surgery improves outcomes in the community at large.

DESIGN

This is a prospective cohort study with a propensity score-matched comparative effectiveness evaluation.

SETTINGS

This study was conducted in Washington State hospitals in the Surgical Care Outcomes Assessment Program from 2012 to 2015.

PATIENTS

Adults undergoing elective colorectal surgery were selected.

INTERVENTIONS

Surgeons used a preoperative checklist that recommended that patients take oral immunonutrition (237 mL, 3 times daily) for 5 days before elective colorectal resection.

MAIN OUTCOME MEASURES

Serious adverse events (infection, anastomotic leak, reoperation, and death) and prolonged length of stay were the primary outcomes measured.

RESULTS

Three thousand three hundred seventy-five patients (mean age 59.9 ± 15.2 years, 56% female) underwent elective colorectal surgery. Patients receiving immunonutrition more commonly were in a higher ASA class (III-V, 44% vs 38%; p = 0.01) or required an ostomy (18% vs 14%; p = 0.02). The rate of serious adverse events was 6.8% vs 8.3% (p = 0.25) and the rate of prolonged length of stay was 13.8% vs 17.3% (p = 0.04) in those who did and did not receive immunonutrition. After propensity score matching, covariates were similar among 960 patients. Although differences in serious adverse events were nonsignificant (relative risk, 0.76; 95% CI, 0.49-1.16), prolonged length of stay (relative risk, 0.77; 95% CI, 0.58-1.01 p = 0.05) was lower in those receiving immunonutrition.

LIMITATIONS

Patient compliance with the intervention was not measured. Residual confounding, including surgeon-level heterogeneity, may influence estimates of the effect of immunonutrition.

CONCLUSIONS

Reductions in prolonged length of stay, likely related to fewer complications, support the use of immunonutrition in quality improvement initiatives related to elective colorectal surgery. This population-based study supports previous trials of immunonutrition, but shows a lower magnitude of benefit, perhaps related to compliance or a lower rate of adverse events, highlighting the value of community-based assessments of comparative effectiveness.

Parenteral or Enteral Arginine Supplementation Safety and Efficacy

Arginine supplementation has the potential to improve the health of patients. Its use in hospitalized patients has been a controversial topic in the nutrition literature, especially concerning supplementation of septic patients. In this article, we review the relevant literature both for and against the use of arginine in critically ill, surgical, and hospitalized patients. The effect of critical illness on arginine metabolism is reviewed, as is its use in septic and critically ill patients. Although mounting evidence supports immunonutrition, there are only a few studies that suggest that this is safe in patients with severe sepsis. The use of arginine has been shown to benefit a variety of critically ill patients. It should be considered for inclusion in combinations of immunonutrients or commercial formulations for groups in whom its benefit has been reported consistently, such as those who have suffered trauma and those in acute surgical settings. The aims of this review are to discuss the role of arginine in health, the controversy surrounding arginine supplementation of septic patients, and the use of arginine in critically ill patients.

Tissue metabolic profiling of lymph node metastasis of colorectal cancer assessed by 1H NMR

Lymph node metastasis is a decisive prognostic and therapeutic staging factor for colorectal cancer (CRC), which is one of the most prevalent types of cancer and a malignant tumor. The metabolic profiling of tissue samples from a large cohort of lymph node non‑metastatic CRC patients (n=73), lymph node metastatic CRC patients (n=52) and normal controls (n=41) was performed using 1H nuclear magnetic resonance (NMR) together with multivariate statistical analyses. Excellent separation was obtained between CRC patients and normal controls, and CRC patients were also perfectly classified according to lymph node metastasis. Forty‑two distinguishing metabolites were identified, which revealed disturbance of glycolysis, glutaminolysis, fatty acid metabolism, choline metabolism and amino acids, suggesting that cellular functions in energy production, macromolecular synthesis, oxidative stress and immune escape of cancer cells are affected in CRC. In total, 10 tissue metabolites were significantly disturbed between non‑metastatic and metastatic CRC patients. The present study firstly staged CRC patients by lymph node metastasis by metabolomic approach. The identified metabolites may be associated with the neoplasia, invasion and metastasis of the tumor. The results suggest the promising application of these metabolites in clinical therapy, and further understanding of the related mechanism warrants further investigation.

Should perioperative immunonutrition for elective surgery be the current standard of care?

Postoperative infectious complications are independently associated with increased hospital length of stay (LOS) and cost and contribute to significant inpatient morbidity. Many strategies such as avoidance of long periods of preoperative fasting, re-establishment of oral feeding as early as possible after surgery, metabolic control and early mobilization have been used to either prevent or reduce the incidence of postoperative infections. Despite these efforts, it remains a big challenge to our current healthcare system to mitigate the cost of postoperative morbidity. Furthermore, preoperative nutritional status has also been implicated as an independent risk factor for postoperative morbidity. Perioperative nutritional support using enteral and parenteral routes has been shown to decrease postoperative morbidity, especially in high-risk patients. Recently, the role of immunonutrition (IMN) in postoperative infectious complications has been studied extensively. These substrates have been found to positively modulate postsurgical immunosuppression and inflammatory responses. They have also been shown to be cost-effective by decreasing both tpostoperative infectious complications and hospital LOS. In this review, we discuss the postoperative positive outcomes associated with the use of perioperative IMN, their cost-effectiveness, current guidelines and future clinical implications.

Preoperative Nutrition and Prehabilitation

Enhanced recovery after surgery is the natural evolution of what were previously referred to as fast track programs and seeks to implement a series of interventions to improve and enhance recovery after major surgical procedures. Two important preoperative aspects are nutrition and prehabilitation. Identifying nutritionally deficient patients allows preoperative intervention to optimize their nutritional status. The contribution of cardiopulmonary exercise testing to the evaluation of perioperative risk, subsequent development of a training program, and the use of indices to risk stratify and measure improvement after a training program allow a personalized preoperative program to be developed for each patient.

Fecal Microbial Transplant After Ileocolic Resection Reduces Ileitis but Restores Colitis in IL-10-/- Mice

BACKGROUND

Ileocolic resection (ICR) is frequently performed for Crohn's disease; however, disease commonly recurs early in the neoterminal ileum. The aim of this study was to use the IL-10(-/-) mouse to determine the effects of ICR on gut microbiome and immune function and if postoperative fecal microbial transplant (FMT) would improve disease.

METHODS

ICR was performed in 129S1/SvlmJ IL10(-/-) mice followed by FMT using stool from wild-type mice. Sham-transplant mice received their own stool. Stool samples were collected on day 0, day 13 (after ICR), and day 27 (after FMT) for whole metagenome shot-gun sequencing. Mucosal-associated bacteria were quantified with quantitative PCR and visualized by fluorescent in situ hybridization. Tissue cytokines were measured with multiplex arrays and mononuclear phagocyte populations by flow cytometry.

RESULTS

Surgery induced microbial functional and taxonomic shifts, decreased diversity, and depleted Bacteroidia and Clostridia. ICR mice had reduced colitis but worse ileitis with bacterial overgrowth, increased translocation, and reduction in tissue macrophages. FMT prevented ileitis but restored colitis and allowed for a bloom of γ-proteobacteria. In the colon, ICR and sham transplant were associated with recruitment of tolerogenic dendritic cells, whereas FMT shifted these immune cell subsets to control profiles along with increasing cytokine levels.

CONCLUSIONS

This study suggests that surgical-induced immune dysfunction and microbial dysbiosis with impaired clearance may be the underlying cause of the early ulcerations found in the ileum of patients with Crohn's disease after ICR. FMT has an immunostimulatory effect on the postoperative intestine, which was beneficial in preventing ileitis, but detrimental in restoring colonic injury after surgery.

Quick Fix for Hospital-Acquired Malnutrition?

Hospital-acquired malnutrition is universally present across the globe. Little progress has been made on overcoming hospital-acquired malnutrition despite known presence for at least 40 years. Technologies and methods to deliver the recommended calories and protein are available in most healthcare settings. Despite this, inadequate nutrient delivery continues to be a problem. Correia and colleagues propose a simplified algorithm that assists clinicians in becoming aware of poor nutrient intake and suggest nutrition interventions.

Perioperative dynamics and significance of amino acid profiles in patients with cancer

Background

Metabolome analysis including amino acid profile is under investigation as an approach in cancer screening. The present study aims to analyze plasma free amino acid (PFAA) profiles in cancer patients and investigate their potential as biomarkers of malignancy.

Methods

Plasma samples from 56 gastric cancer patients, 28 breast cancer patients, 33 thyroid cancer patients, and 137 age-matched healthy controls were collected in the study. PFAA levels were measured and their perioperative alterations were analyzed. Biological effects of ten cancer-related amino acids were further validated in gastric and breast cancer cells.

Results

We found that PFAA profiles of cancer patients differed significantly from those of healthy controls. Decreased concentrations of PFAAs were associated with lymph node metastases in gastric cancer. Levels of PFAAs such as aspartate and alanine increased after tumor resection. PFAA levels correlated with clinical tumor markers in gastric cancer patients and pathological immunohistochemistry markers in breast cancer patients. Specifically, alanine, arginine, aspartate and cysteine had proliferative effects on breast cancer cells. Proliferation of gastric cancer cells was promoted by cysteine, but inhibited by alanine and glutamic acid. Furthermore, alanine treatment decreased total and stable fraction of gastric cancer cells, and alanine and glutamic acid induced apoptosis of gastric cancer cells.

Conclusions

PFAA patterns in cancer patients are altered perioperatively. Tumor-related amino acids identified by dynamic study of PFAA patterns may have the potential to be developed as novel biomarkers for diagnosis and prognosis of cancer patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0408-1) contains supplementary material, which is available to authorized users.

Feeding the gut: how, when and with what -- the metabolic issue

PURPOSE OF REVIEW

To review the literature on feeding critically ill patients with special emphasis on the intestine.

RECENT FINDINGS

Many dogmas have been questioned in the past few years. In particular, the absence of evidence for impact on outcomes in critically ill patients has been highlighted. So 'early enteral feeding', the trophic effect on intestinal mucosa in humans, 'pharmaco-nutrition', postpyloric feeding and prokinetic drugs have all been found to lack proper evidence to affect outcomes.

SUMMARY

The use of gastric feeding in critical illness is recommended. Successful gastric feeding is indicative of a functional gastrointestinal tract. Pharmacological effects of nutrients are questionable, but supplementation of deficits (glutamine, selenium, etc.) may be in the patient's best interest. A more individualized prescription of nutrition in the critically ill is advocated.

The cross talk between microbiota and the immune system: metabolites take center stage

The human meta-organism consists of more than 90% of microbial cells. The gastrointestinal tract harbors trillions of commensal microorganisms that influence the development and homeostasis of the host. Alterations in composition and function of the microbiota, termed dysbiosis, have been implicated in a multitude of metabolic and inflammatory diseases in humans. Thus, understanding the molecular underpinnings the cross talk between commensal bacteria and their host during homeostasis and dysbiosis may hold the key to understanding many idiopathic diseases. While most attention has focused on the innate recognition of immune-stimulatory bacterial molecules, such as cell wall components and nucleic acids, we emphasize here the impact of diet-dependent microbial metabolites on the development and function of the immune system.

Dietary inflammatory index as a potential determinant of a length of hospitalization among surgical patients treated for colorectal cancer

Background/objectives:

Inflammation is a central process responsible for health outcomes among surgical patients. Immunonutrition has been investigated as a promising modifying factor; however, inflammatory properties of habitual diet have not yet been investigated. The purpose of this study was to describe inflammatory properties of diet measured by the dietary inflammatory index (DII) among surgical patients treated for colorectal cancer and to link inflammatory properties of habitual diet with a duration of hospitalization.

Subjects/methods:

A follow-up study among colorectal cancer patients treated surgically was performed in Krakow, Poland. In total, 689 patients were recruited for the study. Habitual diet was assessed using a standardized semiquantitative food frequency questionnaire. Overall, 23 dietary items (including macro-and micronutrients) were used to calculate individuals' DII. Gender, age, marital status, body mass index, smoking status, lifetime physical activity, taking vitamin supplements, number of chronic diseases, cancer site, Duke's staging and surgery type were considered as potential covariates.

Results:

Participants were aged 58 years, with the average hospitalization time of 11 days. Higher DII (meaning diet with higher anti-inflammatory properties) was negatively associated with the duration of hospitalization (univariable linear regression: b=−0.59; P=0.005). Multivariable logistic regression has shown the decrease of the risk of longer stays (>7 days) among patients with the DII >−4.25, but only among younger (⩽60 years) patients, irrespective of Duke's staging.

Conclusions:

The DII might be used as a potential predictor of longer hospitalization among colorectal cancer patients treated surgically. The study provides evidence for the role of dietary-related low-grade inflammation among surgical patients.

Low-grade dietary-related inflammation and survival after colorectal cancer surgery

PURPOSE

Prolong inflammation is a central process observed in several chronic conditions and may be responsible for survival. There is an increasing evidence showing the role of diet in inflammation and habitual diet may be responsible for low-grade inflammation. The purpose of our study was to assess the effect of inflammatory properties of habitual diet measured by the Dietary Inflammatory Index (DII) on survival among surgical patients treated for colorectal cancer (CRC).

METHODS

A follow-up study among 689 CRC patients (mean age 58 years, ±8.9; 56.7 % males) treated surgically was performed in Krakow, Poland. Habitual diet was assessed by a standardized semiquantitative food frequency questionnaire. Next, 23 dietary items were used to calculate DIIs. Vital records were verified to determine status of the participants.

RESULTS

Study has shown linear association between DII and survival time among CRC patients with totally removed cancer treated by chemotherapy (b = -0.13, p = 0.024). After adjustment for several important covariates, DII was associated with survival during up to 3 years after surgery, but only in patients without distant metastases (3-year HRDII>-2.27 = 0.61, 95 % CI 0.38-0.99).

CONCLUSIONS

The results of the investigation have shown the usefulness of the DII as a potential predictor of survival among patients without distant metastases treated surgically for CRC.

The central role of arginine catabolism in T-cell dysfunction and increased susceptibility to infection after physical injury

OBJECTIVE

To explore the hypothesis that decreased arginine availability by myeloid-derived suppressor cells (MDSCs) is a cause of T-cell dysfunction after physical injury (PI).

BACKGROUND

Arginine is an essential amino acid for normal T-cell function whose availability becomes limited after PI. MDSCs expressing arginase 1 are induced by PI. T-cell dysfunction after PI seems to increase the risk of infection but the mechanisms that cause it are unclear.

METHODS

PI was created using a standard laparotomy model. Phenotypical and functional alterations in T cells were evaluated in vivo. MDSCs expressing arginase 1 were measured by flow cytometry. Infection after PI was created by intraperitoneal injection of Listeria monocytogenes. N-Hydroxy-Nor-L-arginine (Nor-NOHA) was used as an arginase inhibitor. The effect of arginine depletion on T-cell function and susceptibility to infection was assessed through adoptive transfer of MDSC or injection of arginase into noninjured mice.

RESULTS

PI caused a decrease in intracellular arginine in T cells, loss of the T-cell receptor (TCR) CD3-ζ chain, inhibition of in vivo T-cell proliferation, memory, and cytotoxicity. PI exponentially increased bacterial growth and mortality to L. monocytogenes. T-cell dysfunction and increased infection were reversed by arginase inhibitor Nor-NOHA but were reproduced by adoptively transferring MDSC or injecting arginase 1 to noninjured mice.

CONCLUSIONS

Arginine availability is decreased after PI coinciding with an induction of MDSC expressing arginase 1. Decreased arginine may inhibit T-cell function and increase susceptibility to infection after injury.

Major surgical trauma differentially affects T-cells and APC

Macrophages have been reported to initiate immunosuppression following trauma and hemorrhage, and recent experimental studies suggest a pivotal role of T-cells in maintaining immunosuppression. The aim of the present study was to investigate the interaction of APC and T-cells in humans following major surgery. First, APC and T-cells from 14 surgical patients were isolated, counted and characterized by their specific surface marker profile 2 and 24 h postoperatively. Then, these cells were co-incubated with cells of the other type, which had been isolated pre-operatively. Chemokine secretion from pre-operative cells as measured by enzyme immunoassay served as a bioassay for the function of the stimulating postoperative cells. CD3+ T-cells and surface marker CD28 were markedly suppressed postoperatively, while CD3+CD25+CD127−Tregs were not suppressed. CD14+APC counts were increased with the most significant increase observed in CD14+HLA-DR− myeloid-derived suppressor cells. In co-cultures, APC showed increased postoperative secretion of TNF-α and IL-6 independently of whether they had been co-incubated with pre- or postoperative T-cells. T-cells incubated with CD14+ cells 2 h postoperatively secreted diminished amounts of IFN-γ. The results of the study suggest that T-cells play a pivotal role in mediating immunosuppression after major abdominal surgery.

Nutrition optimization prior to surgery

Optimization of metabolic state prior to major surgery leads to improved surgical outcomes. Nutrition screening protocols should be implemented in the preoperative evaluation, possibly as part of a bundle. Strategies to minimize hyperglycemia and insulin resistance by aggressive preoperative nutrition and carbohydrate loading may promote maintenance of a perioperative anabolic state, improving healing, reducing complications, and shortening the time to recovery of bowel function and hospital discharge. Short courses of preoperative immune-modulating formulas, using combinations of arginine, ω-3 fatty acids, and other nutrients, have been associated with improved surgical outcomes. These immune-modulating nutrients are key elements of metabolic pathways that promote attenuation of the metabolic response to stress and improve both wound healing and immune function. Patients with severe malnutrition and gastrointestinal dysfunction may benefit from preoperative parenteral nutrition. Continuation of feeding through the intraoperative period for severely stressed hypermetabolic patients undergoing nongastrointestinal surgery is another strategy to optimize metabolic state and reduce prolonged nutrition deficits. In this paper, we review the importance of preoperative nutrition and strategies for effective preoperative nutrition optimization.

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.

Epigenetic silencing of retinoblastoma gene regulates pathologic differentiation of myeloid cells in cancer

Two major populations of myeloid-derived suppressor cells (MDSC), monocytic MDSC (M-MDSC) and polymorphonuclear MDSC (PMN-MDSC) regulate immune responses in cancer and other pathologic conditions. Under physiologic conditions, Ly6C^hiLy6G⁻ inflammatory monocytes, which are the normal counterpart of M-MDSC, differentiate into macrophages and dendritic cells (DCs). PMN-MDSC is the predominant group of MDSC that accumulates in cancer. Here we show that a large proportion of M-MDSC in tumor-bearing mice acquired phenotypic, morphological and functional features of PMN-MDSC. Acquisition of this phenotype, but not the functional attributes of PMN-MDSC, was mediated by transcriptional silencing of the retinoblastoma (Rb) gene through epigenetic modifications mediated by histone deacetylase 2 (HDAC-2). These data demonstrate novel mechanism regulation of myeloid cells in cancer.

Immunonutrition for patients undergoing elective surgery for gastrointestinal cancer: impact on hospital costs

Background

Oral or enteral dietary supplementation with arginine, omega 3 fatty acids and nucleotides (known as immunonutrition) significantly improve outcomes in patients undergoing elective surgery. The objective of the study was to determine the impact on hospital costs of immunonutrition formulas used in patients undergoing elective surgery for gastrointestinal cancer.

Methods

US hospital costs of stay with and without surgical infectious complications, and average cost per day in the hospital for patients undergoing elective surgery for gastrointestinal cancer were estimated using data from the Healthcare Cost and Utilization Project’s 2008 Nationwide Inpatient Sample. These costs were then used to estimate the impact of perioperative immunonutrition on hospital costs using estimates of reduction in infectious complications or length of stay from a meta-analysis of clinical trials in patients undergoing elective surgery for gastrointestinal cancer. Sensitivity of the results to changes in baseline complication rates or length of stay was tested.

Results

From the meta-analysis estimates, use of immunonutrition resulted in savings per patient of $3,300 with costs based on reduction in infectious complication rates or $6,000 with costs based on length of hospital stay. Cost savings per patient were present for baseline complication rates above 3.5% or when baseline length of stay and infectious complication rates were reduced to reflect recent US data for those with upper and lower GI elective cancer surgery (range, $1,200 to $6,300).

Conclusions

Use of immunonutrition for patients undergoing elective surgery for gastrointestinal cancer is an effective and cost-saving intervention.

Arginases and arginine deficiency syndromes

PURPOSE OF REVIEW

Many physiologic and pathophysiologic processes are modulated by arginine availability, which can be regulated by arginase. An understanding of the conditions that result in elevated arginase activity as well as the consequences of arginine deficiency is essential for design of effective nutritional support for disease. This review will emphasize recent findings regarding effects of plasma arginase and arginine deficiencies in disease.

RECENT FINDINGS

Elevations in plasma arginase, derived primarily from hemolysis of red blood cells or liver damage, that are associated with arginine deficiency have been identified in an increasing number of diseases and conditions. Arginine insufficiency not only can activate a stress kinase pathway that impairs function of T lymphocytes but it also can inhibit the mitogen-activated protein kinase signaling pathway required for macrophage production of cytokines in response to bacterial endotoxin/lipopolysaccharide.

SUMMARY

There are at least two broad categories of arginine deficiency syndromes, involving either T-cell dysfunction or endothelial dysfunction, depending on the disease context in which arginine deficiency occurs. There is limited information regarding the safety and efficacy of supplementation with arginine or its precursor citrulline in ameliorating arginine deficiency in specific diseases, indicating the need for further studies.

Nutritional pharmacology in surgery and critical care: 'you must unlearn what you have learned'

PURPOSE OF REVIEW

This review highlights the rapidly evolving field of 'pharmaconutrition' by discussing the mechanistic and clinical data for calorie delivery and nutrients shown to improve outcome in surgical and ICU care.

RECENT FINDINGS

International survey data reveals patients in acute care settings receive approximately 50% of calories/protein they are prescribed. This is, in part, due to the archaic practice of patients remaining nil per os postoperatively until return of bowel sounds. We also know certain nutrients serve as pharmacologic agents and improve clinically relevant outcomes. Thus, larger therapeutic doses of specific nutrients may be required to replace acute deficiencies brought on by specific injury states. Specifically, arginine can reduce postsurgical infection 40% as shown in over 30 trials of more than 3200 patients. Glutamine and fish oil have been shown to reduce mortality in general critical care and acute respiratory distress syndrome patients, respectively.

SUMMARY

We believe the future of surgical and ICU nutrition will involve administering specific pharmaconutrients as separate components, much like drugs are given. The current use of clinical pharmacology, molecular biology, and clinical research principles in the study of pharmaconutrients should yield answers on how to administer the right nutrients, in the right doses, at the right time in sick patients.