Meta-analysis is not enough: The critical role of pathophysiology in determining optimal care in clinical nutrition

Potential mechanisms of multimodal prehabilitation effects on surgical complications: a narrative review

Continuous advances in prehabilitation research over the past several decades have clarified its role in improving preoperative risk factors, yet the evidence demonstrating reduced surgical complications remains uncertain. Describing the potential mechanisms underlying prehabilitation and surgical complications represents an important opportunity to establish biological plausibility, develop targeted therapies, generate hypotheses for future research, and contribute to the rationale for implementation into the standard of care. In this narrative review, we discuss and synthesize the current evidence base for the biological plausibility of multimodal prehabilitation to reduce surgical complications. The goal of this review is to improve prehabilitation interventions and measurement by outlining biologically plausible mechanisms of benefit and generating hypotheses for future research. This is accomplished by synthesizing the available evidence for the mechanistic benefit of exercise, nutrition, and psychological interventions for reducing the incidence and severity of surgical complications reported by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). This review was conducted and reported in accordance with a quality assessment scale for narrative reviews. Findings indicate that prehabilitation has biological plausibility to reduce all complications outlined by NSQIP. Mechanisms for prehabilitation to reduce surgical complications include anti-inflammation, enhanced innate immunity, and attenuation of sympathovagal imbalance. Mechanisms vary depending on the intervention protocol and baseline characteristics of the sample. This review highlights the need for more research in this space while proposing potential mechanisms to be included in future investigations.

Controlling Nutritional Status (CONUT) Score and Prognostic Nutritional Index (PNI) Are Good Candidates for Prognostic Markers for Acute Pancreatitis

Background and Objectives: It has been demonstrated that parameters such as the Controlled Nutrition Status (CONUT) score and Prognostic Nutrition Index (PNI) are beneficial for the assessment of patients’ nutrition. In this study, our objective was to investigate the potential benefits of CONUT and, as a prognostic marker of acute pancreatitis, the PNI. Materials and Methods: The data of 361 patients were analysed retrospectively. The PNI and CONUT scores of these patients were retrospectively calculated. They were categorised as CONUT-high (≥3) and CONUT-low (≤2). A PNI ≥ 45 was considered high and a PNI < 45 low. The AP severity and organ failure due to disease were evaluated based on Atlanta 2012. Results: According to the CONUT score, it was found that 209 patients had normal to mild, whereas 152 patients had severe malnutrition. A total of 293 patients had mild AP and 68 thereof had severe AP. The patients with a high CONUT score used more antibiotics, were hospitalised more in intensive care units and experienced organ failure more frequently. There were no intensive care hospitalisations, mortalities, surgical needs and local complications among the patients with a higher PNI score. Conclusions: CONUT and the PNI have proven to be useful prognostic markers not only for predicting nutritional status but also for estimating the severity and results of AP.

Relationship between Undernutrition and Periodontal Diseases among a Sample of Yemeni Population: A Cross-Sectional Study

Undernutrition is an inadequate supply of energy and nutrients. Periodontal diseases (PDs) are defined as a broad form of chronic inflammatory disease of the gingiva, bone, and ligaments supporting the teeth. This study aimed to reveal the relationship between undernutrition, using body mass index (BMI) and serum albumin level (Alb), and PDs in a sample of Yemeni population. A cross-sectional study was conducted at dental teaching clinics at the Faculty of Dentistry, Sana’a University. Of 1920 patients who attended clinics, only 229 matched the study criteria. Oral examination was performed to assess the periodontal clinical parameter measurements. BMI and Alb were measured. Participants of both genders were involved, with a slight increase in males (n = 134, 58.5%), and most of the study sample was in the age group of 18–35 years (n = 209, 91.3%). Regarding habits, only 18.2% (n = 43) of patients were smokers and about half of the participants (n = 136, 59.4%) were khat chewers. Most cases had mild undernutrition according to BMI (n = 139, 60.7%) and normal Alb level (n = 213, 93%). Regarding the periodontal diagnosis, most of the participants were diagnosed with gingivitis (n = 186, 81.2%). BMI and albumin level were nonsignificantly associated with PDs. PDs were statistically significant with the participant’s age, gender, level of education, and smoking ( $P>0.05$ ). However, BMI, khat chewing, and albumin level were nonsignificant factors of periodontal diseases among Yemeni participants ( $P>0.05$ ). In both genders, variables such as age of the patients, smoking, khat chewing, and PDs were nonsignificantly associated with BMI. This study showed that the majority of the participants had been diagnosed with gingivitis, but there was not an association between PDs and undernutrition. This paper is presented on research square URL // https://www.researchsquare.com/article/rs-429796/v1 with DOI 10.21203/rs.3.rs-429796/v1.

Patient-Related Prognostic Factors for Anastomotic Leakage, Major Complications, and Short-Term Mortality Following Esophagectomy for Cancer: A Systematic Review and Meta-Analyses

OBJECTIVE

The aim of this study is to identify preoperative patient-related prognostic factors for anastomotic leakage, mortality, and major complications in patients undergoing oncological esophagectomy.

BACKGROUND

Esophagectomy is a high-risk procedure with an incidence of major complications around 25% and short-term mortality around 4%.

METHODS

We systematically searched the Medline and Embase databases for studies investigating the associations between patient-related prognostic factors and anastomotic leakage, major postoperative complications (Clavien-Dindo ≥ IIIa), and/or 30-day/in-hospital mortality after esophagectomy for cancer.

RESULTS

Thirty-nine eligible studies identifying 37 prognostic factors were included. Cardiac comorbidity was associated with anastomotic leakage, major complications, and mortality. Male sex and diabetes were prognostic factors for anastomotic leakage and major complications. Additionally, American Society of Anesthesiologists (ASA) score > III and renal disease were associated with anastomotic leakage and mortality. Pulmonary comorbidity, vascular comorbidity, hypertension, and adenocarcinoma tumor histology were identified as prognostic factors for anastomotic leakage. Age > 70 years, habitual alcohol usage, and body mass index (BMI) 18.5-25 kg/m² were associated with increased risk for mortality.

CONCLUSIONS

Various patient-related prognostic factors are associated with anastomotic leakage, major postoperative complications, and postoperative mortality following oncological esophagectomy. This knowledge may define case-mix adjustment models used in benchmarking or auditing and may assist in selection of patients eligible for surgery or tailored perioperative care.

Ethics of ECPR research

The design of emergency medicine trials can raise several ethical concerns - risks may be greater, and randomisation may have to occur before consent. Research in emergency medicine is thus an illuminating context to explore the interplay between risk and randomisation, and the consequences for consent. Using a currently running trial, we describe possible concerns, considerations, and solutions to reconcile the conflicting interests of scientific inquiry, ethical principles, and clinical reality in emergency medicine research.

The Role of Nutritional Access in Malnourished Elderly Undergoing Major Surgery for Acute Abdomen: A Propensity Score-Matched Analysis

BACKGROUND

About 50% of the elderly undergoing emergency abdominal surgery are malnourished. The role of timely surgical nutritional access in this group of patients is unknown.

METHODS

We analyzed the National Inpatient Sample database from 2009 through the first three-quarters of 2015 of patients aged ≥65 years who were malnourished and underwent major abdominal surgery for the acute abdomen within the first 2 days of hospital admission.

RESULTS

Of 3 246 721 patients analyzed, 4311 patients met inclusion criteria. Of these, only 507 (11.8%) patients had surgical nutritional access (gastrostomy or jejunostomy) (group I), while 3804 patients (88.2%) did not (group II). In the propensity score-matched population, there were 482 patients in each group. The patients in group I had lower odds of mortality and postoperative gastrointestinal complications (paralytic ileus, anastomotic dehiscence, and intestinal fistulae) (P-value <.01, respectively).

DISCUSSION

Elderly who receive surgical nutritional access have lower rates of gastrointestinal complications and mortality.

Impact of Artificial Nutrition on Postoperative Complications

Malnutrition is common in surgical cancer patients and it is widely accepted that it can adversely affect their postoperative outcome. Assessing the nutritional status of every patient, in particular care of elderly and cancer patients, is a crucial feature of the therapeutic pathway in order to optimize every strategy. Evidence exists that the advantages of perioperative nutrition are more significant in malnourished patients submitted to major surgery. For patients recognized as malnourished, preoperative nutrition therapies are indicated; the choice between parenteral and enteral nutrition is still controversial in perioperative malnourished surgical cancer patients, although enteral nutrition seems to have the best risk–benefit ratio. Early oral nutrition after surgery is advisable, when feasible, and should be administered in all the patients undergoing elective major surgery, if compliant. In patients with high risk for postoperative infections, perioperative immunonutrition has been proved in some ways to be effective, even if operations including those for cancer have to be delayed.

The Impact of Glucose-Based or Lipid-Based Total Parenteral Nutrition on the Free Fatty Acids Profile in Critically Ill Patients

Introduction: Our study aim was to assess how the macronutrient intake during total parenteral nutrition (TPN) modulates plasma total free fatty acids (FFAs) levels and individual fatty acids in critically ill patients. Method: Adult patients aged 18–80, admitted to the intensive care unit (ICU), who were indicated for TPN, with an expected duration of more than three days, were included in the study. Isoenergetic and isonitrogenous TPN solutions were given with a major non-protein energy source, which was glucose (group G) or glucose and lipid emulsions (Smof lipid; group L). Blood samples were collected on days 0, 1, 3, 6, 9, 14, and 28. Results: A significant decrease (p < 0.001) in total FFAs occurred in both groups with a bigger decrease in group G (p < 0.001) from day 0 (0.41 ± 0.19 mmol∙L⁻¹) to day 28 (0.10 ± 0.07 mmol∙L⁻¹). Increased palmitooleic acid and decreased linoleic and docosahexaenoic acids, with a trend of increased mead acid to arachidonic acid ratio, on day 28 were observed in group G in comparison with group L. Group G had an insignificant increase in leptin with no differences in the concentrations of vitamin E, triacylglycerides, and plasminogen activator inhibitor-1. Conclusion: Decreased plasma FFA in critically ill patients who receive TPN may result from increased insulin sensitivity with a better effect in group G, owing to higher insulin and glucose dosing and no lipid emulsions. It is advisable to include a lipid emulsion at the latest from three weeks of TPN to prevent essential fatty acid deficiency.

Association of Baseline Inflammation With Effectiveness of Nutritional Support Among Patients With Disease-Related Malnutrition: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

Inflammation is a key driver of malnutrition during illness and is often accompanied by metabolic effects, including insulin resistance and reduction of appetite. However, it still remains unclear if inflammation influences the response to nutritional support among patients with disease-related malnutrition.

OBJECTIVE

To examine whether patients' baseline inflammatory status is associated with the effect of nutritional support on 30-day mortality.

DESIGN, SETTING, AND PARTICIPANTS

This is a secondary analysis of the Effect of Early Nutritional Support on Frailty, Functional Outcomes, and Recovery of Malnourished Medical Inpatients Trial (EFFORT), a randomized clinical trial conducted in 8 Swiss hospitals from April 2014 to February 2018. A total of 1950 participants who had C-reactive protein measurements at the time of admission were included in this secondary analysis. Data analysis was conducted between June and July 2019.

INTERVENTIONS

Hospitalized patients at risk for malnutrition were randomly assigned to receive protocol-guided individualized nutritional support to reach protein and energy goals (intervention group) or standard hospital food (control group).

MAIN OUTCOMES AND MEASURES

The primary end point was 30-day mortality. Based on C-reactive protein levels at admission, patients were stratified into groups with low, moderate, or high inflammation (<10 mg/L, 10-100 mg/L, and >100 mg/L, respectively).

RESULTS

A total of 1950 patients (median [interquartile range] age, 75 [65-83] years; 1025 [52.6%] men) were included; 533 (27.3%) had low levels of inflammation, 894 (45.9%) had moderate levels of inflammation, and 523 (26.8%) had high levels of inflammation. Compared with the control group, patients receiving nutritional support showed a significant reduction in 30-day mortality, regardless of C-reactive protein level (adjusted odds ratio, 0.61; 95% CI, 0.43-0.86; P = .005). In the subgroup of patients with high inflammation, there was no beneficial effect of nutritional support (adjusted odds ratio, 1.32; 95% CI, 0.70-2.50; P = .39), providing evidence that inflammation has a significant modifying association (P for interaction = .005).

CONCLUSIONS AND RELEVANCE

Based on this secondary analysis of a multicenter randomized trial, a patient's admission inflammatory status was associated with their response to nutritional support. If validated in future clinical trials, nutritional support may need to be individualized based on a patient's initial presentation and markers of inflammation. These results may also help to explain some of the heterogeneity in treatment effects of nutrition seen in previous critical care trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02517476.

How Anesthetic, Analgesic and Other Non-Surgical Techniques During Cancer Surgery Might Affect Postoperative Oncologic Outcomes: A Summary of Current State of Evidence

The question of whether anesthetic, analgesic or other perioperative intervention during cancer resection surgery might influence long-term oncologic outcomes has generated much attention over the past 13 years. A wealth of experimental and observational clinical data have been published, but the results of prospective, randomized clinical trials are awaited. The European Union supports a pan-European network of researchers, clinicians and industry partners engaged in this question (COST Action 15204: Euro-Periscope). In this narrative review, members of the Euro-Periscope network briefly summarize the current state of evidence pertaining to the potential effects of the most commonly deployed anesthetic and analgesic techniques and other non-surgical interventions during cancer resection surgery on tumor recurrence or metastasis.

Citrulline and muscle protein homeostasis in three different models of hypercatabolism

Supplementation of enteral nutrition (EN) by specific amino acids (AAs) has been proposed to prevent muscle protein loss in intensive care unit (ICU) patients. Citrulline (Cit), which has been shown to stimulate muscle protein synthesis in other situations, may be of interest in this setting. Our aim was to assess the effect of Cit in three catabolic models relevant to critical illness: endotoxemia (LPS), traumatic brain injury (TBI), and TBI with infectious complications (TBI-Ec), which are characterized by different alterations in protein homeostasis. Fifty-eight male Sprague-Dawley rats (200-220 g) were randomized to receive a standard diet ad libitum (CON, n = 9) or to undergo catabolic injuries on day 0 (D0, n = 49), and EN (Sondalis HP energy® 290 kcal/kg/d) from day 1 (D1) combined with Cit (2 g/kg/d) or isonitrogenous non-essential AAs (NEAAs) until day 3 (D3). Endotoxemia was induced by IP injection of LPS from E. coli (3 mg/kg), TBI by hydraulic percussion, and infectious complications (TBI-Ec) by administration of luminescent E. coli on D1. Nitrogen balance (ΔN) and 3-methylhistidine (3-MHis) were measured daily. Muscle protein synthesis (MPS, measured by the SUnSET method) and mTORC1 activation (S6K-1 and 4E-BP1 phosphorylation) were measured on D3 2 h after the arrest of enteral nutrition in soleus, extensor digitorum longus (EDL), gastrocnemius and tibialis muscles. ΔN was lower (p < 0.001) in all three models of injury compared with basal and CON from D1 to D3, and more negative in the LPS-CIT (p < 0.05) than in the LPS group. The 3-MHis/creatinine ratio was significantly increased on D1 in all groups compared with CON, and on D2 only in the LPS and TBI groups (p < 0.0001, LPS and TBI vs. CON). MPS was similar in all groups in soleus and tibialis but significantly higher in EDL in LPS-CIT [LPS-CIT: 4.5 ± 1.7 (mean ± SD) vs. CON: 2.3 ± 1.2; and vs. LPS-NEAA: 3.1 ± 2.3] and in gastrocnemius (LPS-CIT vs. CON; p = 0.05). S6K-1 phosphorylation in the EDL was also higher in LPS-CIT vs. CON (LPS-CIT: 0.94 ± 0.51 CON: 0.42 ± 0.28), but not in gastrocnemius. IL-6 plasma level was significantly higher in all the catabolic groups vs. CON (p < 0.005) with no difference between treatments (Cit or NEAAs). In conclusion, the TBI model showed only a rise in muscle proteolysis, whereas the LPS model displayed a rise in both protein synthesis and proteolysis. Secondly, our results show that the Cit effect varies according to the type of injury and to the muscle under study. The stimulation of MPS rate and the mTOR pathway in LPS-treated rats contrasts with degraded ΔN, suggesting that the Cit effect on protein metabolism in critically ill rats is limited at the whole-body level.

Preoperative nutritional optimization of esophageal cancer patients

Optimization of the nutritional and metabolic state prior to major surgery leads to improved surgical outcomes and is increasingly seen as an important part of oncology disease management. For locally advanced esophageal cancer the treatment is multimodal, including neoadjuvant chemoradiotherapy or perioperative chemotherapy in combination with esophageal resection. Patients undergoing such a multimodal treatment have a higher risk for progressive decline in their nutritional status. Preoperative malnutrition and loss of skeletal muscle mass has been reported to correlate with unfavorable outcomes in patients who undergo esophageal cancer surgery. Decline in nutritional status is most likely caused by insufficient nutritional intake, reduced physical activity, systemic inflammation and the effects of anticancer therapy. To ensure an optimal nutritional status prior to surgery, it is key to assess the nutritional status in all preoperative esophageal cancer patients, preferable early in the treatment trajectory, and to apply nutritional interventions accordingly. Nutritional management of esophageal cancer can be challenging, the optimal nutritional therapy is still under debate, and warrants more nutritional scientific research. In this review, the most recent findings regarding preoperative nutrition associated with outcomes in patients with esophageal cancer will be explored.

Hypoalbuminemia: Pathogenesis and Clinical Significance

Hypoalbuminemia is associated with inflammation. Despite being addressed repeatedly in the literature, there is still confusion regarding its pathogenesis and clinical significance. Inflammation increases capillary permeability and escape of serum albumin, leading to expansion of interstitial space and increasing the distribution volume of albumin. The half‐life of albumin has been shown to shorten, decreasing total albumin mass. These 2 factors lead to hypoalbuminemia despite increased fractional synthesis rates in plasma. Hypoalbuminemia, therefore, results from and reflects the inflammatory state, which interferes with adequate responses to events like surgery or chemotherapy, and is associated with poor quality of life and reduced longevity. Increasing or decreasing serum albumin levels are adequate indicators, respectively, of improvement or deterioration of the clinical state. In the interstitium, albumin acts as the main extracellular scavenger, antioxidative agent, and as supplier of amino acids for cell and matrix synthesis. Albumin infusion has not been shown to diminish fluid requirements, infection rates, and mortality in the intensive care unit, which may imply that there is no body deficit or that the quality of albumin “from the shelf” is unsuitable to play scavenging and antioxidative roles. Management of hypoalbuminaemia should be based on correcting the causes of ongoing inflammation rather than infusion of albumin. After the age of 30 years, muscle mass and function slowly decrease, but this loss is accelerated by comorbidity and associated with decreasing serum albumin levels. Nutrition support cannot fully prevent, but slows down, this chain of events, especially when combined with physical exercise.

Nutrition in peri-operative esophageal cancer management

Nutritional status and dietary intake are increasingly recognized as essential areas in esophageal cancer management. Nutritional management of esophageal cancer is a continuously evolving field and comprises an interesting area for scientific research. Areas covered: This review encompasses the current literature on nutrition in the pre-operative, peri-operative, and post-operative phases of esophageal cancer. Both established interventions and potential novel targets for nutritional management are discussed. Expert commentary: To ensure an optimal pre-operative status and to reduce peri-operative complications, it is key to assess nutritional status in all pre-operative esophageal cancer patients and to apply nutritional interventions accordingly. Since esophagectomy results in a permanent anatomical change, a special focus on nutritional strategies is needed in the post-operative phase, including early initiation of enteral feeding, nutritional interventions for post-operative complications, and attention to long-term nutritional intake and status. Nutritional aspects of pre-optimization and peri-operative management should be incorporated in novel Enhanced Recovery After Surgery programs for esophageal cancer.

When Is Parenteral Nutrition Appropriate?

Parenteral nutrition (PN) represents one of the most notable achievements of modern medicine, serving as a therapeutic modality for all age groups across the healthcare continuum. PN offers a life-sustaining option when intestinal failure prevents adequate oral or enteral nutrition. However, providing nutrients by vein is an expensive form of nutrition support, and serious adverse events can occur. In an effort to provide clinical guidance regarding PN therapy, the Board of Directors of the American Society for Parenteral and Enteral Nutrition (ASPEN) convened a task force to develop consensus recommendations regarding appropriate PN use. The recommendations contained in this document aim to delineate appropriate PN use and promote clinical benefits while minimizing the risks associated with the therapy. These consensus recommendations build on previous ASPEN clinical guidelines and consensus recommendations for PN safety. They are intended to guide evidence-based decisions regarding appropriate PN use for organizations and individual professionals, including physicians, nurses, dietitians, pharmacists, and other clinicians involved in providing PN. They not only support decisions related to initiating and managing PN but also serve as a guide for developing quality monitoring tools for PN and for identifying areas for further research. Finally, the recommendations contained within the document are also designed to inform decisions made by additional stakeholders, such as policy makers and third-party payers, by providing current perspectives regarding the use of PN in a variety of healthcare settings.

Defining malnutrition: A plea to rethink

In a recent consensus report in Clinical Nutrition the undernourished category of malnutrition was proposed to be defined and diagnosed on the basis of a low BMI or unintentional weight loss combined with low BMI or FFMI with certain cut off points. The definition was endorsed by ESPEN despite recent endorsement of a very different definition. The approach aims to assess whether nutritional intake is sufficient but is imprecise because a low BMI does not always indicate malnutrition and individuals with increasing BMI's may have decreasing FFM's. The pathophysiology of individuals, considered to be malnourished in rich countries and in areas with endemic malnutrition, results predominantly from deficient nutrition combined with infection/inflammation. Both elements jointly determine body composition and function and consequently outcome of disease, trauma or treatment. When following the consensus statement only an imprecise estimate is acquired of nutritional intake without knowing the impact of inflammation. Most importantly, functional abilities are not assessed. Consequently it will remain uncertain how well the individual can overcome stressful events, what the causes are of dysfunction, how to set priorities for treatment and how to predict the effect of nutritional support. We therefore advise to consider the pathophysiology of malnourished individuals leading to inclusion of the following elements in the definition of malnutrition: a disordered nutritional state resulting from a combination of inflammation and a negative nutrient balance, leading to changes in body composition, function and outcome. A precise diagnosis of malnutrition should be based on assessment of these elements.