Should enteral nutrition be started in the first week of critical illness?

Personalized Nutrition Strategies for Patients in the Intensive Care Unit: A Narrative Review on the Future of Critical Care Nutrition

Introduction: Critically ill patients in intensive care units (ICUs) are at high risk of malnutrition, which can result in muscle atrophy, polyneuropathy, increased mortality, or prolonged hospitalizations with complications and higher costs during the recovery period. They often develop ICU-acquired weakness, exacerbated by sepsis, immobilization, and drug treatments, leading to rapid muscle mass loss and long-term complications. Studies indicate that adequate protein and calorie intake can decrease mortality and improve prognosis and recovery. However, optimal implementation remains a critical challenge. Objectives: This narrative review aims to summarize recent advances in nutritional strategies for critically ill patients. It highlights the benefits and limitations of current approaches including enteral (EN) and parenteral nutrition (PN) and examines their impact on clinical outcomes and overall mortality. Additionally, the review explores the emerging role of precision nutrition in critical care using technologies such as metabolomics and artificial intelligence (AI) to provide valuable insights into optimizing nutritional care in critically ill patients. Methods: A comprehensive literature search was conducted to identify recent studies, clinical guidelines, and expert consensus papers on nutritional support for ICU patients. The investigation focused on critical aspects such as the optimal timing for intervention, the route of administration, specific protein and energy targets, and technological innovations to support personalized nutrition, ensuring that each patient receives tailored support based on their unique needs. Results: Guidelines recommend initiating EN or PN nutrition within the first 48 h of admission, using indirect calorimetry (IC) to estimate energy needs, and supplementing protein up to 1.2 g/kg/day after stabilization. IC has gained importance in assessing energy needs but is still underused in the ICU. EN is preferred because it maintains intestinal integrity, reduces the risk of infections, and is recommended within the first 48 h of ICU admission. PN is used when EN is infeasible, but it increases the risk of infection. By integrating metabolomics with transcriptomic and genomic data, we can gain a deeper understanding of the effect of nutrition on cellular homeostasis, facilitating personalized treatments and enhancing the recovery of critically ill patients. Conclusions: AI is becoming increasingly important in monitoring and evaluating artificial nutrition, providing a more accurate and efficient alternative to traditional methods. AI can assist in identifying and managing malnutrition and is effective for estimating caloric and nutrient intake. AI minimizes human error, enables continuous monitoring, and integrates various data sources. The nutritional care of critically ill patients requires collaboration among specialists from diverse fields, including physicians, nutritionists, pharmacists, radiologists, IT experts, and policymakers.

Development and validation of a risk prediction model for feeding intolerance in neurocritical patients with enteral nutrition

Background

This study collects and analyzes clinical data on enteral nutrition therapy in neurocritical patients, develops and validates a feeding intolerance (FI) risk prediction model, and provides a theoretical basis for screening patients with high risk of feeding intolerance (FI) and delivering personalized care.

Methods

A convenience sampling method was employed to select 300 patients who were admitted to a tertiary hospital in China for early enteral nutrition therapy in the neurointensive care unit between April 2022 and December 2022. Independent risk factors for FI were identified using univariate and logistic regression analyses. A prediction model was established, and the goodness of fit and discriminant validity of the model were evaluated.

Results

The incidence of FI in neurocritical patients receiving enteral nutrition was 71%. Logistic regression analysis identified age, Glasgow Coma Scale (GCS) scores, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, mechanical ventilation, feeding via the nasogastric tube route, hyperglycemia, and low serum albumin as independent risk factors for the development of FI (p < 0.05). The predictive formula for FI risk was established as follows: Logit p = -14.737 + 1.184 × mechanical ventilation +2.309 × feeding route +1.650 × age + 1.336 × GCS tertile (6-8 points) + 1.696 × GCS tertile (3-5 points) + 1.753 × APACHE II score + 1.683 × blood glucose value +1.954 × serum albumin concentration. The Hosmer-Lemeshow test showed χ2  = 9.622, p = 0.293, and the area under the ROC curve was 0.941 (95% confidence interval: 0.912-0.970, p < 0.001). The optimal critical value was 0.767, with a sensitivity of 85.9%, a specificity of 90.8%, and a Youden index of 0.715.

Conclusion

The early enteral nutrition FI risk prediction model developed in this study demonstrated good predictive ability. This model can serve as a valuable reference for effectively assessing the risk of FI in neurocritical patients, thereby enhancing clinical outcomes.

When can we start early enteral nutrition safely in patients with shock on vasopressors?

Shock is a common critical illness characterized by microcirculatory disorders and insufficient tissue perfusion. Patients with shock and hemodynamic instability generally require vasopressors to maintain the target mean arterial pressure. Enteral nutrition (EN) is an important therapeutic intervention in critically ill patients and has unique benefits for intestinal recovery. However, the initiation of early EN in patients with shock receiving vasopressors remains controversial. Current guidelines make conservative and vague recommendations regarding early EN support in patients with shock. Increasing studies demonstrates that early EN delivery is safe and feasible in patients with shock receiving vasopressors; however, this evidence is based on observational studies. Changes in gastrointestinal blood flow vary by vasopressor and inotrope and are complex. The risk of gastrointestinal complications, especially the life-threatening complications of non-occlusive mesenteric ischemia and non-occlusive bowel necrosis, cannot be ignored in patients with shock during early EN support. It remains a therapeutic challenge in critical care nutrition therapy to determine the initiation time of EN in patients with shock receiving vasopressors and the safe threshold region for initiating EN with vasopressors. Therefore, the current review aimed to summarize the evidence on the optimal and safe timing of early EN initiation in patients with shock receiving vasopressors to improve clinical practice.

Effect of Early Low-Calorie Enteral Nutrition Support in Critically Ill Patients: A Systematic Review and Meta-analysis

Objective

The purpose of this research was to rigorously assess the impact of early low-fever enteral feeding supplementation in critically sick patients.

Methods

PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and Physiotherapy Evidence Database were searched for randomized controlled trials related to enteral nutrition support of critically ill patients (retrieval time was limited to June 30, 2021); data were extracted after screening the literature, and the quality of meta-analysis was evaluated.

Results

When compared to adequate caloric enteral nutrition support, early low caloric enteral nutrition support reduces the incidence of intolerance to nutrition support (MD = 0.60, 95 percent CI: -0.18 to 1.39, P = 0.13) and the insulin dose during enteral nutrition support (MD = -17.21, 95 percent CI: -19.91 to -14.51, P = 0.00001). However, it had no effect on intensive care unit (ICU) treatment duration (MD = 0.60, 95 percent CI: -0.18 to 1.39, P = 0.13), in-hospital mortality (MD = 0.60, 95 percent CI: -0.18 to 1.39, P = 0.13), or infection incidence (OR = 1.00, 95 percent CI: 0.85, 1.19, P = 0.98).

Conclusion

When compared to sufficient caloric enteral nutrition support, early low-calorie enteral nutrition support lowers the risk of severe illness. The rate of intolerance to nutritional assistance and the decrease in insulin dosage supplied had no effect on the length of ICU therapy, patient death, or infection incidence.

The association of macronutrient deficit with functional status at discharge from the intensive care unit: a retrospective study from a single-center critical illness registry

BACKGROUND

Nutrition is often thought to influence outcomes in critically ill patients. However, the relationship between macronutrient delivery and functional status is not well characterized. Our goal was to investigate whether caloric or protein deficit over the course of critical illness is associated with functional status at the time of intensive care unit (ICU) discharge.

METHODS

We performed a retrospective analysis of surgical ICU patients at a teaching hospital in Boston, MA. To investigate the association of caloric or protein deficit with Functional Status Score for the ICU (FSS-ICU), we constructed linear regression models, controlling for age, sex, race, body mass index, Nutritional Risk in the Critically Ill score, and ICU length of stay. We then dichotomized caloric as well as protein deficit, and performed logistic regressions to investigate their association with functional status, controlling for the same variables.

RESULTS

Linear regression models (n = 976) demonstrated a caloric deficit of 238 kcal (237.88; 95%CI 75.13-400.63) or a protein deficit of 14 g (14.23; 95%CI 4.46-24.00) was associated with each unit decrement in FSS-ICU. Logistic regression models demonstrated a 6% likelihood (1.06; 95%CI 1.01-1.14) of caloric deficit ≥6000 vs. <6000 kcal and an 8% likelihood (1.08; 95%CI 1.01-1.15) of protein deficit ≥300 vs. <300 g with each unit decrement in FSS-ICU.

CONCLUSION

In our cohort of patients, macronutrient deficit over the course of critical illness was associated with worse functional status at discharge. Future studies are needed to determine whether optimized macronutrient delivery can improve outcomes in ICU survivors.

Nutritional practices & outcomes in patients with pediatric acute respiratory distress syndrome

BACKGROUND

Pediatric acute respiratory distress syndrome (PARDS) remains a significant cause of morbidity and mortality. Evidence suggests enteral nutrition (EN) may be protective in critically ill children. This study was designed to determine if an association exists between early enteral nutrition (EEN) and PARDS outcomes.

METHODS

Retrospective cohort study comparing intubated patients with PARDS who received EEN and those who did not. We included intubated patients with PARDS aged 2 weeks to 18 years who could receive full nutrition enterally prior to their disease and excluded patients with cyanotic heart disease. Disease severity captured with oxygenation index (OI), oxygen saturation index (OSI), and pediatric logistic organ dysfunction (PELOD-2) scores. EEN defined as having received at least 25% of calculated caloric goal enterally within the first 48 hours of PARDS diagnosis. We compared PICU mortality, PICU length of stay (LOS), and 28-day ventilator-free days between EEN and non-EEN groups.

RESULTS

We included 151 patients. Adjusted for age, OI, and OSI, the EEN group had a lower PICU mortality rate (aOR=0.071, 95% CI 0.009-0.542, p=0.011), higher likelihood of PICU discharge (aRR=1.79, 95% CI 1.25-2.55, p=0.001) and was more likely to have at least one ventilator-free day (aOR=3.96, 95% CI 1.28-12.22, p=0.017). Adjusted for age and PELOD-2, a statistically significant association between the EEN group and lower PICU mortality (p=0.033), shorter PICU LOS (p<0.001), and more ventilator-free days (p=0.037) persisted.

CONCLUSIONS

Our study found EEN was associated with superior mortality rates, PICU LOS, and ventilator-free days in patients with PARDS. This article is protected by copyright. All rights reserved.

Re-examining chemically defined liquid diets through the lens of the microbiome

Trends in nutritional science are rapidly shifting as information regarding the value of eating unprocessed foods and its salutary effect on the human microbiome emerge. Unravelling the evolution and ecology by which humans have harboured a microbiome that participates in every facet of health and disease is daunting. Most strikingly, the host habitat has sought out naturally occurring foodstuff that can fulfil its own metabolic needs and also the needs of its microbiota, each of which remain inexorably connected to one another. With the introduction of modern medicine and complexities of critical care, came the assumption that the best way to feed a critically ill patient is by delivering fibre-free chemically defined sterile liquid foods (that is, total enteral nutrition). In this Perspective, we uncover the potential flaws in this assumption and discuss how emerging technology in microbiome sciences might inform the best method of feeding malnourished and critically ill patients.

Assessing gastric residual volume: a description of nurses' clinical practice

OBJECTIVE

To analyze the differences in nurses' clinical practice for assessing residual gastric volume and identifying the theoretical framework which supports their practice.

METHOD

A cross-sectional study carried out by sending an online questionnaire by e-mail to nurses registered at the Regional Nursing Council of the State of São Paulo.

RESULTS

This study included 598 nursing professionals, with 484 only providing care to adults and 114 exclusively to children. The gastric residual volume test is performed by 83.4% of nursing professionals; in most cases the suspension and prescription of enteral nutritional therapy are performed by the physician. Suspension of enteral nutritional therapy among adults predominantly occurs when the gastric residual volume is equal to 200 ml, and in children when values are less than 100 ml. Procedure after diet suspension involves the return of aspirated gastric contents and maintaining the catheter closed until the next hour in 48.3% of the procedures among adults, and 68.4% among children. 42.9% of the participants in this study were not aware of the theoretical basis that supports the test performance.

CONCLUSION

We can highlight the need for nurses' training and further studies focused on the practice for assessing gastric residual volume.

Early Enteral Nutrition is Associated with Reduced Morbidity in Critically Ill Soft Tissue Patients

Soft tissue diseases including necrotizing soft tissue infections are associated with high mortality and morbidity with hospital-acquired infection rates up to 76 per cent. Critically ill patients with soft tissue infections have increased metabolic requirements; however, the effect of early nutrition on inhospital morbidity including nosocomial infection rates remains unclear. We hypothesized that enteral nutrition within 48 hours of intensive care unit admission would be associated with fewer hospital-acquired infections. We conducted a retrospective review of patients with soft tissue infection requiring intensive care unit admission for >72 hours from January 2013 through December 2014 to a high-volume, dedicated soft tissue service. Variables were compared using chisquared, Student's t test, linear regression, and binary logistic regression analysis. Eighty-five patients met inclusion criteria; 80 per cent started enteral nutrition within 48 hours. Twenty-six per cent had a hospital-acquired infection postadmission requiring treatment. Patients started on enteral nutrition within 48 hours had fewer ventilator days (mean 5 vs 12) and shorter hospital length of stay (mean 18 vs 40 days) when adjusted for age, gender, and confounding variables present on admission. Patients receiving early nutrition also had fewer hospital-acquired infections (18 vs 59%) when adjusted for confounding factors (aOR 0.15, P = 0.045). No significant difference in mortality (13.2% early vs 5.9% late, P = 0.4) or for inhospital morbidity when evaluating percentage of goal calories or protein received or time to goal tube feed rate was found. Early enteral feeding is associated with reduced inhospital morbidity in critically ill soft tissue patients, including fewer hospital-acquired infections and ventilator days, and shorter total length of stay.

The impact of early enteral nutrition on pediatric patients undergoing gastrointestinal anastomosis a propensity score matching analysis

This study was conducted to assess the clinical advantages of early enteral nutrition (EEN) in pediatric patients who underwent surgery with gastrointestinal (GI) anastomosis.EEN has been associated with clinical benefits in various aspect of surgical intervention, including GI function recovery and postoperative complications reduction. Evaluable data documenting clinical advantages with EEN for pediatric patients after surgery with GI anastomosis are limited.We retrospectively reviewed the medical records of 575 pediatric patients undergoing surgical intervention with GI anastomosis. Among them, 278 cases were managed with EEN and the remaining cases were set as late enteral nutrition (LEN) group. Propensity score (PS) matching was conducted to adjust biases in patient selection. Enteral feeding related complications were evaluated with symptoms, including serum electrolyte abnormalities, abdominal distention, abdominal cramps, and diarrhea. Clinical outcomes, including GI function recovery, postoperative complications, length of hospital stay, and postoperative follow-up, were assessed according to EEN or LEN.Following PS matching, the baseline variables of the 2 groups were more comparable. There were no differences in the incidence of enteral feeding-related complications. EEN was associated with postoperative GI function recovery, including time to first defecation (3.1 ± 1.4 days for EEN vs 3.8 ± 1.0 days for LEN, risk ratio [RR], 0.62; 95% confidence interval [CI] 0.43-1.08, P = .042). A lower total episodes of complication, including infectious complications and major complications were noted in patients with EEN than in patients with LEN (117 [45.9%] vs 137 [53.7%]; OR, 0.73, 95% CI 0.52-1.03, P = .046). Mean postoperative length of stay in the EEN group was 7.4 ± 1.8 days versus 9.2 ± 1.4 days in the LEN group (P = .007). Furthermore, the incidence of adhesive small bowel obstruction was lower for patients with laxative administration compared with control, but no significant difference was attained (P = .092)EEN was safe and associated with clinical benefits, including shorten hospital stay, and reduced overall postoperative complications on pediatric patients undergoing GI anastomosis.

Recommendations of the Working Groups from the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) for the management of adult critically ill patients

The standardization of the Intensive Care Medicine may improve the management of the adult critically ill patient. However, these strategies have not been widely applied in the Intensive Care Units (ICUs). The aim is to elaborate the recommendations for the standardization of the treatment of critical patients. A panel of experts from the thirteen working groups (WG) of the Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC) was selected and nominated by virtue of clinical expertise and/or scientific experience to carry out the recommendations. Available scientific literature in the management of adult critically ill patients from 2002 to 2016 was extracted. The clinical evidence was discussed and summarised by the experts in the course of a consensus finding of every WG and finally approved by the WGs after an extensive internal review process that was carried out between December 2015 and December 2016. A total of 65 recommendations were developed, of which 5 corresponded to each of the 13 WGs. These recommendations are based on the opinion of experts and scientific knowledge, and are intended as a guide for the intensivists in the management of critical patients.

Enteral versus parenteral nutrition in critically ill patients: an updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Enteral nutrition (EN) is recommended as the preferred route for early nutrition therapy in critically ill adults over parenteral nutrition (PN). A recent large randomized controlled trial (RCT) showed no outcome differences between the two routes. The objective of this systematic review was to evaluate the effect of the route of nutrition (EN versus PN) on clinical outcomes of critically ill patients.

METHODS

An electronic search from 1980 to 2016 was performed identifying relevant RCTs. Individual trial data were abstracted and methodological quality of included trials scored independently by two reviewers. The primary outcome was overall mortality and secondary outcomes included infectious complications, length of stay (LOS) and mechanical ventilation. Subgroup analyses were performed to examine the treatment effect by dissimilar caloric intakes, year of publication and trial methodology. We performed a test of asymmetry to assess for the presence of publication bias.

RESULTS

A total of 18 RCTs studying 3347 patients met inclusion criteria. Median methodological score was 7 (range, 2-12). No effect on overall mortality was found (1.04, 95 % CI 0.82, 1.33, P = 0.75, heterogeneity I(2) = 11 %). EN compared to PN was associated with a significant reduction in infectious complications (RR 0.64, 95 % CI 0.48, 0.87, P = 0.004, I(2) = 47 %). This was more pronounced in the subgroup of RCTs where the PN group received significantly more calories (RR 0.55, 95 % CI 0.37, 0.82, P = 0.003, I(2) = 0 %), while no effect was seen in trials where EN and PN groups had a similar caloric intake (RR 0.94, 95 % CI 0.80, 1.10, P = 0.44, I(2) = 0 %; test for subgroup differences, P = 0.003). Year of publication and methodological quality did not influence these findings; however, a publication bias may be present as the test of asymmetry was significant (P = 0.003). EN was associated with significant reduction in ICU LOS (weighted mean difference [WMD] -0.80, 95 % CI -1.23, -0.37, P = 0.0003, I(2) = 0 %) while no significant differences in hospital LOS and mechanical ventilation were observed.

CONCLUSIONS

In critically ill patients, the use of EN as compared to PN has no effect on overall mortality but decreases infectious complications and ICU LOS. This may be explained by the benefit of reduced macronutrient intake rather than the enteral route itself.

Influence of gastric fluid reinfusion on enteral nutrition support in intensive care unit patients

AIM: To investigate the influence of gastric juice reinfusion on the effect of early enteral nutrition in intensive care unit (ICU) patients.

METHODS: Eighty patients with enteral nutritional support in ICU of our hospital were randomly divided into an observation group and a control group, with 40 cases in each group. Patients of two groups were both given enteral nutrition, and their gastric juice were collected with a nasogastric tube. In the observation group, the gastric juice after filtration with sterile gauze was reinfused to the jejunum via the nasogastric tube. The control group was given normal saline. Nutritional support related indicators such as serum albumin, plasma total protein and hemoglobin levels were compared in the two groups, and the qualification rate of nutritional support was evaluated. Complications in the two groups were observed and compared.

RESULTS: Serum albumin, serum total protein and hemoglobin levels were significantly improved in the two groups after enteral nutrition (P < 0.05), and the improvement of the observation group was better than that of the control group (P < 0.05). The qualification rate of nutritional support in the observation group was 97.5%, significantly higher than that of the control group (82.5%, P < 0.05). The incidences of abdominal distension, diarrhea, constipation, vomiting and electrolyte imbalance in the observation group were significantly lower than those of the control group (P < 0.05). Length of ICU stay and costs in the observation group were significantly shorter (less) than those of the control group (P < 0.05).

CONCLUSION: Gastric fluid reinfusion can significantly improve the effect of enteral nutrition in ICU patients, and it reduces the incidence of gastrointestinal dysfunctions such as diarrhea, abdominal distension and vomiting.

WITHDRAWN: Early enteral nutrition versus late enteral nutrition for burns patients: A systematic review and meta-analysis

This article has been withdrawn at the request of the authors. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

A few of our favorite unconfirmed ideas

Medical practice is rooted in our dependence on the best available evidence from incremental scientific experimentation and rigorous clinical trials. Progress toward determining the true worth of ongoing practice or suggested innovations can be glacially slow when we insist on following the stepwise scientific pathway, and a prevailing but imperfect paradigm often proves difficult to challenge. Yet most experienced clinicians and clinical scientists harbor strong thoughts about how care could or should be improved, even if the existing evidence base is thin or lacking. One of our Future of Critical Care Medicine conference sessions encouraged sharing of novel ideas, each presented with what the speaker considers a defensible rationale. Our intent was to stimulate insightful thinking and free interchange, and perhaps to point in new directions toward lines of innovative theory and improved care of the critically ill. In what follows, a brief background outlines the rationale for each novel and deliberately provocative unconfirmed idea endorsed by the presenter.

Intestine, immunity, and parenteral nutrition in an era of preferred enteral feeding

PURPOSE OF REVIEW

To review the benefits of enteral nutrition in contrast to the inflammatory consequences of administration of parenteral nutrition and enteral deprivation. To present the most recent evidence for the mechanisms of these immunologic changes and discuss potential areas for modification to decrease infectious complications of its administration.

RECENT FINDINGS

There is significant data supporting the early initiation of enteral nutrition in both medical and surgical patients unable to meet their caloric goals via oral intake alone. Despite the preference for enteral nutrition, some patients are unable to utilize their gut for nutritious gain and therefore require parenteral nutrition administration, along with its infectious complications. The mechanisms behind these complications are multifactorial and have yet to be fully elucidated. Recent study utilizing both animal and human models has provided further information regarding parenteral nutrition's deleterious effect on intestinal epithelial barrier function along with the complications associated with enterocyte deprivation.

SUMMARY

Changes associated with parenteral nutrition administration and enteral deprivation are complex with multiple potential areas for modification to allow for safer administration. Recent discovery of the mechanisms behind these changes present exciting areas for future study as to make parenteral nutrition administration in the enterally deprived patient safer.