Protein Kinetics and Metabolic Effects Related to Disease States in the Intensive Care Unit

[Nutritional support in rehabilitation of victims with severe combined trauma]

OBJECTIVE

To evaluate the clinical and rehabilitation effectiveness of the protein module (Fresubin Protein) in therapeutic nutrition in patients with severe combined injury (polytrauma) at the rehabilitation stage in a specialized department (neurosurgery).

MATERIAL AND METHODS

We examined 43 victims who received a combined injury that required treatment in the intensive care unit with subsequent transfer to a specialized department (neurosurgery). At the stage of treatment and rehabilitation in the specialized department, we assessed the biochemical parameters of carbohydrate, fat and protein metabolism, body composition, as well as energy metabolism using indirect calorimetry, and the functional state of the gastrointestinal tract. In the comparison group, patients received a standard diet at the rate of 30 kcal/kg BW. The main group received a standard diet (30 kcal/kg BW) with the addition of a protein module (0.8 g/kg BW) to the diet as an additional source of protein.

RESULTS

In both observation groups, moderate to severe protein-energy malnutrition was diagnosed before the study (decreased total protein level - 50.63±1.3 g/l, albumin - 27.97±0.95 g/l, transferrin - 1.33±0.9 g/l). Anthropometric parameters (BMI=17.1±1.2 kg/m2, BMD=20.15±1.5 cm, OP=22.2±1.1 cm, TKFST=8.4±0.5 cm) indicated a deficiency of the somatic protein pool, lean and fat body mass. No pronounced disorders of carbohydrate and fat metabolism were noted. A correlation was found between the dynamics of protein metabolism and the inflammatory process parameters (CRP, white blood cell count, r=-0.79, p=0.001). Against the background of nutritional support with the inclusion of a protein module in the diet, by the 21st day, patients of the main group showed a reliable (p<0.05) normalization of protein metabolism parameters, an increase in lean body mass.

CONCLUSION

The results of the studies indicate that in victims with severe combined trauma, upon admission to the treatment and rehabilitation stage in a specialized department, despite the intensive care provided in the intensive care unit, moderate to severe protein-energy malnutrition with severe protein metabolism disorders is diagnosed. This is manifested by a decrease in the concentration of total protein, albumin, transferrin, and somatic protein pool. Low lean mass values indicate a deficiency of the protein component of nutritional support, a decrease in lean and muscle mass. The consequence of which is a limitation of the volume of rehabilitation, an increased risk of complications. The identified protein deficiency dictates the need to increase the protein component of therapeutic nutrition. Inclusion of a protein module in the therapeutic nutrition program at the rate of 0.8 g/kg of body weight ensures adequate correction of protein metabolism disorders, overall nutritional status in severe combined injury and creates the prerequisites for increasing the effectiveness of rehabilitation measures.

Intermittent versus continuous enteral nutrition in critically ill children: A pre-planned secondary analysis of an international prospective cohort study

BACKGROUND & AIMS

Intermittent enteral nutrition (EN) may have physiologic benefits over continuous feeding in critical illness. We aimed to compare nutrition and infection outcomes in critically ill children receiving intermittent or continuous EN.

METHODS

International, multi-center prospective observational study of mechanically ventilated children, 1 month to 18 years of age, receiving EN. Percent energy or protein adequacy (energy or protein delivered/prescribed × 100) and acquired infection rates were compared between intermittent and continuous EN groups using adjusted-multivariable and 4:1 propensity-score matched (PSM) analyses. Sensitivity analyses were performed after excluding patients who crossed over between intermittent and continuous EN.

RESULTS

1375 eligible patients from 66 PICUs were included. Patients receiving continuous EN (N = 1093) had a higher prevalence of respiratory illness and obesity, and lower prevalence of neurologic illness and underweight status on admission, compared to those on intermittent EN (N = 282). Percent energy or protein adequacy, proportion of patients who achieved 60% of energy or protein adequacy in the first 7 days of admission, and rates of acquired infection were not different between the 2 groups in adjusted-multivariable and propensity score matching analyses (P > 0.05).

CONCLUSION

Intermittent versus continuous EN strategy is not associated with differences in energy or protein adequacy, or acquired infections, in mechanically ventilated, critically ill children. Until further evidence is available, an individualized feeding strategy rather than a universal approach may be appropriate.

Comparison of continuous versus intermittent enteral feeding in critically ill patients: a systematic review and meta-analysis

Background

The enteral route is commonly utilised to support the nutritional requirements of critically ill patients. However, there is paucity of data guiding clinicians regarding the appropriate method of delivering the prescribed dose. Continuous enteral feeding is commonly used; however, a bolus or intermittent method of administration may provide several advantages such as minimising interruptions. The purpose of this meta-analysis is to compare a continuous versus an intermittent or bolus enteral nutrition administration method.

Methods

A systematic review and meta-analysis were performed with studies identified from the PubMed, EMBASE, Cochrane Library and Web of Science databases. Studies were included if they compared a continuous with either an intermittent or bolus administration method of enteral nutrition in adult patients admitted to the intensive care unit. Study quality was assessed using the PEDro and Newcastle–Ottawa scoring systems. Review Manager was used for performing the random-effects meta-analysis on the outcomes of mortality, constipation, diarrhoea, increased gastric residuals, pneumonia, and bacterial colonisation.

Results

A total of 5546 articles were identified, and 133 were included for full text review. Fourteen were included in the final analysis. There was an increased risk of constipation with patients receiving continuous enteral nutrition (relative risk 2.24, 95% confidence interval 1.01–4.97, p = 0.05). No difference was identified in other outcome measures. No appreciable bias was identified.

Conclusion

The current meta-analysis has not identified any clinically relevant difference in most outcome measures relevant to the care of critically ill patients. However, there is a paucity of high-quality randomised controlled clinical trials to guide this decision. Therefore, clinicians may consider either dosing regimen in the context of the patient’s care requirements.

A new high protein-to-energy enteral formula with a whey protein hydrolysate to achieve protein targets in critically ill patients: a prospective observational tolerability study

OBJECTIVES

Current guidelines and expert recommendations stress the need to implement enteral feeds with a higher protein-to-energy ratio to meet protein requirements as recommended while avoiding gastrointestinal side effects and energy overfeeding in ICU patients.

MATERIALS AND METHODS

Prospective tolerability study in 18 critically ill patients with a high protein formula (high protein-to-energy (HP:E) formula = Fresubin® Intensive; HPG) compared to a contemporary matched conventional therapy group (CTG). The primary outcome was GI intolerance defined as ≥300 ml daily gastric residual volume (GRV), vomiting, or diarrhea on days 1 and 2. Secondary outcomes were the percentage of patients reaching their protein target on day 4 and overall protein intake.

RESULTS

Groups were comparable regarding demographic characteristics, disease severity, organ failures, mechanical ventilation, and NUTRIC score at baseline. Eighteen patients completed the 4-day feeding period. The number of events of GRV of ≥300 ml/day was equal in both groups (33.3%). The incidence of diarrhea and vomiting was low in the HPG (two patients concerned). EN did not need to be discontinued due to intolerance in any group. Seventy-two percent of patients reached protein targets ≥1.3 g/kgBW/d within 4 days after initiation of enteral feeding, which was superior to the CTG (33%). Post-hoc testing showed group differences of protein intake between HPG and CTG were significant at t = 72 h and t = 96 h. Energy targets were met in both groups.

CONCLUSION

The HP:E formula containing 33% whey protein hydrolysate is well tolerated in this tolerability study. Due to the HP:E ratio protein targets can be reached faster. Larger randomized trials are needed to confirm preliminary results.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02678325. Registered 2 May 2016.

Metabolomic differences between critically Ill women and men

Metabolism differs in women and men at homeostasis. Critically ill patients have profound dysregulation of homeostasis and metabolism. It is not clear if the metabolic response to critical illness differs in women compared to men. Such sex-specific differences in illness response would have consequences for personalized medicine. Our aim was to determine the sex-specific metabolomic response to early critical illness. We performed a post-hoc metabolomics study of the VITdAL-ICU trial where subjects received high dose vitamin D3 or placebo. Using mixed-effects modeling, we studied sex-specific changes in metabolites over time adjusted for age, Simplified Acute Physiology Score II, admission diagnosis, day 0 25-hydroxyvitamin D level, and 25-hydroxyvitamin D response to intervention. In women, multiple members of the sphingomyelin and lysophospholipid metabolite classes had significantly positive Bonferroni corrected associations over time compared to men. Further, multiple representatives of the acylcarnitine, androgenic steroid, bile acid, nucleotide and amino acid metabolite classes had significantly negative Bonferroni corrected associations over time compared to men. Gaussian graphical model analyses revealed sex-specific functional modules. Our findings show that robust and coordinated sex-specific metabolite differences exist early in critical illness.

Narrowing the Protein Deficit Gap in Critically Ill Patients Using a Very High-Protein Enteral Formula

BACKGROUND

Protein deficits have been associated with longer intensive care unit (ICU) stays and increased mortality. Current view suggests if protein goals are met, meeting full energy targets may be less important and prevent deleterious effects of overfeeding. We proposed a very-high protein (VHP) enteral nutrition (EN) formula could provide adequate protein, without overfeeding energy, in the first week of critical illness.

METHODS

This was a retrospective study of medical/surgical ICU patients receiving EN exclusively for ≥5 days during the first week of ICU admission. Twenty participants received standard EN; 20 participants received the VHP-EN formula (1 kcal/mL, 37% protein). Protein and energy prescribed/received, gastrointestinal tolerance, and feeding interruptions were examined.

RESULTS

Forty ICU patients [average Acute Physiology and Chronic Health Evaluation II score of 20.1] were included. Protein prescribed and received was significantly higher in the VHP group vs the standard EN group (135.5 g/d ± 22.9 vs 111.4 g/d ± 25; P = .003 and 112.2 g/d ± 27.8 vs 81.7 g/d ± 16.7, respectively; P = .002). Energy prescribed and received was similar between groups (1696 kcal/d ± 402 vs 1893 kcal/d ± 341, respectively; P = .101 and 1520 kcal/d ± 346 vs 1506 ± 380 kcal/d; P = .901). There were no differences in EN tolerance (P = .065) or feeding interruptions (P = .336).

CONCLUSIONS

Use of a VHP formula in ICU patients resulted in higher protein intakes without overfeeding energy or use of modular protein in the first 5 days of exclusive EN.

Sarcopenia and Psychosocial Variables in Patients in Intensive Care Units: The Role of Nutrition and Rehabilitation in Prevention and Treatment

Critical illness leads to decline in muscle mass that promotes decline in physical function and psychological function and may lead to cognitive decline or dementia. Nurses are key to driving the multidisciplinary interventions that prevent protein loss and promote positive outcomes for critically ill patients.

Exploring the Potential Effectiveness of Combining Optimal Nutrition With Electrical Stimulation to Maintain Muscle Health in Critical Illness: A Narrative Review

Muscle wasting occurs rapidly within days of an admission to the intensive care unit (ICU). Concomitant muscle weakness and impaired physical functioning can ensue, with lasting effects well after hospital discharge. Early physical rehabilitation is a promising intervention to minimize muscle weakness and physical dysfunction. However, there is an often a delay in commencing active functional exercises (such as sitting on the edge of bed, standing and mobilizing) due to sedation, patient alertness, and impaired ability to cooperate in the initial days of ICU admission. Therefore, there is high interest in being able to intervene early through nonvolitional exercise strategies such as electrical muscle stimulation (EMS). Muscle health characterized as the composite of muscle quantity, as well as functional and metabolic integrity, may be potentially maintained when optimal nutrition therapy is provided in complement with early physical rehabilitation in critically ill patients; however, the type, dosage, and timing of these interventions are unclear. This article explores the potential role of nutrition and EMS in maintaining muscle health in critical illness. Within this article, we will evaluate fundamental concepts of muscle wasting and evaluate the effects of EMS, as well as the effects of nutrition therapy on muscle health and the clinical and functional outcomes in critically ill patients. We will also highlight current research gaps in order to advance the field forward in this important area.

Nutrition in the ICU: new trends versus old-fashioned standard enteral feeding?

PURPOSE OF REVIEW

The narrative review aims to summarize the relevant studies from the last 2 years and provide contextual information to understand findings.

RECENT FINDINGS

Recent ICU studies have provided insight in the pathophysiology and time course of catabolism, anabolic resistance, and metabolic and endocrine derangements interacting with the provision of calories and proteins.Early provision of high protein intake and caloric overfeeding may confer harm. Refeeding syndrome warrants caloric restriction and to identify patients at risk phosphate monitoring is mandatory.Infectious complications of parenteral nutrition are associated with overfeeding. In recent studies enteral nutrition is no longer superior over parenteral nutrition.Previously reported benefits of glutamine, selenium, and fish oil seem to have vanished in recent studies; however, studies on vitamin C, thiamine, and corticosteroid combinations show promising results.

SUMMARY

Studies from the last 2 years will have marked impact on future nutritional support strategies and practice guidelines for critical care nutrition as they challenge several old-fashioned concepts.

Current perspective for tube feeding in the elderly: from identifying malnutrition to providing of enteral nutrition

With the number of individuals older than 65 years expected to rise significantly over the next few decades, dramatic changes to our society and health care system will need to take place to meet their needs. Age-related changes in muscle mass and body composition along with medical comorbidities including stroke, dementia, and depression place elderly adults at high risk for developing malnutrition and frailty. This loss of function and decline in muscle mass (ie, sarcopenia) can be associated with reduced mobility and ability to perform the task of daily living, placing the elderly at an increased risk for falls, fractures, and subsequent institutionalization, leading to a decline in the quality of life and increased mortality. There are a number of modifiable factors that can mitigate some of the muscle loss elderly experience especially when hospitalized. Due to this, it is paramount for providers to understand the pathophysiology behind malnutrition and sarcopenia, be able to assess risk factors for malnutrition, and provide appropriate nutrition support. The present review describes the pathophysiology of malnutrition, identifies contributing factors to this condition, discusses tools to assess nutritional status, and proposes key strategies for optimizing enteral nutrition therapy for the elderly.

Protein nutrition and exercise survival kit for critically ill

PURPOSE OF REVIEW

Protein delivery as well as exercise of critically ill in clinical practice is still a highly debated issue. Here we discuss only the most recent updates in the literature concerning protein nutrition and exercise of the critically ill.

RECENT FINDINGS

By lack of randomized controlled trial (RCTs) in protein nutrition we discuss four post-hoc analyses of nutrition studies and one experimental study in mice. Studies mainly confirm some insights that protein and energy effects are separate and that the trajectory of the patient in the ICU might change these effects. Exercise has been studied much more extensively with RCTs in the last year, although also here the differences between patient groups and timing of intervention might play their roles. Overall the effects of protein nutrition and exercise appear to be beneficial. However, studies into the differential effects of protein nutrition and/or exercise, and optimization of their combined use, have not been performed yet and are on the research agenda.

SUMMARY

Optimal protein nutrition, optimal exercise intervention as well as the optimal combination of nutrition, and exercise may help to improve long-term physical performance outcome in the critically ill patients.

Intermittent versus continuous feeding in critically ill adults

PURPOSE OF REVIEW

Early enteral nutrition is recommended in critically ill adult patients. The optimal method of administering enteral nutrition remains unknown. Continuous enteral nutrition administration in critically ill patients remains the most common practice worldwide; however, its practice has recently been called into question in favor of intermittent enteral nutrition administration, where volume is infused multiple times per day. This review will outline the key differences between continuous and intermittent enteral nutrition, describe the metabolic responses to continuous and intermittent enteral nutrition administration and outline recent studies comparing continuous with intermittent enteral nutrition administration on outcomes in critically ill adults.

RECENT FINDINGS

In separate studies, healthy humans and critically ill patients receiving intermittent nutrition (infused over 3 h) had improved whole body protein balance from negative to positive. These studies did not have an isonitrogenous control group. A randomized controlled trial of intermittent bolus versus continuous enteral nutrition in healthy humans found that intermittent bolus feeding increased mesenteric arterial blood flow, increased insulin and peptide YY and reduced blood glucose concentration. A randomized controlled trial comparing intermittent bolus to continuous enteral nutrition in critically ill patients did not demonstrate clinically relevant differences in glycemic variability, insulin use or tube feeding volume or caloric intake between the two groups.

SUMMARY

Studies in healthy humans suggest that intermittent nutrient administration, as opposed to continuous, improves whole body protein synthesis. Unfortunately, similarly designed studies are lacking for critically ill patients. Future studies evaluating the impact of intermittent versus continuous nutrition administration on critical care outcomes should take into account factors such as protein quantity, protein quality and delivery route (enteral and/or parenteral). Until further studies are conducted in critically ill patients, a recommendation for or against intermittent nutrition delivery cannot be made.

Protein in the Hospital: Gaining Perspective and Moving Forward

Provision of adequate protein is crucial for optimizing outcomes in hospitalized patients. However, the methodologies upon which current recommendations are based have limitations, and little is known about true requirements in any clinical population. In this tutorial, we aim to give clinicians an understanding of how current protein recommendations were developed, an appreciation for the limitations of these recommendations, and an overview of more sophisticated approaches that can be applied to better define protein requirements. A broader perspective of the challenges and opportunities in determining clinical protein requirements can help clinicians think critically about the individualized nutrition care they provide to their patients with the goal of administering adequate protein to optimize outcomes.