How Much and What Type of Protein Should a Critically Ill Patient Receive?

Improving enteral nutrition tolerance and protein intake maybe beneficial to intensive care unit patients

Enteral nutrition (EN) is important for critically ill patients. This study investigated the current situation of EN treatment in SHANGHAI intensive care units (ICUs). We hypothesized that improving EN practice in SHANGHAI may benefit the prognosis of ICU patients. Clinical information on EN use was collected using clinic information forms in 2019. The collected data included the patient's general clinical information, EN prescription status, EN tolerance status, and clinical outcomes. The observation time points were days 1, 3, and 7 after starting EN. A total of 491 patients were included. The proportion of EN intolerance (defined as < 20 kcal/kg/day) decreased, with rates of intolerance of 100%, 82.07%, 70.61%, and 52.23% at 1, 3, 7, and 14 days, respectively. Age, mNutric score, and protein intake < 0.5 g/kg/day on day 7 were risk factors for 28-day mortality.The EN tolerance on day 7 and protein intake > 0.5 g/kg/day on day 3 or day 7 might affect the 28-day mortality. Risk factors with EN tolerance on day 7 by logistic regression showed that the AGI grade on day 1 was a major factor against EN tolerance. The proportion of EN tolerance in SHANGHAI ICU patients was low. Achieving tolerance on day 7 after the start of EN is a protective factor for 28-day survival. Improving EN tolerance and protein intake maybe beneficial for ICU patients.

The effect of protein provision and exercise therapy on patient-reported and clinical outcomes in intensive care unit survivors: A systematic review

BACKGROUND

Intensive care unit (ICU) survivors deal with long-term health problems, which negatively affect their quality of life (QoL). Nutritional and exercise intervention could prevent the decline of muscle mass and physical functioning which occurs during critical illness. Despite the growing amount of research, robust evidence is lacking.

METHODS

For this systematic review, Embase, PubMed and Cochrane Central Register of Controlled Trials databases were searched. The effect of protein provision (PP) or combined protein and exercise therapy (CPE) during or after ICU admission on QoL, physical functioning, muscle health, protein/energy intake and mortality was assessed compared to standard care.

RESULTS

Four thousand nine hundred and fifty-seven records were identified. After screening, data were extracted for 15 articles (9 randomised controlled trials and 6 non-randomised studies). Two studies reported improvements in muscle mass, of which one found higher independency in activities of daily living. No significant effect was found on QoL. Overall, protein targets were seldom met and often below recommendations.

CONCLUSION

Evidence for the effect of PP or CPE on patient-reported outcomes in ICU survivors is limited due to study heterogeneity and lack of high-quality studies. Future research and clinical practice should focus on adequate protein delivery with exercise interventions to improve long-term outcomes.

The Effect of Enteral Immunonutrition in the Intensive Care Unit: Does It Impact on Outcomes?

Background: The present research aimed to evaluate the effect on outcomes of immunonutrition (IMN) enteral formulas during the intensive care unit (ICU) stay. Methods: A multicenter prospective observational study was performed. Patient characteristics, disease severity, nutritional status, type of nutritional therapy and outcomes, and laboratory parameters were collected in a database. Statistical differences were analyzed according to the administration of IMN or other types of enteral formulas. Results: In total, 406 patients were included in the analysis, of whom 15.02% (61) received IMN. Univariate analysis showed that patients treated with IMN formulas received higher mean caloric and protein intake, and better 28-day survival (85.2% vs. 73.3%; p = 0.014. Unadjusted Hazard Ratio (HR): 0.15; 95% CI (Confidence Interval): 0.06−0.36; p < 0.001). Once adjusted for confounding factors, multivariate analysis showed a lower need for vasopressor support (OR: 0.49; 95% CI: 0.26−0.91; p = 0.023) and continuous renal replacement therapies (OR: 0.13; 95% CI: 0.01−0.65; p = 0.049) in those patients who received IMN formulas, independently of the severity of the disease. IMN use was also associated with higher protein intake during the administration of nutritional therapy (OR: 6.23; 95% CI: 2.59−15.54; p < 0.001), regardless of the type of patient. No differences were found in the laboratory parameters, except for a trend toward lower triglyceride levels (HR: 0.97; 95% CI: 0.95−0.99; p = 0.045). Conclusion: The use of IMN formulas may be associated with better outcomes (i.e., lower need for vasopressors and continuous renal replacement), together with a trend toward higher protein enteral delivery during the ICU stay. These findings may ultimately be related to their modulating effect on the inflammatory response in the critically ill. NCT Registry: 03634943.

Unraveling the Metabolic Hallmarks for the Optimization of Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients

The daily amount and quality of protein that should be administered by enteral nutrition in pre-dialysis chronic kidney disease (CKD) patients is a widely studied but still controversial issue. This is due to a compromise between the protein necessary to maintain muscular proteostasis avoiding sarcopenia, and the minimal amount required to prevent uremia and the accumulation of nitrogenous toxic substances in blood because of the renal function limitations. This review underlines some intracellular and extracellular features that should be considered to reconcile those two opposite factors. On one hand, the physiological conditions and usual side effects associated with CKD, mTOR and other proteins and nutrients involved in the regulation of protein synthesis in the muscular tissue are discussed. On the other hand, the main digestive features of the most common proteins used for enteral nutrition formulation (i.e., whey, casein and soy protein) are highlighted, due to the importance of supplying key amino acids to serum and tissues to maintain their concentration above the anabolic threshold needed for active protein synthesis, thereby minimizing the catabolic pathways leading to urea formation.

Nutrition during extracorporeal life support: A review of pathophysiological bases and application of guidelines

BACKGROUND

Patients on extracorporeal life support (ECLS), either for respiratory or cardiac support, are at high risk of malnutrition; guidelines on nutrition in critical care have not incorporated solid evidence regarding these settings. The aim of this narrative review is to gather the available evidence in the existing literature and transpose general principles to the ECLS population.

METHODS

A literature review of observational and interventional studies on nutrition during ECLS, and evaluation of nutrition guidelines in this perspective.

RESULTS

Nutrition is paramount for improving outcomes in ECLS, as well as in critically ill patients. The caloric needs during ECLS can vary according to the severity of the clinical state, sedation, paralysis, and temperature stability. Precise evaluation of energy expenditure by indirect calorimetry is difficult because ECLS is a system dedicated to removing carbon dioxide; however, modified equations composed of carbon dioxide values taken from the membrane lung are available. Guidelines suggest starting early enteral nutrition (EN) with a hypocaloric (70%-80% of the needs) strategy, also in acute states such as septic or cardiogenic shock. Moreover, EN, despite previous concerns, is feasible in prone position, an increasingly adopted strategy during mechanical ventilation. The catabolic state is maximal in these patients, causing a protein and muscular reduction. Therefore, adequate protein delivery should be guaranteed by administering a high protein intake of up to 2 g/kg/day.

CONCLUSIONS

Studies on nutrition tailored to ECLS patients are warranted. Early hypocaloric EN with high protein intake, tailored on indirect calorimetry, may be the most appropriate option.

Augmented Renal Clearance, Muscle Catabolism and Urinary Nitrogen Loss: Implications for Nutritional Support in Critically Ill Trauma Patients

The main objective of this pilot study was to determine the association between augmented renal clearance (ARC), urinary nitrogen loss and muscle wasting in critically ill trauma patients. We conducted a retrospective analysis of a local database in 162 critically ill trauma patients without chronic renal dysfunction. Nutritional-related parameters and 24 h urinary biochemical analyses were prospectively collected and averaged over the first ten days after admission. Augmented renal clearance was defined by a mean creatinine clearance (CL_CR) > 130 mL/min/1.73 m². The main outcome was the cumulated nitrogen balance at day 10. The secondary outcome was the variation of muscle psoas cross-sectional area (ΔCSA) calculated in the subgroup of patients who underwent at least two abdominal CT scans during the ICU length of stay. Overall, there was a significant correlation between mean CL_CR and mean urinary nitrogen loss (normalized coefficient: 0.47 ± 0.07, p < 0.0001). ARC was associated with a significantly higher urinary nitrogen loss (17 ± 5 vs. 14 ± 4 g/day, p < 0.0001) and a lower nitrogen balance (−6 ± 5 vs. −4 ± 5 g/day, p = 0.0002), without difference regarding the mean protein intake (0.7 ± 0.2 vs. 0.7 ± 0.3 g/kg/day, p = 0.260). In the subgroup of patients who underwent a second abdominal CT scan (N = 47), both ΔCSA and %ΔCSA were higher in ARC patients (−33 [−41; −25] vs. −15 [−29; −5] mm²/day, p = 0.010 and −3 [−3; −2] vs. −1 [−3; −1] %/day, p = 0.008). Critically ill trauma patients with ARC are thus characterized by a lower nitrogen balance and increased muscle loss over the 10 first days after ICU admission. The interest of an increased protein intake (>1.5 g/kg/day) in such patients remains a matter of controversy and must be confirmed by further randomized trials.

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.

Meeting Calorie and Protein Needs in the Critical Care Unit: A Prospective Observational Pilot Study

Background:

Inadequate calorie and protein intake during critical illness is associated with poor clinical outcomes. Unfortunately, most critically ill patients do not consume adequate levels of these nutrients. An enteral formula with appropriate macronutrient composition may assist patients in meeting nutritional goals.

Design:

This study was a single center, prospective, observational study of 29 adults in the medical intensive care unit who required enteral nutrition for at least 3 days. Subjects received a calorically dense, enzymatically hydrolyzed 100% whey peptide-based enteral formula for up to 5 days to assess the ability to achieve 50% of caloric goals within the first 3 days (primary outcome), the daily percentage of protein goals attained and gastrointestinal tolerance (secondary outcomes).

Result:

A total of 29 subjects consented and began the study. Four subjects dropped out before first day and 25 subjects were included in analyses. Subjects were aged 55.5 ± 16.9 years with mean body mass index (BMI) of 27.9 ± 7.5 kg/m². Most (92%) subjects were on a mechanical ventilator and experienced organ failure. At least 50% of caloric and protein goals were achieved in 78.9% and 73.7% of the subjects, respectively, during the first 3 days. Overall, 75.0 ± 26.3% and 69.3 ± 26.7% of calorie and protein goals were achieved using the study formula.

Conclusions:

Subjects fed enterally with a calorically dense, enzymatically hydrolyzed 100% whey peptide-based enteral formula exceeded 50% of caloric and protein goals in most critically ill subjects included in this study. Use of study formula did not lead to severe gastrointestinal intolerance.

[Muscle in critically ill patients]

Introduction

Polyneuropathy in the critically ill patient was defined as a generalized weakness, acquired during Intensive Care Unit (ICU) admittance and attributed to lesion of the peripheral nerve. Research in this field progressed over time, revealing the crucial role of muscle injury in this disease, to the point of re-naming the disorder as ICU adquired weakness (ICUAW). Muscle damage is common in severe illness, and may be classified in qualitative (weakness) or quantitative (decrease in mass) muscle loss. The most frequent scenario in these patients, is simultaneous change in quality and quantity of muscle; resulting in a challenging and delayed recovery during hospital admittance and after discharge. Multiple causes have been identified in the pathogenesis of this disorder, such as: prolonged bed rest, inadequate intake of nutrients and exposure to drugs that affect muscle structure and contraction. The assessment of muscle mass using images provided by ultrasound or computerized tomography may guide follow up. The prevention and treatment of ICUAW requires a multimodal approach: early mobilization and exercise, appropriate nutritional prescription and, occasionally, muscle protein synthesis stimulants. Further studies will clarify more aspects regarding critically ill patients suffering from muscle injury, in order to better address prevention and treatment of ICUAW.

Amino Acid Availability of a Dairy and Vegetable Protein Blend Compared to Single Casein, Whey, Soy, and Pea Proteins: A Double-Blind, Cross-Over Trial

Protein quality is important for patients needing medical nutrition, especially those dependent on tube feeding. A blend of dairy and vegetable proteins (35% whey, 25% casein, 20% soy, 20% pea; P4) developed to obtain a more balanced amino acid profile with higher chemical scores, was compared to its constituent single proteins. Fourteen healthy elderly subjects received P4, whey, casein, soy, and pea (18 g/360 mL bolus) on five separate visits. Blood samples were collected at baseline until 240 min after intake. Amino acid availability was calculated using incremental maximal concentration (iCmax) and area under the curve (iAUC). Availability for P4 as a sum of all amino acids was similar to casein (iCmax and iAUC) and whey (iCmax) and higher vs. soy (iCmax and iAUC) and pea (iCmax). Individual amino acid availability (iCmax and iAUC) showed different profiles reflecting the composition of the protein sources: availability of leucine and methionine was higher for P4 vs. soy and pea; availability of arginine was higher for P4 vs. casein and whey. Conclusions: The P4 amino acid profile was reflected in post-prandial plasma levels and may be regarded as more balanced compared to the constituent single proteins.

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.

Clinical Nutrition in Critical Care Medicine - Guideline of the German Society for Nutritional Medicine (DGEM)

PURPOSE

Enteral and parenteral nutrition of adult critically ill patients varies in terms of the route of nutrient delivery, the amount and composition of macro- and micronutrients, and the choice of specific, immune-modulating substrates. Variations of clinical nutrition may affect clinical outcomes. The present guideline provides clinicians with updated consensus-based recommendations for clinical nutrition in adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function.

METHODS

The former guidelines of the German Society for Nutritional Medicine (DGEM) were updated according to the current instructions of the Association of the Scientific Medical Societies in Germany (AWMF) valid for a S2k-guideline. According to the S2k-guideline classification, no systematic review of the available evidence was required to make recommendations, which, therefore, do not state evidence- or recommendation grades. Nevertheless, we considered and commented the evidence from randomized-controlled trials, meta-analyses and observational studies with adequate sample size and high methodological quality (until May 2018) as well as from currently valid guidelines of other societies. The liability of each recommendation was described linguistically. Each recommendation was finally validated and consented through a Delphi process.

RESULTS

In the introduction the guideline describes a) the pathophysiological consequences of critical illness possibly affecting metabolism and nutrition of critically ill patients, b) potential definitions for different disease phases during the course of illness, and c) methodological shortcomings of clinical trials on nutrition. Then, we make 69 consented recommendations for essential, practice-relevant elements of clinical nutrition in critically ill patients. Among others, recommendations include the assessment of nutrition status, the indication for clinical nutrition, the timing and route of nutrient delivery, and the amount and composition of substrates (macro- and micronutrients); furthermore, we discuss distinctive aspects of nutrition therapy in obese critically ill patients and those treated with extracorporeal support devices.

CONCLUSION

The current guideline provides clinicians with up-to-date recommendations for enteral and parenteral nutrition of adult critically ill patients who suffer from at least one acute organ dysfunction requiring specific drug therapy and/or a mechanical support device (e.g., mechanical ventilation) to maintain organ function. The period of validity of the guideline is approximately fixed at five years (2018-2023).

Status and nutritional therapy in elective and emergency neurosurgery patients

OBJEVECT

To evaluate the Nutritional Status (NS) and follow the Enteral Nutritional Therapy (ENT) of patients in neurosurgical intervention.

METHOD

Cohort study in emergency or elective surgery patients with exclusive ENT. Anthropometric measurements (Arm Circumference (AC and Triceps Skinfold (TSF)) were measured on the first, seventh and 14th day. For the ENT monitoring, caloric/protein adequacy, fasting, inadvertent output of the enteral probe and residual gastric volume were used.

RESULTS

80 patients, 78.7% in emergency surgery and 21.3% in elective surgery. There was a reduction in AC and Body Mass Index (BMI) (p>0.01), especially for the emergency group. The caloric/protein adequacy was higher in the emergency group (86.7% and 81.8%).

CONCLUSION

The EN change was greater in the emergency group, even with better ENT adequacy. Changes in body composition are frequent in neurosurgical patients, regardless of the type of procedure.

Peptide nutrient-energy dense enteral feeding in critically ill infants: an observational study

BACKGROUND

Enteral feeding is challenging in critically ill infants. Target intakes are often not achieved as a result of fluid restriction, procedural interruptions and perceived enteral feeding intolerance. In those infants perceived to have poor feeding tolerance, the use of a peptide nutrient-energy dense enteral feed (PEF) may improve nutritional intake and minimise feeding interruptions as a result of gastrointestinal symptoms. The aim of this observational study was to characterise the use of a PEF amongst critically ill infants in two paediatric intensive care units (PICUs).

METHODS

Records from critically ill infants aged <12 months admitted to two PICUs were retrospectively reviewed with a PICU length of stay (LOS) ≥ 7 days. Achievement of nutritional targets for the duration of PEF was reviewed. Gastrointestinal symptoms, including gastric residual volume, constipation and vomiting, were evaluated as tolerance parameters.

RESULTS

In total, 53 infants were included, with a median age on admission of 2.6 months. Median admission weight was 3.9 kg in PICU-1 and 4.7 kg in PICU-2. Median (interquatile range) energy intake in PICU-1 and PICU-2 was 68 (47-92) and 90 (63-124) kcal kg^-1 , respectively, and median (interquatile range) protein intake 1.7 (1.1-2.4) g kg^-1 and 2.5 (1.6-3.2) g kg^-1 , respectively. Feeding was withheld because of feeding intolerance in one infant (4%) on two occasions in PICU-1 for 2.5 h and in two infants (7%) on two occasions in PICU-2 for 19.5 h. Gastric residual mean (SD) volumes were 3.5 (5.4) mL kg^-1 in PICU-1 and 16.9 (15.6) mL kg^-1 in PICU-2.

CONCLUSIONS

Peptide nutrient-energy dense feeding in infants admitted to the PICU is feasible, well tolerated and nutritional targets are met. However, with this study design, it is not possible to draw any conclusions regarding the benefit of PEF over standard PE feed in critically ill children and future work is required to clarify this further.

Very high intact-protein formula successfully provides protein intake according to nutritional recommendations in overweight critically ill patients: a double-blind randomized trial

BACKGROUND

Optimal energy and protein provision through enteral nutrition is essential for critically ill patients. However, in clinical practice, the intake achieved is often far below the recommended targets. Because no polymeric formula with sufficient protein content is available, adequate protein intake can be achieved only by supplemental amino acids or semi-elemental formula administration. In the present study, we investigated whether protein intake can be increased with a new, very high intact-protein formula (VHPF) for enteral feeding.

METHODS

In this randomized, controlled, double-blind, multicenter trial, 44 overweight (body mass index ≥ 25 kg/m2) intensive care unit patients received either a VHPF (8 g/100 kcal) or a commercially available standard high protein formula (SHPF) (5 g/100 kcal). Protein and energy intake, gastrointestinal tolerance (gastric residual volume, vomiting, diarrhea, and constipation), adverse events, and serious adverse events were recorded. Total serum amino acid levels were measured at baseline and day 5.

RESULTS

The primary outcome, protein intake at day 5, was 1.49 g/kg body weight (95% CI 1.21-1.78) and 0.76 g/kg body weight (95% CI 0.49-1.03, P < 0.001) for VHPF and SHPF, respectively. Daily protein intake was statistically significantly higher in the VHPF group compared with the SHPF group from day 2 to day 10. Protein intake in the VHPF group as a percentage of target (1.5 g/kg ideal body weight) was 74.7% (IQR 53.2-87.6%) and 111.6% (IQR 51.7-130.7%) during days 1-3 and days 4-10, respectively. Serum amino acid concentrations were higher at day 5 in the VHPF group than in the SHPF group (P = 0.031). No differences were found in energy intake, measures of gastrointestinal tolerance, and safety.

CONCLUSIONS

Enteral feeding with VHPF (8 g/100 kcal) resulted in higher protein intake and plasma amino acid concentrations than an isocaloric SHPF (5 g/100 kcal), without an increase in energy intake. This VHPF facilitates feeding according to nutritional guidelines and is suitable as a first-line nutritional treatment for critically ill overweight patients.

TRIAL REGISTRATION

Netherlands Trial Register, NTR5643 . Registered on 2 February 2016.

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.