The effect of higher protein dosing in critically ill patients with high nutritional risk (EFFORT Protein): an international, multicentre, pragmatic, registry-based randomised trial

BACKGROUND

On the basis of low-quality evidence, international critical care nutrition guidelines recommend a wide range of protein doses. The effect of delivering high-dose protein during critical illness is unknown. We aimed to test the hypothesis that a higher dose of protein provided to critically ill patients would improve their clinical outcomes.

METHODS

This international, investigator-initiated, pragmatic, registry-based, single-blinded, randomised trial was undertaken in 85 intensive care units (ICUs) across 16 countries. We enrolled nutritionally high-risk adults (≥18 years) undergoing mechanical ventilation to compare prescribing high-dose protein (≥2·2 g/kg per day) with usual dose protein (≤1·2 g/kg per day) started within 96 h of ICU admission and continued for up to 28 days or death or transition to oral feeding. Participants were randomly allocated (1:1) to high-dose protein or usual dose protein, stratified by site. As site personnel were involved in both prescribing and delivering protein dose, it was not possible to blind clinicians, but patients were not made aware of the treatment assignment. The primary efficacy outcome was time-to-discharge-alive from hospital up to 60 days after ICU admission and the secondary outcome was 60-day morality. Patients were analysed in the group to which they were randomly assigned regardless of study compliance, although patients who dropped out of the study before receiving the study intervention were excluded. This study is registered with ClinicalTrials.gov, NCT03160547.

FINDINGS

Between Jan 17, 2018, and Dec 3, 2021, 1329 patients were randomised and 1301 (97·9%) were included in the analysis (645 in the high-dose protein group and 656 in usual dose group). By 60 days after randomisation, the cumulative incidence of alive hospital discharge was 46·1% (95 CI 42·0%-50·1%) in the high-dose compared with 50·2% (46·0%-54·3%) in the usual dose protein group (hazard ratio 0·91, 95% CI 0·77-1·07; p=0·27). The 60-day mortality rate was 34·6% (222 of 642) in the high dose protein group compared with 32·1% (208 of 648) in the usual dose protein group (relative risk 1·08, 95% CI 0·92-1·26). There appeared to be a subgroup effect with higher protein provision being particularly harmful in patients with acute kidney injury and higher organ failure scores at baseline.

INTERPRETATION

Delivery of higher doses of protein to mechanically ventilated critically ill patients did not improve the time-to-discharge-alive from hospital and might have worsened outcomes for patients with acute kidney injury and high organ failure scores.

FUNDING

None.

Early metabolic support for critically ill trauma patients: A prospective randomized controlled trial

BACKGROUND

There is a lack of consensus regarding the optimal nutritional support for trauma patients. We hypothesize that early postinjury metabolic support focusing on adequate protein would modify the metabolic signature and alter the inflammatory environment for critically ill trauma patients.

METHODS

We conducted a prospective randomized controlled pilot trial for adult patients admitted to the surgical intensive care unit following traumatic injury. Patients were randomized to receive early metabolic support (EMS) (peripheral amino acid infusions) or standard of care (enteral nutrition as soon as feasible). Routine laboratory assessments, nitrogen balance, cytokines, and metabolomic analyses were assessed at baseline and day 5 after intervention.

RESULTS

A total of 42 trauma patients were randomized into well-balanced groups with similar age (32 years), Injury Severity Score (25), and body mass index (27.4 kg/m2). Early metabolic support provided significantly more protein (1.43 g/kg vs. 0.35 g/kg; p < 0.0001) and more calories (12.6 kcal/kg vs. 7.5 g/kg; p = 0.0012) over the first 5 days as compared with the standard of care. Early metabolic support modified protein catabolism and synthesis as demonstrated by a larger median negative nitrogen balance (-16.3 g vs. -5.3 g; p = 0.03) and a unique metabolomic profile at day 5. The biochemical profile of patients who received EMS was defined by greater declines in circulating levels of stress hormone precursors and increased levels of amino acids. The inflammatory response following EMS resulted in a greater decrease in interleukin-1B (p = 0.02) and increase in soluble interleukin-6 receptor (p = 0.01) between baseline and day 5 as compared with the standard of care. The EMS group had a decreased length of stay (15 vs. 22 days) and decreased surgical intensive care unit length of stay (8 vs. 9 days); however, this disappeared after adjustment for Injury Severity Score in this small population.

CONCLUSIONS

Early metabolic support with amino acid is safe, modifies metabolism, and may downregulate the inflammatory state associated with significant trauma, warranting a larger trial to assess for improved outcomes.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level II.

Adequacy of prescribed caloric and protein intake and reduction of mortality in critically ill patients with body mass indices <30 kg/m2

OBJECTIVE

Although the provision of nutrition helps minimize adverse outcomes in most patients in intensive care units (ICUs), little is known about the relative effect of energy and protein delivered on mortality in ICU patients with different ranges of body mass index (BMI). The aim of this study was to examine the relationships between adequacy of dietary energy and protein intakes separately and simultaneously, and short-term mortality in medical ICU patients across four BMI categories.

METHODS

We enrolled 1693 patients admitted to a medical center ICU in Taiwan during the period of 2005 to 2011, subcategorizing them by BMI levels: <18.5(n = 418), 18.5-24.9 (n = 889), 25-29.9 (n = 289), and ≥30 kg/m² (n = 97). Dietary energy and protein intake (DEI and DPI) were defined by the percent of prescribed dosages that each patient actually received: highly adequate (>80%), moderately adequate (60-80%), and inadequate (<60%), during the first 10 d in the ICU.

RESULTS

Mean DEI was 1237 kcal/d and DPI 47 g protein/d. Analyzed separately in our multiple regression models, moderately and highly adequate DEI (P_trends = 0.003-0.026) and DPI (P_trends = 0.001-0.004) were both significantly correlated with reduced mortality in patients with BMI <18.5, 18.5-24.9, and 25-29.9 kg/m² but not in those with BMI levels ≥30 kg/m². With DEI and DPI analyzed simultaneously, only APACHE II scores and DPI levels remained significantly related to reduced mortality in patients with BMI <30 kg/m².

CONCLUSION

Although the adequacy of delivery of prescribed DEI or DPI dosages appeared to be important for reduced risks for mortality in ICU patients with BMI <30 kg/m² when analyzed separately, DPI had a stronger effect on decreases in ICU mortality when the two were analyzed simultaneously. Further investigation may be needed to study the role of increased protein in improving clinical outcomes.

Effects on physical performance of high protein intake for critically ill adult patients admitted to the intensive care unit: A retrospective propensity-matched analysis

OBJECTIVES

This study aimed to examine the effects of protein intake on physical performance in critically ill adult patients admitted to the intensive care unit (ICU).

METHODS

This was a retrospective cohort study of adult patients mechanically ventilated over 48 h in the ICU who were classified into two groups based on the amount of protein intake: >1.0 g/kg/d (high-protein group) or <1.0 g/kg/d (low-protein group). After adjustment for possible confounding factors with propensity score matching, we compared muscle strength at the time of ICU discharge and the rate of recovery to independent walking between the two groups.

RESULTS

One-to-one propensity score matching created 20 pairs. The high-protein group had significantly higher muscle strength than the low-protein group at the time of discharge from the ICU. In addition, the rate of recovery to independent walking before hospital discharge was higher in the high-protein group than the low-protein group (16 of 20 patients [80%] vs. 8 of 20 patients [40%]; P = 0.032).

CONCLUSIONS

Our findings indicate that a sufficient amount of protein intake may lead to a higher rate of recovery to independent walking before discharge from the hospital in critically ill patients admitted to the ICU. This finding is likely related to preserved muscle strength at the time of ICU discharge.

Evaluation of the effect of high protein supply on diaphragm atrophy in critically ill patients receiving prolonged mechanical ventilation

BACKGROUND

Our aim was to evaluate the effect of high protein to the target of 2.0 g/kg/d on diaphragm atrophy and clinical prognosis of patients receiving prolonged mechanical ventilation (MV).

METHODS

This prospective, randomized, controlled, single-center study included 41 patients who were treated with ≥7 days' MV. The patients were randomly divided into a standard nutrition treatment (SNT) group and intensive nutrition treatment (INT) group, followed by evaluation of computer tomography-analyzed diaphragm volume, the level of butyrylcholinesterase (BChE) as a muscle mass indicator, and respiratory mechanics indices weekly to observe and compare the differences between the groups.

RESULTS

In the INT group, the actual protein (1.70 ± 0.21 vs 1.06 ± 0.21 g/kg/d, P < .001) and calorie intake (33.46 ± 2.78 vs 25.75 ± 4.81 kcal/kg/d, P < .001) were significantly different from those of the SNT group. Compared with the SNT group, the INT group's diaphragm atrophy improved in the fourth and fifth weeks (all P < .05). The BChE after the third week was higher (all P < .05). No significant differences in respiratory mechanical indices and clinical outcomes were found in the surviving patients between the groups.

CONCLUSION

INT improved the diaphragm atrophy and muscle mass of critically ill patients receiving prolonged MV. There was no evidence that increasing protein to the target amount of 2.0 g/kg/d is related to improvement in clinical prognosis for patients receiving prolonged MV.

Review of evolution and current status of protein requirements and provision in acute illness and critical care

Nutrition therapy, by enteral, parenteral, or both routes combined, is a key component of the management of critically ill, surgical, burns, and oncology patients. Established evidence indicates overfeeding (provision of excessive calories) results in increased risk of infection, morbidity, and mortality. This has led to the practice of "permissive underfeeding" of calories; however, this can often lead to inadequate provision of guideline-recommended protein intakes. Acutely ill patients requiring nutritional therapy have high protein requirements, and studies demonstrate that provision of adequate protein can result in reduced mortality and improvement in quality of life. However, a significant challenge to adequate protein delivery is the current lack of concentrated protein solutions. Patients often have fluid administration restrictions and existing protein solutions are frequently not sufficiently concentrated to deliver a patient's protein requirements. This has led to the development of new enteral and parenteral nutrition solutions incorporating higher levels of protein in smaller volumes. This review article summarizes current evidence supporting the role of higher protein intakes, especially during the early phases of nutrition therapy in acute illness, methods for assessing protein requirements, as well as, the currently available high-protein enteral and parenteral nutrition solutions. There is sufficient evidence (albeit limited from true randomized, controlled studies) to indicate that earlier provision of guideline-recommended protein intakes may be key to improving patient outcomes and that nutritional therapy that tailors caloric and protein intake to the patients' needs should be considered a desired standard of care.

The GLIM criteria for adult malnutrition and its relation with adverse outcomes, a prospective observational study

BACKGROUND & AIMS

Malnutrition is considered a risk factor for many complications and mortality among hospitalized patients. Until 2016 there was a wide variety of clinical definitions for malnutrition, until the GLIM criteria proposed a consensual definition. The main goal of this study is to assess the performance of the GLIM criteria at acute care admission to detect those patients with adverse clinical outcomes such as mortality and the need to be transferred to critical care areas (CCA).

METHODS

This was a prospective observational study including every adult patient admitted to the regular ward of the Hospital San Ángel Inn Universidad. Every nutrition and demographic variable evaluated by the nutrition team at hospital admission was captured. The malnutrition definition according to the GLIM and separate criteria were tested for their performance to detect patients at high risk for adverse outcomes (mortality and the need to be transferred to CCA), using odd ratios (OR), their confidence interval of 95% (CI95%) and binary logistic regression accordingly.

RESULTS

A total of 1015 patients were included in the final analysis, with a prevalence of 18.9% of malnutrition (according to the GLIM definition) at hospital admission. Malnutrition was associated with mortality (OR of 59.69,CI95% 7.76-459.28) and unplanned transfer to CCA (OR of 9.453, CI95%4.35-20.56). However, despite being sensitive, the GLIM definition of malnutrition, displayed low positive predictive value, and was therefore associated with many false positives. There was a trend for higher risks for adverse outcomes with higher severity of malnutrition. Muscle wasting, chronic and acute inflammation were independent predictors for mortality and for unplanned transfer to CCA.

CONCLUSIONS

Malnutrition according to the GLIM criteria is strongly associated with mortality and transfer to CCA. Muscle wasting and inflammation (acute and chronic) were independently associated with these outcomes.

Macronutrients in Parenteral Nutrition: Amino Acids

The right amount and quality of amino acids (AAs) supplied to patients on parenteral nutrition (PN) reduces muscle mass loss, may preserve or even increase it, with significant clinical benefits. Several industrial PN mixtures are available so that nutrition specialists can choose the product closest to the patient's needs. In selected cases, there is the possibility of personalizing compounded mixtures in a hospital pharmacy that completely meets the individual nutritional needs of PN patients. This narrative review deals with the AA solutions used in PN mixtures. The physiology, the methods to calculate the AA needs, and the AA and energy requirements suggested by scientific guidelines for each patient type are also reported.

Protein Intake, Nutritional Status and Outcomes in ICU Survivors: A Single Center Cohort Study

Background: We hypothesized that protein delivery during hospitalization in patients who survived critical care would be associated with outcomes following hospital discharge. Methods: We studied 801 patients, age ≥ 18 years, who received critical care between 2004 and 2012 and survived hospitalization. All patients underwent a registered dietitian formal assessment within 48 h of ICU admission. The exposure of interest, grams of protein per kilogram body weight delivered per day, was determined from all oral, enteral and parenteral sources for up to 28 days. Adjusted odds ratios for all cause 90-day post-discharge mortality were estimated by mixed- effects logistic regression models. Results: The 90-day post-discharge mortality was 13.9%. The mean nutrition delivery days recorded was 15. In a mixed-effect logistic regression model adjusted for age, gender, race, Deyo-Charlson comorbidity index, acute organ failures, sepsis and percent energy needs met, the 90-day post-discharge mortality rate was 17% (95% CI: 6–26) lower for each 1 g/kg increase in daily protein delivery (OR = 0.83 (95% CI 0.74–0.94; p = 0.002)). Conclusions: Adult medical ICU patients with improvements in daily protein intake during hospitalization who survive hospitalization have decreased odds of mortality in the 3 months following hospital discharge.

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.

High-Protein Hypocaloric Nutrition for Non-Obese Critically Ill Patients

High-protein hypocaloric nutrition, tailored to each patient's muscle mass, protein-catabolic severity, and exogenous energy tolerance, is the most plausible nutrition therapy in protein-catabolic critical illness. Sufficient protein provision could mitigate the rapid muscle atrophy characteristic of this disease while providing urgently needed amino acids to the central protein compartment and sites of tissue injury. The protein dose may range from 1.5 to 2.5 g protein (1.8-3.0 g free amino acids)/kg dry body weight per day. Nutrition should be low in energy (≈70% of energy expenditure or ≈15 kcal/kg dry body weight per day) because efforts to match energy provision to energy expenditure are physiologically irrational, risk toxic energy overfeeding, and have repeatedly failed in large clinical trials to demonstrate clinical benefit. The American Society for Parenteral and Enteral Nutrition currently suggests high-protein hypocaloric nutrition for obese critically ill patients. Short-term high-protein hypocaloric nutrition is physiologically and clinically sensible for most protein-catabolic critically ill patients, whether obese or not.

Updates in Nutrition Support for Critically Ill Adult Patients

Specialized nutrition support is often employed in critically ill patients who are unable to maintain volitional intake. The Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) recently updated guidelines for the provision of nutrition support in critically ill patients. The purpose of this review is to summarize key changes from the previous guidelines as they relate to recently published literature, which will aid the hospital pharmacist in optimizing nutrition support therapies in the critical care setting.

Parenteral Nutrition: Amino Acids

There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

Will We Ever Agree on Protein Requirements in the Intensive Care Unit?

The precise value of the normal adult protein requirement has long been debated. For many reasons-one of them being the difficulty of carrying out long-term nutrition experiments in free-living people-uncertainty is likely to persist indefinitely. By contrast, the controlled environment of the intensive care unit and relatively short trajectory of many critical illnesses make it feasible to use hard clinical outcome trials to determine protein requirements for critically ill patients in well-defined clinical situations. This article suggests how the physiological principles that underlie our understanding of normal protein requirements can be incorporated into the design of such clinical trials. The main focus is on 3 principles: (1) the rate of body nitrogen loss roughly predicts an individual's minimum protein requirement and is thus essential to measure to identify individual patients and clinical situations in which the minimum protein requirement is importantly increased, (2) existing muscle mass sets an upper limit on the rate at which amino acids can be mobilized from muscle for transfer to central proteins and sites of injury and is thus important to monitor to identify patients who are at greatest risk of protein deficiency-related adverse outcomes, and (3) negative energy balance increases the dietary protein requirement, so calorie-deprived patients-whether obese or not-should be enrolled in hard clinical outcome trials that compare the current practice of "permissive underfeeding" (underprovision of all nutrients, including protein) with hypocaloric nutrition supplemented by a suitably generous amount of protein.

Nutrition in critical illness: a current conundrum

Critically ill people are unable to eat. What’s the best way to feed them? Nutrition authorities have long recommended providing generous amounts of protein and calories to critically ill patients, either intravenously or through feeding tubes, in order to counteract the catabolic state associated with this condition. In practice, however, patients in modern intensive care units are substantially underfed. Several large randomized clinical trials were recently carried out to determine the clinical implications of this situation. Contradicting decades of physiological, clinical, and observational data, the results of these trials have been claimed to justify the current practice of systematic underfeeding in the intensive care unit. This article explains and suggests how to resolve this conundrum.