The Effect of IV Amino Acid Supplementation on Mortality in ICU Patients May Be Dependent on Kidney Function: Post Hoc Subgroup Analyses of a Multicenter Randomized Trial

A Randomized Trial of Intravenous Amino Acids for Kidney Protection

BACKGROUND

Acute kidney injury (AKI) is a serious and common complication of cardiac surgery, for which reduced kidney perfusion is a key contributing factor. Intravenous amino acids increase kidney perfusion and recruit renal functional reserve. However, the efficacy of amino acids in reducing the occurrence of AKI after cardiac surgery is uncertain.

METHODS

In a multinational, double-blind trial, we randomly assigned adult patients who were scheduled to undergo cardiac surgery with cardiopulmonary bypass to receive an intravenous infusion of either a balanced mixture of amino acids, at a dose of 2 g per kilogram of ideal body weight per day, or placebo (Ringer's solution) for up to 3 days. The primary outcome was the occurrence of AKI, defined according to the Kidney Disease: Improving Global Outcomes creatinine criteria. Secondary outcomes included the severity of AKI, the use and duration of kidney-replacement therapy, and all-cause 30-day mortality.

RESULTS

We recruited 3511 patients at 22 centers in three countries and assigned 1759 patients to the amino acid group and 1752 to the placebo group. AKI occurred in 474 patients (26.9%) in the amino acid group and in 555 (31.7%) in the placebo group (relative risk, 0.85; 95% confidence interval [CI], 0.77 to 0.94; P = 0.002). Stage 3 AKI occurred in 29 patients (1.6%) and 52 patients (3.0%), respectively (relative risk, 0.56; 95% CI, 0.35 to 0.87). Kidney-replacement therapy was used in 24 patients (1.4%) in the amino acid group and in 33 patients (1.9%) in the placebo group. There were no substantial differences between the two groups in other secondary outcomes or in adverse events.

CONCLUSIONS

Among adult patients undergoing cardiac surgery, infusion of amino acids reduced the occurrence of AKI. (Funded by the Italian Ministry of Health; PROTECTION ClinicalTrials.gov number, NCT03709264.).

No benefit of higher protein dosing in critically ill patients: a systematic review and meta-analysis of randomized controlled trials

Purpose

The optimal range of protein dosage and effect of high-dose protein on critically ill patients remain controversial. We conducted a meta-analysis to compare higher and lower doses of protein supplementation for nutritional support in critically ill patients.

Methods

We searched the PubMed, Embase, Scopus, and Cochrane Library databases for randomized controlled trials that compared higher (≥1.2 g/kg per day) versus lower (<1.2 g/kg per day) doses of protein supplementation among critically ill adult patients. This search spanned from the inception of relevant databases to November 20, 2023. Our primary endpoint of interest was overall mortality, while secondary endpoints included length of stay in the intensive care unit, length of hospital stay, duration of mechanical ventilation, and incidence of acute kidney injury.

Results

Seventeen studies including 2,965 critically ill patients were included in our meta-analysis. The pooled analyses showed no significant difference in overall mortality (RR 1.03, 95%CI [0.92-1.15], P = 0.65, I2 = 0%), length of intensive care unit stay (MD 0.19, 95%CI [-0.67 to 1.04], P = 0.66, I2 = 25%), length of hospital stay (MD 0.73, 95%CI [-1.59 to 3.04], P = 0.54, I2 = 27%), duration of mechanical ventilation (MD -0.14, 95%CI [-0.83 to 0.54], P = 0.68, I2 = 8%), and incidence of acute kidney injury (RR 1.11, 95%CI [0.87-1.41], P = 0.38, I2 = 0%) between critically ill patients receiving higher or lower doses of protein supplementation.

Conclusions

For critically ill patients, the protein supplementation dose had no significant effect on clinical outcomes, including overall mortality, length of intensive care unit and hospital stay, duration of mechanical ventilation, and incidence of acute kidney injury.

The hospital frailty risk score effectively predicts adverse outcomes in patients with atrial fibrillation in the intensive care unit

Background

Atrial fibrillation (AF) and frailty are significant global public health problems associated with advancing age. However, the relationship between frailty and older patients with AF in the intensive care unit (ICU) has not been thoroughly investigated. This study aimed to investigate whether the hospital frailty risk score (HFRS) is associated with adverse outcomes in older patients with AF in the ICU.

Methods

This was the first retrospective analysis of older patients with AF admitted to the ICU between 2008 and 2019 at a tertiary academic medical center in Boston. The HFRS was used to measure frailty severity. The outcomes of interest were in-hospital and 30-day mortality and the incidence of sepsis and ischemic stroke.

Results

There were 7,792 participants aged approximately 80 years, almost half (44.9%) of whom were female. Among this group, 2,876 individuals were identified as non-frail, while 4,916 were classified as frail. The analysis revealed a significantly greater incidence of in-hospital (18.8% compared to 7.6%) and 30-day mortality (24.5% versus 12.3%) in the frail group. After accounting for potential confounding factors, a multivariate Cox proportional hazards regression analysis revealed that frail participants had a 1.56-fold greater risk of mortality within 30 days (95% CI = 1.38-1.76, p < 0.001).

Conclusions

Frailty is an independent risk factor for adverse outcomes in older patients with AF admitted to the ICU. Therefore, prioritizing frailty assessment and implementing specific intervention strategies to improve prognostic outcomes are recommended.

Nutrition therapy in critically ill patients with severe acute pancreatitis

A significant proportion of patients (10%-20%) with acute pancreatitis develop severe acute pancreatitis characterized by pancreatic necrosis, systemic inflammation, and organ failure, commonly requiring intensive care unit (ICU) admission. In this specific population, nutrition therapy is more challenging than that in the general ICU population, primarily because of inevitable gastrointestinal involvement by pancreatic inflammation. In this review, we discussed several key aspects of nutrition therapy in this population, including key pathophysiology that may impede nutrition therapy, the timing and implementation of enteral nutrition and parenteral nutrition, the importance of specific nutrient supplements, and the long-term outcomes that may be addressed by nutrition therapy.

Association between urea trajectory and protein dose in critically ill adults: a secondary exploratory analysis of the effort protein trial (RE-EFFORT)

BACKGROUND

Delivering higher doses of protein to mechanically ventilated critically ill patients did not improve patient outcomes and may have caused harm. Longitudinal urea measurements could provide additional information about the treatment effect of higher protein doses. We hypothesised that higher urea values over time could explain the potential harmful treatment effects of higher doses of protein.

METHODS

We conducted a reanalysis of a randomised controlled trial of higher protein doses in critical illness (EFFORT Protein). We applied Bayesian joint models to estimate the strength of association of urea with 30-day survival and understand the treatment effect of higher protein doses.

RESULTS

Of the 1301 patients included in EFFORT Protein, 1277 were included in this analysis. There were 344 deaths at 30 days post-randomisation. By day 6, median urea was 2.1 mmol/L higher in the high protein group (95% CI 1.1-3.2), increasing to 3.0 mmol/L (95% CI 1.3-4.7) by day 12. A twofold rise in urea was associated with an increased risk of death at 30 days (hazard ratio 1.34, 95% credible interval 1.21-1.48), following adjustment of baseline characteristics including age, illness severity, renal replacement therapy, and presence of AKI. This association persisted over the duration of 30-day follow-up and in models adjusting for evolution of organ failure over time.

CONCLUSIONS

The increased risk of death in patients randomised to a higher protein dose in the EFFORT Protein trial was estimated to be mediated by increased urea cycle activity, of which serum urea is a biological signature. Serum urea should be taken into consideration when initiating and continuing protein delivery in critically ill patients.

CLINICALTRIALS

gov Identifier: NCT03160547 (2017-05-17).

The effects of higher versus lower protein delivery in critically ill patients: an updated systematic review and meta-analysis of randomized controlled trials with trial sequential analysis

BACKGROUND

A recent large multicentre trial found no difference in clinical outcomes but identified a possibility of increased mortality rates in patients with acute kidney injury (AKI) receiving higher protein. These alarming findings highlighted the urgent need to conduct an updated systematic review and meta-analysis to inform clinical practice.

METHODS

From personal files, citation searching, and three databases searched up to 29-5-2023, we included randomized controlled trials (RCTs) of adult critically ill patients that compared higher vs lower protein delivery with similar energy delivery between groups and reported clinical and/or patient-centred outcomes. We conducted random-effect meta-analyses and subsequently trial sequential analyses (TSA) to control for type-1 and type-2 errors. The main subgroup analysis investigated studies with and without combined early physical rehabilitation intervention. A subgroup analysis of AKI vs no/not known AKI was also conducted.

RESULTS

Twenty-three RCTs (n = 3303) with protein delivery of 1.49 ± 0.48 vs 0.92 ± 0.30 g/kg/d were included. Higher protein delivery was not associated with overall mortality (risk ratio [RR]: 0.99, 95% confidence interval [CI] 0.88-1.11; I2 = 0%; 21 studies; low certainty) and other clinical outcomes. In 2 small studies, higher protein combined with early physical rehabilitation showed a trend towards improved self-reported quality-of-life physical function measurements at day-90 (standardized mean difference 0.40, 95% CI - 0.04 to 0.84; I2 = 30%). In the AKI subgroup, higher protein delivery significantly increased mortality (RR 1.42, 95% CI 1.11-1.82; I2 = 0%; 3 studies; confirmed by TSA with high certainty, and the number needed to harm is 7). Higher protein delivery also significantly increased serum urea (mean difference 2.31 mmol/L, 95% CI 1.64-2.97; I2 = 0%; 7 studies).

CONCLUSION

Higher, compared with lower protein delivery, does not appear to affect clinical outcomes in general critically ill patients but may increase mortality rates in patients with AKI. Further investigation of the combined early physical rehabilitation intervention in non-AKI patients is warranted.

PROSPERO ID

CRD42023441059.

High protein provision of more than 1.2 g/kg improves muscle mass preservation and mortality in ICU patients: A systematic review and meta-analyses

BACKGROUND

ICU patients lose muscle mass rapidly and maintenance of muscle mass may contribute to improved survival rates and quality of life. Protein provision may be beneficial for preservation of muscle mass and other clinical outcomes, including survival. Current protein recommendations are expert-based and range from 1.2 to 2.0 g/kg. Thus, we performed a systematic review and meta-analysis on protein provision and all clinically relevant outcomes recorded in the available literature.

METHODS

We conducted a systematic review and meta-analyses, including studies of all designs except case control and case studies, with patients aged ≥18 years with an ICU stay of ≥2 days and a mean protein provision group of ≥1.2 g/kg as compared to <1.2 g/kg with a difference of ≥0.2 g/kg between protein provision groups. All clinically relevant outcomes were studied. Meta-analyses were performed for all clinically relevant outcomes that were recorded in ≥3 included studies.

RESULTS

A total of 29 studies published between 2012 and 2022 were included. Outcomes reported in the included studies were ICU, hospital, 28-day, 30-day, 42-day, 60-day, 90-day and 6-month mortality, ICU and hospital length of stay, duration of mechanical ventilation, vomiting, diarrhea, gastric residual volume, pneumonia, overall infections, nitrogen balance, changes in muscle mass, destination at hospital discharge, physical performance and psychological status. Meta-analyses showed differences between groups in favour of high protein provision for 60-day mortality, nitrogen balance and changes in muscle mass.

CONCLUSION

High protein provision of more than 1.2 g/kg in critically ill patients seemed to improve nitrogen balance and changes in muscle mass on the short-term and likely 60-day mortality. Data on long-term effects on quality of life are urgently needed.

Japanese Clinical Practice Guidelines for Rehabilitation in Critically Ill Patients 2023 (J-ReCIP 2023)

Providing standardized, high-quality rehabilitation for critically ill patients is a crucial issue. In 2017, the Japanese Society of Intensive Care Medicine (JSICM) promulgated the "Evidence-Based Expert Consensus for Early Rehabilitation in the Intensive Care Unit" to advocate for the early initiation of rehabilitations in Japanese intensive care settings. Building upon this seminal work, JSICM has recently conducted a rigorous systematic review utilizing the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. This endeavor resulted in the formulation of Clinical Practice Guidelines (CPGs), designed to elucidate best practices in early ICU rehabilitation. The primary objective of this guideline is to augment clinical understanding and thereby facilitate evidence-based decision-making, ultimately contributing to the enhancement of patient outcomes in critical care settings. No previous CPGs in the world has focused specifically on rehabilitation of critically ill patients, using the GRADE approach. Multidisciplinary collaboration is extremely important in rehabilitation. Thus, the CPGs were developed by 73 members of a Guideline Development Group consisting of a working group, a systematic review group, and an academic guideline promotion group, with the Committee for the Clinical Practice Guidelines of Early Mobilization and Rehabilitation in Intensive Care of the JSICM at its core. Many members contributed to the development of the guideline, including physicians and healthcare professionals with multiple and diverse specialties, as well as a person who had been patients in ICU. Based on discussions among the group members, eight important clinical areas of focus for this CPG were identified. Fourteen important clinical questions (CQs) were then developed for each area. The public was invited to comment twice, and the answers to the CQs were presented in the form of 10 GRADE recommendations and commentary on the four background questions. In addition, information for each CQ has been created as a visual clinical flow to ensure that the positioning of each CQ can be easily understood. We hope that the CPGs will be a useful tool in the rehabilitation of critically ill patients for multiple professions.

The impact of higher protein dosing on outcomes in critically ill patients with acute kidney injury: a post hoc analysis of the EFFORT protein trial

BACKGROUND

Based on low-quality evidence, current nutrition guidelines recommend the delivery of high-dose protein in critically ill patients. The EFFORT Protein trial showed that higher protein dose is not associated with improved outcomes, whereas the effects in critically ill patients who developed acute kidney injury (AKI) need further evaluation. The overall aim is to evaluate the effects of high-dose protein in critically ill patients who developed different stages of AKI.

METHODS

In this post hoc analysis of the EFFORT Protein trial, we investigated the effect of high versus usual protein dose (≥ 2.2 vs. ≤ 1.2 g/kg body weight/day) on time-to-discharge alive from the hospital (TTDA) and 60-day mortality and in different subgroups in critically ill patients with AKI as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria within 7 days of ICU admission. The associations of protein dose with incidence and duration of kidney replacement therapy (KRT) were also investigated.

RESULTS

Of the 1329 randomized patients, 312 developed AKI and were included in this analysis (163 in the high and 149 in the usual protein dose group). High protein was associated with a slower time-to-discharge alive from the hospital (TTDA) (hazard ratio 0.5, 95% CI 0.4-0.8) and higher 60-day mortality (relative risk 1.4 (95% CI 1.1-1.8). Effect modification was not statistically significant for any subgroup, and no subgroups suggested a beneficial effect of higher protein, although the harmful effect of higher protein target appeared to disappear in patients who received kidney replacement therapy (KRT). Protein dose was not significantly associated with the incidence of AKI and KRT or duration of KRT.

CONCLUSIONS

In critically ill patients with AKI, high protein may be associated with worse outcomes in all AKI stages. Recommendation of higher protein dosing in AKI patients should be carefully re-evaluated to avoid potential harmful effects especially in patients who were not treated with KRT.

TRIAL REGISTRATION

This study is registered at ClinicalTrials.gov (NCT03160547) on May 17th 2017.

Modifiable risk factors for ventilator associated diaphragmatic dysfunction: a multicenter observational study

BACKGROUND

Diaphragmatic dysfunction is known to be associated with difficulties weaning from invasive mechanical ventilation and is related to worse patient outcomes yet our understanding of how to prevent diaphragmatic dysfunction remains incomplete. We examined potentially modifiable risk factors for diaphragmatic dysfunction and attempted to estimate benefits attributable to altering these modifiable risk factors.

METHODS

This prospective multicenter observational study was undertaken in the general ICUs of two tertiary care teaching hospitals. Critically ill adults expected to receive invasive mechanical ventilation for at least 48 h were enrolled. Diaphragm function was assessed by ultrasound each study day, with dysfunction defined as thickening fraction less than 20%.

RESULTS

From January to December 2019, 856 patients were screened and 126 patients were enrolled. Overall, 40.5% (51/126) of patients experienced diaphragmatic dysfunction during invasive mechanical ventilation. Patients with diaphragmatic dysfunction were more likely to develop ventilator associated pneumonia (risk difference [RD] + 12.9%, 95% Confidence Interval [CI] 1.4 to 24.4%, P = 0.028), were more likely to experience extubation failure (RD + 8.5%, 95% CI 0.4 to 16.6%, P = 0.039) and required a longer duration of invasive mechanical ventilation (RD + 1.3 days, 95% CI 0.1 to 2.5 days, P = 0.035). They also required a longer hospital stay (RD + 1.2 days, 95% CI 0.04 to 2.4 days, P = 0.041) and were more likely to die before hospital discharge (RD + 18.1%, 95% CI 3.7 to 32.5%, P = 0.014). Multivariable analysis considered the impact of age, sex, pre-existing nutritional status, caloric intake, amino acid intake, acute disease severity, modes of mechanical ventilation, measures of respiratory status, sedation, pain control and baseline diaphragm thickness. Only SOFA score (P = 0.008) and early amino acid intake (P = 0.001) remained significant independent risk factors for the onset of diaphragmatic dysfunction. Causal path modeling suggested early amino acid intake may significantly reduce diaphragmatic dysfunction (RRR 29%, 95% CI 10% to 48%, P = 0.003) and may also reduce mortality (RRR 49%, 95% CI 25% to 73%, P < 0.0001).

CONCLUSIONS

Amino acid intake during the first 24 h of ICU stay may represent an important, modifiable risk factor for diaphragmatic dysfunction and may have a direct causal effect on mortality. We recommend additional research on this topic.

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.

Intravenous amino acids may mediate the adverse effect of early parenteral nutrition on mortality in critically ill patients requiring mechanical ventilation: A post hoc analysis of the NEED trial

BACKGROUND

There is controversy regarding the optimal timing of initiating parenteral nutrition (PN) in critically ill patients. We aimed to evaluate the association between early PN and clinical outcomes and explore the mediation effects of different macronutrients in a cohort of mechanically ventilated patients.

METHODS

This is a post hoc analysis of the NEED trial aiming to investigate the effect of implementing an evidence-based feeding guideline in newly-admitted critically ill patients. All eligible patients were divided into those who received early PN within the first 3 days of enrollment (early PN) or those who did not (non-early PN). Propensity score matching with a one-to-one nearest neighbor-matching algorithm was applied to control potential confounders. Mediation analysis was used to test the indirect effect of different macronutrients from PN on the relationship between early PN and 28-day mortality.

RESULTS

The propensity score matching created 370 matched pairs of 1154 patients that met the eligibility criteria. Compared with non-early PN, patients receiving early PN had significantly higher 28-day mortality (19.7% vs 12.4%; hazard ratio = 1.904; 95% CI, 1.063-3.410; P = 0.03). Mediation analysis showed that amino acids from early PN mediated 65% (mediation effect = 0.07; 95% CI, 0.02-0.13; P = 0.01) of the detrimental effect of early PN on the 28-day mortality.

CONCLUSION

Early PN is associated with increased 28-day mortality in critically ill patients requiring invasive mechanical ventilation. The detrimental effect may be mediated by intravenous amino acids from early PN.

Safety of increasing protein delivery with an enteral nutrition formula containing very high protein (VHP) and lower carbohydrate concentrations compared to conventional standard (SF) and high protein (HP) formulas

BACKGROUND & AIMS

Studies demonstrate that caloric restriction in the first seven days in the ICU is safe. The amount of protein that should be delivered, however, is still unclear with clinical trials suggesting mixed results. Despite some capacity to customize the delivery of protein using supplemental modules, protein delivered is best determined by the concentration of protein contained in enteral formula (EF) ordered. This fact provides an opportunity to explore the potential clinical effects of protein delivery and lower carbohydrate intake on clinical outcomes compared with conventional enteral formulas.

METHODS

Retrospective analysis of clinical outcomes according to the amount of protein delivered in critically ill patients admitted to intensive care units at Geisinger Health System.

RESULTS

2000 encounters (1899 patients) in patients on enteral nutrition were divided into three groups receiving EF with either ≤20% protein (standard formula - SF), 21-25% protein (high protein - HP) or > 25% protein (VHP). Protein intake increased up to day 7 (p < 0.0001). Patients on VHP received more protein than other groups (p < 0.0001). Multivariable regression analysis showed no evidence of harm. In fact, we observed increased mortality with SF and HP formulas at 30-days post-discharge when compared to patients on VHP even when the effects of other variables (including age, BMI, sex, primary diagnosis, diabetes, history of dialysis, ICU days kept NPO) were taken into consideration.

CONCLUSIONS

Increasing protein intake while reducing carbohydrate intake appears to be safe. Further research aimed at defining a causative effect of increasing protein delivery while reducing carbohydrate load on outcomes is warranted.

Impact of Energy and Protein Delivery to Critically Ill Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Optimal energy and protein delivery goals for critically ill patients remain unknown. The purpose of this systematic review and meta-analysis was to compare the impact of energy and protein delivery during the first 4 to 10 days of an ICU stay on physical impairments. We performed a systematic literature search of MEDLINE, CENTRAL, and ICHUSHI to identify randomized controlled trials (RCTs) that compared energy delivery at a cut-off of 20 kcal/kg/day or 70% of estimated energy expenditure or protein delivery at 1 g/kg/day achieved within 4 to 10 days after admission to the ICU. The primary outcome was activities of daily living (ADL). Secondary outcomes were physical functions, changes in muscle mass, quality of life, mortality, length of hospital stay, and adverse events. Fifteen RCTs on energy delivery and 14 on protein were included in the analysis. No significant differences were observed in any of the outcomes included for energy delivery. However, regarding protein delivery, there was a slight improvement in ADL (odds ratio 21.55, 95% confidence interval (CI) −1.30 to 44.40, p = 0.06) and significantly attenuated muscle loss (mean difference 0.47, 95% CI 0.24 to 0.71, p < 0.0001). Limited numbers of RCTs were available to analyze the effects of physical impairments. In contrast to energy delivery, protein delivery ≥1 g/kg/day achieved within 4 to 10 days after admission to the ICU significantly attenuated muscle loss and slightly improved ADL in critically ill patients. Further RCTs are needed to investigate their effects on physical impairments.

Early high protein provision and mortality in ICU patients including those receiving continuous renal replacement therapy

BACKGROUND

Findings on the association between early high protein provision and mortality in ICU patients are inconsistent. The relation between early high protein provision and mortality in patients receiving CRRT remains unclear. The aim was to study the association between early high protein provision and hospital and ICU mortality and consistency in subgroups.

METHODS

A retrospective cohort study was conducted in 2618 ICU patients with a feeding tube and mechanically ventilated ≥48 h (2003-2016). The association between early high protein provision (≥1.2 g/kg/day at day 4 vs. <1.2 g/kg/day) and hospital and ICU mortality was assessed for the total group, for patients receiving CRRT, and for non-septic and septic patients, by Cox proportional hazards analysis. Adjustments were made for APACHE II score, energy provision, BMI, and age.

RESULTS

Mean protein provision at day 4 was 0.96 ± 0.48 g/kg/day. A significant association between early high protein provision and lower hospital mortality was found in the total group (HR 0.48, 95% CI 0.39-0.60, p = <0.001), CRRT-receiving patients (HR 0.62, 95% CI 0.39-0.99, p = 0.045) and non-septic patients (HR 0.56, 95% CI 0.44-0.71, p = <0.001). However, no association was found in septic patients (HR 0.71, 95% CI 0.39-1.29, p = 0.264). These associations were very similar for ICU mortality. In a sensitivity analysis for patients receiving a relative energy provision >50%, results remained robust in all groups except for patients receiving CRRT.

CONCLUSIONS

Early high protein provision is associated with lower hospital and ICU mortality in ICU patients, including CRRT-receiving patients. There was no association for septic patients.

Catabolism in Critical Illness

OBJECTIVES

Ongoing risk of death and poor functional outcomes are important consequences of prolonged critical illness. Characterizing the catabolic phenotype of prolonged critical illness could illuminate biological processes and inform strategies to attenuate catabolism. We aimed to examine if urea-to-creatinine ratio, a catabolic signature of prolonged critical illness, was associated with mortality after the first week of ICU stay.

DESIGN

Reanalysis of multicenter randomized trial of glutamine supplementation in critical illness (REducing Deaths due to OXidative Stress [REDOXS]).

SETTING

Multiple adult ICUs.

PATIENTS

Adult patients admitted to ICU with two or more organ failures related to their acute illness and surviving to day 7.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The association between time-varying urea-to-creatinine ratio and 30-day mortality was tested using Bayesian joint models adjusted for prespecified-covariates (age, kidney replacement therapy, baseline Sequential Organ Failure Assessment, dietary protein [g/kg/d], kidney dysfunction, and glutamine-randomization). From 1,021 patients surviving to day 7, 166 (16.3%) died by day 30. After adjustment in a joint model, a higher time-varying urea-to-creatinine ratio was associated with increased mortality (hazard ratio [HR], 2.15; 95% credible interval, 1.66-2.82, for a two-fold greater urea-to-creatinine ratio). This association persisted throughout the 30-day follow-up. Mediation analysis was performed to explore urea-to-creatinine ratio as a mediator-variable for the increased risk of death reported in REDOXS when randomized to glutamine, an exogenous nitrogen load. Urea-to-creatinine ratio closest to day 7 was estimated to mediate the risk of death associated with randomization to glutamine supplementation (HR, 1.20; 95% CI, 1.04-1.38; p = 0.014), with no evidence of a direct effect of glutamine (HR, 0.90; 95% CI, 0.62-1.30; p = 0.566).

CONCLUSIONS

The catabolic phenotype measured by increased urea-to-creatinine ratio is associated with increased risk of death during prolonged ICU stay and signals the deleterious effects of glutamine administration in the REDOXS study. Urea-to-creatinine ratio is a promising catabolic signature and potential interventional target.

The importance of protein sources to support muscle anabolism in cancer: An expert group opinion

This opinion paper presents a short review of the potential impact of protein on muscle anabolism in cancer, which is associated with better patient outcomes. Protein source is a topic of interest for patients and clinicians, partly due to recent emphasis on the supposed non-beneficial effect of proteins; therefore, misconceptions involving animal-based (e.g., meat, fish, dairy) and plant-based (e.g., legumes) proteins in cancer are acknowledged and addressed. Although the optimal dietary amino acid composition to support muscle health in cancer is yet to be established, animal-based proteins have a composition that offers superior anabolic potential, compared to plant-derived proteins. Thus, animal-based foods should represent the majority (i.e., ≥65%) of protein intake during active cancer treatment. A diet rich in plant-derived proteins may support muscle anabolism in cancer, albeit requiring a larger quantity of protein to fulfill the optimal amino acid intake. We caution that translating dietary recommendations for cancer prevention to cancer treatment may be inadequate to support the pro-inflammatory and catabolic nature of the disease. We further caution against initiating an exclusively plant-based (i.e., vegan) diet upon a diagnosis of cancer, given the presence of elevated protein requirements and risk of inadequate protein intake to support muscle anabolism. Amino acid combination and the long-term sustainability of a dietary pattern void of animal-based foods requires careful and laborious management of protein intake for patients with cancer. Ultimately, a dietary amino acid composition that promotes muscle anabolism is optimally obtained through combination of animal- and plant-based protein sources.

Qualitative and quantitative muscle ultrasound changes in patients with COVID-19-related ARDS

OBJECTIVES

Severe forms of the novel coronavirus-19 (COVID-19) are associated with systemic inflammation and hypercatabolism. The aims of this study were to compare the time course of the size and quality of both rectus femoris and diaphragm muscles between critically ill, COVID-19 survivors and non-survivors and to explore the correlation between the change in muscles size and quality with the amount of nutritional support delivered and the cumulative fluid balance.

METHODS

This was a prospective observational study in the general intensive care unit (ICU) of a tertiary care hospital for COVID-19. The right rectus femoris cross-sectional area and the right diaphragm thickness, as well as their echo densities were assessed within 24 h from ICU admission and on day 7. We recorded anthropometric and biochemical data, respiratory mechanics and gas exchange, daily fluid balance, and the number of calories and proteins administered.

RESULTS

Twenty-eight patients were analyzed (65 ± 10 y of age; 80% men, body mass index 30 ± 7.8 kg/m²). Rectus femoris and diaphragm sizes were significantly reduced at day 7 (median = -26.1 [interquartile ratio [IQR], = -37.8 to -15.2] and -29.2% [-37.8% to -19.6%], respectively) and this reduction was significantly higher in non-survivors. Both rectus femoris and diaphragm echo density were significantly increased at day 7, with a significantly higher increase in non-survivors. The change in both rectus femoris and diaphragm size at day 7 was related to the cumulative protein deficit (R = 0.664, P < 0.001 and R = 0.640, P < 0.001, respectively), whereas the change in rectus femoris and diaphragm echo density was related to the cumulative fluid balance (R = 0.734, P < 0.001 and R = 0.646, P < 0.001, respectively).

CONCLUSIONS

Early changes in muscle size and quality seem related to the outcome of critically ill COVID-19 patients, and to be influenced by nutritional and fluid management strategies.

High protein versus medium protein delivery under equal total energy delivery in critical care: A randomized controlled trial

BACKGROUND

Appropriate protein delivery amounts during the acute phase of critical care are unknown. Along with nutrition, early mobilization and the combination are important. We conducted a randomized controlled trial during critical care to assess high-protein and medium-protein delivery under equal total energy delivery with and without active early rehabilitation.

METHODS

ICU patients of August 2018-September 2019 were allocated to a high-protein group (target energy 20 kcal/kg/day, protein 1.8 g/kg/day) or a medium-protein group (target energy 20 kcal/kg/day, protein 0.9 g/kg/day) with the same nutrition protocol by day 10. By dividing the study period, standard rehabilitation was administered during the initial period. Rehabilitation with belt-type electrical muscle stimulation was given from day 2 in the latter as a historical comparison. Femoral muscle volume was evaluated on day 1 and day 10 using computed tomography.

RESULTS

This study analyzed 117 eligible patients with similar characteristics assigned to a high-protein or medium-protein group. Total energy delivery was around 20 kcal/kg/day in both groups, but protein delivery was 1.5 g/kg/day and 0.8 g/kg/day. As a primary outcome, femoral muscle volume loss was 12.9 ± 8.5% in the high-protein group and 16.9 ± 7.0% in the medium-protein group, with significant difference (p = 0.0059). Persistent inflammation, immunosuppression, and catabolism syndrome were significantly less frequent in the high-protein group. Muscle volume loss was significantly less in the high-protein group only during the electrical muscle stimulation period.

CONCLUSIONS

For critical care, high protein delivery provided better muscle volume maintenance, but only with active early rehabilitation.

REGISTRATION

University Hospital Medical Information Network, UMIN000033783 Registered on 16 Aug 2018. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000038538.

Nutrition and Exercise in Critical Illness Trial (NEXIS Trial): a protocol of a multicentred, randomised controlled trial of combined cycle ergometry and amino acid supplementation commenced early during critical illness

INTRODUCTION

Survivors of critical illness often experience significant morbidities, including muscle weakness and impairments in physical functioning. This muscle weakness is associated with longer duration mechanical ventilation, greater hospital costs and increased postdischarge impairments in physical function, quality of life and survival. Compared with standard of care, the benefits of greater protein intake combined with structured exercise started early after the onset of critical illness remain uncertain. However, the combination of protein supplementation and exercise in other populations has demonstrated positive effects on strength and function. In the present study, we will evaluate the effects of a combination of early implementation of intravenous amino acid supplementation and in-bed cycle ergometry exercise versus a 'usual care' control group in patients with acute respiratory failure requiring mechanical ventilation in an intensive care unit (ICU).

METHODS AND ANALYSIS

In this multicentre, assessor-blinded, randomised controlled trial, we will randomise 142 patients in a 1:1 ratio to usual care (which commonly consists of minimal exercise and under-achievement of guideline-recommended caloric and protein intake goals) versus a combined intravenous amino acid supplementation and in-bed cycle ergometery exercise intervention. We hypothesise that this novel combined intervention will (1) improve physical functioning at hospital discharge; (2) reduce muscle wasting with improved amino acid metabolism and protein synthesis in-hospital and (3) improve patient-reported outcomes and healthcare resource utilisation at 6 months after enrolment. Key cointerventions will be standardised. In-hospital outcome assessments will be conducted at baseline, ICU discharge and hospital discharge. An intent-to-treat analysis will be used to analyse all data with additional per-protocol analyses.

ETHICS AND DISSEMINATION

The trial received ethics approval at each institution and enrolment has begun. These results will inform both clinical practice and future research in the area. We plan to disseminate trial results in peer-reviewed journals, at national and international conferences, and via nutritional and rehabilitation-focused electronic education and knowledge translation platforms.

TRIAL REGISTRATION NUMBER

NCT03021902; Pre-results.

Preserving the quality of life: nutrition in the ICU

Critically ill patients require adequate nutritional support to meet energy requirements both during and after intensive care unit (ICU) stay to protect against severe catabolism and prevent significant deconditioning. ICU patients often suffer from chronic critical illness causing an increase in energy expenditure, leading to proteolysis and related muscle loss. Careful supplementation and modulation of caloric and protein intake can avoid under- or overfeeding, both associated with poorer outcomes. Indirect calorimetry is the preferred method for assessing resting energy expenditure and the appropriate caloric and protein intake to counter energy and muscle loss. Physical exercise may have favorable effects on muscle preservation and should be considered even early in the hospital course of a critically ill patient. After liberation from the ventilator or during non-invasive ventilation, oral intake should be carefully evaluated and, in case of severe dysphagia, should be avoided and replaced by enteral of parenteral nutrition. Upon transfer from the ICU to the ward, adequate nutrition remains essential for long-term rehabilitation success and continued emphasis on sufficient nutritional supplementation in the ward is necessary to avoid a suboptimal nutritional state.

Do We Have Clinical Equipoise (or Uncertainty) About How Much Protein to Provide to Critically Ill Patients?

The current recommendation for protein dose in critically ill patients is 1.2-2.0 g/kg/d. Despite this recommendation, there is significant variation in the amount of protein prescribed and delivered worldwide. We contend clinical equipoise, or a state of genuine uncertainty about 2 (dosing) strategies, exists because guideline-based recommendations for protein dose in critically ill patients are rooted in a weak evidentiary base, leaving the clinician with no good basis for choosing a lower or higher protein dose. We outline evidence for and against high protein dose and introduce a pragmatic, registry-based, multicenter, randomized controlled trial, known as EFFORT, which aims to resolve the high vs low protein dose controversy.

Early Administration of Protein in Critically Ill Patients: A Retrospective Cohort Study

It is currently uncertain whether early administration of protein improves patient outcomes. We examined mortality rates of critically ill patients receiving early compared to late protein administration. This was a retrospective cohort study of mixed ICU patients receiving enteral or parenteral nutritional support. Patients receiving >0.7 g/kg/d protein within the first 3 days were considered the early protein group and those receiving less were considered the late protein group. The latter were subdivided into late-low group (LL) who received a low protein intake (<0.7 g/kg/d) throughout their stay and the late-high group (LH) who received higher doses (>0.7 g/kg/d) of protein following their first 3 days of admission. The outcome measure was all-cause mortality 60 days after admission. Of the 2253 patients included in the study, 371 (36%) in the early group, and 517 (43%) in the late-high group had died (p < 0.001 for difference). In multivariable Cox regression analysis, while controlling for confounders, early protein administration was associated with increased survival (HR 0.83, 95% CI 0.71–0.97, p = 0.017). Administration of protein early in the course of critical illness appears to be associated with improved survival in a mixed ICU population, even after adjusting for confounding variables.

Achieving protein targets without energy overfeeding in critically ill patients: A prospective feasibility study

BACKGROUND & AIMS

High protein delivery during early critical illness is associated with lower mortality, while energy overfeeding is associated with higher mortality. Protein-to-energy ratios of traditional enteral formulae are sometimes too low to reach protein targets without energy overfeeding. This prospective feasibility study aimed to evaluate the ability of a new enteral formula with a high protein-to-energy ratio to achieve the desired protein target while avoiding energy overfeeding.

METHODS

Mechanically ventilated non-septic patients received the high protein-to-energy ratio nutrition during the first 4 days of ICU stay (n = 20). Nutritional prescription was 90% of measured energy expenditure. Primary endpoint was the percentage of patients reaching a protein target of ≥1.2 g/kg ideal body weight on day 4. Other endpoints included a comparison of nutritional intake to matched historic controls and the response of plasma amino acid concentrations. Safety endpoints were gastro-intestinal tolerance and plasma urea concentrations.

RESULTS

Nineteen (95%) patients reached the protein intake target of ≥1.2 g/kg ideal body weight on day 4, compared to 65% in historic controls (p = 0.024). Mean plasma concentrations of all essential amino acids increased significantly from baseline to day 4. Predefined gastro-intestinal tolerance was good, but unexplained foul smelling diarrhoea occurred in two patients. In one patient plasma urea increased unrelated to acute kidney injury.

CONCLUSIONS

In selected non-septic patients tolerating enteral nutrition, recommended protein targets can be achieved without energy overfeeding using a new high protein-to-energy ratio enteral nutrition.

High protein intake during the early phase of critical illness: yes or no?

The rationale for the provision of nitrogen from proteins given via the enteral route or from intravenous amino acids is to boost the synthesis of muscle proteins, and thereby to limit the severity of intensive care unit-acquired weakness by the prevention of muscle loss. However, the optimal timing for supplemental nitrogen provision is a matter of debate and controversy. Indeed, consistent data from retrospective studies support an association between high early protein intakes and better outcomes, while recent post-hoc findings from prospective studies raise safety concerns. This pro–con paper details the arguments of both sides and highlights the need for large-scale prospective studies assessing the safety and efficacy of different levels of protein intake in combination with physical activity and summarizes the currently recruiting clinical trials.