Comparison of energy intake in critical illness survivors, general medical patients, and healthy volunteers: A descriptive cohort study.

BACKGROUND: Intensive care unit (ICU) survivors have reduced oral intake; it is unknown whether intake and associated barriers are unique to this group. OBJECTIVE: To quantify energy intake and potential barriers in ICU survivors compared with general medical (GM) patients and healthy volunteers. DESIGN: A descriptive cohort study in ICU survivors, GM patients, and healthy volunteers. Following an overnight fast, participants consumed a 200 ml test-meal (213 kcal) and 180 min later an ad libitum meal to measure energy intake (primary outcome). Secondary outcomes; taste recognition, nutrition-impacting symptoms, malnutrition, and quality of life (QoL). Data are mean ± SD, median (interquartile range [IQR]) or number [percentage]). RESULTS: Twelve ICU survivors (57 ± 17 years, BMI: 30 ± 6), eight GM patients (69 ± 19 years, BMI: 30 ± 6), and 25 healthy volunteers (58 ± 27 years, BMI: 25 ± 4) were included. Recruitment ceased early because of slow recruitment and SARS-CoV-2. Energy intake was lower in both patient groups than in health (ICU: 289 [288, 809], GM: 426 [336, 592], health: 815 [654, 1165] kcal). Loss of appetite was most common (ICU: 78%, GM: 67%). For ICU survivors, GM patients and healthy volunteers, respectively, severe malnutrition prevalence; 40%, 14%, and 0%; taste identification; 8.5 [7.0, 11.0], 8.5 [7.0, 9.5], and 8.0 [6.0, 11.0]; and QoL; 60 [40-65], 50 [31-55], and 90 [81-95] out of 100. CONCLUSIONS: Energy intake at a buffet meal is lower in hospital patients than in healthy volunteers but similar between ICU survivors and GM patients. Appetite loss potentially contributes to reduced energy intake.

Observed differences in nutrition management at two time points spanning a decade in critically ill trauma patients with and without head injury.

BACKGROUND: Nutritional needs of trauma patients admitted to the intensive care unit may differ from general critically ill patients, but most current evidence is based on large clinical trials recruiting mixed populations. OBJECTIVE: The aim of the study was to investigate nutrition practices at two time points that span a decade in trauma patients with and without head injury. METHODS: This observational study recruited adult trauma patients receiving mechanical ventilation and artificial nutrition from a single-centre intensive care unit between February 2005 to December 2006 (cohort 1), and December 2018 to September 2020 (cohort 2). Patients were categorised into head injury and non-head injury subgroups. Data regarding energy and protein prescription and delivery were collected. Data are presented as median [interquartile range]. Wilcoxon rank-sum test assessed the differences between cohorts and subgroups, with a P value ≤ 0.05. The protocol was registered with the Australian and New Zealand Clinical Trials Registry (Trial ID: ACTRN12618001816246). RESULTS: Cohort 1 included 109 patients, and 112 patients were included in cohort 2 (age: 46 ± 19 vs 50 ± 19 y; 80 vs 79% M). Overall, nutrition practice did not differ between head-injured and non-head-injured subgroups (all P > 0.05). Energy prescription and delivery decreased from time point one to time point two, regardless of subgroup (Prescription: 9824 [8820-10 581] vs 8318 [7694-9071] kJ; Delivery: 6138 [5130-7188] vs 4715 [3059-5996] kJ; all P < 0.05). Protein prescription did not change from time point one to time point two. Although protein delivery remained constant from time point one to time point two in the head injury group, protein delivery reduced in the non-head injury subgroup (70 [56-82] vs 45 [26-64] g/d, P < 0.05). CONCLUSION: In this single-centre study, energy prescription and delivery in critically ill trauma patients reduced from time point one to time point two. Protein prescription did not change, but protein delivery reduced from time point one to time point two in non-head injury patients. Reasons for these differing trajectories require exploration. STUDY REGISTRATION: Trial registered at www.anzctr.org.au. TRIAL ID: ACTRN12618001816246.

Nutrition practices in critically ill adults receiving noninvasive ventilation: A quantitative survey of Australian and New Zealand intensive care clinicians.

BACKGROUND: Noninvasive ventilation (NIV) is frequently used in the intensive care unit (ICU), yet there is a paucity of evidence to guide nutrition management during this therapy. Understanding clinicians' views on nutrition practices during NIV will inform research to address this knowledge gap. OBJECTIVE: The objective of this study was to describe Australian and New Zealand clinicians' views and perceptions of nutrition management during NIV in critically ill adults. METHODS: A cross-sectional quantitative online survey of Australian and New Zealand medical and nursing staff with ≥12 months ICU experience was disseminated through professional organisations via purposive snowball sampling from 29 August to 9 October 2022. Data collection included demographics, current practices, and views and perceptions of nutrition during NIV. Surveys <50% complete were excluded. Data are represented in number (%). RESULTS: A total of 152 surveys were analysed; 71 (47%) nursing, 69 (45%) medical, and 12 (8%) not specified. There was limited consensus on nutrition management during NIV; however, most clinicians (n = 108, 79%) reported that nutrition during NIV was 'important or very important'. Oral intake was perceived to be the most common route (n = 83, 55%), and 29 (21%) respondents viewed this as the safest. Most respondents (n = 106, 78%) reported that ≤50% of energy targets were met, with gastric enteral nutrition considered most likely to meet targets (n = 55, 40%). Reported nutrition barriers were aspiration risk (n = 87, 64%), fasting for intubation (n = 84, 62%), and nutrition perceived as a lower priority (n = 73, 54%). Reported facilitators were evidence-based guidelines (n = 77, 57%) and an NIV interface compatible with enteral nutrition tube (n = 77, 57%). CONCLUSION: ICU medical and nursing staff reported nutrition during NIV to be important; however, there was a lack of consensus on the route of feeding considered to be the safest and most likely to achieve nutrition targets. Interventions to minimise aspiration and fasting, including an interface with nasoenteric tube compatibility, should be explored.

Nutrition delivery across hospitalisation in critically ill patients with COVID-19: An observational study of the Australian experience.

BACKGROUND: Data on nutrition delivery over the whole hospital admission in critically ill patients with COVID-19 are scarce, particularly in the Australian setting. OBJECTIVES: The objective of this study was to describe nutrition delivery in critically ill patients admitted to Australian intensive care units (ICUs) with coronavirus disease 2019 (COVID-19), with a focus on post-ICU nutrition practices. METHODS: A multicentre observational study conducted at nine sites included adult patients with a positive COVID-19 diagnosis admitted to the ICU for >24 h and discharged to an acute ward over a 12-month recruitment period from 1 March 2020. Data were extracted on baseline characteristics and clinical outcomes. Nutrition practice data from the ICU and weekly in the post-ICU ward (up to week four) included route of feeding, presence of nutrition-impacting symptoms, and nutrition support received. RESULTS: A total of 103 patients were included (71% male, age: 58 ± 14 years, body mass index: 30±7 kg/m2), of whom 41.7% (n = 43) received mechanical ventilation within 14 days of ICU admission. While oral nutrition was received by more patients at any time point in the ICU (n = 93, 91.2% of patients) than enteral nutrition (EN) (n = 43, 42.2%) or parenteral nutrition (PN) (n = 2, 2.0%), EN was delivered for a greater duration of time (69.6% feeding days) than oral and PN (29.7% and 0.7%, respectively). More patients received oral intake than the other modes in the post-ICU ward (n = 95, 95.0%), and 40.0% (n = 38/95) of patients were receiving oral nutrition supplements. In the week after ICU discharge, 51.0% of patients (n = 51) had at least one nutrition-impacting symptom, most commonly a reduced appetite (n = 25; 24.5%) or dysphagia (n = 16; 15.7%). CONCLUSION: Critically ill patients during the COVID-19 pandemic in Australia were more likely to receive oral nutrition than artificial nutrition support at any time point both in the ICU and in the post-ICU ward, whereas EN was provided for a greater duration when it was prescribed. Nutrition-impacting symptoms were common.

Nutrition practices in hospitalized adults receiving noninvasive forms of respiratory support: A scoping review.

The use of noninvasive respiratory support is increasing, with noninvasive ventilation (NIV) and high-flow nasal cannula providing unique barriers to nutrition support. Limited data related to nutrition management for these patients in the intensive care unit (ICU) exist; however, the literature in non-critically ill patients is not well described, and its improvement may help to inform practice within the ICU. Therefore, a scoping review was conducted of MEDLINE, EmCare, and Cumulative Index of Nursing and Allied Health Literature (CINAHL) databases on August 18, 2022, to identify original publications that included adult patients receiving noninvasive respiratory support in a hospital setting with data related to nutrition management. Data were extracted on study design, population, details of respiratory support, and concepts relating to nutrition management (grouped into nutrition screening, assessment, delivery route, intake, and anthropometry). Eleven studies were included, most of which were small (<100 patients), single-center, observational trials in patients receiving NIV only. Five studies reported results related to route of nutrition and nutrition assessment, two on anthropometry, and one each on quantifying intake and nutrition screening; some studies reported multiple parameters. There was a lack of consensus regarding the ideal method for nutrition assessment and route of nutrition. Oral nutrition was the route most frequently reported, yet calorie and protein delivery via this route were inadequate, and barriers to intake included poor appetite, fatigue, and patient cognition. Future research should address barriers pertinent to this population and the impact of nutrition on outcomes.

Dietary assessment methods for measurement of oral intake in acute care and critically ill hospitalised patients: a scoping review.

Quantification of oral intake within the hospital setting is required to guide nutrition care. Multiple dietary assessment methods are available, yet details regarding their application in the acute care setting are scarce. This scoping review, conducted in accordance with JBI methodology, describes dietary assessment methods used to measure oral intake in acute and critical care hospital patients. The search was run across four databases to identify primary research conducted in adult acute or critical care settings from 1st of January 2000-15th March 2023 which quantified oral diet with any dietary assessment method. In total, 155 articles were included, predominantly from the acute care setting (n = 153, 99%). Studies were mainly single-centre (n = 138, 88%) and of observational design (n = 135, 87%). Estimated plate waste (n = 59, 38%) and food records (n = 43, 28%) were the most frequent assessment methods with energy and protein the main nutrients quantified (n = 81, 52%). Validation was completed in 23 (15%) studies, with the majority of these using a reference method reliant on estimation (n = 17, 74%). A quarter of studies (n = 39) quantified completion (either as complete versus incomplete or degree of completeness) and four studies (2.5%) explored factors influencing completion. Findings indicate a lack of high-quality evidence to guide selection and application of existing dietary assessment methods to quantify oral intake with a particular absence of evidence in the critical care setting. Further validation of existing tools and identification of factors influencing completion is needed to guide the optimal approach to quantification of oral intake in both research and clinical contexts.

Characteristics, incidence, and outcomes of gastrointestinal complications post cardiac surgery in a quaternary referral centre: A retrospective study.

BACKGROUND: Gastrointestinal (GI) complications after cardiac surgery are associated with high morbidity and mortality. Early identification and treatment of GI complications could improve patient outcomes. OBJECTIVES: The objective of this study was to ascertain the incidence, risk factors, and clinical outcomes of GI complications following cardiac surgery. METHODS: A retrospective single-centre cohort study of adult patients undergoing cardiac surgery in an Australian quaternary cardiothoracic surgical referral centre was conducted from November 2012 to March 2020. Preoperative, intraoperative, and postoperative characteristics were compared between patients who did and did not develop GI complications. Data are presented as n (%). Between-group comparisons were analysed using Chi-square and Fisher's exact tests (where n < 6) for categorical variables and Wilcoxon rank-sum test for continuous variables. RESULTS: Of the 4417 patients who underwent cardiac surgery, 95 (2.2%) patients developed a total of 100 GI complications, with the most common being paralytic ileus (n = 22/100, 22%). Baseline characteristics and preoperative factors associated with GI complications included an age of >70 years (GI complication vs no GI complication: 55.8% vs 37.6%; p = 0.000), preexisting diabetes (49.5% vs 34.5%; p = 0.002), and a creatinine level >200 mcg/ml (11.6% vs 3.7%; p = 0.000). Intra-operative factors included a cardiopulmonary bypass time >120 min (28.4% vs 15.5%; p < 0.01). Postoperatively, developing a GI complication was associated with return to theatre (36.8% vs 13.9%; p < 0.01) and new stroke, pneumonia, and acute kidney injury (all p < 0.01). Patients with a GI complication had a higher intensive care unit and hospital mortality (7.4% vs 1.1%, and 13.6% vs 1.4%, respectively), and a longer intensive care unit and hospital stay (5.5 vs 2.3 days, and 24.0 vs 10.3 days). CONCLUSIONS: Multiple risk factors associated with GI complications in cardiac surgery patients were identified. These provide potential targets to support the early detection and management of GI complications to reduce morbidity and mortality in these patients.

Study protocol for TARGET protein: The effect of augmented administration of enteral protein to critically ill adults on clinical outcomes: A cluster randomised, cross-sectional, double cross-over, clinical trial.

Background: It is unknown whether increasing dietary protein to 1.2-2.0 g/kg/day as recommended in international guidelines compared to current practice improves outcomes in intensive care unit (ICU) patients. The TARGET Protein trial will evaluate this. Objective: To describe the study protocol for the TARGET Protein trial. Design setting and participants: TARGET Protein is a cluster randomised, cross-sectional, double cross-over, pragmatic clinical trial undertaken in eight ICUs in Australia and New Zealand. Each ICU will be randomised to use one of two trial enteral formulae for three months before crossing over to the other formula, which is then repeated, with enrolment continuing at each ICU for 12 months. All patients aged ≥16 years in their index ICU admission commencing enteral nutrition will be eligible for inclusion. Eligible patients will receive the trial enteral formula to which their ICU is allocated. The two trial enteral formulae are isocaloric with a difference in protein dose: intervention 100g/1000 ml and comparator 63g/1000 ml. Staggered recruitment commenced in May 2022. Main outcomes measures: The primary outcome is days free of the index hospital and alive at day 90. Secondary outcomes include days free of the index hospital at day 90 in survivors, alive at day 90, duration of invasive ventilation, ICU and hospital length of stay, incidence of tracheostomy insertion, renal replacement therapy, and discharge destination. Conclusion: TARGET Protein aims to determine whether augmented enteral protein delivery reduces days free of the index hospital and alive at day 90. Trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12621001484831).

A survey of Australian rheumatologists' perspectives of nutrition needs in systemic sclerosis.

Aim: Systemic sclerosis (scleroderma) is an incurable inflammatory condition synonymous with unique nutrition needs. As rheumatologists are frequently responsible for managing the various organ manifestations, this study aimed to understand the service needs and nutritional concerns of rheumatologists involved in the care of adults with systemic sclerosis. Methods: A 13-item online qualitative and quantitative survey was distributed via REDCap® from January to March 2022 to rheumatologists who are members of the Australian Scleroderma Interest Group and consult patients with systemic sclerosis. Data were collected on rheumatologists' demographics, and their views on symptoms observed, nutrition concerns and priorities, and preferred dietetic service provision for their patients. Data are reported as number (%). Results: Of 27 eligible rheumatologists, 17 (63%) completed the survey. All rheumatologists reported gastrointestinal symptoms in their patients (n = 17, 100%); predominantly reflux (n = 17, 100%) and dysphagia (n = 17, 100%). Weight loss was observed by the majority of rheumatologists (n = 15, 88%). Rheumatologists reported patients used food avoidance/special diets to manage symptoms (n = 12, 71%). Dietetic consultation was reported as potentially beneficial by all rheumatologists, with the preferred time being when symptoms increase or change (n = 15, 88%), and the preferred approaches being written resources (n = 15, 88%), face-to-face (n = 14, 82%) and telephone consultation (n = 14, 82%). Advice on gaining weight (n = 14, 82%) and systemic sclerosis symptom management (n = 13, 77%) were the most desired education topics reported. Conclusion: Rheumatologists commonly observe gastrointestinal symptoms in patients with systemic sclerosis and report dietetics services would be advantageous in supporting their patients to gain weight and better manage their symptoms.

Nutrition care processes across hospitalisation in critically ill patients with COVID-19 in Australia: A multicentre prospective observational study.

BACKGROUND: The COVID-19 pandemic highlighted major challenges with usual nutrition care processes, leading to reports of malnutrition and nutrition-related issues in these patients. OBJECTIVE: The objective of this study was to describe nutrition-related service delivery practices across hospitalisation in critically ill patients with COVID-19 admitted to Australian intensive care units (ICUs) in the initial pandemic phase. METHODS: This was a multicentre (nine site) observational study in Australia, linked with a national registry of critically ill patients with COVID-19. Adult patients with COVID-19 who were discharged to an acute ward following ICU admission were included over a 12-month period. Data are presented as n (%), median (interquartile range [IQR]), and odds ratio (OR [95% confidence interval {CI}]). RESULTS: A total of 103 patients were included. Oral nutrition was the most common mode of nutrition (93 [93%]). In the ICU, there were 53 (52%) patients seen by a dietitian (median 4 [2-8] occasions) and malnutrition screening occurred in 51 (50%) patients most commonly with the malnutrition screening tool (50 [98%]). The odds of receiving a higher malnutrition screening tool score increased by 36% for every screening in the ICU (1st to 4th, OR: 1.39 [95% CI: 1.05-1.77] p = 0.018) (indicating increasing risk of malnutrition). On the ward, 51 (50.5%) patients were seen by a dietitian (median time to consult: 44 [22.5-75] hours post ICU discharge). The odds of dietetic consult increased by 39% every week while on the ward (OR: 1.39 [1.03-1.89], p = 0.034). Patients who received mechanical ventilation (MV) were more likely to receive dietetic input than those who never received MV. CONCLUSIONS: During the initial phases of the COVID-19 pandemic in Australia, approximately half of the patients included were seen by a dietitian. An increased number of malnutrition screens were associated with a higher risk score in the ICU and likelihood of dietetic consult increased if patients received MV and as length of ward stay increased.

Nutrition management of critically ill adult patients requiring non-invasive ventilation: a scoping review protocol.

OBJECTIVE: This scoping review will identify the current available literature and key concepts in the nutrition management of critically ill adult patients requiring non-invasive ventilation. INTRODUCTION: Current international nutrition guidelines include recommendations for the nutrition management of critically ill patients who are receiving invasive mechanical ventilation; however, these guidelines do not address nutrition management of patients receiving non-invasive ventilation. This scoping review aims to explore and describe the existing available literature on the nutrition management of critically ill adults requiring non-invasive ventilation. INCLUSION CRITERIA: This review will consider original research (qualitative, quantitative, or mixed methods studies) reporting on any nutrition parameter for critically ill adult patients (≥16 years) requiring non-invasive ventilation in the intensive care unit. Concepts of interest based on the general intensive care nutrition literature include route of nutrition, recommendations related to macro- or micro-nutrients, nutrition provision, barriers to nutrition provision, and strategies for nutrition management. METHODS: This review will be conducted in accordance with JBI methodology for scoping reviews using a three-step search strategy. MEDLINE, Embase, Scopus, and Web of Science will be searched to obtain original research available in English and published after 1990. Google Scholar will be searched for gray literature. Duplicates will be removed and studies will be selected by two independent reviewers based on the inclusion criteria. The same two reviewers will extract data in duplicate using a data extraction tool. Any disagreements will be resolved via consensus with a third reviewer. Data extraction will be synthesized in tabular and diagrammatic format.

Muscle size, strength, and physical function in response to augmented calorie delivery: A TARGET sub-study.

PURPOSE: Augmented calories may attenuate muscle loss experienced in critical illness. This exploratory sub-study assessed the effect of augmented calorie delivery on muscle mass, strength, and function. MATERIALS AND METHODS: Patients in The Augmented versus Routine approach to Giving Energy Trial (TARGET) randomised to 1.5 kcal/ml or 1.0 kcal/ml enteral formulae at a single-centre were included. Ultrasound-derived muscle layer thickness (MLT) at quadriceps, forearm and mid-upper arm, and handgrip strength, were measured weekly from baseline to hospital discharge, and 3- and 6-months. Physical function was assessed at 3- and 6-months using the 'get up and go' and 6-min walk tests. Data are mean ± SD. RESULTS: Eighty patients were recruited (1.5 kcal: n = 38, 58 ± 14y, 60%M, APACHE II 20 ± 7; 1.0 kcal: n = 42, 54 ± 18y, 66%M, APACHE II 22 ± 10). The 1.5 kcal/ml group received more calories with no difference in quadriceps MLT at any timepoint including ICU discharge (primary outcome) (2.90 ± 1.27 vs 2.39 ± 1.06 cm; P = 0.141). Relationships were similar for all MLT measures, handgrip strength, and 6-min walk test. Patients in the 1.5 kcal/ml group had improved 'get up and go' test at 3-months (6.66 ± 1.33 vs. 9.11 ± 2.94 s; P = 0.014). CONCLUSION: Augmented calorie delivery may not attenuate muscle loss or recovery of strength or function 6-months post-ICU, but this requires exploration in a larger trial.

Higher versus lower enteral calorie delivery and gastrointestinal dysfunction in critical illness: A systematic review and meta-analysis.

BACKGROUND AND AIMS: In critical illness, enteral nutrition (EN) is frequently limited by gastrointestinal (GI) dysfunction. The aim of this systematic review and meta-analysis was to determine relationships between enteral calorie delivery and GI dysfunction in critically ill adults. METHODS: MEDLINE, EMCARE, EMBASE, and CINAHL databases were searched from 1 January 2000 to 11 August 2021 to identify parallel group randomised controlled trials of an EN intervention that resulted in a significant difference in calorie delivery between groups and reported at least one outcome relating to GI dysfunction. Study groups were categorised as 'higher' or 'lower' calorie delivery and data were extracted on study interventions, GI dysfunction and clinical outcomes. Extracted data were aggregated using a random effects model and presented as risk ratio with 95% confidence intervals. A P-value <0.05 was considered significant. The risk of publication bias was assessed graphically using a funnel plot. RESULTS: From 13 studies involving 6824 patients the mean calorie delivery in the higher calorie group was 1673 ± 468 kcal/day compared to 1121 ± 312 kcal/day in the lower calorie group. The higher calorie group had an increased risk of a large (any volume ≥300 ml) gastric residual volume (GRV) (RR 1.40; 95% CI 1.09, 1.80; P = 0.009) and prokinetic administration (RR 1.18; 95% CI 1.11, 1.27; P < 0.00001). There were no between group differences in the presence of vomiting/regurgitation (RR 0.93; 95% CI 0.58, 1.49; P = 0.76), diarrhoea (RR 1.12; 95% CI 0.93, 1.35; P = 0.22) or abdominal distension (RR 0.71; 95% CI 0.49, 1.04; P = 0.08). There was no evidence of publication bias. CONCLUSION: Higher calorie delivery is associated with increased rates of GRV≥300 ml and prokinetic administration, but not vomiting/regurgitation, diarrhoea or abdominal distension. OTHER: No funding was received for the conduct of this systematic review and meta-analysis. The protocol was prospectively registered with PROSPERO (CRD42021268876).

Attenuating Muscle Mass Loss in Critical Illness: the Role of Nutrition and Exercise.

PURPOSE OF REVIEW: Impaired recovery following an intensive care unit (ICU) admission is thought related to muscle wasting. Nutrition and physical activity are considered potential avenues to attenuate muscle wasting. The aim of this review was to present evidence for these interventions in attenuating muscle loss or improving strength and function. RECENT FINDINGS: Randomised controlled trials on the impact of nutrition or physical activity interventions in critically ill adult patients on muscle mass, strength or function are presented. No nutrition intervention has shown an effect on strength or function, and the effect on muscle mass is conflicting. RCTs on the effect of physical activity demonstrate conflicting results; yet, there is a signal for improved strength and function with higher levels of physical activity, particularly when commenced early. Further research is needed to elucidate the impact of nutrition and physical activity on muscle mass, strength and function, particularly in combination.

Methodological Rigor and Transparency in Clinical Practice Guidelines for Nutrition Care in Critically Ill Adults: A Systematic Review Using the AGREE II and AGREE-REX Tools.

Background: To evaluate the methodological quality of (1) clinical practice guidelines (CPGs) that inform nutrition care in critically ill adults using the AGREE II tool and (2) CPG recommendations for determining energy expenditure using the AGREE-REX tool. Methods: CPGs by a professional society or academic group, intended to guide nutrition care in critically ill adults, that used a systematic literature search and rated the evidence were included. Four databases and grey literature were searched from January 2011 to 19 January 2022. Five investigators assessed the methodological quality of CPGs and recommendations specific to energy expenditure determination. Scaled domain scores were calculated for AGREE II and a scaled total score for AGREE-REX. Data are presented as medians (interquartile range). Results: Eleven CPGs were included. Highest scoring domains for AGREE II were clarity of presentation (82% [76-87%]) and scope and purpose (78% [66-83%]). Lowest scoring domains were applicability (37% [32-42%]) and stakeholder involvement (46% [33-51%]). Eight (73%) CPGs provided recommendations relating to energy expenditure determination; scores were low overall (37% [36-40%]) and across individual domains. Conclusions: Nutrition CPGs for critically ill patients are developed using systematic methods but lack engagement with key stakeholders and guidance to support application. The quality of energy expenditure determination recommendations is low.

Protein metabolism in critical illness.

PURPOSE OF REVIEW: Critically ill patients experience skeletal muscle wasting that may contribute to the profound functional deficits in those that survive the initial injury. Augmented protein delivery has the potential to attenuate muscle loss, yet the ability for dietary protein to improve patient outcomes is reliant on effective protein metabolism. This review will discuss the recent literature on protein delivery and digestion, amino acid absorption, and muscle protein synthesis (MPS) in critically ill adults. RECENT FINDINGS: Critically ill patients are prescribed protein doses similar to international recommendations, yet actual delivery remains inadequate. The majority of trials that have achieved higher protein doses have observed no effect on muscle mass, strength or function. Critically ill patients have been observed to have minimal deficits in protein digestion and amino acid absorption when delivery bypasses the stomach, yet postprandial MPS is impaired. However, the literature is limited due to the complexities in the direct measurement of protein handling. SUMMARY: Postprandial MPS is impaired in critically ill patients and may exacerbate muscle wasting experienced by these patients. Studies in critically ill patients require assessment not only of protein delivery, but also utilization prior to implementation of augmented protein doses.

Muscle Protein Synthesis after Protein Administration in Critical Illness.

Rationale: Dietary protein may attenuate the muscle atrophy experienced by patients in the ICU, yet protein handling is poorly understood. Objectives: To quantify protein digestion and amino acid absorption and fasting and postprandial myofibrillar protein synthesis during critical illness. Methods: Fifteen mechanically ventilated adults (12 male; aged 50 ± 17 yr; body mass index, 27 ± 5 kg⋅m-2) and 10 healthy control subjects (6 male; 54 ± 23 yr; body mass index, 27 ± 4 kg⋅m-2) received a primed intravenous L-[ring-2H5]-phenylalanine, L-[3,5-2H2]-tyrosine, and L-[1-13C]-leucine infusion over 9.5 hours and a duodenal bolus of intrinsically labeled (L-[1-13C]-phenylalanine and L-[1-13C]-leucine) intact milk protein (20 g protein) over 60 minutes. Arterial blood and muscle samples were taken at baseline (fasting) and for 6 hours following duodenal protein administration. Data are mean ± SD, analyzed with two-way repeated measures ANOVA and independent samples t test. Measurements and Main Results: Fasting myofibrillar protein synthesis rates did not differ between ICU patients and healthy control subjects (0.023 ± 0.013% h-1 vs. 0.034 ± 0.016% h-1; P = 0.077). After protein administration, plasma amino acid availability did not differ between groups (ICU patients, 54.2 ± 9.1%, vs. healthy control subjects, 61.8 ± 13.1%; P = 0.12), and myofibrillar protein synthesis rates increased in both groups (0.028 ± 0.010% h-1 vs. 0.043 ± 0.018% h-1; main time effect P = 0.046; P-interaction = 0.584) with lower rates in ICU patients than in healthy control subjects (main group effect P = 0.001). Incorporation of protein-derived phenylalanine into myofibrillar protein was ∼60% lower in ICU patients (0.007 ± 0.007 mol percent excess vs. 0.017 ± 0.009 mol percent excess; P = 0.007). Conclusions: The capacity for critically ill patients to use ingested protein for muscle protein synthesis is markedly blunted despite relatively normal protein digestion and amino acid absorption.

Gastrointestinal dysfunction during enteral nutrition delivery in intensive care unit (ICU) patients: Risk factors, natural history, and clinical implications. A post-hoc analysis of The Augmented versus Routine approach to Giving Energy Trial (TARGET).

BACKGROUND: Slow gastric emptying occurs frequently during critical illness and is roughly quantified at bedside by large gastric residual volumes (GRVs). A previously published trial (The Augmented versus Routine approach to Giving Energy Trial; TARGET) reported larger GRVs with energy-dense (1.5 kcal/mL) compared with standard (1.0 kcal/mL) enteral nutrition (EN), warranting further exploration. OBJECTIVE: To assess the incidence, risk factors, duration, and timing of large GRVs (≥250 mL) and its relation to clinical outcomes in mechanically ventilated adults. METHODS: A post-hoc analysis of TARGET data in patients with ≥1 GRV recorded. Data are n (%) or median [IQR]. RESULTS: Of 3876 included patients, 1777 (46%) had ≥1 GRV ≥250 mL, which was more common in males (50 compared with 39%; P < 0.001) and in patients receiving energy-dense compared with standard EN (52 compared with 40%; RR = 1.27 (95% CI: 1.19, 1.36); P < 0.001) in whom it also lasted longer (1 [0-2] compared with 0 [0-1] d; P < 0.001), with no difference in time of onset after EN initiation (day 1 [0-2] compared with 1 [0-2]; P = 0.970). Patients with GRV ≥250 mL were more likely to have the following: vasopressor administration (88 compared with 76%; RR = 1.15 [1.12, 1.19]; P < 0.001), positive blood cultures (16 compared with 8%; RR = 1.92 [1.60, 2.31]; P < 0.001), intravenous antimicrobials (88 compared with 81%; RR = 1.09 [1.06, 1.12]; P < 0.001), and prolonged intensive care unit (ICU) stay (ICU-free days to day 28; 12.9 [0.0-21.0] compared with 20.0 [3.9-24.0]; P < 0.001), hospital stay (hospital-free days to day 28: 0.0 [0.0-12.0] compared with 7.0 [0.0-17.6] d; P < 0.001), ventilatory support (ventilator-free days to day 28: 16.0 [0.0-23.0] compared with 22.0 [8.0-25.0]; P < 0.001), and a higher 90-d mortality (29 compared with 23%; adjusted: RR = 1.17 [1.05, 1.30]; P = 0.003). CONCLUSION: Large GRVs were more common in males and those receiving energy-dense formulae, occurred early and were short-lived, and were associated with a number of negative clinical sequelae, including increased mortality, even when adjusted for illness severity. This trial was registered at clinicaltrials.gov as NCT02306746.