Nutrition delivery and the relationship with changes in muscle mass in adult patients receiving extracorporeal membrane oxygenation: A retrospective observational study.

BACKGROUND: Adverse changes in muscle health (size and quality) are common in patients receiving extracorporeal membrane oxygenation (ECMO). Nutrition delivery may attenuate such changes, yet the relationship with muscle health remains poorly understood. This study explored the association between energy and protein delivery and changes in muscle health measured using ultrasound from baseline to day 10 and 20 in patients receiving ECMO. METHODS: A secondary analysis of data from a prospective study quantifying changes in muscle health using ultrasound in adults receiving ECMO was completed. Patients were eligible for inclusion if they were prescribed artificial nutrition within 3 days of enrolment and had >1 ultrasound measurement. The primary outcome was the association between protein delivery (grams delivered and percentage of targets received) and change in rectus femoris cross-sectional area (RF-CSA) till day 20. Secondary outcomes were the association between energy and protein delivery and change in RF-CSA till day 10, RF-echogenicity, and quadriceps muscle layer thickness to day 10 and 20. Associations were assessed using Spearman's rank correlation. RESULTS: Twenty-three patients (age: 48 [standard deviation {SD}: 14], 44% male) were included. Mean energy and protein delivery were 1633 kcal (SD: 374 kcal) and 70 g (SD: 17 g) equating to 79% (SD: 19%) of energy and 73% (SD: 17%) of protein targets. No association was observed between protein delivery (r = 0.167; p = 0.495) or the percentage of targets received (r = 0.096; p = 0.694) and change in RF-CSA till day 20. No other significant associations were found between energy or protein delivery and change in RF-CSA, echogenicity, or quadriceps muscle layer thickness at any time point. CONCLUSIONS: This exploratory study observed no association between nutrition delivery and changes in muscle health measured using ultrasound in patients receiving ECMO. Larger prospective studies are required to investigate the association between nutrition delivery and changes in muscle health in patients receiving ECMO.

Muscularity of older trauma patients at intensive care unit admission, association with functional outcomes, and relationship with frailty: A retrospective observational study.

BACKGROUND: Older individuals are at an increased risk of delayed recovery following a traumatic injury. Measurement of muscularity and frailty at hospital admission may aid with prognostication and risk stratification. OBJECTIVE: This study aimed to describe muscularity at intensive care unit (ICU) admission in patients admitted following trauma and assess the relationship between muscularity and clinical, long-term functional outcomes and frailty at ICU admission. METHODS: This retrospective study utilised data from a prospective observational study investigating frailty in patients aged ≥50 years, admitted to the ICU following trauma. Patients were eligible if they had a Computed Tomography (CT) scan including the third lumbar vertebra at ICU admission. Specialist software was used to quantify CT-derived skeletal muscle cross-sectional area. Muscularity status was classified as normal or low using published sex-specific cut-points. Demographic data, frailty, clinical, and long-term functional outcomes (Glasgow Outcome Scale-Extended and EQ-5DL-5L Visual analogue scale and utility score) were extracted from the original study. RESULTS: One hundred patients were screened; 71 patients had a CT scan on admission with 66 scans suitable for muscle assessment. Patients with low muscularity (n = 25, 38%) were older and had a higher Acute Physiology and Chronic Health Evaluation II score and lower body mass index than patients with normal muscularity. Low muscularity was associated with frailty at admission (32% vs 5%, p = 0.005) but not with long term outcomes at 6 or 12 months. As a continuous variable, lower muscle cross-sectional area was associated with a poorer outcome on the Glasgow Outcome Scale-Extended at 6 months (mean [standard deviation]: 150 [43] and 180 [44], respectively; p = 0.014), no association was observed after adjustment for age p = 0.43). CONCLUSION: In a population of older adults hospitalised following trauma, low muscularity at ICU admission was prevalent. Low muscularity was associated with frailty but not long-term functional outcomes. Larger studies are warranted to better understand the relationship between muscularity and long-term functional outcomes.

How do guideline recommended energy targets compare with measured energy expenditure in critically ill adults with obesity: A systematic literature review.

BACKGROUND: Critically ill patients with obesity have unique and complex nutritional needs, with clinical practice guidelines conflicting regarding recommended energy targets. The aim of this systematic review was to 1) describe measured resting energy expenditure (mREE) reported in the literature and; 2) compare mREE to predicted energy targets using the European (ESPEN) and American (ASPEN) guideline recommendations when indirect calorimetry is not available in critically ill patients with obesity. METHODS: The protocol was registered apriori and literature was searched until 17th March, 2022. Original studies were included if they reported mREE using indirect calorimetry in critically ill patients with obesity (BMI≥30 kg/m2). Group-level mREE data was reported as per the primary publication using mean ± standard deviation or median [interquartile range]. Where individual patient data was available, Bland-Altman analysis was used to assess mean bias (95% limits of agreement) between guideline recommendations and mREE targets (i.e. ASPEN for BMI 30-50, 11-14 kcal/kg actual weight compared to 70% mREE and ESPEN 20-25 kcal/kg adjusted weight compared to 100% mREE). Accuracy was assessed by the percentage (%) of estimates within ±10% of mREE targets. RESULTS: After searching 8019 articles, 24 studies were included. mREE ranged from 1607 ± 385 to 2919 [2318-3362]kcal and 12-32kcal/actual body weight. For the ASPEN recommendations of 11-14 kcal/kg, a mean bias of -18% (-50% to +13%) and 4% (-36% to +44%) was observed, respectively (n = 104). For the ESPEN recommendations 20-25 kcal/kg, a bias of -22% (-51% to +7%) and -4% (-43% to +34%), was observed, respectively (n = 114). The guideline recommendations were able to accurately predict mREE targets on 30%-39% occasions (11-14 kcal/kg actual) and 15%-45% occasions (20-25 kcal/kg adjusted), for ASPEN and ESPEN recommendations, respectively. CONCLUSIONS: Measured energy expenditure in critically ill patients with obesity is variable. Energy targets generated using predictive equations recommended in both the ASPEN and ESPEN clinical guidelines have poor agreement with mREE and are frequently not able to accurately predict within ±10% of mREE, most commonly underestimating energy needs.

Doubly labelled water for determining total energy expenditure in adult critically ill and acute care hospitalized inpatients: A scoping review.

BACKGROUND & AIMS: Doubly labelled water (DLW) is considered the reference standard method of measuring total energy expenditure (TEE), but there is limited information on its use in the Intensive Care Unit (ICU) and acute care setting. This scoping review aims to systematically summarize the available literature on TEE measured using DLW in these contexts. METHODS: Four online databases (MEDLINE, Embase, Emcare and CINAHL) were searched up to Dec 12, 2020. Studies in English were included if they measured TEE using DLW in adults in the ICU and/or acute care setting. Key considerations, concerns and practical recommendations were identified and qualitatively synthesized. RESULTS: The search retrieved 7582 studies and nine studies were included; one in the ICU and eight in the acute care setting. TEE was measured over 7-15-days, in predominantly clinically stable patients. DLW measurements were not commenced until four days post admission or surgery in one study and following a 10-14-day stabilization period on parenteral nutrition (PN) in three studies. Variable dosages of isotopes were administered, and several equations used to calculate TEE. Four main considerations were identified with the use of DLW in these settings: variation in background isotopic abundance; excess isotopes leaving body water as carbon dioxide or water; fluctuations in rates of isotope elimination and costs. CONCLUSION: A stabilization period on intravenous fluid and PN regimens is recommended prior to DLW measurement. The DLW technique can be utilized in medically stable ICU and acute care patients, with careful considerations given to protocol design.

Nutrition guidelines for critically ill adults admitted with COVID-19: Is there consensus?

INTRODUCTION: The Coronavirus Disease 2019 (COVID-19) pandemic has overwhelmed hospital systems globally, resulting in less experienced staff caring for critically ill patients within the intensive care unit (ICU). Many guidelines have been developed to guide nutrition care. AIM: To identify key guidelines or practice recommendations for nutrition support practices in critically ill adults admitted with COVID-19, to describe similarities and differences between recommendations, and to discuss implications for clinical practice. METHODS: A literature review was conducted to identify guidelines affiliated with or endorsed by international nutrition societies or dietetic associations which included recommendations for the nutritional management of critically ill adult patients with COVID-19. Data were extracted on pre-defined key aspects of nutritional care including nutrition prescription, delivery, monitoring and workforce recommendations, and key similarities and discrepancies, as well as implications for clinical practice were summarized. RESULTS: Ten clinical practice guidelines were identified. Similar recommendations included: the use of high protein, volume restricted enteral formula delivered gastrically and commenced early in ICU and introduced gradually, while taking into consideration non-nutritional calories to avoid overfeeding. Specific advice for patients in the prone position was common, and non-intubated patients were highlighted as a population at high nutritional risk. Major discrepancies included the use of indirect calorimetry to guide energy targets and advice around using gastric residual volumes (GRVs) to monitor feeding tolerance. CONCLUSION: Overall, common recommendations around formula type and route of feeding exist, with major discrepancies being around the use of indirect calorimetry and GRVs, which reflect international ICU nutrition guidelines.

Marked losses of computed tomography-derived skeletal muscle area and density over the first month of a critical illness are not associated with energy and protein delivery.

OBJECTIVES: Changes in muscularity during different phases of critical illness are not well described. This retrospective study aimed to describe changes in computed tomography (CT)-derived skeletal muscle area (SMA) and density (SMD) across different weeks of critical illness and investigate associations between changes in these parameters and energy and protein delivery. METHODS: Thirty-two adults admitted to the intensive care unit (ICU) who had ≥2 CT scans at the third lumbar area performed ≥7 d apart were included in the study. CT-derived SMA (cm2) and SMD (Hounsfield units) were determined using specialized software. A range of clinical and nutrition variables were collected for each day between comparator scans. Associations were assessed by Pearson or Spearman correlations. RESULTS: There was a significant decrease in SMA between the two comparator scans where the first CT scan was performed in ICU wk 1 (n = 20; P < .001), wk 2 (n = 11; P < .007), and wk 3 to 4 (n = 7; P = .012). There was no significant change in SMA beyond ICU wk 5 to 7 (P = .943). A significant decline in SMD was observed across the first 3 wk of ICU admission (P < .001). Overall, patients received a mean 24 ± 6 kcal energy/kg and 1.1 ± 0.4 g protein/kg per study day and 83% of energy and protein requirements according to dietitian estimates. No association between SMA or SMD changes and nutrition delivery were found. CONCLUSIONS: Critically ill patients experience marked losses of SMA over the first month of critical illness, attenuated after wk 5 to 7. Energy and protein delivery were not associated with degree of muscle loss.

Comparison of Ultrasound-Derived Muscle Thickness With Computed Tomography Muscle Cross-Sectional Area on Admission to the Intensive Care Unit: A Pilot Cross-Sectional Study.

INTRODUCTION: The development of bedside methods to assess muscularity is an essential critical care nutrition research priority. We aimed to compare ultrasound-derived muscle thickness at 5 landmarks with computed tomography (CT) muscle area at intensive care unit (ICU) admission. Secondary aims were to (1) combine muscle thicknesses and baseline covariates to evaluate correlation with CT muscle area and (2) assess the ability of the best-performing ultrasound model to identify patients with low CT muscle area. METHODS: Adult patients who underwent CT scanning at the third lumbar area <72 hours after ICU admission were prospectively recruited. Muscle thickness was measured at mid-upper arm, forearm, abdomen, and thighs. Low CT muscle area was determined using published cutoffs. Pearson correlation compared ultrasound-derived muscle thickness and CT muscle area. Linear regression was used to develop ultrasound prediction models. Bland-Altman analyses compared ultrasound-predicted and CT-measured muscle area. RESULTS: Fifty ICU patients were enrolled, aged 52 ± 20 years. Ultrasound-derived muscle thickness at each landmark correlated with CT muscle area (P < .001). The sum of muscle thickness at mid-upper arm and bilateral thighs, including age, sex, and the Charlson Comorbidity Index, improved the correlation with CT muscle area (r = 0.85; P < .001). Mean difference between ultrasound-predicted and CT-measured muscle area was -2 cm2 (95% limits of agreement, -40 cm2 to +36 cm2 ). The best-performing ultrasound model demonstrated good ability to identify 14 patients with low CT muscle area (area under curve = 0.79). CONCLUSION: Ultrasound shows potential for assessing muscularity at ICU admission (Clinicaltrials.gov NCT03019913).

Nutrition management of obese critically ill adults: A survey of critical care dietitians in Australia and New Zealand.

BACKGROUND: Guideline recommendations for nutrition therapy in critically ill obese adults are inconsistent. This study aimed to describe how dietitians working in an intensive care unit (ICU) in Australia and New Zealand (ANZ) approach managing the nutritional needs of an obese, critically ill adult. METHODS: Invitations to participate were via personal email communication. The survey was also disseminated through a research email list and a dietitian-based newsletter. The multiple-choice case-based survey consisted of 12 questions relating to nutrition prescription and were based on international nutrition guideline recommendations including (i) weight used in energy and protein predictive equations; (ii) energy and protein prescription at ICU admission and day 7, (iii) commencement of enteral nutrition, and; (iv) use of supplemental protein. Data are reported as n (%). RESULTS: Sixty-three dietitians participated in the survey. Most commonly, adjusted body weight calculated as 'weight at BMI 25 kg/m2 + 25% excess weight' was used in equations to guide energy (44 respondents, 70%) and protein (39 respondents, 62%) prescription. At day 1, energy and protein prescription was most commonly based on the European Society of Parenteral and Enteral Nutrition (ESPEN) guideline recommendation of 20-25 kcal/kg (39 respondents, 62%) and 1.3 g protein/kg adjusted body weight (36 respondents, 57%). Thirteen (21%) respondents had an indirect calorimetry device in their ICU to measure energy expenditure. On day 7, the ESPEN recommendations were again the most common method used for prescribing energy (30 respondents, 48%) and protein (23 respondents. 48%) needs. Thirty-eight dietitians (60%) reported they would use early supplemental protein to meet protein requirements. CONCLUSIONS: ICU dietitians in ANZ who responded to the survey most commonly report using the ESPEN ICU guideline recommendations (20-25 kcal/kg and 1.3 g protein/kg adjusted body weight) to guide nutrition prescription in an obese critically ill adult. Prospective studies are required to confirm these findings.

Nutrition therapy in critical illness: a review of the literature for clinicians.

Nutrition therapy during critical illness has been a focus of recent research, with a rapid increase in publications accompanied by two updated international clinical guidelines. However, the translation of evidence into practice is challenging due to the continually evolving, often conflicting trial findings and guideline recommendations. This narrative review aims to provide a comprehensive synthesis and interpretation of the adult critical care nutrition literature, with a particular focus on continuing practice gaps and areas with new data, to assist clinicians in making practical, yet evidence-based decisions regarding nutrition management during the different stages of critical illness.

Association of Energy and Protein Delivery on Skeletal Muscle Mass Changes in Critically Ill Adults: A Systematic Review.

Critically ill patients experience significant and rapid loss of skeletal muscle mass, which has been associated with negative clinical outcomes. The aetiology of muscle wasting is multifactorial and nutrition delivery may play a role. A systematic literature review was conducted to examine the association of energy and/or protein provision on changes in skeletal muscle mass in critically ill patients. Key databases were searched up until March 2016 to identify studies that measured skeletal muscle mass and/or total body protein (TBP) at 2 or more time points during acute critical illness (up to 2 weeks after an intensive care unit [ICU] stay). Studies were included if there was documentation of participant energy balance or mean energy delivered to participants during the time period between body composition measurements. Six studies met inclusion criteria. A variety of methods were used to assess skeletal muscle mass or TBP. Participants in included studies experienced differing levels of muscle loss (0%-22.5%) during the first 2 weeks of ICU admission. No association between energy and protein delivery and changes in skeletal muscle mass were observed. This review highlights that there is currently limited high-quality evidence to clearly define the association between energy and/or protein delivery and skeletal muscle mass changes in acute critical illness. Future studies in this area should be adequately powered, account for all potential confounding factors to changes in skeletal muscle mass, and detail all sources and quantities of energy and protein delivered to participants.