Prevalence of Underprescription or Overprescription of Energy Needs in Critically Ill Mechanically Ventilated Adults as Determined by Indirect Calorimetry: A Systematic Literature Review

Longitudinal analysis of caloric requirements in critically ill trauma patients: a retrospective cohort study

PURPOSE

Nutrition is of paramount importance in critically ill trauma patients. However, adequate supply is difficult to achieve, as caloric requirements are unknown. This study investigated caloric requirements over time, based on indirect calorimetry, in critically ill trauma patients.

METHODS

Retrospective cohort study at a tertiary trauma center including critically ill trauma patients who underwent indirect calorimetry 2012-2019. Caloric requirements were assessed as resting energy expenditure (REE) during the intensive care unit stay up to 28 days and analyzed in patient-clustered linear regression analysis.

RESULTS

A total of 129 patients were included. Median REE per day was 2376 kcal. The caloric intake did not meet REE at any time with a median daily deficit of 1167 kcal. In univariable analysis, ISS was not significantly associated with REE over time (RC 0.03, p = 0.600). Multivariable analysis revealed a significant REE increase (RC 0.62, p < 0.001) and subsequent decrease (RC - 0.03, p < 0.001) over time. Age < 65 years (RC 2.07, p = 0.018), male sex (RC 4.38, p < 0.001), and BMI ≥ 35 kg/m2 (RC 6.94, p < 0.001) were identified as independent predictors for higher REE over time. Severe head trauma was associated with lower REE over time (RC - 2.10, p = 0.030).

CONCLUSION

In critically ill trauma patients, caloric requirements significantly increased and subsequently decreased over time. Younger age, male sex and higher BMI were identified as independent predictors for higher caloric requirements, whereas severe head trauma was associated with lower caloric requirements over time. These results support the use of IC and will help to adjust nutritional support in critically ill trauma patients.

Effects of Energy Delivery Guided by Indirect Calorimetry in Critically Ill Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The utility of using indirect calorimetry (IC) to estimate energy needs and methods for its application to this purpose remain unclear. This systematic review investigated whether using IC to estimate energy expenditure in critically ill patients is more meaningful for improving survival than other estimation methods.

METHODS

Comprehensive searches were conducted in MEDLINE using PubMed, Cochrane Central Register of Controlled Trials, and Igaku-Chuo-Zasshi up to March 2023.

RESULTS

Nine RCTs involving 1178 patients were included in the meta-analysis. The evidence obtained suggested that energy delivery by IC improved short-term mortality (risk ratio, 0.86; 95% confidence interval [CI], 0.70 to 1.06). However, the use of IC did not appear to affect the length of ICU stay (mean difference [MD], 0.86; 95% CI, -0.98 to 2.70) or the duration of mechanical ventilation (MD, 0.66; 95% CI, -0.39 to 1.72). Post hoc analyses using short-term mortality as the outcome found no significant difference by target calories in resting energy expenditure, whereas more frequent IC estimates were associated with lower short-term mortality and were more effective in mechanically ventilated patients.

CONCLUSIONS

This updated meta-analysis revealed that the use of IC may improve short-term mortality in patients with critical illness and did not increase adverse events.

Smartfeeding: A Dynamic Strategy to Increase Nutritional Efficiency in Critically Ill Patients-Positioning Document of the Metabolism and Nutrition Working Group and the Early Mobilization Working Group of the Catalan Society of Intensive and Critical Care Medicine (SOCMiC)

Adequate medical nutrition therapy for critically ill patients has an impact on their prognoses. However, it requires an individualized approach that takes into account the activity (phases of metabolic stress) and particularity of these patients. We propose a comprehensive strategy considering the patients' nutritional status and the set of modifiable circumstances in these patients, in order to optimize/support nutritional efficiency: (1) A detailed anamnesis and an adequate initial nutritional assessment must be performed in order to implement medical nutrition therapy that is in line with the needs and characteristics of each patient. Furthermore, risks associated with refeeding syndrome, nutritrauma or gastrointestinal dysfunction must be considered and prevented. (2) A safe transition between nutrition therapy routes and between health care units will greatly contribute to recovery. The main objective is to preserve lean mass in critically ill patients, considering metabolic factors, adequate protein intake and muscle stimulation. (3) Continuous monitoring is required for the successful implementation of any health strategy. We lack precise tools for calculating nutritional efficiency in critically ill patients, therefore thorough monitoring of the process is essential. (4) The medical nutrition approach in critically ill patients is multidisciplinary and requires the participation of the entire team involved. A comprehensive strategy such as this can make a significant difference in the functional recovery of critically ill patients, but leaders must be identified to promote training, evaluation, analysis and feedback as essential components of its implementation, and to coordinate this process with the recognition of hospital management.

Clinical practice guidelines for nutritional assessment and monitoring of adult ICU patients in China

The Chinese Society of Critical Care Medicine (CSCCM) has developed clinical practice guidelines for nutrition assessment and monitoring for patients in adult intensive care units (ICUs) in China. This guideline focuses on nutrition evaluation and metabolic monitoring to achieve optimal and personalized nutrition therapy for critically ill patients. This guideline was developed by experts in critical care medicine and evidence-based medicine methodology and was developed after a thorough review of the system and a summary of relevant trials or studies published from 2000 to July 2023. A total of 18 recommendations were formed and consensus was reached through discussions and reviews by expert groups in critical care medicine, parenteral and enteral nutrition, and surgery. The recommendations are based on currently available evidence and cover several key fields, including screening and assessment, evaluation and assessment of enteral feeding intolerance, metabolic and nutritional measurement and monitoring during nutrition therapy, and organ function evaluation related to nutrition supply. Each question was analyzed according to the Population, Intervention, Comparison, and Outcome (PICO) principle. In addition, interpretations were provided for four questions that did not reach a consensus but may have potential clinical and research value. The plan is to update this nutrition assessment and monitoring guideline using the international guideline update method within 3-5 years.

Measurement and estimation of energy in the critically ill

PURPOSE OF REVIEW

Recent changes in guidelines recommendation during early phase of critical illness and use of indirect calorimetry. The aim of this review is to discuss methods of determining energy requirements in the critically ill and highlight factors impacting resting energy expenditure.

RECENT FINDING

An appraisal of recent literature discussing indirect calorimetry guided-nutrition potential benefits or pitfalls. Recent attempts to devise strategy and pilot indirect calorimetry use in the critically ill patients requiring continuous renal replacement therapy or extracorporeal membrane oxygenation are also discussed. Additionally, we briefly touched on variability between guidelines recommended energy target and measured energy expenditure for adult critically ill patients with obesity.

SUMMARY

While energy requirement in the critically ill continues to be an area of controversy, recent guidelines recommendations shift toward providing less aggressive calories during acute phase of illness in the first week of ICU.Use of indirect calorimetry may provide more accurate energy target compared to the use of predictive equations. Despite the absence of literature to support long term mortality benefits, there are many potential benefits for the use of indirect calorimetry when available.

Association between energy surplus and intensive care unit length of stay in critically ill patients: A retrospective cohort study

BACKGROUND

Patients experiencing persistent critical illness have poor short-term and long-term outcomes and consume disproportionate amounts of health care resources. Nutrition optimization may improve outcomes, though few data exist on resting energy expenditure and nutrition requirements. We hypothesized that increased energy surplus per day is associated with increased intensive care unit (ICU) length of stay (LoS) in critically ill patients.

METHODS

Patients from a single ICU at Royal London Hospital were included in this retrospective cohort study.

EXPOSURE

energy surplus measured by serial indirect calorimetry (IC) and nutrition intake.

INCLUSION CRITERIA

mechanical ventilation of ≥3 days and expected to remain ventilated.

PRIMARY OUTCOME

ICU LoS.

RESULTS

Across 30 patients (median LoS 21 days), increased ICU LoS was associated with actual daily energy intake surplus to resting energy expenditure (REE) (R2 0.16; P < 0.005). Median REE was less than predicted energy requirements: 24 kcal per day per kilogram of ideal body weight (IBW) (interquartile range [IQR], 20-28) vs 28 kcal/day/kg IBW (IQR, 26-29) (P < 0.001). Patients with COVID-19 had a median energy surplus (actual intake- REE) + 344 kcal/day (IQR 35-517) vs -57 kcal/day (IQR -324 to 211) in other patients (P = 0.011); however, they had a median LoS of 44 days (IQR 26-58) vs 10 days (IQR 7-24), respectively (P < 0.001). Patients with obesity had a median energy deficit of -32 kcal/day (IQR -384 to 335) vs +234 kcal/day (IQR -79 to 499) for nonobese patients (P = 0.021).

CONCLUSION

Overfeeding represents an easily modifiable factor to improve outcomes in patients experiencing persistent critical illness, for which IC may be useful.

Very low-calorie ketogenic diet in the treatment of adaptive thermogenesis: A case report

OBJECTIVES

The management of the phenomenon of adaptive thermogenesis poses a challenge to the successful treatment of overweight/obesity with a nutritional intervention that minimizes the loss of muscle mass, with little cognitive restraint use and disorganization of eating behavior. On the other hand, it creates a significant calorie deficit for the reduction of body fat. The aim of this case report was to discuss the effects of a very low-calorie ketogenic diet in a woman with obesity and low resting metabolic rate.

CASE DESCRIPTION

A 36-y-old white woman with a history of obesity and bulimia nervosa who has had difficulty losing and maintaining weight despite numerous dietary and pharmacologic treatments.

RESULTS

There was a loss of 12 kg in 115 d, reaching 13.4 kg, with 11.4 kg of fat mass (FM). The resting metabolic rate showed an increase of 79% in relation to the initial rate, reaching normal levels for the predictive equations and maintaining this level in the first-year follow-up. Additionally, improvement of metabolic laboratory parameters and eating behavior traits were described.

CONCLUSIONS

In this specific case of bulimia nervosa resulting in hypometabolism (low resting metabolic rate/fat-free mass) and obesity, the very low-calorie ketogenic diet intervention has demonstrated a possibility of weight loss with little cognitive restraint use, thereby increasing resting metabolic rate in the short and medium terms, ultimately promoting a negative energy balance. In relation to the numeric results, it seems positive; however, more research is necessary to evaluate the effects on the overall relationship with food and its long-term repercussions.

Comparison of predictive equations and indirect calorimetry in critical care: Does the accuracy differ by body mass index classification?

BACKGROUND

Nutrition support professionals are tasked with estimating energy requirements for critically ill patients. Estimating energy leads to suboptimal feeding practices and adverse outcomes. Indirect calorimetry (IC) is the gold standard for determining energy expenditure. However, access is limited, so clinicians must rely on predictive equations.

METHODS

A retrospective chart review of critically ill patients who underwent IC in 2019 was conducted. The Mifflin-St Jeor equation (MSJ), Penn State University equation (PSU), and weight-based nomograms were calculated using admission weights. Demographic, anthropometric, and IC data were extracted from the medical record. Data were stratified by body mass index (BMI) classifications, and relationships between estimated energy requirements and IC were compared.

RESULTS

Participants (N = 326) were included. Median age was 59.2 years, and BMI was 30.1. The MSJ and PSU were positively correlated with IC in all BMI classes (all P < 0.001). Median measured energy expenditure was 2004 kcal/day, which was 1.1-fold greater than PSU, 1.2-fold greater than MSJ, and 1.3-fold greater than weight-based nomograms (all P < 0.001).

CONCLUSION

Despite the significant relationships between measured and estimated energy requirements, the significant fold-differences suggest that using predictive equations leads to significant underfeeding, which may result in poor clinical outcomes. Clinicians should rely on IC when available, and increased training in the interpretation of IC is warranted. In the absence of IC, the use of admission weight in weight-based nomograms could serve as a surrogate, as these calculations provided the closest estimate to IC in participants with normal weight and overweight, but not obesity.

ESPEN practical and partially revised guideline: Clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous 2019 guideline to provide best medical nutritional therapy to critically ill patients has been shortened and partially revised. Following this update, we propose this publication as a practical guideline based on the published scientific guideline, but shortened and illustrated by flow charts. The main goal of this practical guideline is to increase understanding and allow the practitioner to implement the Nutrition in the ICU guidelines. All the items discussed in the previous guidelines are included as well as special conditions.

Modified indirect calorimetry for patients on venoarterial extracorporeal membrane oxygenation: a pilot feasibility study

BACKGROUND/OBJECTIVES

Traditional indirect calorimetry is unable to capture complete gas exchange in patients receiving venoarterial extracorporeal membrane oxygenation (VA ECMO). We aimed to determine the feasibility of using a modified indirect calorimetry protocol in patients receiving VA ECMO, report measured energy expenditure (EE) and compare EE to control critically ill patients.

SUBJECTS/METHODS

Mechanically ventilated adult patients receiving VA ECMO were included. EE was measured within 72 h of VA ECMO commencement (timepoint one [T1]) and on approximately day seven of Intensive Care Unit (ICU) admission (timepoint two [T2]). Traditional indirect calorimetry via the ventilator was combined with calculations of oxygen consumption and carbon dioxide production derived from pre- and post-ECMO membrane blood gas analyses. Completion of ≥60% EE measurements was deemed feasible. Measured EE was compared between T1 and T2 and to control patients not receiving VA ECMO. Data is presented as n(%) and median[interquartile range (IQR)].

RESULTS

Twenty-one patients were recruited; 16(76%) male, aged 55[42-64] years. The protocol was feasible to complete at T1 (14(67%)) but not at T2 (7(33%)) due to predominantly ECMO decannulation, extubation or death. EE was 1454[1213-1860] at T1 and 1657[1570-2074] kcal/d at T2 (P = 0.043). In patients receiving VA ECMO versus controls, EE was 1577[1434-1801] versus 2092[1609-2272] kcal/d, respectively (P = 0.056).

CONCLUSION

Modified indirect calorimetry is feasible early in admission to ICU but is not possible in all patients receiving VA ECMO, especially later in admission. EE increases during the first week of ICU admission but may be lower than EE in control critically ill patients.

Comparison of resting energy expenditure measured with metabolic cart and calculated with predictive formulas in critically ill patients on mechanical ventilation

INTRODUCTION

The purpose was to compare the resting energy expenditure (REE) measured with the Q-NRG™+ metabolic-cart (MREE) with REE predicted by equations (the Harris-Benedict formula and an equation developed in ward, REE-HB and REE-W, respectively). We also aimed to assess the agreement of the measurements of oxygen consumption (V̇O₂) and carbon dioxide production (V̇CO₂) at different inspired fractions of oxygen (FiO₂).

METHODS

27 mechanically ventilated ICU patients were enrolled. V̇O₂ and V̇CO₂ were measured by Q-NRG™+ during breathing 40% and 60% FiO₂. MREE was compared with REE-W and REE-HB normalized for body weight.

RESULTS

V̇O₂ was 233.0 (95.2) ml/min and 217.5 (89.8) ml/min at FiO₂ 40% and 60%, respectively (NS). V̇CO₂ was 199.0 (91.7) ml/min at FiO₂ 40%, and 197.5 (85.5) ml/min at FiO₂ 60% (NS). The REE estimated from the equations was significantly different from the MREE. The best agreement was found for the Harris-Benedict equation without correction for stress-factors. Harris-Benedict equation corrected overestimates REE.

CONCLUSIONS

This new metabolic cart Q-NRG™+ provides a concordance of values for V̇O₂ and V̇CO₂ when measured at different FiO₂, and is a reliable tool for estimating energy expenditure and assessing the nutritional needs of the patient. This study demonstrates that the estimation of REE using predictive formulas does not allow accurate calculation of metabolic demands in ventilated intensive care patient. However, predictive equations allow for a rapid assessment of REE and calculation of the amount of energy derived from different substrates.

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.

Accuracy of predictive equations for resting energy expenditure estimation in mechanically ventilated Thai patients

Background

Indirect calorimetry (IC) is the most precise approach for estimating calorie demand in critically ill patients. Despite this, owing to unaffordable devices, it is rarely used in practice. Predictive equations are the alternatives.

Objectives

To assess the accuracy of 14 predictive resting energy expenditure(REE) equations in ventilated Thai patients.

Methods

We compared the accuracy and agreement of 14 equations. The equations included the American College of Chest Physicians(ACCP) equation, Harris-Benedict equation(HBE), 1.2×HBE, 1.5×HBE, Mifflin-St. Jeor(MSJ), Ireton-Jones 1992 and 2002, Penn State 2003(HBE and MSJ) and 2010, Swinamer 1990, Faisy, Brandi 1999, and 25 kcal/kg equation. An equation was ascertained as accurate if the calculated values fell within ±10% of the measured REEs. Spearman correlation coefficient, Bland-Altman method, and intraclass correlation coefficient were used to analysis.

Results

We obtained data from 24 ventilated patients undergoing REE measurement by IC. Fifty percent of them were male with a median age of 64.5 years, a median height of 160 cm, and a median body mass index of 22.95 kg/m2. The predictive precision of all equations was poor, with largely different accuracies from 6.7% to 48.1%. The most reliable equation was Penn State 2010. The ACCP, HBE, MSJ, and Penn State 2003(HBE) tended to underestimate calorie need. Contrastingly, the other equations tended to overestimate REEs. Despite a moderate degree of correlations, the Bland-Altman plots demonstrated clinically unacceptable discrepancies between measured REE and REE calculated by each equation.

Conclusions

In ventilated Thai patients, there were no precise equations for determining REE.

The Role of Indirect Calorimetry in Care of the Surgical Patient

Purpose of Review

This is a review of recent literature on the role of indirect calorimetry in surgical nutrition.

Recent Findings

All critical care societal guidelines recommend the use of indirect calorimetry as the standard of care to determine energy needs. Recent studies confirm discrepancy between measured and equation-predicted energy expenditure and further demonstrate improved outcomes with indirect calorimetry-guided nutrition. Patients that undergo ECMO, CRRT and those with COVID-19 would benefit from the use of indirect calorimetry.

Summary

Indirect calorimetry-guided nutrition is the standard of care in mechanically ventilated surgical patients.

Nutrition adequacy, gastrointestinal and hepatic function during extracorporeal membrane oxygenation in critically ill adults: a retrospective observational study

AIMS

To identify clinical and biochemical markers associated with nutrition adequacy and gastrointestinal and liver dysfunction in adults on extracorporeal membrane oxygenation (ECMO).

METHODS

A retrospective, observational, study was conducted at 2 centres in Australia. Adult patients who received ECMO from July 2011 to June 2015 were included. Mode of ECMO used, fluid balance, number of systemic inflammatory response syndrome (SIRS) criteria present, vasoactive-inotropic scores (VIS) and liver function tests (LFTs) were collected for the duration of ECMO until 7 days after ECMO cessation. Multiple regression models were used to determine if the collected variables were associated with nutrition adequacy. The mean LFTs during ECMO were also compared to mean LFTs post ECMO cessation.

RESULTS

During the first 5 days of ECMO commencement, mean nutrition adequacy was 10% higher in the veno-venous (VV) ECMO group than in the veno-arterial (VA) group (95% confidence interval [CI], 2% to 17%). For every 5,000 ml increase of fluid balance, an associated decrease in nutrition adequacy was observed (-8%, 95% CI, -15% to -2%). A doubling of bilirubin and VIS were associated with a mean reduction in nutrition adequacy of -5% (CI -8% to -2%) and -2% (CI, -3% to -1%), respectively.

CONCLUSIONS

In the first 5 days of ECMO commencement, higher nutrition adequacy was associated with the VV mode of ECMO and reduced nutrition adequacy with increased fluid balance, more vasopressor and inotropic support and raised bilirubin. Prospective investigation is required to confirm whether these associations have a causal relationship.

How much underfeeding can the critically ill adult patient tolerate?

Critical illness leads to significant metabolic alterations that should be considered when providing nutritional support. Findings from key randomized controlled trials (RCTs) indicate that underfeeding (<70% of energy expenditure [EE]) during the acute phase of critical illness (first 7 days of intensive care unit [ICU] admission) may not be harmful and could instead promote autophagy and prevent overfeeding in light of endogenous energy production. However, the optimal energy target during this period is unclear and full starvation is unlikely to be beneficial. There are limited data regarding the effects of prolonged underfeeding on clinical outcomes in critically ill patients, but recent studies show that oral food intake is suboptimal both in the ICU and following discharge to the acute care setting. It is hypothesized that provision of full nutrition (70-100% of EE) may be important in the recovery phase of critical illness (>7 days of ICU admission) for promoting recovery and rehabilitation; however, studies on nutritional intervention delivered from ICU admission through hospital discharge are needed. The aim of this review is to provide a narrative synthesis of the existing literature on metabolic alterations experienced during critical illness and the impact of underfeeding on clinical outcomes in the critically ill adult patient.

Do we need different predictive equations for the acute and late phases of critical illness? A prospective observational study with repeated indirect calorimetry measurements

BACKGROUND

Predictive equations (PEs) for estimating resting energy expenditure (REE) that have been developed from acute phase data may not be applicable in the late phase and vice versa. This study aimed to assess whether separate PEs are needed for acute and late phases of critical illness and to develop and validate PE(s) based on the results of this assessment.

METHODS

Using indirect calorimetry, REE was measured at acute (≤5 days; n = 294) and late (≥6 days; n = 180) phases of intensive care unit admission. PEs were developed by multiple linear regression. A multi-fold cross-validation approach was used to validate the PEs. The best PEs were selected based on the highest coefficient of determination (R²), the lowest root mean square error (RMSE) and the lowest standard error of estimate (SEE). Two PEs developed from paired 168-patient data were compared with measured REE using mean absolute percentage difference.

RESULTS

Mean absolute percentage difference between predicted and measured REE was <20%, which is not clinically significant. Thus, a single PE was developed and validated from data of the larger sample size measured in the acute phase. The best PE for REE (kcal/day) was 891.6(Height) + 9.0(Weight) + 39.7(Minute Ventilation)-5.6(Age) - 354, with R² = 0.442, RMSE = 348.3, SEE = 325.6 and mean absolute percentage difference with measured REE was: 15.1 ± 14.2% [acute], 15.0 ± 13.1% [late].

CONCLUSIONS

Separate PEs for acute and late phases may not be necessary. Thus, we have developed and validated a PE from acute phase data and demonstrated that it can provide optimal estimates of REE for patients in both acute and late phases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03319329.

Estimated versus measured energy expenditure in ventilated surgical-trauma critically Ill patients

BACKGROUND

The American and European guidelines recommend measuring resting energy expenditure (REE) using indirect calorimetry (IC). Predictive equations (PEs) are used to estimate REE, but there is limited evidence for their use in critically ill patients. The aim of this study is to evaluate the degree of agreement and accuracy between IC-REE and ten different PEs in mechanically ventilated surgical-trauma critically ill patients who met their estimated caloric requirement.

METHODS

IC-REE was retrospectively compared to PE-REE by 10 PEs. Degree of agreement between REE-PE and REE-IC was analyzed by the Bland-Altman test (BAt) and the Concordance Correlation Coefficient (CCC). The accuracy was calculated by the percentage of patients whose REE-PE values differ by up to ±10% in relation to REE-IC. All analyses were stratified by gender and BMI (< 25 vs ≥ 25).

RESULTS

104 patients were analyzed and the closest estimate to IC-REE was the modified Harris-Benedict equation (mHB) by the BAt with a mean difference of 49.2 overall, 61.6 for males, 28.5 for females, 67.5 for BMI < 25 and 42.5 for BMI ≥ 25. The overall CCC between the IC-REE and mHB was 0.652; 0.560 for males; 0.496 for females; 0.570 for BMI < 25; and 0.598 for BMI ≥ 25. Modified HB equation was the most accurate with overall accuracy of 44.2%.

CONCLUSIONS

Effectiveness of PEs for estimating REE of mechanically ventilated surgical-trauma critically ill patients is limited. Nonetheless, of all the 10 equations examined, the closest to IC measured REE was the modified HB equation. This article is protected by copyright. All rights reserved.

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 support for critically ill patients

Nutrition support is an important aspect of the management of critically ill patients. This review highlights the emerging evidence on critical care nutrition and focuses on the pathophysiologic interplay between critical illness, the gastrointestinal tract, and nutrition support and the evidence on the best route, dose, and timing of nutrition. Although indirect calorimetry is recommended to measure energy expenditure, predictive equations are commonly used but are limited by their inaccuracy in individual patients. The current evidence supports early enteral nutrition (EN) in most patients, with a gradual increase in the daily dose over the first week. Delayed EN is warranted in patients with severe shock. According to recent trials, parenteral nutrition seems to be as effective as EN and may be started if adequate EN is not achieved by the first week of critical illness. A high protein dose has been recommended, but the best timing is unclear. Immuno-nutrition should not be routinely provided to critically ill patients. Patients receiving artificial nutrition should be monitored for metabolic derangements. Additional adequately powered studies are still needed to resolve many unanswered questions.

Methods for Estimating Energy Expenditure in Critically Ill Adults

Energy expenditure (EE) is the sum of metabolic activity within the body at a given time and comprises basal EE, diet-induced thermogenesis, and physical activity. In the intensive care unit, EE is most often assessed to determine a patient's caloric requirements. Energy expenditure also may be useful to understand disease states and the metabolic impact of interventions. Several methods for estimating EE are relevant for clinical use, including indirect calorimetry, predictive equations, exhaled carbon dioxide volume, and the Fick method. Indirect calorimetry is the preferred method for evaluating EE and is considered the gold standard for estimating EE in hospitalized patients. However, use of indirect calorimetry is not always practical or possible. Therefore, other methods of estimating EE must be considered. In this review, methods of evaluating EE in critically ill adults are examined and the benefits and limitations of each method are discussed, with practical considerations for use.

The effect of indirect calorimetry guided isocaloric nutrition on mortality in critically ill patients-a systematic review and meta-analysis

Indirect calorimetry (IC)-guided nutrition might positively affect the clinical outcome of critically ill patients. In this systematic review and meta-analysis, our objective was to assess the benefit of isocaloric nutrition guided by IC, compared to hypocaloric nutrition, for critically ill patients admitted to the intensive care unit (ICU). We performed a systematic review of all randomized controlled trials published through January 2021, assessing the benefit of isocaloric nutrition guided by IC. The primary outcome was 28-day all-cause mortality. Secondary outcomes were ICU and 90-day all-cause mortality, rate of nosocomial infections, and adverse events. Four trials evaluating 1052 patients were included. Patients treated with isocaloric nutrition had a lower 28-day mortality rate (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.63-0.99, P = 0.04). No between-group difference was found in ICU and 90-day mortality (RR 0.92, 95% CI 0.68-1.23, P = 0.56 and RR 0.88, 95% CI 0.72-1.07; P = 0.2, respectively) and in the rate of nosocomial infections (RR 1.15, 95% CI 0.77-1.72, P = 0.51). A pooled analysis of studies that evaluated the benefit of isocaloric nutrition guided by IC, for critically ill patients in the ICU, has shown reduced 28-day mortality. However, there was no difference in 90-day mortality and nosocomial infection rate.

How Have Nutrition Practices in the ICU Changed in the Last Decade (2011-2020): A Scoping Review

Malnutrition is more prevalent in the critically ill than ambulatory patients due to a variety of factors. Strategies employed in the optimization of nutrition practices rely largely on the review of published literature and guidelines. While the last decade was marked by some landmark large randomized controlled trials taking place and some high-quality systematic reviews, it still has left us with many unanswered questions. The evidence generated by these trials can, to a good extent, extrapolate to the developed countries. However, its implementation in developing and third-world countries needs further elaboration and logistical considerations. With this scoping review, we attempt to provide insights into the landmark developments in the decade 2011-2020. Solutions to employ and implement the results of these developments and ways for their corroboration into a larger population are also discussed.

A Single-Center Prospective Observational Study Comparing Resting Energy Expenditure in Different Phases of Critical Illness: Indirect Calorimetry Versus Predictive Equations

OBJECTIVES

Several predictive equations have been developed for estimation of resting energy expenditure, but no study has been done to compare predictive equations against indirect calorimetry among critically ill patients at different phases of critical illness. This study aimed to determine the degree of agreement and accuracy of predictive equations among ICU patients during acute phase (≤ 5 d), late phase (6-10 d), and chronic phase (≥ 11 d).

DESIGN

This was a single-center prospective observational study that compared resting energy expenditure estimated by 15 commonly used predictive equations against resting energy expenditure measured by indirect calorimetry at different phases. Degree of agreement between resting energy expenditure calculated by predictive equations and resting energy expenditure measured by indirect calorimetry was analyzed using intraclass correlation coefficient and Bland-Altman analyses. Resting energy expenditure values calculated from predictive equations differing by ± 10% from resting energy expenditure measured by indirect calorimetry was used to assess accuracy. A score ranking method was developed to determine the best predictive equations.

SETTING

General Intensive Care Unit, University of Malaya Medical Centre.

PATIENTS

Mechanically ventilated critically ill patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Indirect calorimetry was measured thrice during acute, late, and chronic phases among 305, 180, and 91 ICU patients, respectively. There were significant differences (F= 3.447; p = 0.034) in mean resting energy expenditure measured by indirect calorimetry among the three phases. Pairwise comparison showed mean resting energy expenditure measured by indirect calorimetry in late phase (1,878 ± 517 kcal) was significantly higher than during acute phase (1,765 ± 456 kcal) (p = 0.037). The predictive equations with the best agreement and accuracy for acute phase was Swinamer (1990), for late phase was Brandi (1999) and Swinamer (1990), and for chronic phase was Swinamer (1990). None of the resting energy expenditure calculated from predictive equations showed very good agreement or accuracy.

CONCLUSIONS

Predictive equations tend to either over- or underestimate resting energy expenditure at different phases. Predictive equations with "dynamic" variables and respiratory data had better agreement with resting energy expenditure measured by indirect calorimetry compared with predictive equations developed for healthy adults or predictive equations based on "static" variables. Although none of the resting energy expenditure calculated from predictive equations had very good agreement, Swinamer (1990) appears to provide relatively good agreement across three phases and could be used to predict resting energy expenditure when indirect calorimetry is not available.

Nutritional Support in the Intensive Care Unit: Implications for Nursing Care From Evidence-Based Guidelines and Supporting Literature

Several nursing practices are related to oral, enteral, or parenteral feeding on the intensive care unit. Nurses are the group of health care professionals who provide 24-hour care for patients. Therefore, they play a key role in not only identifying nutritional problems but also in ensuring the success of nutritional therapy by implementing evidence-based feeding protocols and ongoing care for (par)enteral access devices. Having an up-to-date evidence-based knowledge about nutritional support can increase safety and quality of care and can contribute to better outcomes. In this narrative review, the most recent European intensive care unit nutrition guidelines and related research are highlighted, and where appropriate, specific applications for nursing practice are described.

The centenary of the Harris-Benedict equations: How to assess energy requirements best? Recommendations from the ESPEN expert group

BACKGROUND & AIMS

The year 2019 marked the centenary of the publication of the Harris and Benedict equations for estimation of energy expenditure. In October 2019 a Scientific Symposium was organized by the European Society for Clinical Nutrition and Metabolism (ESPEN) in Vienna, Austria, to celebrate this historical landmark, looking at what is currently known about the estimation and measurement of energy expenditure.

METHODS

Current evidence was discussed during the symposium, including the scientific basis and clinical knowledge, and is summarized here to assist with the estimation and measurement of energy requirements that later translate into energy prescription.

RESULTS

In most clinical settings, the majority of predictive equations have low to moderate performance, with the best generally reaching an accuracy of no more than 70%, and often lead to large errors in estimating the true needs of patients. Generally speaking, the addition of body composition measurements did not add to the accuracy of predictive equations. Indirect calorimetry is the most reliable method to measure energy expenditure and guide energy prescription, but carries inherent limitations, greatly restricting its use in real life clinical practice.

CONCLUSIONS

While the limitations of predictive equations are clear, their use is still the mainstay in clinical practice. It is imperative to recognize specific patient populations for whom a specific equation should be preferred. When available, the use of indirect calorimetry is advised in a variety of clinical settings, aiming to avoid under-as well as overfeeding.

Energy delivery guided by indirect calorimetry in critically ill patients: a systematic review and meta-analysis

BACKGROUND

The use of indirect calorimetry (IC) is increasing due to its precision in resting energy expenditure (REE) measurement in critically ill patients. Thus, we aimed to evaluate the clinical outcomes of an IC-guided nutrition therapy compared to predictive equations strategy in such a patient population.

METHODS

We searched PubMed, EMBASE, and Cochrane library databases up to October 25, 2020. Randomized controlled trials (RCTs) were included if they focused on energy delivery guided by either IC or predictive equations in critically ill adults. We used the Cochrane risk-of-bias tool to assess the quality of the included studies. Short-term mortality was the primary outcome. The meta-analysis was performed with the fixed-effect model or random-effect model according to the heterogeneity.

RESULTS

Eight RCTs with 991 adults met the inclusion criteria. The overall quality of the included studies was moderate. Significantly higher mean energy delivered per day was observed in the IC group, as well as percent delivered energy over REE targets, than the control group. IC-guided energy delivery significantly reduced short-term mortality compared with the control group (risk ratio = 0.77; 95% CI 0.60 to 0.98; I² = 3%, P = 0.03). IC-guided strategy did not significantly prolong the duration of mechanical ventilation (mean difference [MD] = 0.61 days; 95% CI - 1.08 to 2.29; P = 0.48), length of stay in ICU (MD = 0.32 days; 95% CI - 2.51 to 3.16; P = 0.82) and hospital (MD = 0.30 days; 95% CI - 3.23 to 3.83; P = 0.87). Additionally, adverse events were similar between the two groups.

CONCLUSIONS

This meta-analysis indicates that IC-guided energy delivery significantly reduces short-term mortality in critically ill patients. This finding encourages the use of IC-guided energy delivery during critical nutrition support. But more high-quality studies are still needed to confirm these findings.

Reliability of ActiGraph GT3X+ placement location in the estimation of energy expenditure during moderate and high-intensity physical activities in young and older adults

WHO defines physical activity (PA) as any bodily movement produced by skeletal muscles that requires energy expenditure (EE). The purpose of this study was to compare the EE estimations by ActiGraph GT3X+ with a gold standard measurement, the portable gas analyser in a set of 3 different PAs. This cross-sectional study involved 56 participants, age range (years, [min, max]: young people [20, 33], older adults [65, 83]). Participants completed a single session of three experimental PAs including biking, treadmill walking, and treadmill running. Each participant wore five GT3X+ triaxial accelerometers and a portable gas analyser used as the gold standard measurement. The GT3X+ were placed on the wrists, the waist (centred at the pelvis), and the ankles. ActiGraph GT3X+ and MetaMax3B records were investigated through intraclass correlation coefficient. Magnitude of measurement error was estimated using Effect Size. The GT3X+ wrist and GT3X+ waist underestimated EE regardless of the PA type. The GT3X+ ankles strongly overestimated EE during biking (mean bias = 489 ± 392%) and walking (mean bias = 106 ± 58%), while it underestimated EE during running (mean bias = -47 ± 27%). The ActiGraph GT3X+ does not provide accurate EE estimates across a range of placement locations during moderate and high-intensity PA.

Energy expenditure and indirect calorimetry in critical illness and convalescence: current evidence and practical considerations

The use of indirect calorimetry is strongly recommended to guide nutrition therapy in critically ill patients, preventing the detrimental effects of under- and overfeeding. However, the course of energy expenditure is complex, and clinical studies on indirect calorimetry during critical illness and convalescence are scarce. Energy expenditure is influenced by many individual and iatrogenic factors and different metabolic phases of critical illness and convalescence. In the first days, energy production from endogenous sources appears to be increased due to a catabolic state and is likely near-sufficient to meet energy requirements. Full nutrition support in this phase may lead to overfeeding as exogenous nutrition cannot abolish this endogenous energy production, and mitochondria are unable to process the excess substrate. However, energy expenditure is reported to increase hereafter and is still shown to be elevated 3 weeks after ICU admission, when endogenous energy production is reduced, and exogenous nutrition support is indispensable. Indirect calorimetry is the gold standard for bedside calculation of energy expenditure. However, the superiority of IC-guided nutritional therapy has not yet been unequivocally proven in clinical trials and many practical aspects and pitfalls should be taken into account when measuring energy expenditure in critically ill patients. Furthermore, the contribution of endogenously produced energy cannot be measured. Nevertheless, routine use of indirect calorimetry to aid personalized nutrition has strong potential to improve nutritional status and consequently, the long-term outcome of critically ill patients.

Energy Expenditure and Shivering Severity During Targeted Temperature Management at 36°C After Cardiac Arrest: A Case Series

Patients undergoing targeted temperature management (TTM) after cardiac arrest are at risk for shivering, which increases energy expenditure (EE) and may attenuate TTM benefits. This article reports patterns of EE for patients with and without shivering who received TTM at 36°C after cardiac arrest. Based on 96 case assessments, there were 14 occasions when more than one 15-minute interval period was required to appropriately modify the Bedside Shivering Assessment Scale (BSAS) score. Investigators noted that although higher EE was related to higher BSAS scores, there may be opportunities for earlier detection of shivering.

Frequent and personalized nutritional support leads to improved nutritional status, activities of daily living, and dysphagia after stroke

OBJECTIVES

Evidence for appropriate nutritional assessment, energy prediction, and adaptation and their effect on outcomes after stroke is scarce. We sought to determine the frequency of individualized dietary prescriptions issued for individuals undergoing rehabilitation after stroke and to analyze the effect of diet-prescription frequency on outcomes after stroke.

METHODS

This single-center prospective cohort study included poststroke patients newly admitted to convalescent rehabilitation wards. The frequency and content of dietary prescriptions issued as part of nutritional assessments were examined. Study outcomes were nutritional status assessed using changes in skeletal muscle mass, physical function assessed using the Functional Independence Measure motor score, dysphagia status assessed using the Food Intake LEVEL Scale (score < 7), and length of hospital stay. Multivariate analyses were performed to determine whether the frequency of dietary prescriptions issued during hospitalization was independently associated with outcomes of interest, after adjusting for potential confounders.

RESULTS

A total of 454 participants (mean age = 71.8 y; 53.1% men, 46.9% women) were included in the final analysis data set. A median of five (range, 2-11) dietary prescriptions were issued per participant during the median 96 d of hospitalization, with the most common items being diet-texture modification for dysphagia and oral energy/protein enhancement. In multivariate analyses, the frequency of dietary prescriptions was independently associated with the change in skeletal muscle mass (β = 0.165, P = 0.028), Functional Independence Measure motor scores at discharge (β = 0.104, P = 0.045), length of stay (β = -0.056, P = 0.019), and presence of dysphagia at discharge (odds ratio = 0.949, P = 0.032).

CONCLUSIONS

Frequent and individualized nutritional support is associated with improved nutritional status, physical function, and dysphagia after stroke. Intensive nutritional support through multidisciplinary discussion plays a central role in the prevention and management of malnutrition to maximize the improvement of patient outcomes. This study is the first to report this association.

Oral Nutrition during and after Critical Illness: SPICES for Quality of Care!

Malnutrition is associated to poor outcomes in critically ill patients. Oral nutrition is the route of feeding in less than half of the patients during the intensive care unit (ICU) stay and in the majority of ICU survivors. There are growing data indicating that insufficient and/or inadequate intakes in macronutrients and micronutrients are prevalent within these populations. The present narrative review focuses on barriers to food intakes and considers the different points that should be addressed in order to optimize oral intakes, both during and after ICU stay. They are gathered in the SPICES concept, which should help ICU teams improve the quality of nutrition care following 5 themes: swallowing disorders screening and management, patient global status overview, involvement of dieticians and nutritionists, clinical evaluation of nutritional intakes and outcomes, and finally, supplementation in macro-or micronutrients.

Clinical Impact of Prescribed Doses of Nutrients for Patients Exclusively Receiving Parenteral Nutrition in Japanese Hospitals: A Retrospective Cohort Study

BACKGROUND

In patients receiving parenteral nutrition (PN), the association between nutrition achievement in accordance with nutrition guidelines and outcomes remains unclear. Our purpose was to assess the association between nutrition achievement and clinical outcomes, including in-hospital mortality, activity of daily living (ADL), and readmission.

METHODS

In this retrospective cohort study, data were extracted from an inpatient medical-claims database at 380 acute care hospitals. This study included patients who underwent central venous catheter insertion between January 2009 and December 2018. Patients were classified into 3 groups: (1) target-not-achieved; (2) target-partially-achieved; and (3) target-achieved. The target doses of energy, amino acids, and lipid were defined as ≥20 kcal/kg/day, ≥1.0 g/kg/day, and ≥2.5 g/day, respectively. To examine the effect of nutrition achievement on outcomes, a multivariable logistic regression analysis was performed.

RESULTS

A total of 54,687 patients were included; of these, 21,383 patients were in the target-not-achieved group, 29,610 patients were in the target-partially-achieved group, and 3694 patients were in the target-achieved group. The adjusted odds ratio (OR) (95% CI) for in-hospital mortality was 0.69 (0.66-0.72) in the target-partially-achieved group and 0.47 (0.43-0.52) in the target-achieved group with reference to the target-not-achieved group. The adjusted ORs for deteriorated ADL was 0.93 (0.85-1.01) in the target-partially-achieved group and 0.77 (0.65-0.92) in the target-achieved group with reference to the target-not-achieved group. Readmission was not associated with nutrition achievement.

CONCLUSION

In-hospital mortality was lower and deteriorated ADL was suppressed in patients whose PN management was in accordance with the nutrition guidelines.

A survey on total parenteral nutrition in 55,000 hospitalized patients: Retrospective cohort study using a medical claims database

BACKGROUND & AIMS

Identifying the prevalence of underfed patients and risk factors for underfeeding in patients with total parenteral nutrition (TPN) is essential to improve the management of patients receiving TPN. The aim of this study was to examine the prevalence and risk factors for underfeeding using a medical claims database.

METHODS

In this retrospective cohort study using a medical claims database, we analyzed patient characteristics, timing and duration of nutrition prescription, daily dose of nutrients, and types of parenteral nutrition products administered after central venous catheter (CVC) insertion in hospitalized Japanese patients between 2009 and 2018. The mean prescriptions of energy <20 kcal/kg/day, amino acids <1.0 g/kg/day, and fat <2.5 g/day received by patients between the 4th and 10th day after CVC insertion were regarded as underfeeding. To study the association between nutritional adequacy and body mass index (BMI) with TPN, the proportions of patients with a prescription of energy ≥20 kcal/kg/day or amino acids ≥1.0 g/kg/day were calculated and categorized according to BMI, and the Cochran-Armitage trend test was performed.

RESULTS

Of 54,687 patients included in the study, 70.3% were aged ≥70 years, and 31.3% had a BMI <18.5. The mean prescription of energy was insufficient in 49.9% of patients, and 82.9% were insufficiently prescribed with amino acids. In addition, 44.4% of the patients were never prescribed a single dose of fat emulsion during their hospital stay. On the 10th day after CVC insertion, the majority of patients used commercial 2-in-1 compounds containing carbohydrates and amino acids. A higher BMI was associated with underfeeding of energy and amino acids (both p < 0.001).

CONCLUSIONS

It is important to adjust the nutrition dose according to the patient's body size and weight, and it is necessary to supplement inadequate nutrients by single-nutrition solutions in addition to compounded solutions.

Impact of enteral nutrition interruptions on underfeeding in intensive care unit

BACKGROUND & AIMS

Malnutrition leads to poor outcomes for critically ill patients; however, underfeeding remains a prevalent issue in the intensive care unit (ICU). One of the reasons for underfeeding is enteral nutrition interruption (ENI). Our aim was to investigate the causes, frequency, and duration of ENIs and their association with underfeeding in critical care.

METHODS

This was a prospective observational study conducted at the Vilnius University Hospital Santaros Clinics, Lithuania, between December 2017 and February 2018. It included adult medical and surgical ICU patients who received enteral nutrition (EN). Data on ENIs and caloric, as well as protein intake were collected during the entire ICU stay. Nutritional goals were assessed using indirect calorimetry, where available.

RESULTS

In total 73 patients were enrolled in the study. Data from 1023 trial days and 131 ENI episodes were collected; 68% of the patients experienced ENI during the ICU stay, and EN was interrupted during 35% of the trial days. The main reasons for ENIs were haemodynamic instability (20%), high gastric residual volume (GRV) (17%), tracheostomy (16%), or other surgical interventions (16%). The median duration of ENI was 12 [6-24] h, and the longest ENIs were due to patient-related factors (22 [12-42] h). The rate of underfeeding was 54% vs. 15% in the trial days with and without ENI (p < 0.001), respectively. Feeding goal was achieved in 26% of the days with ENI vs. 45% of days without ENI (p < 0.001). The daily average caloric provision was 77 ± 36% vs. 106 ± 29% in the trial days with and without ENI (p < 0.001) and protein provision was 0.96 ± 0.5 vs. 1.3 ± 0.5 g/kg, respectively (p < 0.001).

CONCLUSIONS

The episodes of ENI in critically ill patients are frequent and prolonged, often leading to underfeeding. Similar observations have been reported by other studies; however, the causes and duration of ENI vary, mainly because of different practices worldwide. Hence, safe and internationally recognised reduced-fasting guidelines and protocols for critically ill patients are needed in order to minimise ENI-related underfeeding and malnutrition.

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.

Early Hypermetabolism is Uncommon in Trauma Intensive Care Unit Patients

BACKGROUND

Classic experiments demonstrating hypermetabolism after major trauma were performed in a different era of critical care. We aim to describe the modern posttraumatic metabolic response in the trauma intensive care unit (TICU).

METHODS

This prospective observational study enrolled TICU mechanically ventilated adults (aged ≥18) from 3/2018-2/2019. Multiple, daily resting energy expenditure (REE) measurements were recorded. Basal energy expenditure (BEE) was calculated by the Harris-Benedict equation. Hypometabolism was defined as average daily REE < 0.85*BEE and hypermetabolism defined as average daily REE > 1.15*BEE. Demographics, interventions, and clinical outcomes were abstracted. Descriptive statistics and multivariable logistical regression models evaluating demographics with the outcome variable of hypermetabolism for the first 3 days ("sustained hypermetabolism") were performed, along with group-based trajectory modeling (GBTM).

RESULTS

Fifty-five patients were analyzed: median age was 38 (28-56) years; 38 (69%) were male; body mass index (kg/m² ) was 28 (26-32); and Injury Severity Score was 27 (19-34), with (38 [71%] blunt, 8 [15%] penetrating, 7 [13%] burn) injury mechanism. Overall, 19 (35%) had hypermetabolism on day 1 ("immediate hypermetabolism"), and 11 (21%) had sustained hypermetabolism for the first 3 days. Logistic regression analysis identified penetrating mechanism (adjusted odds ratio [AOR], 16.4; 95% CI, 1.9-199.6; p = .015), burn mechanism (AOR, 11.1; 95% CI, 1.3-116.8; p =.029), and maximum temperature (AOR, 4.2; 95% CI, 1.3-20.3; p= .041) as independent predictors of sustained hypermetabolism. GBTM identified 4 nutrition phenotypes, with 2 hyperconsumptive phenotypes associated with increased risk of malnutrition at discharge.

CONCLUSION

Only a minority of injured patients is hypermetabolic in the first week after injury. Elevated temperature, penetrating mechanism, and burn mechanism are independently associated with sustained hypermetabolism. Hyperconsumptive phenotype patients are more likely to develop malnutrition during hospitalization.

Is Energy Delivery Guided by Indirect Calorimetry Associated With Improved Clinical Outcomes in Critically Ill Patients? A Systematic Review and Meta-analysis

Background:

Indirect calorimetry (IC) is recommended to guide energy delivery over predictive equations in critical illness due to its precision. However, the impact of using IC to measure energy expenditure on clinical outcomes is uncertain.

Objective:

To evaluate whether using IC to measure energy expenditure to inform energy delivery reduced hospital mortality and improved other important outcomes compared to using predictive equations in critically ill adults.

Methods:

A systematic literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Medline, Embase, CINAHL, and the Cochrane Library were searched for studies using IC to guide energy delivery compared to a predictive equation in adult critically ill patients with the primary outcome (hospital mortality) or any of the secondary outcomes reported (including but not limited to hospital and intensive care unit (ICU) length of stay (LOS) and duration mechanical ventilation (MV). Risk of bias within studies was assessed using the Cochrane “Risk of Bias” 1 tool. Random-effect meta-analyses were used when heterogeneity between studies existed (I² > 50%). Data are reported as median (interquartile range [IQR]), binomial outcomes as odds ratio (OR), 95% confidence interval (CI), and continuous outcomes as mean difference (MD).

Results:

Of 4060 articles, 4 randomized controlled trials were identified with 396 patients included in analysis. Three studies were considered low risk of bias and 1 as high risk. Two studies reported hospital mortality (n = 130 and 40 participants, respectively). When combined, no association between IC-guided energy delivery and hospital mortality was found (OR = 0.81, 95% CI = [0.25, 2.67], P = 0.73, I² = 52). No differences were reported with ICU mortality and hospital LOS between groups, but ICU LOS and duration of MV varied across all studies. According to the meta-analysis, no differences were observed in ICU LOS (MD = 1.39, 95% CI = [–5.01, 7.79], P = 0.67, I² = 81%), although the duration of MV was increased when energy delivery was guided by IC (MD = 2.01, 95% CI = [0.45, 3.57], P = 0.01, I² = 26%). In all 4 studies, prescribed energy targets were more closely met when energy delivery was informed by IC compared to a predictive equation. Three studies reported the percentage delivered versus the prescribed energy target, with the median (IQR) delta between the IC and predictive equation arms 19% (10%-32%).

Conclusion:

Limited data exist to assess the impact of using IC to inform energy delivery in comparison to predictive equations on hospital mortality. The association of IC use with other important outcomes, including duration of MV, needs to be further explored before definitive conclusions can be made.

Advances in Medical Nutrition Therapy: Parenteral Nutrition

Parenteral nutrition has evolved tremendously, with parenteral formulas now safer and more accessible than ever. "All-in-one" admixtures are now available, which simplify parenteral nutrition usage and decrease line infection rates alongside other methods of infectious control. Recently published data on the benefits of parenteral nutrition versus enteral nutrition together with the widespread use of indirect calorimetry solve many safety issues that have emerged over the years. All these advances, alongside a better understanding of glycemic control and lipid and protein formulation improvements, make parenteral nutrition a safe alternative to enteral nutrition.

Evaluating the TARGET and EAT-ICU trials: how important are accurate caloric goals? Point-counterpoint: the pro position

PURPOSE OF REVIEW

Controversies about the adequate amount of energy to deliver to critically ill patients are still going on, trying to find if hypocaloric or normocaloric regimen is beneficial in this population. Our purpose is to review recent publications using or not indirect calorimetry.

RECENT FINDINGS

Numerous studies have compared hypocaloric to normocaloric regimen using predictive equations. However, these equations have been demonstrated to be inaccurate in most of the cases. Some recent PRCT using indirect calorimetry are finding some advantages to isocalorie regimens, but others not. Timing of the nutrition respecting or not the early substrate endogenous production, use of an adequate amount of protein, respect of the daily variability of needs may explain the divergent results observed.

SUMMARY

Indirect calorimetry should be used to define the energy expenditure of the patient and to determine its requirements. More studies comparing isocalorie to hypocalorie regimens with fixed protein intake are necessary to confirm the observational and some of the PRCT-positive studies.

Measured Energy Expenditure Compared With Best-Practice Recommendations for Obese, Critically Ill Patients-A Prospective Observational Study

BACKGROUND

This study aimed to compare recommendations in the American Society for Parenteral and Enteral Nutrition (ASPEN) Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient with measured energy expenditure in obese, critically ill adults.

METHODS

After enrollment, measured energy expenditure was attempted at baseline and twice weekly to extubation or day 14. Data are reported as median [interquartile range].

RESULTS

Twenty patients were included. The median baseline and subsequent measured energy expenditures were 2438 [1807-2703] kcal and 2919 [2318-3362] kcal, respectively. Baseline measured energy expenditures were -491 [-788 to -323] kcal lower than subsequent measurements, and week 1 measurements were lower than those of week 2. The median bias between the guideline recommendation of 11-14 kcal/kg of actual body weight and measured expenditure at baseline was -950 [-1254 to -595] kcal/d and -1618 [-1820 to -866] kcal/d at subsequent measurements.

CONCLUSION

Clinically significant variation was observed between measured expenditure and guideline recommendations at all time points.

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.

Energy Expenditure in Critically Ill Adult Patients With Acute Brain Injury: Indirect Calorimetry vs. Predictive Equations

Introduction: Predictive equations (PE) are used in lieu of indirect calorimetry (IC) due to cost and limited resources; however, these equations may not be as accurate as IC in estimating resting energy expenditure (REE) in critically ill patients, putting them at risk of malnutrition. The purpose of this study is to compare predicted and measured energy expenditure (MEE) in critically ill adults with acute brain injury.

Materials and Methods: This was a retrospective review of adult patients admitted to the Neurosciences ICU with acute brain injury between May 1st, 2014 and April 1st, 2016 who had IC performed. The Harris Benedict (HBE), Penn State University, and Mifflin St Jeor (MSJ) PE were used in comparison to IC results. Subgroup analyses stratified patients based on BMI and type of acute brain injury.

Results: One hundred and forty-four patients met inclusion criteria. Comparing predicted and MEE found no significant difference (p = 0.1). High degrees of interpatient variability were discovered, with standard deviations ranging from 17 to 29% of each PE. Pearson's correlations indicated weak associations when HBE, Penn State, and MSJ were individually compared to MEE (r = 0.372, 0.409, and 0.372, respectively). A significant difference was found between predicted and MEE in patients with a BMI < 30 kg/m² (p < 0.01) and in those with aneurysmal subarachnoid hemorrhage (p < 0.01).

Discussion: Due to interpatient variability that exists among REE of critically ill patients with acute brain injury, IC should be used when feasible.

Clinical Nutrition of Critically Ill Patients in the Context of the Latest ESPEN Guidelines

The group of patients most frequently in need of nutritional support are intensive care patients. This year (i.e., 2019), new European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines of clinical nutrition in intensive care were published, updating and gathering current knowledge on the subject of this group of patients. Planning the right nutritional intervention is often a challenging task involving the necessity of the choice of the enteral nutrition (EN) or parenteral nutrition (PN) route of administration, time of initiation, energy demand, amino acid content and demand as well as the use of immunomodulatory nutrition. The aim of this study was to specify and discuss the basic aspects of the clinical nutrition of critically ill patients recommended by ESPEN guidelines. Clinical nutrition in intensive care seems to be the best-studied type of nutritional intervention. However, meta-analyses and clinical studies comparing EN and PN and their impact on the prognosis of the intensive care patients showed ambiguous results. The nutritional interventions, starting with EN, should be initiated within 24-48 h whereas PN, if recommended, should be implemented within 3-7 days. The recommended method of calculation of the energy demand is indirect calorimetry, however, there are also validated equations used worldwide in everyday practice. The recommended protein intake in this group of patients and the results of insufficient or too high supply was addressed. In light of the concept of immunomodulatory nutrition, the use of appropriate amino acid solutions and lipid emulsion that can bring a positive effect on the modulation of the immune response was discussed.

[Effect of hypocaloric versus standard enteral feeding on clinical outcomes in critically ill adults - A meta-analysis of randomized controlled trials with trial sequential analysis]

OBJECTIVES

To compare the effect of hypocaloric versus standard enteral feeding on clinical outcomes in critically ill adults, and to investigate the influence of protein intake upon the outcome effects of hypocaloric feeding.

DESIGN

A meta-analysis of randomized controlled trials (RCTs) and trial sequential analysis (TSA) were carried out.

SETTING

Intensive Care Unit (ICU).

PATIENTS

Or participants Critically ill adults.

INTERVENTIONS

Hypocaloric enteral feeding versus standard enteral feeding.

MAIN VARIABLES OF INTEREST

The primary outcomes were all-cause short-term mortality and the incidence of nosocomial infection.

RESULTS

Eleven RCTs met the inclusion criteria; of these trials, two were judged as having low risk of bias. Compared with standard enteral feeding, hypocaloric enteral feeding had no benefits in terms of reducing short-term mortality, the incidence of nosocomial infection, or long-term mortality, though it had a positive impact upon the incidence of gastrointestinal intolerance. The TSA further confirmed these results. In turn, hypocaloric enteral feeding had no effects upon the incidence of bloodstream infection, pneumonia, hypoglycemia or the duration of mechanical ventilation, ICU stay, or in-hospital stay. The above results remained unchanged in the sub-analysis of trials with a low risk of bias, trials administering a similar dose of protein, or trials administering different doses of protein.

CONCLUSIONS

Compared with standard enteral feeding, hypocaloric enteral feeding was not associated with better clinical outcomes in critically ill adults, except for a lower risk of gastrointestinal intolerance. The difference in protein intake between groups might have no influence on the outcome effects of hypocaloric enteral feeding. High quality randomized controlled trials are needed to confirm this, however.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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