Accurate Determination of Energy Needs in Hospitalized Patients

A Proposed Predictive Equation for Energy Expenditure Estimation Among Noncritically Ill Patients With Acute Kidney Injury

OBJECTIVE

The incidence of acute kidney injury (AKI) is identified more frequently in noncritical compared with intensive care settings. The prognosis of malnourished AKI patients is far worse than those with normal nutritional status. However, a method for estimating the optimal amount of energy required to guide nutritional support among noncritically ill AKI patients is yet to be determined.

METHODS

We evaluated the performance of weight-based formulas (20-30 kcal/kg/day) with the reference values of energy expenditure (EE) measured by indirect calorimetry (IC) among noncritically ill AKI patients during hospitalization. The statistics for assessing agreement, including total deviation index and accuracy within 10% represent the percentage of estimations falling within the IC value range of ±10%, were tested. Parameters for predicting the EE equation were also developed using a regression analysis model.

RESULTS

A total of 40 noncritically ill AKI patients were recruited. The mean age of participants was 62.5 ± 16.5 years with 50% being male. The average IC-derived EE was 1,124.6 ± 278.9 kcal/day with respiratory quotients 0.8-1.3, indicating good validity of the IC test. Receiving dialysis, protein catabolic rate, and age was not significantly associated with measured EE. Nearly all weight-based formulas overestimated measured EE. The magnitude of total deviation index values was broad with the proportion of patients achieving an accuracy of 10% being as low as 20%. The proposed equation to predict EE derived from this study was EE (kcal/day) = 618.27 + (8.98 x weight in kg) + 137.0 if diabetes - 199.7 if female (r2 = 0.68, P < .001). In the validation study with an independent group of noncritically ill AKI patients, predicted EE using the newly derived equation was also significantly correlated with measured EE by IC (r = 0.69, P = .004).

CONCLUSION

Estimation of EE by weight-based formulas usually overestimated measured EE among noncritically ill AKI patients. In the absence of IC, the proposed predictive equation, specifically for noncritically ill AKI patients might be useful, in addition to weight-based formulas, for guiding caloric dosing in clinical practice.

Measured versus estimated energy requirement in hospitalized patients

BACKGROUND & AIM

Failure to identify a patient's energy requirement has a variety of consequences both physiological and economical. Previous studies have shown that predictive formulas, including the Harris Benedict equation (HB), both over- and underestimates energy requirement in severely ill patients and healthy younger adults, compared to the golden standard, indirect calorimetry (IC). The comparison between measured and estimated energy requirements in hospitalized patients in regular wards is underreported. The aim of this study was to assess the agreement between measured energy requirements and requirements estimated by HB in the individual hospitalized patients, and to investigate whether those findings were associated with other specific patient characteristics.

METHODS

IC (n = 86) was used to measure resting energy expenditure (REE) and bioimpedance analysis (BIA) (n = 67) was used for body composition in patients admitted to Aalborg University Hospital. Furthermore, height, weight, body mass index, calf circumference, while information regarding hospital ward, vital values, dieticians estimated energy requirements and blood samples were collected in the patients' electronic medical records. Bland-Altman plots, multiple linear regression analysis, and Chi2 tests were performed.

RESULTS

On average a difference between IC compared with the HB (6.2%), dietitians' estimation (7.8%) and BIA (4.50%) was observed (p < 0.05). Association between REE and skeletal muscle mass (SMM) (R2 = 0.58, β = 149.0 kJ), body fat mass (BFM) (R2 = 0.51, β = 59.1 kJ), and weight (R2 = 0.62, β = 45.6 kJ) were found (p < 0.05). A positive association between measured REE and HB were found in the following variables (p < 0.05): CRP, age, surgical patients, and respiratory rate.

CONCLUSION

This study found a general underestimation of estimated energy expenditure compared to measured REE. A positive correlation between measured REE and SMM, BRM and weight was found. Lastly, the study found a greater association between CRP, age, surgical patients, and respiratory rate and a general greater than ±10% difference between measured and estimation of energy requirements.

Nutrition in the intensive care unit and early recovery influence functional outcomes for survivors of critical illness: A prospective cohort study

BACKGROUND

Patients who are critically ill may receive suboptimal nutrition that leads to weight loss and increased risk of functional deficits.

METHODS

Our overarching hypothesis is that nutrition in the intensive care unit (ICU) and the early recovery phase associates with functional outcomes at short-term follow-up. We enrolled adult patients who attended the University of Kentucky ICU recovery clinic (ICU-RC) from November 2021 to June 2022. Patients participated in muscle and functional assessments. Nutrition intake and status during the ICU stay were analyzed. The Subjective Global Assessment and a nutrition questionnaire were used to identify changes in intake, ongoing gastrointestinal symptoms, and patient's access to food at the ICU-RC appointment.

RESULTS

Forty-one patients enrolled with a median hospital length of stay (LOS) of 23 days. Patients with 0 days of nil per os (NPO) status throughout hospitalization had a shorter LOS (P = 0.05), were able to complete the five times sit-to-stand test (P = 0.02), and were less likely to experience ICU-acquired weakness (P = 0.04) at short-term follow-up compared with patients with ≥1 day of NPO status. Twenty (48%) patients reported changes in nutrition intake in early recovery compared with before hospitalization. Eight (20%) patients reported symptoms leading to decreased intake and four (10%) reported access to food as a barrier to intake.

CONCLUSION

Barriers to nutrition exist during critical illness and persist after discharge, with almost half of patients reporting a change in intake. Inpatient nutrition intake is associated with functional outcomes and warrants further exploration.

ESPEN guideline on nutritional support for polymorbid medical inpatients

BACKGROUND

Disease-related malnutrition in polymorbid medical inpatients is a highly prevalent syndrome associated with significantly increased morbidity, disability, short- and long-term mortality, impaired recovery from illness, and cost of care.

AIM

As there are uncertainties in applying disease-specific guidelines to patients with multiple conditions, our aim was to provide evidence-based recommendations on nutritional support for the polymorbid patient population hospitalized in medical wards.

METHODS

This update adheres to the standard operating procedures for ESPEN guidelines. We did a systematic literature search for 15 clinical questions in three different databases (Medline, Embase and the Cochrane Library), as well as in secondary sources (e.g. published guidelines), until July 12th. Retrieved abstracts were screened to identify relevant studies that were used to develop recommendations (incl. SIGN grading), which was followed by submission to Delphi voting.

RESULTS

From a total of 3527 retrieved abstracts, 60 new relevant studies were analyzed and used to generate a guideline draft that proposed 32 recommendations (7x A, 11x B, 10x O and 4x GPP), which encompass different aspects of nutritional support including indication, route of feeding, energy and protein requirements, micronutrient requirements, disease-specific nutrients, timing, monitoring and procedure of intervention. The results of the first online voting showed a strong consensus (agreement of >90%) on 100% of the recommendations. Therefore, no final consensus conference was needed.

CONCLUSIONS

Recent high-quality trials have provided increasing evidence that nutritional support can reduce morbidity and other complications associated with malnutrition in polymorbid patients. The timely screening of patients for risk of malnutrition at hospital admission followed by individualized nutritional support interventions for at-risk patients should be part of routine clinical care and multimodal treatment in hospitals worldwide. Use of this updated guideline offers an evidence-based nutritional approach to the polymorbid medical inpatients and may improve their outcomes.

Metabolic and nutritional aspects in continuous renal replacement therapy

Nutrition is one of the foundations for supporting and treating critically ill patients. Nutritional support provides calories, protein, electrolytes, vitamins, and trace elements via the enteral or parenteral route. Acute kidney injury (AKI) is a common and devastating problem in critically ill patients and has significant metabolic and nutritional consequences. Moreover, renal replacement therapy (RRT), whatever the modality used, also profoundly impacts metabolism. RRT and of the extracorporeal circuit impede 'effect the evaluation of a patient's energy requirements by clinicians. Substrates added and removed within the extracorporeal treatment are not always taken into consideration, making treatment even more challenging. Furthermore, evidence on nutritional support during continuous renal replacement therapy (CRRT) is scarce, and there are no clinical guidelines for nutrition adaptations during CRRT in critically ill patients. Most recommendations are based on expert opinions. This review discusses the complex interaction between nutritional support and CRRT and presents some milestones for nutritional support in critically ill patients on CRRT.

Predictive Equations Overestimate Resting Metabolic Rate in Young Chilean Women with Excess Body Fat

Underestimating/overestimating resting metabolic rate (RMR) affects energy prescription. The objective was to compare RMR by indirect calorimetry (RMR IC) and RMR estimated by predictive equations in women with excess body fat. This was an analytical cross-sectional study with 41 women aged 18-28 with overnutrition according to body composition. The RMR IC was measured and RMR estimated using the FAO/WHO/UNU (1985), FAO/WHO/UNU (2004), Harris-Benedict, and Mifflin-St Jeor equations. The percentage of adequacy (90-110%), overestimation (>110%), and underestimation (<90%) were evaluated for RMR IC. Data were described by percentiles because of non-normal distribution according to the Shapiro-Wilk test. The Kruskal-Wallis test and Bland-Altman analysis were applied at a significance level of α < 0.05. The RMR IC was 1192 and 1183 calories/day (p = 0.429) in women with obesity and overweight, respectively. The FAO/WHO/UNU (1985), FAO/WHO/UNU (2004), Harris-Benedict, and Mifflin-St Jeor equations overestimated the RMR IC by 283.2, 311.2, 292.7, and 203.0 calories/day and by 296.7, 413.8, 280.0, and 176.6 calories/day for women with overweight and obesity (p < 0.001), respectively. The Harris-Benedict adjusted weight (0.5) equation underestimated RMR IC by 254.7 calories/day. The predictive equations overestimated RMR IC in women with excess body fat. The Mifflin-St Jeor equation showed less overestimation and better adequacy, but was not exempt from inaccuracy.

Dose-response relationship between physical activity and cardiometabolic risk in obese children and adolescents: A pre-post quasi-experimental study

Objective: This study aims to explore the dose-response relationship between the daily duration of moderate to vigorous physical activity and the improvement of cardiometabolic risk indicators in obese children and adolescents. Methods: Seventy-seven obese children and adolescents aged 10-17 years were randomly recruited for a 4-week exercise intervention in a closed camp during 2019-2021, physical activity was monitored by ActiGraph GT3X + to obtain daily MVPA duration, and the improvement of CMR indicators were reflected by the changes (Δ) of waist circumference, systolic blood pressure, diastolic blood pressure, total cholesterol, triglyceride , high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting insulin, fasting plasma glucose, and homeostasis model assessment of insulin resistance before and after the intervention, calculated as ''Δ+indicator" = values after intervention-values before intervention. The groups were divided into different doses of Q1∼Q3 according to the daily MVPA duration from low to high. The differences in the improvement of different dose groups were compared by one-way analysis of covariance, and the dose-response relationship between MVPA duration and CMR indicators improvement was analyzed by linear regression and piecewise regression. The nonlinear relationship was analyzed by restricted cubic spline. Results: 1) Compared with indicators before the intervention, WC, SBP, DBP, TC, TG, HDL-C, LDL-C, FINS, and HOMA-IR were significantly lower after the intervention (p-value < 0.05). 2) The dose-response relationship between MVPA and LDL-C improvement was non-linear (P-Nonlinear < 0.05). When MVPA >77.1min/day, ΔLDL-C further decreased with the increase of MVPA duration [β = -0.009, 95% confidence interval (CI): -0.013, -0.005], and when MVPA ≤77.1min/day, increasing the MVPA duration did not increase the improvement of ΔLDL-C. Conclusion: There was a nonlinear dose-response relationship between the daily MVPA duration and LDL-C improvement in obese children and adolescents. In order to obtain more significant improvement in LDL-C through increased MVPA duration, MVPA duration should be higher than 77.1 min/day.

Resting Energy Expenditure in the Critically Ill and Healthy Elderly-A Retrospective Matched Cohort Study

The use of indirect calorimetry to measure resting energy expenditure (mREE) is widely recommended as opposed to calculating REE (cREE) by predictive equations (PE). The aim of this study was to compare mREE with cREE in critically ill, mechanically ventilated patients aged ≥ 75 years and a healthy control group matched by age, gender and body mass index. The primary outcome was the PE accuracy rate of mREE/cREE, derived using Bland Altman plots. Secondary analyses included linear regression analyses for determinants of intraindividual mREE/cREE differences in the critically ill and interindividual mREE differences in the matched healthy cohort. In this retrospective study, 90 critically ill patients (median age 80 years) and 58 matched healthy persons were included. Median mREE was significantly higher in the critically ill (1457 kcal/d) versus the healthy cohort (1351 kcal/d), with low PE accuracy rates (21% to 49%). Independent predictors of mREE/cREE differences in the critically ill were body temperature, heart rate, FiO₂, hematocrit, serum sodium and urea. Body temperature, respiratory rate, and FiO₂ were independent predictors of interindividual mREE differences (critically ill versus healthy control). In conclusion, the commonly used PE in the elderly critically ill are inaccurate. Respiratory, metabolic and energy homeostasis variables may explain intraindividual mREE/cREE as well as interindividual mREE differences.

The Caloric Necessities of Critical Care Patients During the First Week of Admission

INTRODUCTION

 The nutritional needs of critically ill patients have been the subject of intense controversy. In accordance with international guidelines, it is advocated to optimize a nutritional intake based on the following recommendation: 25-30 kcal/kg body weight per day. However, there still are authors who recommend permissive underfeeding in the first week of hospitalization. Nevertheless, energy expenditure (EE) and necessity are influenced by the catabolic phase of critical illness, which may vary over time on a patient and from patient to patient.

OBJECTIVE

The objective of this study is to assess if the energy needs of critically ill patients admitted in our intensive care unit (ICU) in the first week of hospitalization are in line with those recommended by the European Society for Clinical Nutrition and Metabolism (ESPEN) international guidelines.

METHODS

A prospective cross-sectional study was carried out from September to December 2019. The energy needs were evaluated by indirect calorimetry and by the Harris-Benedict equation. Stress variables were evaluated, namely, the type of pathology, hemodynamic support, sedation, temperature, sequential organ failure assessment (SOFA) score, and state at discharge.

RESULTS

Forty-six patients were included in this study, with an average energy expenditure by indirect calorimetry of 19.22 ± 4.67 kcal/kg/day. The energy expenditure was less than 20 kcal/kg/day in 63% of the measurements. The concordance rate did not show the relationship between the Harris-Benedict equation and the values of indirect calorimetry. Stress variables were analyzed, with the SOFA score as the only variable with values close to statistical significance.

CONCLUSION

In our ICU, the energy needs of critically ill patients in the first week of hospitalization are lower than the intake recommended by the guidelines.

Resting and exercise metabolic characteristics in obese children with insulin resistance

Purpose: This study aimed to explore the characteristics of resting energy expenditure (REE) and lipid metabolism during incremental load exercise in obese children and adolescents with insulin resistance (IR) to provide evidence for exercise intervention in obese children and adolescents with IR.

Method: From July 2019 to August 2021, 195 obese children and adolescents aged 13–17 were recruited through a summer camp. The participants were divided into IR (n = 67) and no-IR (without insulin resistance, n = 128) groups and underwent morphology, blood indicators, body composition, and resting energy consumption gas metabolism tests. Thirty participants each were randomly selected from the IR and no-IR groups to carry out the incremental treadmill test.

Results: Significant metabolic differences in resting and exercise duration were found between the IR and no-IR groups. In the resting state, the resting metabolic equivalents (4.33 ± 0.94 ml/min/kg vs. 3.91 ± 0.73 ml/min/kg, p = 0.001) and REE (2464.03 ± 462.29 kcal/d vs. 2143.88 ± 380.07 kcal/d, p &lt; 0.001) in the IR group were significantly higher than in the no-IR group. During exercise, the absolute maximal fat oxidation (0.33 ± 0.07 g/min vs. 0.36 ± 0.09 g/min, p = 0.002) in the IR group was significantly lower than in the no-IR group; maximal fat oxidation intensity (130.9 ± 8.9 bpm vs. 139.9 ± 7.4 bpm, p = 0.040) was significantly lower in the IR group.

Conclusion: Significant resting and exercise metabolic differences were found between obese IR and no-IR children and adolescents. Obese IR children and adolescents have higher REE and lower maximal fat oxidation intensity than obese no-IR children and adolescents.

Predictive Equation to Estimate Resting Metabolic Rate in Older Chilean Women

Resting metabolic rate (RMR) depends on body fat-free mass (FFM) and fat mass (FM), whereas abdominal fat distribution is an aspect that has yet to be adequately studied. The objective of the present study was to analyze the influence of waist circumference (WC) in predicting RMR and propose a specific estimation equation for older Chilean women. This is an analytical cross-sectional study with a sample of 45 women between the ages of 60 and 85 years. Weight, height, body mass index (BMI), and WC were evaluated. RMR was measured by indirect calorimetry (IC) and %FM using the Siri equation. Adequacy (90% to 110%), overestimation (>110%), and underestimation (<90%) of the FAO/WHO/UNU, Harris−Benedict, Mifflin-St Jeor, and Carrasco equations, as well as those of the proposed equation, were evaluated in relation to RMR as measured by IC. Normal distribution was determined according to the Shapiro−Wilk test. The relationship of body composition and WC with RMR IC was analyzed by multiple linear regression analysis. The RMR IC was 1083.6 ± 171.9 kcal/day, which was significantly and positively correlated with FFM, body weight, WC, and FM and inversely correlated with age (p < 0.001). Among the investigated equations, our proposed equation showed the best adequacy and lowest overestimation. The predictive formulae that consider WC improve RMR prediction, thus preventing overestimation in older women.

Obese Women Have a High Carbohydrate Intake without Changes in the Resting Metabolic Rate in the Luteal Phase

Hormonal changes are caused by the menstrual cycle phases, which influence resting metabolic rate and eating behavior. The aim of the study was to determine resting metabolic rate (RMR) and its association with dietary intake according to the menstrual cycle phase in lean and obese Chilean women. This cross-sectional analytical study included 30 adult women (15 lean and 15 with obesity). Body composition was measured with a tetrapolar bioelectrical impedance meter. Nutritional status was determined by adiposity. A 24-h recall of three nonconsecutive days verifies dietary intake. The RMR was measured by indirect calorimetry. All measurements were performed in both the follicular and luteal phases of the menstrual cycle. Statistical analyses were performed with STATA software at a significance level, which was α = 0.05. The RMR (β = 121.6 kcal/d), temperature (β = 0.36 °C), calorie intake (β = 317.1 kcal/d), and intake of lipids (β = 13.8 g/d) were associated with the luteal phase in lean women. Only extracellular water (β = 1.11%) and carbohydrate consumption (β = 45.2 g/d) were associated in women with obesity. Lean women showed increased RMR, caloric intake, and lipid intake during the luteal phase. For women with obesity, carbohydrate intake increased but not RMR.

Assessment of resting energy expenditure in patients with cirrhosis

BACKGROUND

Malnutrition affects 20% to 50% of patients with cirrhosis. It may be associated with serious complications and has a direct impact on prognosis. Resting energy expenditure (REE) is an important parameter to guide the optimization of therapy and recovery of nutritional status in patients with cirrhosis. However, the REE of patients with cirrhosis is still unclear, casting doubt upon the optimal nutritional management approach.

AIM

To identify the best method that predicts the REE of cirrhotic patients, using indirect calorimetry (IC) as the gold standard.

METHODS

An observational study was performed on 90 patients with cirrhosis. REE was assessed by IC, bioelectrical impedance analysis (BIA), and predictive formulas, which were compared using Bland-Altman plots and the Student’s t-test.

RESULTS

REE values measured by IC (1607.72 ± 257.4 kcal) differed significantly from those determined by all other methods (BIA: 1790.48 ± 352.1 kcal; Harris & Benedict equation: 2373.54 ± 254.9 kcal; IOM equation: 1648.95 ± 185.6 kcal; Cunningham equation: 1764.29 ± 246.2 kcal), except the Food and Agriculture Organization of the United Nations, World Health Organization, and United Nations University (FAO/WHO/UNU) (1616.07 ± 214.6 kcal) and McArdle (1611.30 ± 241.8 kcal) equations. We found no significant association when comparing IC and 24-h dietary recall among different Child-Pugh classes of cirrhosis.

CONCLUSION

The IOM and FAO/WHO/UNU equations have the best agreement with the CI. These results indicate a possibility of different tools for the clinical practice on cirrhotic patients.

Inflection-Point Nutrition Support Determined by Oral Mucosal Apoptosis Rate Is a Novel Assessment Strategy for Personalized Nutrition: A Prospective Cohort Study

Background: Energy intake and nutritional status influences a patient’s recovery from major abdominal surgery. The aim of this study is to explore and validate the clinical feasibility of an inflection-point nutrition strategy for personalized nutrition in gastric cancer patients after surgery. Methods: We conducted a prospective cohort study from a single tertiary referral hospital. Patients diagnosed with gastric cancer who met the inclusion criteria were included in this study. We collected the demographic and clinic pathological characteristics of included patients. Patients were divided into a formular nutrition (FN) and inflection-point nutrition (IPN) group. We monitored the perioperative dynamics of the oral mucosal epithelia cell apoptosis rate. Predictive factors for inflection phenomenon were investigated in univariate and multivariate analysis. Results: A total of 53 gastric cancer patients were included. A total of 30 (56.6%) patients showed the inflection phenomenon, with 9 (34.6%) patients in the FN group and 21 (77.8%) patients in the IPN group, respectively. We found that patients with the inflection phenomenon had a shorter duration of hospital stay compared to patients without the inflection phenomenon (p = 0.04). In multivariate analysis, independent predictive factors for inflection phenomenon were age (p = 0.015), operation time ≤ 300 min (p = 0.012), and average energy intake ≥ 25 Kcal/kg/day (p = 0.038). Conclusions: Our findings for the first time revealed that the oral epithelial cell apoptosis rate can promptly reflect the patients’ perioperative nutrition needs. Meanwhile, we developing a novel and feasible nutrition therapy guided by the oral epithelial cell apoptosis rate is novel in gastric cancer patients that have undergone laparoscopic gastrectomy.

Caloric adequacy of parenteral nutrition and its influence on the clinical outcome of hospitalised patients

Background: The adaptation of Parenteral Nutrition (PN) to actual energy requirements of hospitalised patients is essential, since excessive and insufficient nutritional intake have been associated with poor clinical outcomes. Aim: To evaluate the adaptation of prescribed PN to the estimated nutritional requirements using three predictive equations and the influence of excessive/insufficient nutrient intake on patient clinical outcomes (nutritional parameters, metabolic and infectious complications). Methods: Prospective, observational study in hospitalised patients nutritionally assessed. Data was collected the first and fifth/sixth day of PN with clinical (infection, length of hospital stay), biochemical (visceral proteins, cholesterol, glucose, triglycerides, lymphocytes, CRP) and anthropometric parameters (skin folds, height, weight). Theoretical requirements were calculated using Harris-Benedict (HB), Mifflin-St Jeor (MF) and 25 Kcal/Kg/day formulas. The HB formula was used to compare estimated and provided requirements. Results: A total of 94 patients (mean: 72 ± 13.7 years old) were included with initial mean weight and height of 69.2 Kg and 162.8 cm, respectively (mean BMI: 26.1 Kg/m²). No statistically significant differences were found between the actual (1620 Kcal/day) and estimated caloric mean calculated with HB (1643 Kcal/day) and MF (1628 Kcal/day). When comparing with the caloric estimation, 31.9% of patients were underfed, while 14.9% were overfed. Intergroup analysis demonstrated significant variations in albumin, prealbumin, glucose, cholesterol, triglycerides and MUAC, with a significant increase of hyperglycaemia (+37.86; p < 0.05) and hypertriglyceridemia (+63.10; p < 0.05), being higher in overfed patients. Conclusion: In our study, inadequate nutrient intake was associated with a higher degree of hyperglycaemia and hypertriglyceridemia, without positive impact on anthropometric parameters.

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.

Indirect Calorimetry as an Instrument of Research to Identify the Effect of Hypermetabolism in Critical Patients' Prognosis

Background: Energy expenditure (EE) evaluation in Intensive Care Unit (ICU) patients can be very challenging. Critical illness is characterized by great variability in EE, which is influenced by the disease itself and the effects of treatment. Indirect calorimetry (IC) is currently the gold standard to measure EE in Intensive Care Unit (ICU) patients. However, calorimeters are not widely available, and predictive formulas (PF) are still commonly used, leading to under or overfeeding and deleterious consequences.Important metabolic changes occur and catabolism becomes prominent in critically ill patients.Both hyper and hypometabolism can be observed, but hypermetabolic patients appear to have higher mortality rates compared to metabolically normal patients. This study aimed to assess hypermetabolism incidence and compare clinical outcomes between hypermetabolic and normometabolic patients in ICU.

Methods: A single-center, retrospective, and observational study was conducted in the ICU of the Hospital do Divino Espírito Santo in Ponta Delgada, between August 2018 and February 2021. Only invasively mechanically ventilated patients were included. Resting energy expenditure (REE) was predicted by 25 kcal/kg/day formula to obtain predicted resting energy expenditure (PREE), and REE was measured by IC to obtain measured resting energy expenditure (MREE). According to their metabolic state (PREE/MREE), patients were divided into hypermetabolic (≥1.3) and normometabolic (<1.3). To determine the limits of agreement between PREE and MREE, we performed a Bland-Altman (BA) analysis. Baseline characteristics, severity criteria, nutritional status, and main diagnosis on admission were compared. The primary outcome considered was 30-day mortality. Other outcomes such as the ICU length of stay (LOS), in-hospital LOS, and length of invasive ventilation were also evaluated.

Results: Among the 80 ICU patients included in the final analysis, 67 patients were normometabolic (83.4%). Patients admitted due to pneumonia were more hypermetabolic, 8 (61.5%) vs. 10 (14.9%); p<0.001. Hypermetabolism was found also in patients admitted due to sepsis/septic shock, 7 (53.8%) vs. 16 (23.9%); p=0.029. Hypermetabolic patients had lower body mass index (22.5 [interquartile range (IQR): 21.5-24.9] vs. 27.7 [IQR: 25.0-32.4] kg/m²; p=0.001) and higher MREE (2715.0 [2399.0-3090.0] vs. 1690.0 [1410.0-2190.0] kcal/day; p<0.001). Bland-Altman analysis showed a mean difference of -5.6 ± 744.7 Kcal/day between the PREE and MREE by IC. No statistically significant difference was found between the two groups, neither in 30-day mortality nor in the other outcomes considered.

Conclusions: Hypermetabolism was not seen to present a greater risk of death in mechanically ventilated patients in ICU. Lower BMI, sepsis/septic shock, and pneumonia appear to be associated with a hypermetabolic state.

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.

Endogenous Glucose Production in Critical Illness

Regulation of endogenous glucose production (EGP) by hormonal, neuronal, and metabolic signaling pathways contributes to the maintenance of euglycemia under normal physiologic conditions. EGP is defined by the generation of glucose from substrates through glycogenolysis and gluconeogenesis, usually in fasted states, for local and systemic use. Abnormal increases in EGP are noted in patients with diabetes mellitus type 2, and elevated EGP may also impact the pathogenesis of nonalcoholic fatty liver disease and congestive heart failure. In this narrative review, we performed a literature search in PubMed to identify recently published English language articles characterizing EGP in critical illness. Evidence from preclinical and clinical studies demonstrates that critical illness can disrupt EGP through multiple mechanisms including increased systemic inflammation, counterregulatory hormone and catecholamine release, alterations in the hypothalamic-pituitary axis, insulin resistance, lactic acidosis, and iatrogenic insults such as vasopressors and glucocorticoids administered as part of clinical care. EGP contributes to hyperglycemia in critical illness when abnormally elevated and to hypoglycemia when abnormally depressed, each of which has been independently associated with increased mortality. Increased EGP may also promote protein catabolism that could worsen critical illness myopathy and impede recovery. Better understanding of the mechanisms and factors contributing to dysregulated EGP in critical illness may help in the development of therapeutic strategies that promote euglycemia, reduce intensive care unit-associated catabolism, and improve patient outcomes.

Point-Counterpoint: Indirect Calorimetry Is not Necessary for Optimal Nutrition Therapy in Critical Illness

Clinicians have widely recognized that indirect calorimetry (IC) is the "gold standard" for measuring energy expenditure (EE) and thus would intuitively anticipate that its use would be needed to provide optimal nutrition support in critical illness. Recent studies in the literature as well as dramatic changes in clinical practice over the past decade, though, would suggest that such a precise measure by IC to set energy goals is not required to maximize clinical benefit from early feeding in the intensive care unit (ICU). Results from randomized controlled trials evaluating permissive underfeeding, use of supplemental parenteral nutrition to achieve tight calorie control, and caloric density of formulas to increase energy delivery have provided an important perspective on 3 pertinent issues. First, a simple weight-based predictive equation (25 kcal/kg/day) provides a clinically useful approximation of EE. Second, a precise measure of EE by IC does not appear to improve outcomes compared with use of this less accurate estimation of energy requirements. And third, providing some percentage of requirements (50%-80%), achieves similar clinical benefit to full feeding (100%) in the early phases of critical illness. The value from IC use lies in the determination of caloric requirements in conditions for which weight-based equations are rendered inaccurate (anasarca, amputation, severe obesity) or the clinical state is markedly altered (such as the prolonged hyperinflammatory state of coronavirus disease 2019 [COVID-19]). In most other circumstances, routine use of IC would not be expected to change clinical outcomes from early nutrition therapy in the ICU.

ESPEN guideline on clinical nutrition in hospitalized patients with acute or chronic kidney disease

Acute kidney disease (AKD) - which includes acute kidney injury (AKI) - and chronic kidney disease (CKD) are highly prevalent among hospitalized patients, including those in nephrology and medicine wards, surgical wards, and intensive care units (ICU), and they have important metabolic and nutritional consequences. Moreover, in case kidney replacement therapy (KRT) is started, whatever is the modality used, the possible impact on nutritional profiles, substrate balance, and nutritional treatment processes cannot be neglected. The present guideline is aimed at providing evidence-based recommendations for clinical nutrition in hospitalized patients with AKD and CKD. Due to the significant heterogeneity of this patient population as well as the paucity of high-quality evidence data, the present guideline is to be intended as a basic framework of both evidence and - in most cases - expert opinions, aggregated in a structured consensus process, in order to update the two previous ESPEN Guidelines on Enteral (2006) and Parenteral (2009) Nutrition in Adult Renal Failure. Nutritional care for patients with stable CKD (i.e., controlled protein content diets/low protein diets with or without amino acid/ketoanalogue integration in outpatients up to CKD stages four and five), nutrition in kidney transplantation, and pediatric kidney disease will not be addressed in the present guideline.

The use of a portable metabolic monitoring device for measuring RMR in healthy adults

Objective measurement of RMR may be important for optimal nutritional care but is hindered by the price and practicality of the metabolic monitoring device. This study compared two metabolic monitoring devices for measuring RMR and VO2 and compared the measured RMR with the predicted RMR calculated from equations. RMR was measured using QUARK RMR (reference device) and Fitmate GS (COSMED) in a random order for 30 min, each on fasted participants. In total, sixty-eight adults participated (median age 22 years, interquartile range 21-32). Pearson correlation showed that RMR (r 0·86) and VO2 (r 0·86) were highly correlated between the two devices (P < 0·05). Intraclass correlation coefficients (ICC) showed good relative agreements regarding RMR (ICC = 0·84) and VO2 (ICC = 0·84) (P < 0·05). RMR measured by QUARK RMR was significantly higher (649 (sd 753) kJ/d) than Fitmate GS. Equations significantly overpredicted RMR. Accurate RMR (i.e. within ±10 % of the RMR measured by QUARK RMR) was found among 38 % of the participants for Fitmate GS and among 46-68 % depending on the equations. Bland-Altman analysis showed a low absolute agreement with QUARK RMR at an individual level for both Fitmate GS (limits of agreement (LOA): -828 to +2125 kJ/d) and equations (LOA ranged from -1979 to +1879 kJ/d). In conclusion, both Fitmate GS and predictive equations had low absolute agreements with QUARK RMR at an individual level. Therefore, these limitations should be considered when determining RMR using Fitmate GS or equations.

Accuracy of resting metabolic rate prediction equations among healthy adults in Trinidad and Tobago

BACKGROUND

Over 50% of adults in Latin America and the Caribbean have a body mass index (BMI) ≥ 25 suggesting excess energy intakes relative to energy expenditure. Accurate estimation of resting metabolic rate (RMR), the largest component of total energy requirements, is crucial to strategies aimed at reducing the prevalence and incidence of overweight and obesity.

AIM

We evaluated the accuracies of established and locally developed RMR prediction equations (RMR_P) among adults.

METHODS

Four hundred adult volunteers ages 20 to 65 years had RMR measured (RMR_M) with a MedGem® indirect calorimeter according to recommended procedures. RMR_P were compared to RMR_M with values ± 10% of RMR_M deemed accurate. Anthropometry was measured using standard procedure. Linear regression with bootstrap analyses was used to develop local RMR_P equations based on anthropometric and demographic variables. The University of the West Indies Ethics Committee approved the study.

RESULTS

Males had higher mean absolute RMR (p < 0.001) but similar mean age-adjusted measured RMR per kg of body (20.9 vs. 21.5 kcals/day; p = 0.1) to females. The top performing established anthropometry-based RMR_P among participants by sex, physical activity (PA) level and BMI status subgroups were Mifflin-St Jeor, Owen, Korth, Harris-Benedict, and Livingston, while Johnstone, Cunningham, Müller (body composition (BC)), Katch and McArdle, Mifflin-St Jeor (BC) were the most accurate BC-based RMR_P. Locally developed RMR_P had accuracies comparable to their top-ranked established RMR_P counterparts.

CONCLUSIONS

Accuracies of established RMR_P depended on habitual PA level, BMI status, BC and sex. Furthermore, locally developed RMR_P provide useful alternatives to established RMR_P.

Measured and Predicted Resting Energy Expenditure in Malnourished Older Hospitalized Patients: A Cross-Sectional and Longitudinal Comparison

A number of equations have been proposed to predict resting energy expenditure (REE). The role of nutritional status in the accuracy and validity of the REE predicted in older patients has been paid less attention. We aimed to compare REE measured by indirect calorimetry (IC) and REE predicted by the Harris–Benedict formula in malnourished older hospitalized patients. Twenty-three malnourished older patients (age range 67–93 years, 65% women) participated in this prospective longitudinal observational study. Malnutrition was defined as Mini Nutritional Assessment Long Form (MNA-SF) score of less than 17. REE was measured (REE_measured) and predicted (REE_predicted) on admission and at discharge. REE_predicted within ±10% of the REE_measured was considered as accuracy. Nutritional support was provided to all malnourished patients during hospitalization. All patients were malnourished with a median MNA-LF score of 14. REE_measured and REE_predicted increased significantly during 2-week nutritional therapy (+212.6 kcal and +19.5 kcal, respectively). Mean REE_predicted (1190.4 kcal) was significantly higher than REE_measured (967.5 kcal) on admission (p < 0.001). This difference disappeared at discharge (p = 0.713). The average REE_predicted exceeded the REE_measured on admission and at discharge by 29% and 11%, respectively. The magnitude of difference between REE_measured and REE_predicted increased along with the degree of malnutrition (r = 0.42, p = 0.042) as deviations ranged from −582 to +310 kcal/day in severe to mildly malnourished patients, respectively. REE_predicted by the Harris–Benedict formula is not accurate in malnourished older hospitalized patients. REE measured by IC is considered precise, but it may not represent the true energy requirements to recover from malnutrition. Therefore, the effect of malnutrition on measured REE must be taken into account when estimating energy needs in these patients.

Insufficient Calorie Intake Worsens Post-Discharge Quality of Life and Increases Readmission Burden in Heart Failure

OBJECTIVES

The purpose of this study was to evaluate the relationship between calorie intake and post-discharge outcomes in hospitalized patients with heart failure (HF).

BACKGROUND

Malnutrition increases adverse outcomes in HF, and dietary sodium restriction may inadvertently worsen nutritional intake.

METHODS

In a dietary intervention trial, baseline nutritional intake in HF inpatients was estimated using the Block Food Frequency Questionnaire (FFQ), and the Nutritional Risk Index (NRI) was calculated. Insufficient calorie intake was defined as <90% of metabolic needs, and a 15-point micronutrient deficiency score was created. Adjusted linear, logistic, and negative binomial regression were used to evaluate associations between insufficient calorie intake and quality of life (using the Kansas City Cardiomyopathy Questionnaire Clinical Summary [KCCQ-CS]), readmission risk, and days rehospitalized over 12 weeks.

RESULTS

Among 57 participants (70 ± 8 years of age; 31% female; mean body mass index 32 ± 8 kg/m²); median sodium and calorie intake amounts were 2,987 mg/day (interquartile range [IQR]: 2,160 to 3,540 mg/day) and 1,602 kcal/day (IQR: 1,201 to 2,142 kcal/day), respectively; 11% of these patients were screened as malnourished by the NRI. All patients consuming <2,000 mg/day sodium had insufficient calorie intake; this group also more frequently had dietary micronutrient and protein deficiencies. At 12 weeks, patients with insufficient calorie intake had less improvement in the KCCQ-CS score (β = -14.6; 95% confidence interval [CI]: -27.3 to -1.9), higher odds of readmission (odds ratio: 14.5; 95% CI: 2.2 to 94.4), and more days rehospitalized (incident rate ratio: 31.3; 95% CI: 4.3 to 229.3).

CONCLUSIONS

Despite a high prevalence for obesity and rare overt malnutrition, insufficient calorie intake was associated with poorer post-discharge quality of life and increased burden of readmission in patients with HF. Inpatient dietary assessment could improve readmission risk stratification and identify patients for nutritional intervention. (Geriatric Out of Hospital Randomized Meal Trial in Heart Failure [GOURMET-HF] NCT02148679).

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.

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 Impact of Nutritional Status and Energy Balance in Elderly Hospitalized Patients

OBJECTIVES

This study aimed 1) to assess the nutritional status of patients hospitalized in a geriatric ward using the recent Global Leadership Initiative on Malnutrition (GLIM) criteria, 2) to determine the balance between the energy intake (EI) with an enriched diet and the energy requirement (ER) using indirect calorimetry, and 3) to assess whether undernutrition is associated with 1-year outcome.

DESIGN

This is a prospective cross-sectional study.

SETTING

This study was performed in a geriatric unit.

PARTICIPANTS

Patients of this geriatric unit were eligible for the study if they agreed to participate and if they did not meet the exclusion criteria (presence of malignant tumour, uncontrolled heart or renal failure, thyroidal disease, uncontrolled sepsis, oedema of the lower limbs, wearing of a pacemaker, biological thyroid dysfunction and inability to perform walking tests).

MEASUREMENTS

Rest energy expenditure (REE) was measured by indirect calorimetry within the week of hospitalization. Total energy expenditure (TEE) was obtained by multiplying REE by a physical activity level coefficient and energy expenditure that was related to thermogenesis (i.e., 10% of the total amount of energy ingested over 24 h) was added. Food intake was measured over a 3-day period. Undernutrition was defined using MNA and the criteria of the GLIM leadership. Clinical outcomes included 1-year institutionalisation and mortality.

RESULTS

Seventy-nine patients (84.9 ± 5.3 years) were included. A total of 21 (26.6 %) patients were found undernourished. REE was 1088 ± 181kcal/day (17.8 ± 2.9 kcal/kg/day) and TEE was 1556 ± 258 kcal/day (25.4 ± 4.2 kcal/kg/day). Weight-adjusted REE and TEE were higher in undernourished patients compared to those well-nourished (19.8 ± 3.1 vs. 17.1 ± 2.6 kcal/day and 28.4±4.5 vs. 24.4±3.7 kcal/day) (p<0.05). The lower was the Body Mass Index (BMI), the higher was the energy needs (p<0.01). EI was significantly greater than energy requirements (difference requirements - intake with enriched diet = -354 ± 491 kcal/day; p<0.0001). This difference did not depend on BMI (p=0.82), appendicular skeletal mass index (ASMI) (p=0.63), or the presence of undernutrition (p=0.33). At 1-year follow-up, 15 (19%) patients died and 20 (25.6%) were institutionalized. On multivariable analysis, male gender (OR=5.63; p=0.015) and undernutrition (OR=7.29; p=0.0043) emerged as independently associated with death. On multivariable analysis, only ASMI (OR 0.59 (0.35-0.99), p=0.044) and activities of daily living (ADL) (OR 1.14 (1.00-1.30), p=0.043) were significantly associated with institutionalization.

CONCLUSIONS

Undernutrition as assessed by the GLIM criteria remains common in elderly patients hospitalized in a geriatric unit and is associated with increased 1-year mortality but not with institutionalization. Energy requirements are higher in undernourished patients and in patients with a low BMI. Enriched energy intakes could sufficiently cover the energy needs of this population.

Energy Expenditure in Older People Hospitalized for an Acute Episode

Weight loss and worsening of nutritional state is a frequent downfall of acute hospitalization in older people. It is usually accepted that acute inflammation is responsible for hypercatabolism. However, several studies suggest, on the contrary, a reduction in resting energy expenditure (REE). This study aimed to obtain a reliable measure of REE and total energy expenditure (TEE) in older patients hospitalized for an acute episode in order to better assess patients’ energy requirements and help understand the mechanisms of weight loss in this situation. Nineteen hospitalized older patients (mean age 83 years) with C-reactive protein (CRP) level >20mg/L were recruited. REE and TEE were measured using gold standard methods of indirect calorimetry and doubly labeled water (DLW), respectively. REE was then compared to data from a previous study on aged volunteers from nursing homes who were free of an acute stressor event. Energy requirements measured by DLW were confirmed at 1.3 × REE. Energy intake covered the needs but did not prevent weight loss in these patients. TEE was not increased in hospitalized patients and was not influenced by inflammation, while the relationship between REE and inflammation was uncertain. Our results suggest that lean mass remains the major determinant of REE in hospitalized older people and that weight loss may not be explained solely by a state of hypercatabolism.

Medical Nutrition Therapy in Critically Ill Patients Treated on Intensive and Intermediate Care Units: A Literature Review

Medical nutrition therapy in critically ill patients remains challenging, not only because of the pronounced stress response with a higher risk for complications, but also due to their heterogeneity evolving from different phases of illness. The present review aims to address current knowledge and guidelines in order to summarize how they can be best implemented into daily clinical practice. Further studies are urgently needed to answer such important questions as best timing, route, dose, and composition of medical nutrition therapy for critically ill patients and to determine how to assess and to adapt to patients’ individual needs.

Indirect Calorimetry in Clinical Practice

Indirect calorimetry (IC) is considered as the gold standard to determine energy expenditure, by measuring pulmonary gas exchanges. It is a non-invasive technique that allows clinicians to personalize the prescription of nutrition support to the metabolic needs and promote a better clinical outcome. Recent technical developments allow accurate and easy IC measurements in spontaneously breathing patients as well as in those on mechanical ventilation. The implementation of IC in clinical routine should be promoted in order to optimize the cost–benefit balance of nutrition therapy. This review aims at summarizing the latest innovations of IC as well as the clinical indications, benefits, and limitations.

Use of Predictive Equations for Energy Prescription Results in Inaccurate Estimation in Trauma Patients

BACKGROUND

Overfeeding and underfeeding are associated with poor clinical outcomes. In the absence of indirect calorimetry (IC), the Society of Critical Care Medicine/ASPEN recommend prescribing 25-30 kcal/kg. The Harris-Benedict equation (HBE) multiplied by a stress factor is commonly applied in critically ill patients. We describe the difference between estimated and actual energy needs in critically injured patients.

METHODS

From March to November 2018, we collected demographics and energy needs determined by continuous IC (started within 4 days) in intubated adults. Ideal or adjusted body weight was used for 25-30 kcal/kg, and HBE was multiplied by a 1.3 stress factor (1.3HBE). Daily requirements up to 14 days, extubation, or death were calculated using all 3 methods and compared with IC.

RESULTS

Fifty-five subjects were included. Median age was 38 [27-58] years, 38 (69%) were male, body mass index was 28 [25-33] kg/m² , and Acute Physiology and Chronic Health Evaluation II score was 17 [14-24] Mechanism of injury was blunt (38, 69%), penetrating (9, 16%), and burn (8, 15%). By day 14, compared with measured energy requirements by IC, the other methods could result in a cumulative 1827-kcal (+7%) surplus (1.3HBE), a 1313-kcal (-5%) deficit (25 kcal/kg), or a 3950-kcal (+14%) surplus (30 kcal/kg) per patient over a median 9 days.

CONCLUSION

In critically injured patients, predictive equations for energy needs do not account for dynamic metabolic changes over time and could result in underfeeding or overfeeding. Adjusting daily prescription based on continuous IC may result in better individualized treatment.

Energy expenditure in acute pancreatitis evaluated by the Harris-Benedict equation compared with indirect calorimetry

OBJECTIVES

Enteral nutrition (EN) is recommended for severe acute pancreatitis (AP) and for biliary AP if cholecystectomy is delayed. Energy expenditure (EE) is calculated using the Harris-Benedict equation (HBE), but indirect calorimetry (IC) can also be employed. We wished to compare EE evaluated by the HBE equation, modified HBE (mHBE) and IC at study inclusion and 1 month after AP resolution.

METHODS

We undertook a single-center prospective study in Paris, France.

RESULTS

Among 35 patients, 19 had biliary AP and 11 alcoholic-related AP. Eleven cases had severe AP. There was no significant difference between EE calculated by the HBE and that using IC at study inclusion. However, the EE calculated by the mHBE was significantly higher than that calculated using IC. For severe AP, the HBE underestimated EE whereas the mHBE overestimated it. No difference was found based on the cause of AP. There was no difference between methods for EE at 30 days.

CONCLUSIONS

The HBE underestimated EE for severe AP, whereas the mHBE overestimated it. IC seems to be the best means of EE evaluation for AP.

Reliability of, and Agreement Between, two Breath-by-Breath Indirect Calorimeters at Varying Levels of Inspiratory Oxygen

BACKGROUND

Indirect calorimetry (IC) is considered the accurate way of measuring energy expenditure (EE). IC devices often apply the Haldane transformation, introducing errors at inspiratory oxygen fraction (FiO₂ ) >60%. The aim was to assess measurement reliability and agreement between an unevaluated IC (device 2) (Beacon Caresystem, Mermaid Care A/S, Noerresundby, Denmark) not using Haldane transformation and an IC that does (device 1) (Ecovx, GE, Helsinki, Finland) at varying FiO₂ .

METHODS

Twenty healthy male subjects participated, with 16 completing the study (33 ± 9 years, 83.3 ± 16 kg, 1.83 ± 0.08 m). Subjects were mechanically ventilated in pressure support (3cmH₂ O; positive end-expiratory pressure: 3cmH₂ O) at FiO₂ of 21%, 50%, 85%, and 21% for 15 minutes at each FiO₂ . Mean EE, oxygen consumption (VO₂ ), and CO₂ production (VCO₂ ) were compared within and between devices across FiO₂ levels.

RESULTS

Device 2 showed within-device EE significant differences at 21% vs 50% FiO₂ and device 1 for VCO₂ at 50% vs. 85% FiO₂ . For all variables, both devices showed reliable measurements at 21% and 50% FiO₂ , but at 85%, FiO₂ bias and limits of agreement increased. Between devices, there were significant differences for EE at both 21% and 85% FiO₂ for VO₂ and for VCO₂ at 85% FiO₂ .

CONCLUSION

Both systems measured EE, VO₂ , and VCO₂ at 21%-85% FiO₂ reliably but with bias at 85% FiO₂ . The devices were in agreement at 21% and 50% FiO₂ , but further studies need to confirm accuracy at high FiO₂ .

Energy Requirements in Critically Ill Patients

During the management of critical illness, optimal nutritional support is an important key for achieving positive clinical outcomes. Compared to healthy people, critically ill patients have higher energy expenditure, thereby their energy requirements and risk of malnutrition being increased. Assessing individual nutritional requirement is essential for a successful nutritional support, including the adequate energy supply. Methods to assess energy requirements include indirect calorimetry (IC) which is considered as a reference method, and the predictive equations which are commonly used due to the difficulty of using IC in certain conditions. In this study, a literature review was conducted on the energy metabolic changes in critically ill patients, and the implications for the estimation of energy requirements in this population. In addition, the issue of optimal caloric goal during nutrition support is discussed, as well as the accuracy of selected resting energy expenditure predictive equations, commonly used in critically ill patients.

Determination of the energy requirements in mechanically ventilated critically ill elderly patients in different BMI groups using the Harris-Benedict equation

BACKGROUND

Due to studies on calorie requirement in mechanically ventilated critically ill elderly patients are few, and indirect calorimetry (IC) is not available in every intensive care unit (ICU). The aim of this study was to compare IC and Harris-Benedict (HB) predictive equation in different BMI groups.

METHODS

A total of 177 mechanically ventilated critically ill elderly patients (≧65 years old) underwent IC for measured resting energy expenditure (MREE). Estimated calorie requirement was calculated by the HB equation, using actual body weight (ABW) and ideal body weight (IBW) separately. Patients were divided into four BMI groups. One-way ANOVA and Pearson's correlation coefficient were used for statistical analyses.

RESULTS

The mean MREE was 1443.6 ± 318.2 kcal/day, HB(ABW) was 1110.9 ± 177.0 kcal/day and HB(IBW) was 1101.5 ± 113.1 kcal/day. The stress factor (SFA = MREE ÷ HB(ABW)) was 1.43 ± 0.26 for the underweight, 1.30 ± 0.27 for the normal weight, 1.20 ± 0.19 for the overweight, and 1.20 ± 0.31 for the obese. The SFI (SFI = MREE ÷ HB(IBW)) was 1.24 ± 0.24 for the underweight, 1.31 ± 0.26 for the normal weight, 1.36 ± 0.21 for the overweight, and 1.52 ± 0.39 for the obese. MREE had significant correlation both with REE(ABW) = HB(ABW) × SFA (r = 0.46; P < 0.0001) and REE(IBW) = HB(IBW) × SFI (r = 0.43; P < 0.0001).

CONCLUSION

IC is the best accurate method for assessing calorie requirement of mechanically ventilated critically ill elderly patients. When IC is not available, using the predictive HB equation is an alternative choice. Calorie requirement can be predicted by HB(ABW) × 1.20-1.43 for critically ill elderly patients according to different BMI groups, or using HB(IBW) × 1.24-1.52 for patients with edema, ascites or no available body weight data.

Preserved Fat-Free Mass after Gastric Bypass and Duodenal Switch

Background

Concerns for the possibility of an excessive loss of fat-free mass (FFM) and resting metabolic rate (RMR) after bariatric surgery, such as Roux-en-Y gastric bypass (RYGB) and duodenal switch (BPD/DS), have been raised.

Objectives

This study aims to examine body composition and RMR in patients after RYGB and BPD/DS and in non-operated controls.

Methods

Body composition and RMR were studied with Bod Pod and indirect calorimetry in weight-stable RYGB (n = 15) and BPD/DS patients (n = 12) and compared with non-operated controls (n = 17). All patients were 30–55 years old and weight stable with BMI 28–35 kg/m².

Results

FFM% was 58% (RYGB), 61% (BPD/DS), and 58% (controls). Body composition did not differ after RYGB and BPD/DS compared to controls, despite 27 and 40% total body weight loss, respectively. No difference in RMR or RMR/FFM was observed (1539, 1617, and 1490 kcal/24 h; and 28.9, 28.4, and 28.8 kcal/24 h/kg).

Conclusion

Weight-stable patients with BMI 28–35 kg/m² after RYGB and BPD/DS have a body composition and RMR similar to that of non-operated individuals within the same BMI interval.

Development and Validation of a New Cardio-Specific Resting Energy Expenditure Equation for Adults

BACKGROUND

This study tested the accuracy of resting energy expenditure (REE) equations among patients who underwent cardiopulmonary bypass and developed/validated a more accurate cardio-specific equation (CSE).

MATERIALS AND METHODS

Prospective observational cohort of 240 adults (derivation data set, 170 patients; validation data set, 70 patients). REEs were calculated with 6 equations-Penn State 2003a, Penn State 2003b, Ireton-Jones, Swinamer, Faisy, and American College of Chest Physicians-and results were compared with indirect calorimetry (IC). Multivariable linear regression analysis was used to develop the CSE. Agreement between measured and calculated REEs was assessed with Lin's concordance correlation coefficient (LCCC), Bland-Altman plot, and regression analysis.

RESULTS

LCCCs present poor agreement between measured and calculated REEs: 0.24 (95% CI, 0.19-0.29), for the Faisy equation; 0.15 (95% CI, 0.1-0.19), Ireton-Jones; 0.31 (95% CI, 0.25-0.37), Swinamer; 0.17 (95% CI, 0.13-0.21), Penn State 2003a; 0.19 (95% CI, 0.14-0.23), Penn State 2003b; and 0.11 (95% CI, 0.07-0.15), American College of Chest Physicians. Based on the derivation data set, REEs are explained by the following equation: CSE = 616 - 8 × age in years + 13 × weight in kilograms + 450 if on ventilator + 159 × MV in liters + 145 if on inotropes. Based on the validation study results, the LCCC between IC and the CSE was 0.82 (95% CI, 0.73-0.88).

CONCLUSION

The CSE has adequate precision and could be used for REE estimation for patients undergoing cardiopulmonary bypass if IC is unavailable.

Assessment of parenteral nutrition prescription in Canadian acute care settings

BACKGROUND

Parenteral nutrition (PN) prescription can be challenging in patients with complex conditions and has potential complications.

OBJECTIVE

To assess PN prescription, monitoring, and PN-related complications in a Canadian acute care setting.

METHODS

This was a prospective cohort study in which patients receiving PN were assessed by an auditor for nutritional status, PN-related prescription, monitoring, and complications. In addition, length of stay and mortality were recorded.

RESULTS

147 patients (mean ± SD 56.1 ± 16.4 y) with complex diseases (Charlson comorbidity index, median [p25-p75] 2 [1-4]) were enrolled. Before starting PN, 18.6%, 63.9%, and 17.5% of patients were classified as subjective global assessment A, B, and C, respectively. Body mass index remained unchanged during the period on PN. On average, 89% and 73% of patients received <90% of their energy and protein requirements, respectively, but 65% received oral or enteral nutrition at some point during PN. The average daily energy provided by PN increased and stabilized on day 10, reaching 87.2 ± 20.1% of the requirements. Line sepsis (6.8% of patients) and hyperglycemia (6.9%) were the most common complications. The overall mortality was 15.6%. For those alive, length of stay was 30 (range: 4-268) d. PN was discontinued because of transitioning to an oral diet (56.6%), enteral nutrition (17.6%), home PN (14.7%), palliative care (5.1%), death (4.4%), or other (1.5%).

CONCLUSION

Most patients were malnourished at the start of PN. Energy and protein provided from PN were less than requirements, and the goals were reached with delay. Mortality was high, possibly as a result of complex diseases.

Effects of intraoperative nutrients administration on energy expenditure during general anesthesia

OBJECTIVES

Recent reports have shown that intraoperative infusions of glucose and amino acids exert anticatabolic effects. The appropriate dosages of these amino acids and glucose during general anesthesia remain unknown.

METHODS

Patients who underwent esophagectomy for thoracic esophageal cancer were infused with acetated Ringer's solution that contained glucose and amino acids (B1 group [10 patients]: glucose, 3 g/h; amino acids, 1.2 g/h; B2 group [12 patients]: glucose, 4.5 g/h; amino acids, 1.8 g/h) or did not contain glucose and amino acids (C group, 10 patients). The measured energy expenditure was measured by indirect calorimetry. Nitrogen balance was measured during the anesthesia, and the lengths of the hospital stay were recorded.

RESULTS

Resting energy expenditure (B1: 1230 ± 228; B2: 1317 ± 282; C: 1012 ± 153 kcal/h; B2 vs C, P < 0.05) and nitrogen balance (B1: -1.78 ± 0.78 g; B2: -0.85 ± 0.98 g; C: -2.94 ± 2.4 g; B2 vs C, P < 0.05) differed significantly between the B2 and C groups. The lengths of the hospital stay differed between the B2 and C groups (B1: 29 ± 15 d; B2: 18 ± 6 d; C: 37 ± 27 d; B2 vs C, P = 0.06).

CONCLUSIONS

The administration of amino acids and glucose increased measured energy expenditure, alleviated nitrogen balance, and may decrease the length of the hospital stay.

Prognostic value of respiratory quotients in severe polytrauma patients with nutritional support

OBJECTIVE

The association between energy metabolism and prognosis in polytrauma patients has not yet been defined. The aim of this study was to describe energy metabolism and analyze the prognostic value of respiratory quotient (RQ) and nonprotein respiratory quotient (npRQ) in fasting polytrauma patients (fPP) and polytrauma patients with nutritional support (nsPP).

METHODS

Twenty-two polytrauma patients (before and after parenteral nutrition administration) and 22 healthy controls (after overnight fasting) were examined on day 4 (median) after admission to the intensive care unit. To evaluate energy expenditure in nsPP and resting energy expenditure in fPP and controls with RQ and npRQ in all groups, we used indirect calorimetry. With regression analysis, the descriptive models of intensive care unit (ICU) length of stay (LOS) and mechanical ventilation time (VT) were derived.

RESULTS

RQ and npRQ were significantly lower in fPP than in controls (P < 0.05 and P < 0.01, respectively) and in nsPP (P < 0.05). In nsPP, relationships between RQ or npRQ and the ICU LOS or mechanical VT were demonstrated (P < 0.0001, r = -0.78 for RQ and VT; P < 0.0001, r = -0.78 for npRQ and VT; P < 0.001, r = -0.69 for RQ and LOS; P < 0.001, r = -0.72 for npRQ and LOS).

CONCLUSIONS

RQ and npRQ parameters measured by indirect calorimetry in polytrauma patients with parenteral nutrition on the fourth day of ICU stay related to clinical outcomes such as duration of mechanical ventilation and ICU LOS.

Optimization of brain metabolism using metabolic-targeted therapeutic hypothermia can reduce mortality from traumatic brain injury

BACKGROUND

Therapeutic hypothermia is widely used to treat traumatic brain injuries (TBIs). However, determining the best hypothermia therapy strategy remains a challenge. We hypothesized that reducing the metabolic rate, rather than reaching a fixed body temperature, would be an appropriate target because optimizing metabolic conditions especially the brain metabolic environment may enhance neurologic protection. A pilot single-blind randomized controlled trial was designed to test this hypothesis, and a nested metabolomics study was conducted to explore the mechanics thereof.

METHODS

Severe TBI patients (Glasgow Coma Scale score, 3-8) were randomly divided into the metabolic-targeted hypothermia treatment (MTHT) group, 50% to 60% rest metabolic ratio as the hypothermia therapy target, and the body temperature-targeted hypothermia treatment (BTHT) control group, hypothermia therapy target of 32°C to 35°C body temperature. Brain and circulatory metabolic pool blood samples were collected at baseline and on days 1, 3, and 7 during the hypothermia treatment, which were selected randomly from a subgroup of MTHT and BTHT groups. The primary outcome was mortality. Using H nuclear magnetic resonance technology, we tracked and located the disturbances of metabolic networks.

RESULTS

Eighty-eight severe TBI patients were recruited and analyzed from December 2013 to December 2014, 44 each were assigned in the MTHT and BTHT groups (median age, 42 years; 69.32% men; mean Glasgow Coma Scale score, 6.17 ± 1.02). The mortality was significantly lower in the MTHT than the BTHT group (15.91% vs. 34.09%; p = 0.049). From these, eight cases of MTHT and six cases from BTHT group were enrolled for metabolomics analysis, which showed a significant difference between the brain and circulatory metabolic patterns in MTHT group on day 7 based on the model parameters and scores plots. Finally, metabolites representing potential neuroprotective monitoring parameters for hypothermia treatment were identified through H nuclear magnetic resonance metabolomics.

CONCLUSION

MTHT can significantly reduce the mortality of severe TBI patients. Metabolomics research showed that this strategy could effectively improve brain metabolism, suggesting that reducing the metabolic rate to 50% to 60% should be set as the hypothermia therapy target.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Energy and Protein in Critically Ill Patients with AKI: A Prospective, Multicenter Observational Study Using Indirect Calorimetry and Protein Catabolic Rate

The optimal nutritional support in Acute Kidney Injury (AKI) still remains an open issue. The present study was aimed at evaluating the validity of conventional predictive formulas for the calculation of both energy expenditure and protein needs in critically ill patients with AKI. A prospective, multicenter, observational study was conducted on adult patients hospitalized with AKI in three different intensive care units (ICU). Nutrient needs were estimated by different methods: the Guidelines of the European Society of Parenteral and Enteral Nutrition (ESPEN) for both calories and proteins, the Harris-Benedict equation, the Penn-State and Faisy-Fagon equations for energy. Actual energy and protein needs were repeatedly measured by indirect calorimetry (IC) and protein catabolic rate (PCR) until oral nutrition start, hospital discharge or renal function recovery. Forty-two patients with AKI were enrolled, with 130 IC and 123 PCR measurements obtained over 654 days of artificial nutrition. No predictive formula was precise enough, and Bland-Altman plots wide limits of agreement for all equations highlight the potential to under- or overfeed individual patients. Conventional predictive formulas may frequently lead to incorrect energy and protein need estimation. In critically ill patients with AKI an increased risk for under- or overfeeding is likely when nutrient needs are estimated instead of measured.

ESPEN guidelines on nutritional support for polymorbid internal medicine patients

BACKGROUND & AIMS

Polymorbidity (also known as multimorbidity) - defined as the co-occurrence of at least two chronic health conditions - is highly prevalent, particularly in the hospitalized population. Nonetheless, clinical guidelines largely address individual diseases and rarely account for polymorbidity. The aim of this project was to develop guidelines on nutritional support for polymorbid patients hospitalized in medical wards.

METHODS

The methodology used for the development of the current project follows the standard operating procedures for ESPEN guidelines. It started with an initial meeting of the Working Group in January 2015, where twelve key clinical questions were developed that encompassed different aspects of nutritional support: indication, route of feeding, energy and protein requirements, micronutrient requirements, disease-specific nutrients, timing, monitoring and procedure of intervention. Systematic literature searches were conducted in three different databases (Medline, Embase and the Cochrane Library), as well as in secondary sources (e.g. published guidelines), until April 2016. Retrieved abstracts were screened to identify relevant studies that were used to develop recommendations, which were followed by submission to Delphi voting rounds.

RESULTS

From a total of 4532 retrieved abstracts, 38 relevant studies were analyzed and used to generate a guideline draft that proposed 22 recommendations and four statements. The results of the first online voting showed a strong consensus (agreement of >90%) in 68% of recommendations and 75% of statements, and consensus (agreement of >75-90%) in 32% of recommendations and 25% of statements. At the final consensus conference, a consensus greater than 89% was reached for all of the recommendations.

CONCLUSIONS

Despite the methodological difficulties in creating non-disease specific guidelines, the evidence behind several important aspects of nutritional support for polymorbid medical inpatients was reviewed and summarized into practical clinical recommendations. Use of these guidelines offer an evidence-based nutritional approach to the polymorbid medical inpatient and may improve their outcomes.