Development of a new equation and validation of earlier resting energy expenditure predicting equations in adults living in Tehran.

Background: Predictive equations have been considered as a practical approach for estimating resting energy expenditure (REE) across multiple populations, but their accuracy for each community remains to be determined. Thus, the purposes of this study were to determine the validity of REE predictive equations and to develop a new REE predictive equation in adults living in Tehran. Methods: The study included 284 subjects (158 females) aged 18-60 years old from two cross-sectional studies conducted in Tehrani populations. Anthropometric measurements were assessed using standard protocols. REE was measured using indirect calorimetry (IC) and was estimated using preexisting equations. A new equation was also developed based on the REE from IC and variables such as age, sex, height, and weight. Measured REE was compared to new equation and preexisting predictive equations via correlation, linear regression, and Bland-Altman tests. Results: The new equation and the equations by Mifflin-St. Jeor, Livingston, Frankenfield, Nichols, Müller, and Ganpule demonstrated the best predictive value at a group level (mean percentage error=-2.2 to 2.4 %). At an individual level, the new equation and the equations by Mara, Frankenfield, Roza, Nikooyeh, and Harris & Benedict showed the greatest accuracies compared to measured REE (accuracy prediction=50-53%). Conclusion: This study highlights the importance of considering race when predicting REE. It also demonstrates that the newly developed equation is more appropriate in a clinical setting at group but not individual level. Thus, further research is needed to examine the new equation in an independent sample.

Efficacy of providing energy expenditure information to guide weight loss interventions in people with obesity: A randomized controlled trial.

Resting energy expenditure (REE) and metabolic fuel utilization (carbohydrate or fat) proxied by respiratory quotient (RQ) from indirect calorimetry enables more precise measurement of energy needs and fat oxidation capacity. The study compared the effectiveness of providing energy expenditure information during diet and exercise weight intervention versus standard of care (SOC) on weight loss outcomes. Fifty-two participants with obesity were recruited from a specialist weight loss service, randomized 1:1 to intervention (INT) or SOC only. Participants in INT received four-weekly dietetic counselling, using biofeedback from energy expenditure data to recommend caloric restriction and physical activity goals, in addition to SOC. The primary outcome was the mean difference in weight loss between both groups after 24 weeks. Secondary outcomes include participant acceptability and tolerability using indirect calorimetry. Participants in the INT group demonstrated additional weight loss (-2.3 kg [95% CI: -3.1, -1.5]; p <.001), reduced waist circumference (-3.9 cm [95% CI: -5.48, -2.26]; p <.001), and decreased body fat percentage (-1.5% [95% CI:-2.31, -0.72], p <.001), compared to SOC, after adjusting for baseline body mass index, age, and sex. Forty-two percent (10/24) of participants in INT group achieved the minimum clinically significant threshold of 5% weight loss from baseline, compared to 8% (2/26) in the SOC group (p = .007). Participant acceptability and tolerability of indirect calorimetry were high, with mean scores of 4.5 ± 0.6 and 4.2 ± 0.7 (5-point Likert scale). The study establishes the safety and practical integration of biofeedback using indirect calorimetry promoting improved self-regulation and enhancing weight loss.

The overlapping of phenotypes in Wiedemann-Steiner, Kleefstra and Coffin-Siris syndromes: a study of eleven patients.

BACKGROUND: Some chromatinopathies may present with common clinical findings (intellectual disability, brain and limb malformation, facial dysmorphism). Furthermore, one of their cardinal shared features is growth dysregulation.We aimed to assess and deepen this resemblance in three specific conditions, namely Wiedemann-Steiner (WDSTS), Kleefstra (KLEFS1) and Coffin-Siris syndrome (CSS1), with a particular focus on possible metabolic roots. METHODS: Eleven patients were enrolled, three with WDSTS, five with KLEFS1 and three with CSS1, referring to Fondazione IRCCS Ca' Granda Ospedale Maggiore, Milan, Italy. We performed both a physical examination with detailed anthropometric measurements and an evaluation of the patients' REE (rest energy expenditure) by indirect calorimetry, comparing the results with age- and sex-matched healthy controls. RESULTS: We observed new clinical features and overlap between these conditions suggesting that different disturbances of epigenetic machinery genes can converge on a common effect, leading to overlapping clinical phenotypes.The REE was not distinguishable between the three conditions and healthy controls. CONCLUSIONS: Epigenetic machinery plays an essential role both in growth regulation and in neurodevelopment; we recommend evaluating skeletal [craniovertebral junction abnormalities (CVJ) polydactyly], otolaryngological [obstructive sleep apnea syndrome (OSAs), recurrent otitis media], dental [tooth agenesis, talon cusps], and central nervous system (CNS) [olfactory bulbs and cerebellum anomalies] features. These features could be included in monitoring guidelines. Further studies are needed to deepen the knowledge about energy metabolism.

Whole-body volume of oxygen consumption while walking: Agreement between measured and estimated values.

Predictive equations are widely employed for estimating the volume of oxygen consumption (VO2) while walking, which is ultimately employed to determine energy expenditure and tailor exercise prescription. This study aimed to test the agreement between the measured VO2 and estimated VO2 during a walking protocol on a treadmill at 3.5, 4.5, 5.5, and 6.5 km/h. Thirty-eight young adults (50% women) participated in this cross-sectional study. The Omnical (Maastricht Instruments, Maastricht, The Netherlands) and K5 (Cosmed, Rome, Italy) metabolic systems were used to measure VO2. To determine the predictive equations, a comprehensive literature search was conducted using the MEDLINE database from May 2022 to July 2023. Seven predictive equations were found and included for estimating VO2 values. We calculated the mean bias (mean difference between measured VO2 and estimated VO2) obtained at each speed using one-sample t-tests. We compared the VO2 measured and estimated values using repeated measures analysis of variance and the Bland-Altman method. One-sample t-tests showed that all score errors were different from zero (ranging from 1.1 to 5.4 mL/kg/min). Thus, no predictive equation estimated similar VO2 values in comparison with the Omnical and K5 metabolic systems at all intensities. However, the Weyand equation showed the lowest bias across all intensities (score error of 1.1 mL/kg/min). This study showed a lack of agreement between the Omnical and K5 systems compared to diverse predictive equations specially designed to estimate VO2 during walking. Nevertheless, based on our results, the Weyand equation should be the preferred option.

A retrospective study of resting energy expenditure in children hospitalized with different nutritional status.

Background: Resting energy expenditure (REE) refers to the energy consumption of the body in a resting state without skeletal muscle activity. This study aimed to examine the REE among children hospitalized with varying nutritional status. Methods: This was a retrospective study. We enrolled 109 pediatric cases that underwent indirect calorimetry (IC) and divided into four groups: mild malnutrition group (15 cases), moderate malnutrition group (30 cases), severe malnutrition group (32 cases), and obesity group (32 cases). We compared and analyzed the measured REE (mREE) using IC with the predicted REE (pREE) using five energy equations. The paired t-test was used to compare the results of two samples. Pearson analysis was used to assess the correlation between two values. The agreement analysis was performed using the Bland-Altman method. Results: There was no significant difference in mREE between the mild, moderate, and severe malnutrition groups, but each differed significantly from the obesity group. All populations exhibited significant correlation between the mREEs and all five energy equations, and the equation with the highest predictive accuracy was the Schofield equation, which achieved an accuracy of 47.7%. In subgroup analysis, there was no significant difference between mREE and pREE for each of the five equations in the mild, moderate malnutrition groups. Only the prediction result of the Liu equation was not significantly different from the mREE in the severe malnutrition group. The prediction accuracy of the Liu equation was relatively the highest (34.4%). However, in the obese group, there were significant differences in pREE and mREE between the Liu equation and Mifflin equation. Under different nutritional statuses, the results of the Bland-Altman analysis suggested that deviation values between REEs predicted by each equation and mREE were greater than ±10%. Conclusions: There were differences in REE among children with different nutritional status. The results obtained from the five predictive energy equations deviated from the IC results. When REE cannot be measured by IC, it is essential to choose an appropriate predictive energy equation based on the nutritional status of the individual.

Energy utilization in lactating Jersey cows consuming a mixture of DDGS and straw replacing alfalfa hay.

Some forages require significant amounts of water to grow, causing the dairy industry to be dependent on a limited resource. Feeding crop residues and feed coproducts in dairy rations may represent opportunities when alfalfa is not readily available, and to reduce the industry's use of water. A study using indirect calorimetry and 12 multiparous lactating Jersey cows (BW = 447.5 ± 43.7 kg; DIM = 71 ± 11 d, mean ± SD) was conducted to determine the effect of feeding dried distillers grains and solubles (DDGS) and straw in replacement of alfalfa hay on milk production and energy utilization. A triplicated 4 × 4 Latin square design was used to evaluate the replacement of alfalfa hay with a coproduct mixture (COP) of wheat straw and DDGS. Animals were blocked by milk yield and randomly assigned to 1 of 4 experimental treatments including (proportions on a DM basis): a control diet (CON) containing 18.2% of alfalfa hay, a low-coproduct diet (LCOP) that contained 8.1% of COP, a medium-coproduct diet (MCOP) that contained 16.3% of COP, and a high-coproduct diet (HCOP) that contained 24.3% of COP. No differences were observed for daily dry matter intake or milk yield (mean ± SEM) 19.5 kg ± 0.60, 29.6 kg ± 0.91, respectively. A quadratic tendency was observed where increasing inclusion of COP up to 16.3% maintained ECM and milk fat yield but decreased when animals were fed 24.3% COP. Total methane production decreased linearly from 429.4 to 345.0 ± 22.8 L/d from CON to HCOP diets, respectively. The digestibility of CP increased linearly from 64.0 to 70.4 ± 0.95% and N balance increased linearly from 43.3 to 90.7 ± 15.0 g/d in animals consuming CON to HCOP diets. Total time spent ruminating was lowest in animals consuming the HCOP diet. A linear increasing tendency in digestible and metabolizable energy of 2.92 to 3.02 ± 0.041 Mcal/kg and 2.58 to 2.70 ± 0.047 Mcal/kg was observed in animals consuming CON to HCOP. The proportion ME from DE (ME/DE) tended to linearly increase from 88.3 to 89.4 ± 0.454 when COP was added to the diet. Results of this study indicate that alfalfa hay with a mixture of straw and DDGS can maintain milk production and DMI, but the partial or full replacement of alfalfa with the COP mixture may result in differences in energy utilization in part driven by effects on CH4 reduction.

Relationship between energetic gap and sensitivity to anti-programmed cell death 1 immune checkpoint inhibitors in non-small cell lung cancer patients: The ELY-2 study.

BACKGROUND & AIMS: We previously reported in the ELY prospective study that increased resting energy expenditure (REE) - so-called hypermetabolism - worsened tumor response, 6-month progression-free (PFS) and overall survival (OS) in metastatic non-small cell lung cancer (mNSCLC) patients treated with immune checkpoint inhibitors (ICI). Here, we investigated the effect of caloric coverage on the sensitivity to ICI. METHODS: We retrospectively analysed a multicentric database of mNSCLC patients treated with ICI. All patients had a baseline nutritional assessment including REE measured with indirect calorimetry and a dietitian estimation of food intakes. Measured/theoretical REE ≥110% defined hypermetabolism. Intakes ≥90% of estimated needs defined caloric coverage. The primary endpoint was PFS. Secondary endpoints included response rate and OS. RESULTS: Among 162 patients, 84 (51.9%) were normometabolic, and 78 (48.1%) hypermetabolic. In hypermetabolic patients, 40 (51.3%) met their caloric needs (group A) while 38 (48.7%) did not (group B). Median PFS was 4.3 vs. 1.9 months in groups A and B, respectively (HR: 0.49, 95%CI [0.31-0.80], p = 0.004). The PFS achieved in the group A and in normometabolic patients were similar (HR: 0.99, 95%CI [0.65-1.51], p = 0.95). In multivariate analysis, caloric coverage was independently associated with improved PFS in hypermetabolic patients (HR: 0.56, 95%CI [0.31-0.99], p = 0.048). Among hypermetabolic patients, the median OS was higher in the group A (HR: 0.58, 95%CI [0.35-0.95], p = 0.03). CONCLUSION: Energy supply is a critical determinant of the sensitivity to ICI in NSCLC patients. A randomized study to evaluate the benefit of early nutritional intervention is warranted.

Author Response: Emphasizing Patient-centered Outcomes and Improved Exclusion Criteria in Randomized Control Trials for Clinical Nutrition in ICU.

How to cite this article: Govil D, Chandrasekaran A, Pachisia AV, Harne R, Patel SJ, Pal D. Author Response: Emphasizing Patient-centered Outcomes and Improved Exclusion Criteria in Randomized Control Trials for Clinical Nutrition in ICU. Indian J Crit Care Med 2024;28(8):806-807.

Emphasizing Patient-centered Outcomes and Improved Exclusion Criteria in Randomized Controlled Trials for Clinical Nutrition in Critically Ill Patients.

How to cite this article: Sundarsingh V, Kumar M. Emphasizing Patient-centered Outcomes and Improved Exclusion Criteria in Randomized Controlled Trials for Clinical Nutrition in Critically Ill Patients. Indian J Crit Care Med 2024;28(8):804-805.

Resting energy expenditure in patients with liver cirrhosis: Indirect calorimetry vs. predictive equations.

BACKGROUND AND OBJECTIVES: The objective of our study was to explore the accuracy of previously published prediction equations in predicting resting energy expenditure (REE) in patients with liver cirrhosis (LC). We also aimed to develop a novel equation to estimate REE for Chinese patients with LC. METHODS AND STUDY DESIGN: In 90 patients with LC, the agreement between REE measured by Indirect calorimetry (IC) and predictive equations was quantified using paired T-test and visualized using a Bland-Altman Plot. Pearson correlation coefficient (R) was used to measure a linear correlation between REE measured by IC and different predictive equations. Stepwise multiple regression analysis was used to create a new REE equation. RESULTS: The estimated REEs of previous equations were underestimated against REE measured by IC (1610 ± 334 kcal). Lean body mass (LBM) was positively correlated with REE measured by IC (r = 0.723, p < 0.01). The newly derived estimation equation for REE (kcal) was 1274.3 - 209.0 * sex - 5.73 * age + 3.69 * waist circumference + 22.89 * LBM. The newly derived estimation equation was found to have a Pearson-r value of 0.765 compared with REE measured by IC. CONCLUSIONS: REE in liver cirrhosis was underestimated by using predictive equations. The new predictive equation developed by using age, sex, waist circumference, and LBM may help estimate REE in Chinese patients with LC accurately and easily.

Utilization of a Clark electrode device as a respirometer for small insects: A convincing test on ants allowing to detect discontinuous gas exchange.

Respirometry provides a direct measure of an organism's O2 consumption rate (VO2), which is a significant component of its metabolic rate (energy expenditure). Amongst ants, variations in lifespan between different social castes (such as workers and queens) can be substantial, varying depending on the species. As metabolic rate is higher in short-living species, we aimed to determine how VO2 and longevity may have coevolved within ant casts. Measuring VO2 in such tiny animal models can be challenging, and as a first methodological step, we validate the use of a Clark electrode, initially designed for measuring mitochondrial respiration control pathways, for assessing VO2 in ants within a sealed chamber. This was done by comparing it with stop-flow VO2 and CO2 production, using a traditional indirect calorimetry device. The global aim is to provide a reliable protocol to conduct accurate comparisons of metabolic rates within and among ant species. As expected, using the Clark electrode entails high time resolution and revealed that queens and workers exhibited discontinuous gas exchange, with episodes of apnea lasting up to 20 min.

Clarifying main nutritional aspects and resting energy expenditure in children with Smith-Magenis syndrome.

Our study aims to define resting energy expenditure (REE) and describe the main nutritional patterns in a single-center cohort of children with Smith-Magenis syndrome (SMS). REE was calculated using indirect calorimetry. Patients' metabolic status was assessed by comparing measured REE (mREE) with predictive REE (pREE). Patients also underwent multidisciplinary evaluation, anthropometric measurements and an assessment of average energy intake, using a 3-day food diary, which was reviewed by a specialized dietitian. Twenty-four patients (13 M) were included, the median age was 9 years (IC 95%, 6-14 years), 84% had 17p11.2 deletion, and 16% had RAI1 variants. REE was not reduced in SMS pediatric patients, and the mREE did not differ from the pREE. In patients with RAI1 variants (16%, n = 3/24), obesity was more prevalent than those with 17p11.2 deletion (100% vs 38%). Lower proteins intake and higher total energy intake were reported in obese and overweight patients, compared to healthy weight children. No significant difference was found between males and females in energy or macronutrient intake. CONCLUSIONS: In SMS, the onset of obesity is not explained by REE abnormalities, but dietary factors seem to be crucial. Greater concern should be addressed to patients with RAI1 variants. A better understanding of the molecular mechanisms causing obesity in SMS patients could set the basis for possible future targeted therapies. WHAT IS KNOWN: • More than 90% of SMS patients after the age of 10 are overweight or obese. WHAT IS NEW: • Onset of overweight and obesity in SMS pediatric patients is not explained by abnormal resting energy expenditure. • The development of syndrome-specific dietary guidelines for SMS patients should be of utmost relevance and are highly needed.

How to interpret and apply the results of indirect calorimetry studies: A case-based tutorial.

Evidence is growing that the individual adjustment of energy targets guided by indirect calorimetry (IC) can improve outcome. With the development of a new generation of devices that are easier to use and rapid, it appears important to share knowledge and expertise that may be used to individualize nutrition care. Despite the focus of this tutorial being on one contemporary device, the principles of IC apply across existing devices and can assist tailoring the nutrition prescription and in assessing response to nutrition therapy. The present tutorial addresses its clinical application in intubated mechanically ventilated and spontaneously breathing adult patients (canopy), i.e. it covers the range from critical illness to outpatients. The cases that are presented show how the measured energy expenditure (mEE), and the respiratory quotient (RQ), i.e. the ratio of expired CO2 to consumed O2, should be applied in different cases, to adapt and individualize nutrition prescription, as it is a good marker of over- or underfeeding at the different stages of disease. The RQ also informs about the patient's body's capacity to use different substrates: the variations of RQ indicating the metabolic changes revealing insufficient or excessive feeding. The different cases reflect the use of a new generation device as a metabolic monitor that should be combined with other clinical observations and laboratory biomarkers. The tutorial also points to some shortcomings of the method, proposing alternatives.

Comparison between Effect of Indirect Calorimetry vs Weight-based Equation (25 kcal/kg/day)-guided Nutrition on Quadriceps Muscle Thickness as Assessed by Bedside Ultrasonography in Medical Intensive Care Unit Patients: A Randomized Clinical Trial.

Aim and background: Sarcopenia is a substantial contributor to intensive care unit (ICU)-acquired weakness and is associated with significant short- and long-term outcomes. It can, however, be mitigated by providing appropriate nutrition. Indirect calorimetry (IC) is believed to be the gold standard in determining caloric targets in the dynamic environment of critical illness. We conducted this study to compare the effect of IC vs weight-based (25 kcal/kg/day) feeding on quadriceps muscle thickness (QMT) by ultrasound in critically ill patients. Materials and methods: A prospective study was conducted on 60 mechanically ventilated patients randomized to two groups [weight-based equation (WBE) group or the IC group] in medical ICU after obtaining institutional ethics committee approval, and fed accordingly. The right QMT measurement using ultrasound and caloric targets were documented on day 1, 3 and 7 and analyzed statistically. The IC readings were obtained from the metabolic cart E-COVX ModuleTM. Results: The baseline demographics, APACHE-II, NUTRIC score, and SOFA scores on day 1, 3, and 7 were comparable between the two groups. The resting energy expenditure (REE) obtained in the IC group was significantly less than the WBE energy targets and the former were fed with significantly less calories. A significantly less percent reduction of QMT in the IC group compared with the WBE group was observed from day 1 to day 3, day 3 to day 7, and day 1 to day 7. Conclusion: From our study, we conclude that IC-REE-based nutrition is associated with lesser reduction in QMT and lesser calories fed in critically ill mechanically ventilated patients compared from WBE. CTRI registration-CTRI/2023/01/049119. How to cite this article: Chandrasekaran A, Pal D, Harne R, Patel SJ, Jagadeesh KN, Pachisia AV, et al. Comparison between Effect of Indirect Calorimetry vs Weight-based Equation (25 kcal/kg/day)-guided Nutrition on Quadriceps Muscle Thickness as Assessed by Bedside Ultrasonography in Medical Intensive Care Unit Patients: A Randomized Clinical Trial. Indian J Crit Care Med 2024;28(6):587-594.

Predictive Energy Equations Inaccurately Estimate Metabolic Demands of Older Adult Trauma Patients.

INTRODUCTION: Suboptimal nutrition promotes unfavorable outcomes in trauma patients, particularly among those aged 60 and over. While many institutions employ predictive energy equations to determine patients' energy requirements, mounting evidence shows these equations inaccurately estimate caloric needs. In this pilot randomized controlled trial, we sought to quantify the discrepancy between predictive equations and indirect calorimetry (IC)-the gold standard for determining energy requirements-in the older adult trauma population. METHODS: This is a nested cohort study within a pilot randomized control trial in which 32 older adult trauma patients were randomized 3:1 to receive IC-guided nutrition delivery versus standard of care. IC requirements of patients in the intervention arm were compared to Mifflin St. Jeor (MSJ), Harris-Benedict (HB), and the American Society for Parenteral and Enteral Nutrition-Society of Critical Care Medicine (ASPEN-SCCM) predictive energy equations. RESULTS: Twenty patients underwent IC to assess measured resting energy expenditure (mREE), yielding a mean (standard deviation) mREE of 23.1 ± 4.8 kcal/kg/d. MSJ and HB gave mean predictive resting energy expenditures of 17.5 ± 2.0 and 18.5 ± 2.0 kcal/kg/d in these patients, demonstrating that IC-derived values were 32.1% and 25.0% higher, respectively. When patients were stratified by body mass index (BMI), MSJ, and HB more severely underestimated caloric requirements in individuals with BMI <30 versus BMI 30-50. While the mean mREE fell within the mean predictive resting energy expenditure range prescribed by ASPEN-SCCM equations (21.4 ± 4.1 to 26.2 ± 4.3 kcal/kg/d), individuals' IC-derived values fell within their personal range in 8 of 20 cases. CONCLUSIONS: The MSJ and HB predictive energy equations consistently and significantly underpredict metabolic demands of older adult trauma patients compared to IC and perform worse in lower BMI individuals. ASPEN-SCCM equations frequently overpredict or underpredict resting energy expenditure. While these findings should be confirmed in a larger randomized control trial, this study suggests that institutions should prioritize IC to accurately identify the metabolic demands of older trauma patients.

Evaluating predictive equations for energy requirements throughout breast cancer trajectory: A comparative study.

BACKGROUND & AIMS: Accurately estimating resting energy requirements is crucial for optimizing energy intake, particularly in the context of patients with varying energy needs, such as individuals with cancer. We sought to evaluate the agreement between resting energy expenditure (REE) predicted by 40 equations and that measured by reference methods in women undergoing active breast cancer treatment stage (I-IV) and post-completion (i.e., survivors). METHODS: Data from 4 studies were combined. REE values estimated from 40 predictive equations identified by a systematic search were compared with REE assessed by indirect calorimetry (IC) using a metabolic cart (MC-REE N = 46) or a whole-room indirect calorimeter (WRIC-REE N = 44). Agreement between methods was evaluated using Bland-Altman and Lin's concordance coefficient correlation (Lin's CCC). RESULTS: Ninety participants (24 % survivors, 61.1% had early-stage breast cancer I or II, mean age: 56.8 ± 11 years; body mass index: 28.7 ± 6.4 kg/m2) were included in this analysis. Mean MC-REE and WRIC-REE values were 1389 ± 199 kcal/day and 1506 ± 247 kcal/day, respectively. Limits of agreement were wide for all equations compared to both MC and WRIC (∼300 kcal for both methods), including the most commonly used ones, such as Harris-Benedict and Mifflin ST. Jeor equations; none had a bias within ±10% of measured REE, and all had low agreement per Lin's CCC analysis (<0.90). The Korth equation exhibited the best performance against WRIC and the Lvingston-Kohlstadt equation against MC. Similar patterns of bias were observed between survivors and patients and between patients with stages I-III versus IV cancer. CONCLUSION: Most equations failed to accurately predict REE at the group level, and none were effective at the individual level. This inaccuracy has significant implications for women with or surviving breast cancer, who may experience weight gain, maintenance, or loss due to inaccurate energy needs estimations. Therefore, our research underscores the need for further efforts to improve REE estimation.

The usefulness of a new indirect calorimeter in critically ill adult patients.

BACKGROUND & AIMS: The use of indirect calorimetry to determine energy requirements is highly recommended in critically ill patients. To facilitate this a new and easy to use calorimeter (Q-NRG+, Cosmed) was developed. The primary aim of our study was to describe the usefulness of this calorimeter and, secondarily, to investigate the agreement between measured and predicted energy needs in a large cohort of critically ill adult patients. METHODS: A prospective observational study was conducted among adult mechanically ventilated patients with COVID-19. Indirect calorimetry (Q-NRG+) to measure resting energy expenditure (mREE) was performed in the first week after admission and, wherever possible, repeated weekly. Reasons for not performing indirect calorimetry were reported. Parameters of indirect calorimetry and patient's conditions during the measurements were collected. Measurements were defined as valid if less than 10% overall variation in VO2 and VCO2 and respiratory quotient ranges between 0.67 and 1.1 were observed. mREE was compared with predictive REE (pREE) using standard formulas to explore hypo (<90%)-and hypermetabolism. (>110%). Bland-Altman method and two-way mixed intraclass correlation coefficients (ICC) (single measures) were used to assess the agreement between mREE and pREE. RESULTS: Indirect calorimetric measurements were performed in 180 of the 432 admitted patients (42%). Of the 276 performed measurements 85% were valid, and of these 90% were used to tailor nutritional therapy. Most patients were male (71%), median age was 62 years [IQR 52; 70]. Logistical issues (absence of measuring staff, no device, no stock of disposables, MRSA isolation) and clinical issues (e.g Fio2>70%, detubated but still in ICU) were the main reasons for not performing indirect calorimetry. The majority of the REE-measurements indicated either hypo- or hypermetabolism (57% week 1 and 56% week 2). The correlation between mREE and pREE was very moderate (ICC = 0.527). CONCLUSIONS: Although indirect calorimetry was performed in less than half of the patients, it proved to be of value to guide nutritional therapy. We conclude that the technique is easily applicable and expect that its impact can be significantly increased with the resolution of logistical and organizational issues.

[Nutritional status and nutritional support of patients with chronic disorders of consciousness at the stage of medical rehabilitation].

Chronic disturbances of consciousness (CDC) are a consequence of severe brain damage and are conditions that arise after emerging from a coma with the preservation of the sleep-wake cycle in the absence of signs of conscious behavior. When conducting inpatient medical rehabilitation of this group of patients, the state of nutritional status is not always taken into account and, as a rule, there is no nutritional support with an assessment of metabolic needs, including the introduction of various modes of physical activity during physical therapy and an increase in physical load on the patient's body. The purpose of the study was to assess the nutritional status and optimize the nutritional support system in patients with CDC at the inpatient stage of medical rehabilitation (MR). Material and methods. The study analyzed the results of examination and treatment of 152 patients with CDC of traumatic origin who received medical rehabilitation from 2016 to 2022 in the Department of Physical and Rehabilitation Medicine of the Nikiforov Russian Center of Emergency and Radiation Medicine, Ministry of Russian Federation for Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters. Results. In patients with CDC of traumatic genesis, signs of malnutrition (objective, anthropometric, laboratory) were diagnosed at the inpatient stage of MR, and there were also risks of malnutrition progression with the introduction of additional physical activity. Conclusion. To create an effective and adequate nutritional support system during inpatient MR, metabolic monitoring (indirect calorimetry) is of fundamental importance, taking into account the influence of additional physical activity. The use of a calculation method for estimating energy requirements can lead to hyperalimentation.

[Bioimpedance analysis of body composition and rest energy expenditure in highly trained cross-country skiers].

The body composition monitoring using bioimpedance analysis (BIA) is important in assessing the functional state of athletes in sports. Based on changes of body composition, it is possible to optimize the actual dietary intake, as well as successfully organize the training process. The purpose of this research was to conduct a comparative assessment of BIA parameters and rest energy expenditure (REE) in highly trained cross-country skiers and young non-athletes. Material and methods. The members of the national cross-country skiing team from the Komi Republic and Russian Federation (n=30; age - 22.3±2.7 years) were examined. Practically healthy medical students served as a control group for the present study (n=40; age - 20.2±2.4 years). The participants successively passed the following study steps: assessment of the body composition by BIA (ACCUNIQ BC380), REE determination by indirect non-fasting calorimetry and calculation technique. Results. The parameters of total body water, fat-free mass, lean tissue and body cell mass were higher in contrast to the fat mass percentage in the athletes (р<0.001). The calculated REE was lower than measured REE among all the participants. At the same time, the REE calculated by the Ketch-McArdle formula significantly differed between the groups, while no differences were found between the REE calculated by the Harris-Benedict prediction equation. The measured REE were significantly higher by 16% (p<0.001) i n athletes compared to those in the control group. Conclusion. The body composition of athletes was distinguished by a significantly higher amounts of total body water, fat-free mass, skeletal muscle, active cell mass, and lower percentage of fat mass compared to healthy untrained individuals. The results obtained among athletes coincided with the idea that the magnitude of REE is determined by the mass of metabolically active tissues and to a lesser extent depends on the fat mass. BIA results can be used to monitor athletes' body composition during the training process.

System for continuous metabolic monitoring of mechanically ventilated patients.

In clinical settings, due largely to the cost, size and calibration complexity of existing indirect calorimetry systems, there is seldom instrumentation available to provide reliable, continuous tracking of a mechanically ventilated patient's metabolic output in support of proper nutrition. The atypical metabolisms associated with critically ill patients are difficult to predict and both underfeeding and overfeeding lead to negative impacts on both mortality and the recovery and healing processes. With these issues in mind, a novel ventilator-agnostic indirect calorimetry sensor design, prototype development, and validation were undertaken with the goal of enabling 24/7 metabolic monitoring of mechanically ventilated patients by means of a passive, rate-proportional side-stream sampling scheme and miniature mixing chamber. The miniature mixing chamber enables the use of small, low-cost gas concentration and flow sensing components to ensure the affordability of commercial design-for-manufacture implementations of the prototype sensor. In addition to continuous measurement of patient metabolism, the prototype sensor also enables autonomous monitoring and detection of calibration drift in the gas measurement sensors without disrupting the patient ventilation.