Feeding the critically ill obese patient: a systematic review protocol

Liver at crossroads: unraveling the links between obesity, chronic liver diseases, and the mysterious obesity paradox

Obesity is a global health issue that is intricately linked to the development and progression of chronic liver disease (CLD). This bidirectional connection, coupled with the obesity paradox (OP), presents a management dilemma. The established influence of obesity on the development and progression of chronic liver disease (CLD) is surpassed by the liver's impact on the onset and advancement of obesity. Patients with CLD always experience increased energy expenditure, reduced appetite, and low protein synthesis, all of which might lead to weight loss. However, metabolic disturbances, hormonal imbalances, inflammatory signaling, immobility, drugs, and alterations in nutrient metabolism can contribute to the development and exacerbation of obesity. Despite the propagation of the OP concept, none of the guidelines has changed, recommending being overweight. Research bias and confounders might be the lifebuoy explanation. Additionally, overlooking the lethal morbidities of obesity for survival benefits full of suffering seems to be an illogical idea. Therefore, rather than endorsing an overweight status, emphasis should be placed on improving cardiorespiratory fitness and preventing sarcopenia to achieve better outcomes in patients with CLD. Accordingly, the complex interplay between obesity, CLD, and the concept of OP requires a sophisticated individualized management approach. Maximizing cardiorespiratory fitness and mitigating sarcopenia should be considered essential strategies for attaining the most favourable outcomes in patients with chronic liver disease (CLD).

Exploring Adiposity and Chronic Kidney Disease: Clinical Implications, Management Strategies, Prognostic Considerations

Obesity poses a significant and growing risk factor for chronic kidney disease (CKD), requiring comprehensive evaluation and management strategies. This review explores the intricate relationship between obesity and CKD, emphasizing the diverse phenotypes of obesity, including sarcopenic obesity and metabolically healthy versus unhealthy obesity, and their differential impact on kidney function. We discuss the epidemiological evidence linking elevated body mass index (BMI) with CKD risk while also addressing the paradoxical survival benefits observed in obese CKD patients. Various measures of obesity, such as BMI, waist circumference, and visceral fat assessment, are evaluated in the context of CKD progression and outcomes. Mechanistic insights into how obesity promotes renal dysfunction through lipid metabolism, inflammation, and altered renal hemodynamics are elucidated, underscoring the role of adipokines and the renin-angiotensin-aldosterone system. Furthermore, the review examines current strategies for assessing kidney function in obese individuals, including the strengths and limitations of filtration markers and predictive equations. The management of obesity and associated comorbidities like arterial hypertension, type 2 diabetes mellitus, and non-alcoholic fatty liver disease in CKD patients is discussed. Finally, gaps in the current literature and future research directions aimed at optimizing the management of obesity-related CKD are highlighted, emphasizing the need for personalized therapeutic approaches to mitigate the growing burden of this intertwined epidemic.

Risk Factors of Enternal Nutrition Intolerance in Septic Patients: A Case-control Study

OBJECTIVE

This study aimed to investigate the incidence of enteral nutrition intolerance (ENI) in patients with sepsis and explore potential risk factors.

METHODS

A case-control study was conducted in patients with sepsis who were receiving enteral nutrition (EN) at a tertiary hospital in China. The included patients were divided into the ENI group and the non-ENI group. Univariate and multivariate analyses were performed to identify the risk factors for ENI.

RESULTS

A total of 859 patients were included in the study. Among them, 288 (33.53%) patients experienced symptoms of ENI, including diarrhea, vomiting, bloating, and gastric retention. Logistic regression analysis revealed that the Acute Physiology and Chronic Health Evaluation H (APACHE H) score, thoracocentesis, and usage of cardiotonic drugs (namely, inotropes) were independent predictors of the ENI.

CONCLUSION

The incidence of ENI is relatively high in patients with sepsis, especially in those who have higher APACHE H scores, have undergone thoracocentesis, and have received inotropes.

Association between obesity and short- and medium-term mortality in critically ill patients with atrial fibrillation: a retrospective cohort study

BACKGROUND

There has been controversy about how obesity affects the clinical prognosis for patients with atrial fibrillation (AF), and the relationship between obesity and outcomes in critically ill patients with AF remains unclear. The purpose of this study was to explore the association between obesity and short- and medium-term mortality in critically ill patients with AF.

METHODS

The Medical Information Mart for Intensive Care-IV (MIMIC-IV) database was used to conduct a retrospective cohort analysis on 9282 critically ill patients with AF. Patients were categorized into four groups based on their body mass index (BMI) values: underweight, normal-weight, overweight, and obese. The outcomes of this study were 30-day, 90-day, and 1-year all-cause mortality. Cox proportional-hazards models and restricted cubic spline analyses were performed to investigate the association between BMI and mortality.

RESULTS

For 30-day mortality, after adjustment for all confounding factors, the hazard ratio (HR) with 95% confidence interval (CI) for the underweight, overweight, and obese categories were 1.58 (1.21, 2.07), 0.82 (0.72, 0.93), and 0.79 (0.68, 0.91), respectively, compared to the normal-weight category. Using multivariable-adjusted restricted cubic spline analysis, an "L-shaped" correlation was observed between BMI and 30-day mortality. For each 1 kg/m² increase in BMI when BMI was less than 30 kg/m², the risk of 30-day mortality decreased by 6.4% (HR, 95% CI: 0.936 [0.918, 0.954]; P < 0.001); however, this relationship was not present when BMI was greater than or equal to 30 kg/m². Similar results were observed for 90-day and 1-year mortality.

CONCLUSIONS

There was a nonlinear relationship between BMI and all-cause mortality among critically ill patients with AF. All-cause mortality and the BMI were negatively correlated when the BMI was less than 30 kg/m².

An analysis of non-nutritive calories from propofol, dextrose, and citrate among critically ill patients receiving continuous renal replacement therapy

BACKGROUND

Propofol, dextrose, and citrate infusions are necessary treatment modalities in the intensive care units (ICUs). They are, however, a potential source of non-nutritive calories (NNCs) which may cause over-feeding and adverse complications. The literature surrounding the role of NNCs is limited. We aimed to examine the energy contribution of NNCs. Our secondary aim is to assess the nutritional impact of NNCs, especially among patients receiving continuous renal replacement therapy (CRRT).

MATERIALS /METHODS

We enrolled 177 mechanically ventilated patients admitted to medical-surgical ICUs from August to December 2019. Patients were monitored over the first 7 days of admission. Infusion rates of EN/PN and NNCs, as well as clinical characteristics, were examined. Patients receiving CRRT were compared to those without.

RESULTS

In total, 24% received additional energy from citrate. Patients received a maximum of 331kcal from citrate, 492kcal from propofol, and 992kcal from dextrose per ICU day. CRRT-group achieved higher total energy on the first two days (Day 1 - 55.1% vs. 46.4%; p=0.008, Day 2 - 73.2% vs. 55.4%, p=0.025). They also received higher mean NNCs on all days, except for Day 1 (p=0.068).

CONCLUSION

NNCs, especially citrate, are significant sources of energy. Patients receiving CRRT may have greater nutritional risk. There should be close monitoring and adaption of energy prescription accordingly to prevent over-feeding. This article is protected by copyright. All rights reserved.

Association Between Obesity and Lower Short- and Long-Term Mortality in Coronary Care Unit Patients: A Cohort Study of the MIMIC-III Database

INTRODUCTION

Obesity has long been considered an independent risk factor for cardiovascular diseases (CVD), even in the COVID-19 pandemic. However, recent studies have found that a certain degree of obesity may be beneficial for patients who have already suffered from CVD, which is called the "obesity paradox". Our objective was to investigate whether the obesity paradox existed in coronary care unit (CCU) patients and the relationship between body mass index (BMI) and short- and long-term mortality.

METHODS

We performed a cohort analysis of 3,502 adult CCU patients from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients were divided into four groups according to the WHO BMI categories. Both multivariable logistic regression and Cox regression were used to reveal the relation between BMI and mortality. Subgroup analyses were performed based on Simplified Acute Physiology Score (SAPS) and age.

RESULTS

After adjusting for confounders, obese patients had 33% and 30% lower mortality risk at 30-day and 1-year (OR 0.67, 95% CI 0.51 to 0.89; HR 0.70, 95% CI 0.59 to 0.83; respectively) compared with normal-weight patients, while the underweight group were opposite, with 141% and 81% higher in short- and long-term (OR 2.41, 95% CI 1.37 to 4.12; HR 1.81, 95% CI 1.34 to 2.46; respectively). Overweight patients did not have a significant survival advantage at 30-day (OR 0.91, 95% CI 0.70 to 1.17), but did have a 22% lower mortality risk at 1-year (HR 0.78; 95% CI 0.67 to 0.91). The results were consistent after being stratified by SAPS and age.

CONCLUSION

Our study supports that obesity improved survival at both 30-day and 1-year after CCU admission, and the obesity paradox existed in CCU patients.

Common Limitations and Challenges of Dietary Clinical Trials for Translation into Clinical Practices

The progressive development of clinical and public health nutrition has long relied on dietary clinical trials (DCTs), investigating the causal relationship between diet and multiple risk factors of non-communicable and chronic diseases. DCTs are also hallmarks for establishing dietary requirements and promoting overall nutritional health among the population. Despite their critical importance in translation into public health strategies and practices, DCTs have several limitations and challenges for study design, implementation and finding interpretation. The complex nature of nutrition interventions, collinearity between diet components, multi-target effects of the interventions, diverse dietary behaviors, and food culture are the most challenging issues. Furthermore, baseline exposure and dietary status, appropriate control groups, blinding, randomization, and poor adherence undermine the effectiveness of DCTs in translation into practices. Disruptive factors will be minimized if researchers are committed to following good clinical practice (GCP) standards available for common designs of clinical trials. Planning DCTs, however, needs careful considerations for hypothesis generation, study design development, the definition of primary and secondary outcome measures, and target population.

Environmental Factors Affecting Early Mobilization and Physical Disability Post-Intensive Care: An Integrative Review Through the Lens of the World Health Organization International Classification of Functioning, Disability, and Health

BACKGROUND

Early mobilization (EM) is one of few potential protective factors associated with reduced physical disability post-intensive care (PD PIC). However, only 45% of intensive care units (ICUs) in the United States routinely practice EM despite its recognized benefits.

OBJECTIVES

To analyze the evidence on the relationship between critical care EM, PD PIC, and environmental factors, using the theoretical lens of the World Health Organization's (WHO's) International Classification of Functioning, Disability, and Health (ICF).

METHOD

The Whittemore and Knafl methodology for integrative reviews and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines were followed. Qualitative, quantitative, and mixed-methods studies (n = 38) that evaluated EM and 1 or more domains of the WHO ICF were included. Quality was appraised using the Mixed-Methods Appraisal Tool. Study characteristics were evaluated for common themes and relationships. The ICF domains and subdomains pertaining to each study were synthesized.

RESULTS

Early mobilization was related to improved functioning on the disability continuum of the WHO ICF. Early mobilization was influenced by several WHO ICF environmental factors. Dedicated physical and occupational therapy teams in the ICU, interdisciplinary rounds, and positive family and staff perception of EM facilitated intervention delivery. However, poor staffing levels, negative unit culture, perceived workload burden, and lack of equipment, education, and financial support impeded delivery of EM.

DISCUSSION

Early mobilization is a promising intervention that may reduce PD PIC. However, environmental factors negatively influence delivery of EM in the ICU. Several gaps in EM research limit its acceptability in ICU practice. Existing EM research is challenged by poor methodological quality. Further study is necessary to better understand the role of EM on PD PIC and improve patient outcomes following critical illness.

Nitrogen recycling buffers against ammonia toxicity from skeletal muscle breakdown in hibernating arctic ground squirrels

Hibernation is a state of extraordinary metabolic plasticity. The pathways of amino acid metabolism as they relate to nitrogen homeostasis in hibernating mammals in vivo are unknown. Here we show, using pulse isotopic tracing, evidence of increased myofibrillar (skeletal muscle) protein breakdown and suppressed whole-body production of metabolites in vivo throughout deep torpor. As whole-body production of metabolites is suppressed, amino acids with nitrogenous side chains accumulate during torpor, while urea cycle intermediates do not. Using ¹⁵N stable isotope methodology in arctic ground squirrels (Urocitellus parryii), we provide evidence that free nitrogen is buffered and recycled into essential amino acids, non-essential amino acids and the gamma-glutamyl system during the inter-bout arousal period of hibernation. In the absence of nutrient intake or physical activity, our data illustrate the orchestration of metabolic pathways that sustain the provision of essential and non-essential amino acids and prevent ammonia toxicity during hibernation.

Protein Intake and Exercise-Induced Skeletal Muscle Hypertrophy: An Update

Skeletal muscle mass is critical for sport performance and in many pathological conditions. The combination of protein intake and resistance exercise is the most efficient strategy to promote skeletal muscle hypertrophy and remodeling. However, to be really efficient, certain conditions need to be considered. The amount, type and source of proteins do all matter as well as the timing of ingestion and spreading over the whole day. Optimizing those conditions favor a positive net protein balance, which in the long term, may result in muscle mass accretion. Last but not least, it is also essential to take the nutritional status and the exercise training load into consideration when looking for maintenance or gain of skeletal muscle mass.

Safety and efficacy of volume-based feeding in critically ill, mechanically ventilated adults using the 'Protein & Energy Requirements Fed for Every Critically ill patient every Time' (PERFECT) protocol: a before-and-after study

BACKGROUND

Underfeeding in critical illness is common and associated with poor outcomes. According to large prospective hospital studies, volume-based feeding (VBF) safely and effectively improves energy and protein delivery to critically ill patients compared to traditional rate-based feeding (RBF) and might improve patient outcomes. A before-and-after study was designed to evaluate the safety, efficacy and clinical outcomes associated with VBF compared to RBF in a single intensive care unit (ICU).

METHODS

The sample included consecutively admitted critically ill adults, mechanically ventilated for at least 72 h and fed enterally for a minimum of 48 h. The first cohort (n = 46) was fed using RBF, the second (n = 46) using VBF, and observed for 7 days, or until extubation or death. Statistical comparison of percentage feed volume, energy and protein delivered, plus indices of feed intolerance, were the primary outcomes of interest. Secondary observations included ventilation period, mortality, and length of ICU stay (LOICUS).

RESULTS

Groups were comparable in baseline clinical and demographic characteristics and nutrition practices. Volume delivered to the VBF group increased significantly by 11.2% (p ≤ 0.001), energy by 13.4% (p ≤ 0.001) and protein by 8.4% (p = 0.02), compared to the RBF group. In the VBF group, patients meeting > 90% of energy requirements increased significantly from 47.8 to 84.8% (p ≤ 0.001); those meeting > 90% of protein requirements changed from 56.5 to 73.9% (p = 0.134). VBF did not increase symptoms of feed intolerance. Adjusted binomial logistic regression found each additional 1% of prescribed feed delivered decreased the odds of vomiting by 0.942 (5.8%), 95% CI [0.900-0.985], p = 0.010. No differences in mortality or LOICUS were identified. Kaplan-Meier found a significantly increased extubation rate in patients receiving > 90% of protein requirements compared to those meeting < 80%, (p = 0.006). Adjusted Cox regression found the daily probability of being extubated tripled in patients receiving > 90% of their protein needs compared to the group receiving < 80%, hazard ratio 3.473, p = 0.021, 95% CI [1.205-10.014].

CONCLUSION

VBF safely and effectively increased the delivery of energy and protein to critically ill patients. Increased protein delivery may improve extubation rate which has positive patient-centred and financial implications, warranting larger confirmatory trials. This investigation adds weight to the ICU literature supporting VBF, and the growing evidence which advocates for enhanced protein delivery to improve patient outcomes.

Effects of Mogrosides on High-Fat-Diet-Induced Obesity and Nonalcoholic Fatty Liver Disease in Mice

Obesity and nonalcoholic fatty liver disease (NAFLD) are highly prevalent and cause numerous metabolic diseases. However, drugs for the prevention and treatment of obesity and NAFLD remain unavailable. In this study, we investigated the effects of mogrosides (luo han guo, LH) in Siraitia grosvenorii saponins on high-fat-diet-induced obesity and NAFLD in mice. We found that compared with the negative control, LH reduced body and liver weight. LH also decreased fat accumulation and increased AMP-activated protein kinase (AMPK) phosphorylation (pAMPK) levels in mouse livers. We also found that high-purity mogroside V upregulated pAMPK expression in HepG2 cells. In addition, high-purity mogroside V inhibited reactive oxygen species production and upregulated sequestosome-1 (SQSTM1, p62) expression in THP-1 cells. These results suggest that LH may affect obesity and NAFLD by enhancing fat metabolism and antioxidative defenses. Mogroside V may be a main component of LH. However, the exact molecular mechanisms and active components responsible for the inhibitory effects of LH on obesity and NAFLD require further investigation.

Nutrition therapy: A new criterion for treatment of patients in diverse clinical and metabolic situations

OBJECTIVE

This study developed an instrument in table format to help determine the energy requirements of patients in adverse situations. The instrument allows for the weekly adjustment of nutrition therapy and energy intake, advocating a new approach to treatment based on clinical observation performed by staff specialized in individualized nutrition therapy.

METHODS

The table was elaborated by grouping patients according to the following criteria: criticality, chronicity, and stability of the clinical status. Energy supply was readjusted weekly to respect the cyclicity of the patient's metabolic response.

RESULTS

The table should be used in the following order: Obese > Elderly > Specific Clinical Situations > Chronic Diseases > Stable Clinical Situations. The protein requirements of patients with pressure ulcers or with wounds healing by secondary intention should be increased by 30% to 50%. Current patient weight should always be used, except in patients with anasarca. In these cases, the patient's last known dry weight or the ideal weight should be used. For elderly patients whose weight is not known and who cannot be weighed because of the patient's clinical condition, a body mass index of 23 should be assumed.

CONCLUSION

The proposed nutrition table allows for management of optimal energy and protein intake for patients in different clinical situations, while respecting the different phases of the posttraumatic metabolic response, thus leading to favorable clinical outcomes.