Nutrition in critical illness: a current conundrum

Nutrition in the intensive care unit: from the acute phase to beyond

Recent randomized controlled trials (RCTs) have shown no benefit but  dose-dependent harm by early full nutritional support in critically ill patients. Lack of benefit may be explained by anabolic resistance, suppression of cellular repair processes, and aggravation of hyperglycemia and insulin needs. Also early high amino acid doses did not provide benefit, but instead associated with harm in patients with organ dysfunctions. However, most studies focused on nutritional interventions initiated during the first days after intensive care unit admission. Although the intervention window of some RCTs extended into the post-acute phase of critical illness, no large RCTs studied nutritional interventions initiated beyond the first week. Hence, clear evidence-based guidance on when and how to initiate and advance nutrition is lacking. Prolonged underfeeding will come at a price as there is no validated metabolic monitor that indicates readiness for medical nutrition therapy, and an adequate response to nutrition, which likely varies between patients. Also micronutrient status cannot be assessed reliably, as inflammation can cause redistribution, so that plasma micronutrient concentrations are not necessarily reflective of total body stores. Moreover, high doses of individual micronutrients have not proven beneficial. Accordingly, current evidence provides clear guidance on which nutritional strategies to avoid, but the ideal nutritional regimen for individual patients remains unclear. In this narrative review, we summarize the findings of recent studies, discuss possible mechanisms explaining the results, point out pitfalls in interpretation of RCTs and their effect on clinical practice, and formulate suggestions for future research.

Nutritional support team intervention in surgical ICUs and its effect on nutrition delivery and quality in critically ill patients

RATIONAL

Critically ill surgical patients pose one of the greatest challenges in achieving nutritional goals. Several published papers have demonstrated clear benefits when nutrition support (NS) is managed by a multidisciplinary nutrition support team (NST). We hypothesized that implementing a NST in a surgical intensive care unit (ICU) would increase the number of patients achieving their nutritional goals.

MATERIAL AND METHOD

Multicenter "BEFORE & AFTER" study. In the BEFORE phase, an audit of the previous state of NS was conducted in three ICUs without a NST.

INTERVENTION

Implementation of a NST and protocol. In the AFTER phase, a new audit of NS was conducted. Continuous variables (presented as mean ± SD or median Q1-Q3) were tested using the t-test and Mann-Whitney U test. Categorical variables (presented as frequencies and percentages) were assessed using the chi-square test. A binomial logistic regression model was performed, with independent variables introduced using a stepwise forward method. A difference was considered to be significant with a two-sided P-value <0.05. Statistical analysis was conducted using IBM-SPSS 26.

RESULTS

A total of 83 patients were included in the BEFORE phase, and 85 in the AFTER phase. The latter group showed a higher frequency of nutritional risk and malnutrition (SGA B+C odds ratio 2.314, 95% CI 1.164-4.600). Laparoscopy was more frequently utilized as a surgical technique in the AFTER phase. No differences were observed in ICU and hospital LOS or 90 days' survival rates. Two variables remained independent factors to predict NS achievement: NST implementation (odds ratio 3.582, 95% CI 1.733-7.404), and surgical technique (odds ratio 3.231, 95% CI 1.312-7.959).

CONCLUSION

NST positively impacts the chance of achieving NS goals in critically ill surgical patients.

A Narrative Review: Analysis of Supplemental Parenteral Nutrition in Adults at the End of Life

"End of life" is a stage defined by the existence of an irreversible prognosis that ends with a person's death. One of the aspects of interest regarding end of life focuses on parenteral nutrition, which is usually administered in order to avoid malnutrition and associated complications. However, parenteral nutrition can be adapted to specific circumstances and evolve in its functionality through supplementation with certain nutrients that can have a beneficial effect. This narrative review aims to carry out a situation analysis of the role that could be adopted by supplemental parenteral nutrition in attenuating alterations typical of end of life and potential improvement in quality of life.

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.

Prognostic values of modified NUTRIC score to assess outcomes in critically ill patients admitted to the intensive care units: prospective observational study

PURPOSE

Modified Nutrition Risk in the Critically Ill (NUTRIC) score (mNUTRIC score) have been validated as screening tool for quantifying risk of adverse outcome critically ill patients admitted to the intensive care units (ICUs). The aim of this study was to evaluate the prognostic value of mNUTRIC score to assess outcomes in this population.

MATERIALS AND METHODS

This prospective, observational study was conducted on adult patients admitted to the general ICUs of two university affiliated hospital in northwest of Iran. The association between the mNUTRIC score and outcomes was assessed using the univariate and multivariate binary logistic regression. The performance of mNUTRIC score to predict outcomes was assessed using the receiver operating characteristic (ROC)-curve.

RESULTS

In total 445 ICU patients were enrolled. Based on mNUTRIC score, 62 (13.9%) and 383 (86.1%) individuals were identified at high and low nutritional risk, respectively. The area under the curve (AUC) for predicting ICU mortality, using vasopressor, duration of vasopressor, and mechanical ventilation (MV) duration were (AUC: 0.973, 95% CI: 0.954-0.986, P < 0.001), (AUC: 0.807, 95% CI: 0.767-0.843, P < 0.001), (AUC: 0.726, 95% CI: 0.680-0.769, P < 0.001) and (AUC: 0.710, 95% CI: 0.666-0.752, P < 0.001), respectively.

CONCLUSIONS

An excellent and good predictive performance of the mNUTRIC score was found regarding ICU mortality and using vasopressor, respectively. However, this predictive was fair for MV and vasopressor duration and poor for ICU and hospital length of stay.

Toward nutrition improving outcome of critically ill patients: How to interpret recent feeding RCTs?

Although numerous observational studies associated underfeeding with poor outcome, recent randomized controlled trials (RCTs) have shown that early full nutritional support does not benefit critically ill patients and may induce dose-dependent harm. Some researchers have suggested that the absence of benefit in RCTs may be attributed to overrepresentation of patients deemed at low nutritional risk, or to a too low amino acid versus non-protein energy dose in the nutritional formula. However, these hypotheses have not been confirmed by strong evidence. RCTs have not revealed any subgroup benefiting from early full nutritional support, nor benefit from increased amino acid doses or from indirect calorimetry-based energy dosing targeted at 100% of energy expenditure. Mechanistic studies attributed the absence of benefit of early feeding to anabolic resistance and futile catabolism of extra provided amino acids, and to feeding-induced suppression of recovery-enhancing pathways such as autophagy and ketogenesis, which opened perspectives for fasting-mimicking diets and ketone supplementation. Yet, the presence or absence of an anabolic response to feeding cannot be predicted or monitored and likely differs over time and among patients. In the absence of such monitor, the value of indirect calorimetry seems obscure, especially in the acute phase of illness. Until now, large feeding RCTs have focused on interventions that were initiated in the first week of critical illness. There are no large RCTs that investigated the impact of different feeding strategies initiated after the acute phase and continued after discharge from the intensive care unit in patients recovering from critical illness.

Prediction of Prognosis in Geriatric Palliative Care Patients with Diagnosed Malnutrition: A Comparison of Nutritional Assessment Parameters

Objective

Malnutrition is very commonly encountered in palliative care centers (PCC), especially in geriatric patients. It is known that development of malnutrition increases morbidity and mortality. In this study, we aimed to investigate the effectiveness of commonly used nutritional assessment parameters in predicting prognosis in geriatric patients diagnosed in PCC with malnutrition.

Methods

Our study included 1451 patients aged ≥65 years, who were diagnosed with malnutrition in PCC between 2016-2020 and did not yet start receiving nutritional support. Demographic data, comorbidities, The Nutritional Risk Screening 2002 (NRS-2002), body mass index (BMI), albumin, prealbumin and C-reactive protein (CRP) values of the patients were recorded. Prognostic course was evaluated by dividing the patients into 3 groups, namely mortal patients during PCC follow-up, patients transferred from PCC to Intensive Care (ICU) and patients discharged to home from PCC.

Results

Logistic Regression analysis showed that low albumin levels affected transfer to ICU (P<0.05). Elevated NRS-2002 and low albumin and prealbumin levels were found to be factors affecting mortality (P<0.05). Areas under the ROC Curve were calculated to attain patients' differential diagnosis. The area under the ROC Curve of low albumin in patients transferred to ICU was found to be significant (P<0.05). In the differential diagnosis of patients with mortal course, the area under the ROC Curve of low albumin and prealbumin and high CRP was found to be significant (P<0.05).

Conclusion

We found that BMI had no prognostic predictive effects in geriatric PCC patients with malnutrition. We concluded that NRS-2002 and high CRP and low albumin and prealbumin can be used to predict mortality. In addition, we found that low albumin indicates a poor prognosis and predicts patients to be transferred to ICU.

Practical parameters that can be used for nutritional assessment in patients hospitalized in the intensive care unit with the diagnosis of chronic obstructive pulmonary disease: Prognostic nutritional index, neutrophil-to-lymphocyte, platelet-to-lymphocyte, and lymphocyte-to-monocyte ratio

Malnutrition is an important condition in patients diagnosed with chronic obstructive pulmonary disease (COPD). There is a need for practical and objective nutritional assessment methods in patients hospitalized in the intensive care unit with the diagnosis of COPD. In this study, it was aimed to determine the parameters that can practically evaluate the nutritional status of these patients. It was aimed to determine the relationship between prognostic nutritional index (PNI), and nutritional risk screening (NRS)-2002, nutrition risk in the critical ill (Nutric) Score and to determine a cut-off value for PNI, neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and other complete blood count parameters.Hemogram values, albumin values, NLR, PLR, LMR, NRS-2002, PNI and modified Nutric Score calculations of the patients hospitalized in the intensive care unit due to COPD were recorded. The relationship between PNI and NRS-2002 and modified Nutric Score, as well as the relationship between NLR, PLR, LMR, hemogram parameters and PNI were analyzed using statistical methods.The PNI cut-off value for nutritional assessment in patients hospitalized in the intensive care unit due to COPD was determined as 38.5 (area under curve = 0.891, sensitivity 80.8%, specificity 88.1%, positive predictive value 92.9%, negative predictive value 88%). High-risk group according to PNI compared to low-risk group, lymphocyte count (P < .001), basophil count (P = .004), red blood cell (P < .001), hemoglobin (P < .001), hematocrit (P < .001), and LMR (P = .001) were statistically significantly lower, while NLR (P < .001) and PLR (P = .001) were statistically significantly higher. Cut-off values for lymphocyte count, basophil count, NLR, PLR, and LMR were found to be 1.18, 0.035, 7.97, 291.10, and 2.606, respectively.Nutritional risk assessment can be made in a practical way by using PNI in patients hospitalized in intensive care unit due to COPD. For this, the PNI cut-off value was determined as 38.5 in our study. In addition, NLR, PLR, LMR, basophil and lymphocyte values, which can be calculated using complete blood count parameters, may also be useful in the evaluation of nutritional status in these patients. In our study, the cut-off values determined for NLR, PLR, LMR, basophil and lymphocyte were 7.97, 291.10 and 2.606, 0.035 and 1.18, respectively. We think that the results we have obtained can provide preliminary information for future research.

Early renal impairment is associated with in-hospital death of patients with COVID-19

Introduction

Renal impairment is a common complication in coronavirus disease 2019 (COVID‐19), although its prognostic significance remains unknown.

Objectives

This study determines the impact of early renal impairment on the clinical outcome of COVID‐19.

Methods

Patients diagnosed with COVID‐19 and hospitalized in Xiaogan Central Hospital from 20 January to 29 February 2020 were retrospectively included and grouped into two cohorts (cohort with normal renal function and cohort with renal insufficiency) based on the renal function detected on admission. Records of clinical manifestation, laboratory findings and clinical outcome were collected and compared between these two cohorts.

Results

A total 543 COVID‐19 patients were included. Among these patients, 70 patients developed early renal impairment, with an incidence of 12.89%. A significantly higher white blood cell (WBC) count, C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), serum creatine (Cr), blood urine nitrogen (BUN) and brain natriuretic peptide (BNP) and a significantly lower blood platelet (PLT), lymphocyte count, prealbumin and albumin (ALB) were detected in the cohort with renal insufficiency (P < 0.05). Patients with early renal impairment were also associated with higher incidences of haematuria/proteinuria, higher incidences of mortality and prolonged hospitalization duration. The independent risk factors for in‐hospital death included age >65 years old, complication of diabetes, renal impairment on admission (Cr > 73 μmol/L and eGFR < 60 ml/min 1.73 m²), WBC > 9.5 × 10⁹/L and ALB < 35 g/L.

Conclusion

Early renal impairment is associated with higher risk of in‐hospital death for patients with COVID‐19. Risk stratification according to renal function can better guide the clinical management of COVID‐19.

Early metabolic support for critically ill trauma patients: A prospective randomized controlled trial

BACKGROUND

There is a lack of consensus regarding the optimal nutritional support for trauma patients. We hypothesize that early postinjury metabolic support focusing on adequate protein would modify the metabolic signature and alter the inflammatory environment for critically ill trauma patients.

METHODS

We conducted a prospective randomized controlled pilot trial for adult patients admitted to the surgical intensive care unit following traumatic injury. Patients were randomized to receive early metabolic support (EMS) (peripheral amino acid infusions) or standard of care (enteral nutrition as soon as feasible). Routine laboratory assessments, nitrogen balance, cytokines, and metabolomic analyses were assessed at baseline and day 5 after intervention.

RESULTS

A total of 42 trauma patients were randomized into well-balanced groups with similar age (32 years), Injury Severity Score (25), and body mass index (27.4 kg/m2). Early metabolic support provided significantly more protein (1.43 g/kg vs. 0.35 g/kg; p < 0.0001) and more calories (12.6 kcal/kg vs. 7.5 g/kg; p = 0.0012) over the first 5 days as compared with the standard of care. Early metabolic support modified protein catabolism and synthesis as demonstrated by a larger median negative nitrogen balance (-16.3 g vs. -5.3 g; p = 0.03) and a unique metabolomic profile at day 5. The biochemical profile of patients who received EMS was defined by greater declines in circulating levels of stress hormone precursors and increased levels of amino acids. The inflammatory response following EMS resulted in a greater decrease in interleukin-1B (p = 0.02) and increase in soluble interleukin-6 receptor (p = 0.01) between baseline and day 5 as compared with the standard of care. The EMS group had a decreased length of stay (15 vs. 22 days) and decreased surgical intensive care unit length of stay (8 vs. 9 days); however, this disappeared after adjustment for Injury Severity Score in this small population.

CONCLUSIONS

Early metabolic support with amino acid is safe, modifies metabolism, and may downregulate the inflammatory state associated with significant trauma, warranting a larger trial to assess for improved outcomes.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level II.

The Relationship Between Mortality, Nutritional Status, and Laboratory Parameters in Geriatric Chronic Obstructive Pulmonary Disease Patients

BACKGROUND

In geriatric patients, limitations in physical, mental, and/or social functions occur as a result of acute and/or chronic disease along with age-related degenerative changes. This study aimed to investigate the relationship between nutritional status, mean platelet volume (MPV), C-reactive protein (CRP)-to-albumin ratio (CAR), and mortality in geriatric chronic obstructive pulmonary disease (COPD) patients.

METHODS

Patients aged 65 years and older who were tertiary state hospitalized with COPD were included in the study. Demographic data of the patients, diagnosis, nutritional risk score-2002 (NRS-2002) score, and body mass index (BMI) were recorded. Glucose, MPV, CRP, albumin, CAR values of the patients, as well as 30-day and 90-day mortality status after nutritional evaluation, were determined. Patients hospitalized for a reason other than COPD, those using anti-inflammatory drugs, patients with missing data, and those in intensive care units were excluded from the study. Patients were divided into two groups based on NRS-2002: NRS-2002; 1 and 2, and NRS-2002; ≥3.

RESULTS

Four hundred eighteen patients were hospitalized for COPD. Of these patients, 279 were aged 65 and over, but due to missing data, only 261 patients' data were analyzed. The 30-day and 90-day mortality rates were quite high in patients with a diagnosis of COPD who needed nutritional support (37.5% and 49.8%). When the demographic data and laboratory values of the patients are examined according to the 30-day and 90-day mortality status, the MPV value is statistically significantly higher in those with mortality at the end of 90 days (p < 0.05). Despite the fact that the NRS-2002 ≥3 group had higher 30-day and 90-day mortality rates than the NRS-2002 1 or 2 groups, there was no statistically significant difference between the groups (p > 0.05).

CONCLUSIONS

As a result, 90-day mortality was observed in approximately half of the patients, and the majority of these patients were male. Parameters that could predict 30-day and 90-day mortality could not be determined without MPV. Inflammatory parameters such as MPV can guide the determination of nutritional needs, especially in geriatric patients with COPD. Because of the high mortality rates in geriatric patients with COPD who need nutritional support, nutritional support should be started without delay in these patients. There is a need for prospective randomized controlled multicenter studies on this subject.

Associations between systemic inflammation and intestinal permeability with Onodera's prognostic nutritional index in critically ill patients

Background

Malnutrition is a serious condition in critically ill patients. The aim of this study is to evaluate the relationships between the Onodera’s prognostic nutritional index (OPNI) and intestinal permeability and between OPNI and systemic inflammation in critically ill patients.

Methods

This was a cross-sectional study conducted in the general intensive care unit (ICU) of a university-affiliated hospital. A total of 162 patients admitted between May 2018 and December 2019, was included in the study. The OPNI was calculated at admission and categorized as ≤40 or >40. We assessed plasma endotoxin and zonulin concentrations as markers of intestinal permeability as well as serum interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) as markers of systemic inflammation upon admission under stringent conditions. The relationships between these markers and OPNI were assessed after adjusting for potential confounders through estimation of a binary logistic regression model.

Results

Median (interquartile range) hs-CRP, IL-6 zonulin, and endotoxin were significantly greater in the low OPNI subgroup than in the high OPNI subgroup (all P<0.05). Multivariate analyses showed significant association between serum IL-6 (odds ratio [OR], 0.88; 95% confidence interval [CI], 0.64–0.96), serum hs-CRP (OR, 0.77; 95% CI, 0.53–0.92), plasma endotoxin (OR, 0.81; 95% CI, 0.72–0.93), and plasma zonulin (OR, 0.83; 95% CI, 0.75–0.98) levels with OPNI in the overall population.

Conclusions

Our results provide evidence that higher plasma endotoxin, zonulin, IL-6, and hs-CRP levels are associated with progressively lower OPNI in mixed ICU populations, particularly in surgical ICU patients.

A psychometric evaluation of the Family Decision-Making Self-Efficacy Scale among surrogate decision-makers of the critically ill

OBJECTIVES

The purpose of this study was to report the psychometric properties, in terms of validity and reliability, of the Unconscious Version of the Family Decision-Making Self-Efficacy Scale (FDMSE).

METHODS

A convenience sample of 215 surrogate decision-makers for critically ill patients undergoing mechanical ventilation was recruited from four intensive care units at a tertiary hospital. Cross-sectional data were collected from participants between days 3 and 7 of a decisionally impaired patient's exposure to acute mechanical ventilation. Participants completed a self-report demographic form and subjective measures of family decision-making self-efficacy, preparation for decision-making, and decisional fatigue. Exploratory factor analyses, correlation coefficients, and internal consistency reliability estimates were computed to evaluate the FDMSE's validity and reliability in surrogate decision-makers of critically ill patients.

RESULTS

The exploratory factor analyses revealed a two-factor, 11-item version of the FDMSE was the most parsimonious in this sample. Furthermore, modified 11-item FDMSE demonstrated discriminant validity with the measures of fatigue and preparation for decision-making and demonstrated acceptable internal consistency reliability estimates.

SIGNIFICANCE OF RESULTS

This is the first known study to provide evidence for a two-factor structure for a modified, 11-item FDMSE. These dimensions represent treatment and palliation-related domains of family decision-making self-efficacy. The modified FDMSE is a valid and reliable instrument that can be used to measure family decision-making self-efficacy among surrogate decision-makers of the critically ill.

How to Increase Muscle Mass in Critically Ill Patients: Lessons Learned from Athletes and Bodybuilders

PURPOSE OF REVIEW

Decades of research on nutrition and exercise on athletes and bodybuilders has yielded various strategies to promote anabolism and improve muscle health and growth. We reviewed these interventions in the context of muscle loss in critically ill patients.

RECENT FINDINGS

For critically ill patients, ensuring optimum protein intake is important, potentially using a whey-containing source and supplemented with vitamin D and leucine. Agents like hydroxyl β-methylbutyrate and creatine can be used to promote muscle synthesis. Polyunsaturated fatty acids stimulate muscle production as well as have anti-inflammatory properties that may be useful in critical illness. Adjuncts like oxandralone promote anabolism. Resistance training has shown mixed results in the ICU setting but needs to be explored further with specific outcomes. Critically ill patients suffer from severe proteolysis during hospitalization as well as persistent inflammation, immunosuppression, and catabolism syndrome after discharge. High protein supplementation, ergogenic aids, anti-inflammatories, and anabolic adjuncts have shown potential in alleviating muscle loss and should be used in intensive care units to optimize patient recovery.

Role of ketones, ketogenic diets and intermittent fasting in ICU

PURPOSE OF REVIEW

To summarize the clinical evidence for beneficial effects of ketones, ketogenic diets and intermittent fasting in critical illness, and to review potential mechanisms behind such effects.

RECENT FINDINGS

Recent evidence demonstrates that activation of a metabolic fasting response may be beneficial to recover from critical insults. Potential protective mechanisms are, among others, activation of ketogenesis and of damage removal by autophagy. Novel feeding strategies, including ketone supplements, ketogenic diets and intermittent fasting regimens, can activate these pathways - at least partially - in critically ill patients. Randomized controlled trials (RCTs) studying these novel feeding strategies as compared with standard care, are scarce and have not shown consistent benefit. Yet, all RCTs were small and underpowered for clinical endpoints. Moreover, in intermittent fasting studies, the duration of the fasting interval may have been too short to develop a sustained metabolic fasting response.

SUMMARY

These findings open perspectives for the further development of fasting-mimicking diets. Ultimately, clinical benefit should be confirmed by RCTs that are adequately powered for clinically relevant, patient-centered endpoints.

A Retrospective Analysis of Feeding Practices and Complications in Patients with Critical Bronchiolitis on Non-Invasive Respiratory Support

Limited data exist regarding feeding pediatric patients managed on non-invasive respiratory support (NRS) modes that augment oxygenation and ventilation in the setting of acute respiratory failure. We conducted a retrospective cohort study to explore the safety of feeding patients managed on NRS with acute respiratory failure secondary to bronchiolitis. Children up to two years old with critical bronchiolitis managed on continuous positive airway pressure, bilevel positive airway pressure, or RAM cannula were included. Of the 178 eligible patients, 64 were reportedly nil per os (NPO), while 114 received enteral nutrition (EN). Overall equivalent in severity of illness, younger patients populated the EN group, while the NPO group experienced a higher incidence of intubation. Duration of stay in the pediatric intensive care unit and non-invasive respiratory support were shorter in the NPO group, though intubation eliminated the former difference. Within the EN group, ninety percent had feeds initiated within 48 h and 94% reached full feeds within 7 days of NRS initiation, with an 8% complication and <1% aspiration rate. Reported complications did not result in escalation of respiratory support. Notably, a significant improvement in heart rate and respiratory rate was noted after feeds initiation. Taken together, our study supports the practice of early enteral nutrition in patients with critical bronchiolitis requiring NRS.

Effect of gut microbiota modulation on feeding tolerance of enterally fed critically ill adult patients: a systematic review

PURPOSE

The objective of this systematic review was to evaluate the effect of pre-, pro-, and synbiotics on feeding tolerance of enterally fed critically ill adult patients.

METHODS

MEDLINE, Science Direct, Web of Knowledge, and the Cochrane Central Register of Controlled Trials were searched up to November 2019. English language randomized controlled trials reporting the effect of pre, pro or synbiotics on the feeding tolerance of enterally fed critically ill adult patients were included.

RESULTS

Overall, 15 papers were selected for review. Among six studies reporting the energy intake, only two studies showed significantly higher energy intake in the prebiotic-receiving groups. Among four RCTs reporting frequency or time to achieve the target calorie, only one found a significant effect of probiotics to reduce the time to achieve a target dose of calorie. About the prevalence or duration of diarrhea, 7 out of 12 RCTs reported a beneficial effect. All but one study found no beneficial effects for gut microbiota manipulation on clinical endpoints including length of stay (LOS) in hospital and intensive care unit (ICU).

CONCLUSION

It should be noticed that the heterogeneity in study designs, product format, and ICU patient populations makes it difficult to draw any general conclusion. Overall, it seems that pre, pro, or synbiotics have no significant beneficial effect on feeding tolerance and clinical endpoints in critically ill adults, but they may reduce the prevalence or duration of diarrhea.

Advances in Medical Nutrition Therapy: Parenteral Nutrition

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

Case report of an exercise training and nutritional intervention plan in a patient with A350P mutation in DES gene

Performing a supplementation intervention with creatine and protein, in conjunction with low-intensity endurance and resistance exercise is safe and has a positive effect on the quality of life in a patient with desminopathy.

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.

Protein Intake, Nutritional Status and Outcomes in ICU Survivors: A Single Center Cohort Study

Background: We hypothesized that protein delivery during hospitalization in patients who survived critical care would be associated with outcomes following hospital discharge. Methods: We studied 801 patients, age ≥ 18 years, who received critical care between 2004 and 2012 and survived hospitalization. All patients underwent a registered dietitian formal assessment within 48 h of ICU admission. The exposure of interest, grams of protein per kilogram body weight delivered per day, was determined from all oral, enteral and parenteral sources for up to 28 days. Adjusted odds ratios for all cause 90-day post-discharge mortality were estimated by mixed- effects logistic regression models. Results: The 90-day post-discharge mortality was 13.9%. The mean nutrition delivery days recorded was 15. In a mixed-effect logistic regression model adjusted for age, gender, race, Deyo-Charlson comorbidity index, acute organ failures, sepsis and percent energy needs met, the 90-day post-discharge mortality rate was 17% (95% CI: 6–26) lower for each 1 g/kg increase in daily protein delivery (OR = 0.83 (95% CI 0.74–0.94; p = 0.002)). Conclusions: Adult medical ICU patients with improvements in daily protein intake during hospitalization who survive hospitalization have decreased odds of mortality in the 3 months following hospital discharge.

Muscle wasting in the presence of disease, why is it so variable?

Skeletal muscle wasting is a common clinical feature of many chronic diseases and also occurs in response to single acute events. The accompanying loss of strength can lead to significant disability, increased care needs and have profound negative effects on quality of life. As muscle is the most abundant source of amino acids in the body, it appears to function as a buffer for fuel and substrates that can be used to repair damage elsewhere and to feed the immune system. In essence, the fundamentals of muscle wasting are simple: less muscle is made than is broken down. However, although well-described mechanisms modulate muscle protein turnover, significant individual differences in the amount of muscle lost in the presence of a given severity of disease complicate the understanding of underlying mechanisms and suggest that individuals have different sensitivities to signals for muscle loss. Furthermore, the rate at which muscle protein is turned over under normal conditions means that clinically significant muscle loss can occur with changes in the rate of protein synthesis and/or breakdown that are too small to be measurable. Consequently, the changes in expression of factors regulating muscle turnover required to cause a decline in muscle mass are small and, except in cases of rapid wasting, there is no consistent pattern of change in the expression of factors that regulate muscle mass. MicroRNAs are fine tuners of cell phenotype and are therefore ideally suited to cause the subtle changes in proteome required to tilt the balance between synthesis and degradation in a way that causes clinically significant wasting. Herein we present a model in which muscle loss as a consequence of disease in non-muscle tissue is modulated by a set of microRNAs, the muscle expression of which is associated with severity of disease in the non-muscle tissue. These microRNAs alter fundamental biological processes including the synthesis of ribosomes and mitochondria leading to reduced protein synthesis and increased protein breakdown, thereby freeing amino acids from the muscle. We argue that the variability in muscle loss observed in the human population arises from at least two sources. The first is from pre-existing or disease-induced variation in the expression of microRNAs controlling the sensitivity of muscle to the atrophic signal and the second is from the expression of microRNAs from imprinted loci (i.e. only expressed from the maternally or paternally inherited allele) and may control the rate of myonuclear recruitment. In the absence of disease, these factors do not correlate with muscle mass, since there is no challenge to the established balance. However, in the presence of such a challenge, these microRNAs determine the rate of decline for a given disease severity. Together these mechanisms provide novel insight into the loss of muscle mass and its variation in the human population. The involvement of imprinted loci also suggests that genes that regulate early development also contribute to the ability of individuals to resist muscle loss in response to disease.

Protein Provision in Critically Ill Adults Requiring Enteral Nutrition: Are Guidelines Being Met?

BACKGROUND

In a previous audit, 81% of enteral protein prescriptions failed to meet protein guidelines. To address this, a very high-protein enteral formula and protein supplements were introduced, and protein prescriptions were adjusted to account for nonnutrition energy sources displacing enteral formula. This follow-up audit compared protein provision in critically ill adults requiring exclusive enteral nutrition (EN), first, with local and international guidelines, and second, after changes to practice, with the previous audit in the same intensive care unit (ICU).

METHODS

Data were collected from 106 adults consecutively admitted to the ICU of a U.K. tertiary hospital and requiring exclusive EN ≥3 days. Protein targets based on local guidelines (1.25, 1.5, or 2.0 g/kg/d), nutrition prescription, and delivery were recorded for 24 hours between days 1-3, 5-7, 8-10, and 18-20 post-ICU admission.

RESULTS

The proportion of day 1-3 protein prescriptions meeting protein targets increased from 19% in 2015 to 69% in 2017 (P < .0005, φ = 0.50). The median percentage of protein target delivered was lower than prescribed (79% vs 103%; (P < .0005; r = 0.53) and EN delivery only met the target of 22% of patients. The proportion of protein prescriptions meeting protein targets was similar for days 1-3 (69%), 5-7 (71%), and 8-10 (68%), but increased slightly by days 18-20 (74%). The proportion of patients for which EN delivery met protein targets increased with the number of days post-ICU admission (22%, 26%, 37%, and 53% for days 1-3, 5-7, 8-10, and 18-20, respectively).

CONCLUSION

The proportion of protein prescriptions meeting guideline targets was higher after changes to practice.

Intensive Care Nutrition and Post-Intensive Care Recovery

Intensive care unit (ICU)-acquired weakness frequently complicates critical illness, which prolongs intensive care dependency and causes long-term burden. Observational studies have suggested that prolonged underfeeding could aggravate ICU-acquired weakness and impair outcome. However, recent large randomized controlled trials have failed to show a benefit of early enhanced nutrition to critically ill patients. Moreover, early parenteral nutrition was even shown to increase ICU-acquired weakness and prolong organ failure and intensive care dependency, which may be explained by feeding-induced suppression of autophagy. Currently, the ideal timing of artificial nutrition for critically ill patients as well as the optimal dose and composition remain unclear.

Parenteral nutrition in the critically ill

PURPOSE OF REVIEW

Feeding guidelines have recommended early, full nutritional support in critically ill patients to prevent hypercatabolism and muscle weakness. Early enteral nutrition was suggested to be superior to early parenteral nutrition. When enteral nutrition fails to meet nutritional target, it was recommended to administer supplemental parenteral nutrition, albeit with a varying starting point. Sufficient amounts of amino acids were recommended, with addition of glutamine in subgroups. Recently, several large randomized controlled trials (RCTs) have yielded important new insights. This review summarizes recent evidence with regard to the indication, timing, and dosing of parenteral nutrition in critically ill patients.

RECENT FINDINGS

One large RCT revealed no difference between early enteral nutrition and early parenteral nutrition. Two large multicenter RCTs showed harm by early supplementation of insufficient enteral nutrition with parenteral nutrition, which could be explained by feeding-induced suppression of autophagy. Several RCTs found either no benefit or harm with a higher amino acid or caloric intake, as well as harm by administration of glutamine.

SUMMARY

Although unanswered questions remain, current evidence supports accepting low macronutrient intake during the acute phase of critical illness and does not support use of early parenteral nutrition. The timing when parenteral nutrition can be initiated safely and effectively is unclear.

Parenteral nutrition in intensive care patients: medicoeconomic aspects

PURPOSE OF REVIEW

Parenteral nutrition (PN) alone or as supplemental parenteral nutrition (SPN) has been shown to prevent negative cumulative energy balance, to improve protein delivery and, in some studies, to reduce infectious morbidity in ICU patients who fail to cover their needs with enteral nutrition (EN) alone.

RECENT FINDINGS

The optimization of energy provision to an individualized energy target using either early PN or SPN within 3-4 days after admission has recently been reported to be a cost-saving strategy mediated by a reduction of infectious complications in selected intensive care patients.

SUMMARY

EN alone is often insufficient, or occasionally contraindicated, in critically ill patients and results in growing energy and protein deficit. The cost benefit of using early PN in patients with short-term relative contraindications to EN has been reported. In selected patients SPN has been associated with a decreased risk of infection, a reduced duration of mechanical ventilation, a shorter stay in the ICU. Altogether four studies have investigated the costs associated with these interventions since 2012: two of them from Australia and Switzerland have shown that optimization of energy provision using SPN results in cost reduction, conflicting with other studies. The latter encouraging findings require further validation.

High-Protein Hypocaloric Nutrition for Non-Obese Critically Ill Patients

High-protein hypocaloric nutrition, tailored to each patient's muscle mass, protein-catabolic severity, and exogenous energy tolerance, is the most plausible nutrition therapy in protein-catabolic critical illness. Sufficient protein provision could mitigate the rapid muscle atrophy characteristic of this disease while providing urgently needed amino acids to the central protein compartment and sites of tissue injury. The protein dose may range from 1.5 to 2.5 g protein (1.8-3.0 g free amino acids)/kg dry body weight per day. Nutrition should be low in energy (≈70% of energy expenditure or ≈15 kcal/kg dry body weight per day) because efforts to match energy provision to energy expenditure are physiologically irrational, risk toxic energy overfeeding, and have repeatedly failed in large clinical trials to demonstrate clinical benefit. The American Society for Parenteral and Enteral Nutrition currently suggests high-protein hypocaloric nutrition for obese critically ill patients. Short-term high-protein hypocaloric nutrition is physiologically and clinically sensible for most protein-catabolic critically ill patients, whether obese or not.

Enteral/Parenteral Nutrition in Foals and Adult Horses Practical Guidelines for the Practitioner

Nutritional support is an important adjunct to medical therapy in the sick, injured, or debilitated equine patient. What is not clear is the optimal route, composition, or amounts of support. The enteral route should be chosen whenever possible to maximize the benefits to the gastrointestinal tract and the patient as a whole. Complete or partial parenteral nutrition is most useful as a bridge during recovery and transition to enteral feeding in the horse. The reader is encouraged to consider nutritional support whether enteral or parenteral in any anorexic, chronically debilitated, or sick equine patient.

Glucose homeostasis in two degrees of sepsis lethality induced by caecum ligation and puncture in mice

Sepsis is associated with high mortality. Both critically ill humans and animal models of sepsis exhibit changes in their glucose homeostasis, that is, hypoglycaemia, with the progression of infection. However, the relationship between basal glycaemia, glucose tolerance and insulin sensitivity is not well understood. Thus, we aimed to evaluate this glucose homeostasis triad at the late stage of sepsis (24 h after surgery) in male Swiss mice subjected to lethal and sublethal sepsis by the caecal ligation and puncture (CLP) model. The percentage of survival 24 h after CLP procedure in the Lethal and Sublethal groups was around 66% and 100% respectively. Both Lethal and Sublethal groups became hypoglycaemic in fasting and fed states 24 h after surgery. The pronounced fed hypoglycaemia in the Lethal group was not due to worsening anorexic behaviour or hepatic inability to deliver glucose in relation to the Sublethal group. Reduction in insulin sensitivity in CLP mice occurred in a lethality-dependent manner and was not associated with glucose intolerance. Analysis of oral and intraperitoneal glucose tolerance tests, as well as the gastrointestinal motility data, indicated that CLP mice had reduced intestinal glucose absorption. Altogether, we suggest cessation of appetite and intestinal glucose malabsorption are key contributors to the hypoglycaemic state observed during experimental severe sepsis.

Amino acid supplements in critically ill patients

Observational studies have associated a low amino acid intake with adverse outcome of critical illness. Although this finding could theoretically be explained by differences in feeding tolerance related to illness severity, guidelines have recommended to administer sufficient amounts of amino acids from early onwards in the disease course. Recently, however, several high quality randomized controlled trials have not shown benefit by early amino acid supplementation and some trials even found potential harm, thus questioning this recommendation. These negative results could be related to amino acid-induced suppression of autophagy, to the inability to suppress bulk catabolism by exogenous amino acids, or to the administration of an amino acid mixture with an inappropriate composition. Currently, there is no evidence supporting administration of individual amino acid supplements during critical illness and glutamine administration may be harmful. The optimal timing, dose and composition of the amino acid mixture for critically ill patients remain unclear.

Impact and outcomes of nutritional support team intervention in patients with gastrointestinal disease in the intensive care unit

Nutritional support has become an important intervention for critically ill patients. Many studies have reported on the effects of nutritional support for the patients within the intensive care unit (ICU); however, no studies have specifically assessed patients with gastrointestinal diseases who may have difficulty absorbing enteral nutrition (EN) in the ICU.Sixty-two patients with gastrointestinal disease were admitted to the ICU between August 2014 and August 2016 at a single tertiary university hospital. We analyzed 2 different patient groups in a retrospective cohort study: those who received nutritional support team (NST) intervention and those who did not.Forty-four (71.0%) patients received nutritional support in ICU and 18 (29.0%) did not. Variables including male sex, high albumin or prealbumin level at the time of ICU admission, and short transition period into EN showed statistically significant association with lower mortality on the univariate analysis (all P < .05). Multivariate analysis revealed that longer length of hospital stay (P = .013; hazard ratio [HR], 0.972; 95% confidence interval [CI], 0.951-0.994), shorter transition into EN (P = .014; HR, 1.040; 95% CI, 1.008-1.072), higher prealbumin level (P = .049; HR, 0.988; 95% CI, 0.976-1.000), and NST intervention (P = .022; HR, 0.356; 95% CI, 0.147-0.862) were independent prognostic factors for lower mortality.In conclusion, NST intervention related to early initiated EN, and high prealbumin levels are beneficial to decrease mortality in the acutely ill patients with GI disease.

Parenteral Nutrition: Amino Acids

There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

Will We Ever Agree on Protein Requirements in the Intensive Care Unit?

The precise value of the normal adult protein requirement has long been debated. For many reasons-one of them being the difficulty of carrying out long-term nutrition experiments in free-living people-uncertainty is likely to persist indefinitely. By contrast, the controlled environment of the intensive care unit and relatively short trajectory of many critical illnesses make it feasible to use hard clinical outcome trials to determine protein requirements for critically ill patients in well-defined clinical situations. This article suggests how the physiological principles that underlie our understanding of normal protein requirements can be incorporated into the design of such clinical trials. The main focus is on 3 principles: (1) the rate of body nitrogen loss roughly predicts an individual's minimum protein requirement and is thus essential to measure to identify individual patients and clinical situations in which the minimum protein requirement is importantly increased, (2) existing muscle mass sets an upper limit on the rate at which amino acids can be mobilized from muscle for transfer to central proteins and sites of injury and is thus important to monitor to identify patients who are at greatest risk of protein deficiency-related adverse outcomes, and (3) negative energy balance increases the dietary protein requirement, so calorie-deprived patients-whether obese or not-should be enrolled in hard clinical outcome trials that compare the current practice of "permissive underfeeding" (underprovision of all nutrients, including protein) with hypocaloric nutrition supplemented by a suitably generous amount of protein.

Protein Turnover and Metabolism in the Elderly Intensive Care Unit Patient

Many intensive care unit (ICU) patients do not achieve target protein intakes particularly in the early days following admittance. This period of iatrogenic protein undernutrition contributes to a rapid loss of lean, in particular muscle, mass in the ICU. The loss of muscle in older (aged >60 years) patients in the ICU may be particularly rapid due to a perfect storm of increased catabolic factors, including systemic inflammation, disuse, protein malnutrition, and reduced anabolic stimuli. This loss of muscle mass has marked consequences. It is likely that the older patient is already experiencing muscle loss due to sarcopenia; however, the period of stay in the ICU represents a greatly accelerated period of muscle loss. Thus, on discharge, the older ICU patient is now on a steeper downward trajectory of muscle loss, more likely to have ICU-acquired muscle weakness, and at risk of becoming sarcopenic and/or frail. One practice that has been shown to have benefit during ICU stays is early ambulation and physical therapy (PT), and it is likely that both are potent stimuli to induce a sensitivity of protein anabolism. Thus, recommendations for the older ICU patient would be provision of at least 1.2-1.5 g protein/kg usual body weight/d, regular and early utilization of ambulation (if possible) and/or PT, and follow-up rehabilitation for the older discharged ICU patient that includes rehabilitation, physical activity, and higher habitual dietary protein to change the trajectory of ICU-mediated muscle mass loss and weakness.