Hypocaloric vs Normocaloric Nutrition in Critically Ill Patients: A Prospective Randomized Pilot Trial

Metabolic support in the critically ill: a consensus of 19

Metabolic alterations in the critically ill have been studied for more than a century, but the heterogeneity of the critically ill patient population, the varying duration and severity of the acute phase of illness, and the many confounding factors have hindered progress in the field. These factors may explain why management of metabolic alterations and related conditions in critically ill patients has for many years been guided by recommendations based essentially on expert opinion. Over the last decade, a number of randomized controlled trials have been conducted, providing us with important population-level evidence that refutes several longstanding paradigms. However, between-patient variation means there is still substantial uncertainty when translating population-level evidence to individuals. A cornerstone of metabolic care is nutrition, for which there is a multifold of published guidelines that agree on many issues but disagree on others. Using a series of nine questions, we provide a review of the latest data in this field and a background to promote efforts to address the need for international consistency in recommendations related to the metabolic care of the critically ill patient. Our purpose is not to replace existing guidelines, but to comment on differences and add perspective.

Evaluation of the accuracy and precision of a new generation indirect calorimeter in canopy dilution mode

BACKGROUND & AIMS

Indirect calorimetry (IC) is the only way to measure in real time energy expenditure (EE) and to optimize nutrition support in acutely and chronically ill patients. Unfortunately, most of the commercially available indirect calorimeters are rather complex to use, expensive and poorly accurate and precise. Therefore, an innovative device (Q-NRG®, COSMED, Rome, Italy) that matches clinicians' needs has been developed as part of the multicenter ICALIC study supported by the two academic societies ESPEN and ESICM. The aim of this study was to evaluate the accuracy and intra- and inter-unit precision of this new device in canopy dilution mode in vitro and in spontaneously breathing adults.

METHODS

Accuracy and precision of oxygen consumption (VO₂) and carbon dioxide production (VCO₂) measurements were evaluated in vitro and in 15 spontaneously breathing healthy adults by interchanging three Q-NRG® units in a random order. In vitro validation was performed by gas exchange simulation using high-precision gas mixture and mass flow controller. Accuracy was calculated as error of measured values against expected ones based on volume of gas infused. Respiratory coefficient (RQ) accuracy was furthermore assessed using the ethanol-burning test. To evaluate the intra- and inter-unit precisions, the coefficient of variation (CV% = SD/Mean*100) was calculated, respectively, from the mean ± SD or the mean ± SD of the three mean values of VO₂, VCO₂, RQ and EE measured by each Q-NRG® units. In vivo accuracy measurement of the Q-NRG® was assessed by simultaneous comparison with mass spectrometry (MS) gas analysis, using Bland-Altman plot, Pearson correlation and paired t-test (significance level of p = 0.05).

RESULTS

In vitro evaluation of the Q-NRG® accuracy showed measurement errors <1% for VO₂, VCO₂ and EE and <1.5% for RQ. Evaluation of the intra- and inter-unit precision showed CV% ≤1% for VO₂ and EE and CV% ≤1.5% for VCO₂ and RQ measurements, except for one Q-NRG® unit where CV% was 2.3% for VO₂ and 3% for RQ. Very good inter-unit precision was confirmed in vivo with CV% equal to 2.4%, 3%, 2.8% and 2.3% for VO₂, VCCO₂, RQ and EE, respectively. Comparison with MS showed correlation of 0.997, 0.987, 0.913 and 0.997 for VO₂, VCO₂, RQ and EE respectively (p ≤ 0.05). Mean deviation of paired differences was 1.6 ± 1.4% for VO₂, -1.5 ± 2.5% for VCO₂, -3.1 ± 2.6% for RQ and 0.9 ± 1.4% for EE.

CONCLUSION

Both in vitro and in vivo measurements of VO₂, VCO₂, RQ and EE on three Q-NRG® units showed minimal differences compared to expected values and MS and very low intra- and inter-unit variability. These results confirm the very good accuracy and precision of the Q-NRG® indirect calorimeter in canopy dilution mode in spontaneously breathing adults.

Indirect Calorimetry in Clinical Practice

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

Relationship between Nutrition Intake and 28-Day Mortality Using Modified NUTRIC Score in Patients with Sepsis

In critically ill patients, malnutrition is known to increase morbidity and mortality. We investigated the relationship between nutritional support and 28-day mortality using the modified NUTrition RIsk in the Critically ill (NUTRIC) score in patients with sepsis. This retrospective cohort study included patients with sepsis admitted to the medical intensive care unit (ICU) between January 2011 and June 2017. Nutritional support for energy and protein intakes at day 7 of ICU admission were categorized into <20, 20 to <25, and ≥25 kcal/kg and <1.0, 1.0 to <1.2, and ≥1.2 g/kg, respectively. NUTRIC scores ≥4 were considered to indicate high nutritional risk. Among patients with low nutritional risk, higher intakes of energy (≥25 kcal/kg) and protein (≥1.2 g/kg) were not significantly associated with lower 28-day mortality. In patients with high nutritional risk, higher energy intakes of ≥25 kcal/kg were significantly associated with lower 28-day mortality compared to intakes of <20 kcal/kg (adjusted hazard ratio (aHR): 0.569, 95% confidence interval (CI): 0.339-0.962, p = 0.035). Higher protein intakes of ≥1.2 g/kg were also significantly associated with lower 28-day mortality compared to intakes of <1.0 g/kg (aHR: 0.502, 95% CI: 0.280-0.900, p = 0.021). Appropriate energy (≥25 kcal/kg) and protein (≥1.2 g/kg) intakes during the first week may improve outcomes in patients with sepsis having high nutritional risk.

The fragility of statistically significant results from clinical nutrition randomized controlled trials

BACKGROUND & AIMS

Recently, a parameter called "Fragility index" (FI) has been proposed, which measures how many events the statistical significance relies on. The lower the FI the more "fragile" the results, and thus more care should be taken when interpreting the results. Our aim in this study was to check FI of nutritional trials.

METHODS

We conducted a systematic review of human clinical nutrition RCTs that report statistically significant dichotomous primary outcomes. We searched the EMBASE, MEDLINE, and Scopus databases. The FI of primary outcomes using the Fisher exact test was calculated and checked the correlations of FI with the number of randomised trials, the p-value of primary outcomes, the publication date, the journal impact factor and the number of patients lost to follow-up.

RESULTS

The initial database search revealed 5790 articles, 37 of which were included in qualitative synthesis. The median (IQR) FI for all studies was 1 (1-3). 28 studies (75.7%) had an FI lower or equal to 2, and in 12 (32.43%) articles, the FI was lower than the number of patients lost to follow-up. No correlations were found between FI and the study characteristics (number of randomized patients, p value of primary outcome, event ratio in experimental group, event ratio in control group, publication date, journal impact factor, lost to follow-up).

CONCLUSION

The results of RCTs in nutritional research often rely on a small number of events or patients. The number of patients lost to follow-up is frequently higher than the FI calculation. Formulating recommendations based on RCTs should be done with caution and FI may be used as auxiliary parameter when assessing the robustness of their findings.

Status and nutritional therapy in elective and emergency neurosurgery patients

OBJEVECT

To evaluate the Nutritional Status (NS) and follow the Enteral Nutritional Therapy (ENT) of patients in neurosurgical intervention.

METHOD

Cohort study in emergency or elective surgery patients with exclusive ENT. Anthropometric measurements (Arm Circumference (AC and Triceps Skinfold (TSF)) were measured on the first, seventh and 14th day. For the ENT monitoring, caloric/protein adequacy, fasting, inadvertent output of the enteral probe and residual gastric volume were used.

RESULTS

80 patients, 78.7% in emergency surgery and 21.3% in elective surgery. There was a reduction in AC and Body Mass Index (BMI) (p>0.01), especially for the emergency group. The caloric/protein adequacy was higher in the emergency group (86.7% and 81.8%).

CONCLUSION

The EN change was greater in the emergency group, even with better ENT adequacy. Changes in body composition are frequent in neurosurgical patients, regardless of the type of procedure.

Dietary Management of Blood Glucose in Medical Critically Ill Overweight and Obese Patients: An Open-Label Randomized Trial

BACKGROUND

Enteral nutrition (EN) increases hyperglycemia due to high carbohydrate concentrations while providing insufficient protein. The study tested whether an EN formula with very high-protein- and low-carbohydrate-facilitated glucose control delivered higher protein concentrations within a hypocaloric protocol.

METHODS

This was a multicenter, randomized, open-label clinical trial with parallel design in overweight/obese mechanically ventilated critically ill patients prescribed 1.5 g protein/kg ideal body weight/day. Patients received either an experimental very high-protein (37%) and low-carbohydrate (29%) or control high-protein (25%) and conventional-carbohydrate (45%) EN formula.

RESULTS

A prespecified interim analysis was performed after enrollment of 105 patients (52 experimental, 53 control). Protein and energy delivery for controls and experimental groups on days 1-5 were 1.2 ± 0.4 and 1.1 ± 0.3 g/kg ideal body weight/day (P = .83), and 18.2 ± 6.0 and 12.5 ± 3.7 kcals/kg ideal body weight/day (P < .0001), respectively. The combined rate of glucose events outside the range of >110 and ≤150 mg/dL were not different (P = .54, primary endpoint); thereby the trial was terminated. The mean blood glucose for the control and the experimental groups were 138 (-SD 108, +SD 177) and 126 (-SD 99, +SD 160) mg/dL (P = .004), respectively. Mean rate of glucose events >150 mg/dL decreased (Δ = -13%, P = .015), whereas that of 80-110 mg/dL increased (Δ = 14%, P = .0007). Insulin administration decreased 10.9% (95% CI, -22% to 0.1%; P = .048) in the experimental group relative to the controls. Glycemic events ≤80 mg/dL and rescue dextrose use were not different (P = .23 and P = .53).

CONCLUSIONS

A very high-protein and low-carbohydrate EN formula in a hypocaloric protocol reduces hyperglycemic events and insulin requirements while increasing glycemic events between 80-110 mg/dL.

Energy balance in obese, mechanically ventilated intensive care unit patients

OBJECTIVES

The aims of this study were, first, to compare the predicted (calculated) energy requirements based on standard equations with target energy requirement based on indirect calorimetry (IC) in critically ill, obese mechanically ventilated patients; and second, to compare actual energy intake to target energy requirements.

METHODS

We conducted a prospective cohort study of mechanically ventilated critically ill patients with body mass index ≥30.0 kg/m² for whom enteral feeding was planned. Clinical and demographic data were prospectively collected. Resting energy expenditure was measured by open-circuit IC. American Society of Parenteral and Enteral Nutrition (APSPEN)/Society of Critical Care Medicine (SCCM) 2016 equations were used to determine predicted (calculated) energy requirements. Target energy requirements were set at 65% to 70% of measured resting energy expenditure as recommended by ASPEN/SCCM. Nitrogen balance was determined via simultaneous measurement of 24-h urinary nitrogen concentration and protein intake.

RESULTS

Twenty-five patients (mean age: 64.5 ± 11.8 y, mean body mass index: 35.2 ± 3.6 kg/m²) underwent IC. The mean predicted energy requirement was 1227 kcal/d compared with mean measured target energy requirement of 1691 kcal/d. Predicted (calculated) energy requirements derived from ASPEN/SCCM equations were less than the target energy requirements in most cases. Actual energy intake from enteral nutrition met 57% of target energy requirements. Protein intake met 25% of target protein requirement and the mean nitrogen balance was -2.3 ± 5.1 g/d.

CONCLUSIONS

Predictive equations underestimated target energy needs in this population. Further, we found that feeding to goal was often delayed resulting in failure to meet both protein and energy intake goals.

Enteral Nutrition in the Mechanically Ventilated Patient

Mechanically ventilated patients are unable to take food orally and therefore are dependent on enteral nutrition for provision of both energy and protein requirements. Enteral nutrition is supportive therapy and may impact patient outcomes in the intensive care unit. Early enteral nutrition has been shown to decrease complications and hospital length of stay and improve the prognosis at discharge. Nutrition support is unique for patients on mechanical ventilation and, as recently published literature shows, should be tailored to the individuals' underlying pathology. This review will discuss the most current literature and recommendations for enteral nutrition in patients receiving mechanical ventilation.

Insufficient Nutrition and Mortality Risk in Septic Patients Admitted to ICU with a Focus on Immune Dysfunction

Immune dysfunction is seen both in sepsis patients and in those with malnutrition. This study aimed to determine whether insufficient nutrition and immune dysfunction have a synergistic effect on mortality in critically ill septic patients. We conducted a prospective observational study from adult sepsis patients admitted to intensive care units (ICUs) between August 2013 and June 2016. Baseline characteristics including age, gender, body mass index, NUTRIC, Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores were recorded. Immune dysfunction, defined by human leukocyte antigen DR (HLA-DR) expression, was tested at days 1, 3, and 7 of ICU admission. The study included 151 patients with sepsis who were admitted to the ICU. The 28-day survivors had higher day 7 caloric intakes (89% vs. 73%, p = 0.042) and higher day 1-HLA-DR expression (88.4 vs. 79.1, p = 0.045). The cut-off points of day 7 caloric intake and day 1-HLA-DR determined by operating characteristic curves were 65.1% and 87.2%, respectively. Immune dysfunction was defined as patients with day 1-HLA-DR < 87.2%. Insufficient nutrition had no influence on survival outcomes in patients with immune dysfunction. However, patients with insufficient nutrition had poor prognosis when they were immune competent. Insufficient nutrition and immune dysfunction did not have a synergistic effect on mortality in critically ill septic patients.

Indirect calorimetry as point of care testing

Determining energy requirement is a fundamental of nutrition support. Indirect calorimetry (IC) has been long recognized as the gold standard for assessing basal or resting energy expenditure (REE). The measurement of REE is recommended particularly in the situation where adjustment of energy provision is critical. The result of the IC measurement can lead to changes in treatment and since the change can be carried out immediately at the bedside, this may be considered as point-of-care testing. Beyond the nutritional aspects, studies of energy expenditure with IC have brought out more understanding of the metabolic changes during the natural course of diseases or conditions as well as those related to the intervention. The literature in various disease states has shown that changes in energy expenditure may reveal hidden metabolic information that might be translated into clinical information and have the potential of being both prognostic indicators and/or treatment targets.

Comment je prends en charge la nutrition d’un patient en état de choc

La réponse métabolique à l’agression correspond à un ensemble de réactions à la base de l’adaptation de l’organisme aux nouvelles conditions. Ces modifications concernent des aspects métaboliques spécifiques comme le maintien de la masse protéique et/ou l’état des réserves énergétiques. L’une des principales difficultés de l’optimisation du support métabolique consiste à distinguer les changements métaboliques bénéfiques de ceux qui sont délétères pour l’organisme. Dans ce contexte, les objectifs thérapeutiques peuvent se limiter à une approche nutritionnelle s’attachant à limiter le déficit énergétique et les pertes protéiques et musculaires. Ils peuvent être plus ambitieux en essayant d’adapter les apports aux différents besoins d’un point de vue quantitatif comme qualitatif. La limitation du déficit énergétique semble être un objectif raisonnable à atteindre selon les données de la littérature. Enfin, essayer d’interférer avec la réponse métabolique à l’agression (immunomodulation, manipulations pharmacologiques des voies métaboliques, etc.) représente le degré d’intervention métabolique le plus élaboré et, si quelques données ont pu être encourageantes, il n’est pas possible d’affirmer que cet objectif soit complètement réaliste, voire même bénéfique. Les apports nutritionnels doivent être intégrés à la stratégie thérapeutique globale de prise en charge. La réponse optimale du support nutritionnel a pour but « de donner les moyens métaboliques » de la guérison.

Association of Inadequate Caloric Supplementation with 30-Day Mortality in Critically Ill Postoperative Patients with High Modified NUTRIC Score

Modified NUTRIC (mNUTRIC) score is a useful assessment tool to determine the risk of malnutrition in patients on mechanical ventilation (MV). We identified associations between postoperative calorie adequacy, 30-day mortality, and surgical outcomes in patients with high mNUTRIC scores. Medical records of 272 patients in the intensive care unit who required MV support for >24 h after emergency gastro-intestinal (GI) surgery between January 2007 and December 2017 were reviewed. Calorie adequacy in percentage (Calorie intake in 5 days ÷ Calorie requirement for 5 days × 100) was assessed in patients with high (5–9) and low (0–4) mNUTRIC scores. In the high mNUTRIC score group, patients with inadequate calorie supplementation (calorie adequacy <70%) had higher 30-day mortality than those with adequate supplementation (31.5% vs. 11.1%; p = 0.010); this was not observed in patients with low mNUTRIC scores. This result was also confirmed through Kaplan–Meier survival curve (p = 0.022). Inadequate calorie supplementation in the high mNUTRIC score group was not associated with Intra-abdominal infection (p = 1.000), pulmonary complication (p = 0.695), wound complication (p = 0.407), postoperative leakage (p = 1.000), or infections (p = 0.847). Inadequate calorie supplementation after GI surgery was associated with higher 30-day mortality in patients with high mNUTRIC scores. Therefore, adequate calorie supplementation could contribute to improved survival of critically ill postoperative patients with high risk of malnutrition.

High protein intake during the early phase of critical illness: yes or no?

The rationale for the provision of nitrogen from proteins given via the enteral route or from intravenous amino acids is to boost the synthesis of muscle proteins, and thereby to limit the severity of intensive care unit-acquired weakness by the prevention of muscle loss. However, the optimal timing for supplemental nitrogen provision is a matter of debate and controversy. Indeed, consistent data from retrospective studies support an association between high early protein intakes and better outcomes, while recent post-hoc findings from prospective studies raise safety concerns. This pro–con paper details the arguments of both sides and highlights the need for large-scale prospective studies assessing the safety and efficacy of different levels of protein intake in combination with physical activity and summarizes the currently recruiting clinical trials.

Major Predictors of Incidence of Congestive Heart Failure and the Responsive Character of Enteral Nutrition: Meta-Analysis

Background

Statistical data from the USA estimate that 5.7 million Americans over 20 years of age have congestive heart failure (CHF) and this number is expected to increase approximately 46.0% between 2012 and 2030. In Brazil, there are no epidemiological studies involving the incidence of heart failure; however, according to other countries, it can be estimated that up to 6.4 million Brazilians suffer from this syndrome. Randomized and controlled clinical studies on the efficacy of enteral nutrition (EN) in patients with CHF are lacking. The aim of the present study was to perform a systematic review of the main predictors of CHF that promote EN, as well as to find if the literary findings were conclusive in the efficacy of EN for treatment and prophylaxis of CHF.

Methods

A total of 105 papers were submitted to the eligibility analysis, after which 28 studies were selected, following the rules of the systematic review - PRISMA. The search strategy was followed in MEDLINE/Pubmed, Web of Science, ScienceDirect Journals (Elsevier), Scopus (Elsevier) and ONEFile (Gale), with the following steps: search for mesh terms and use of bouleanos “and” between terms and “or” between historical findings.

Results

The present study listed the major predictors of CHF with indication for EN. After testing the normality of each group of variables of causes of decompensation in CHF, it was analyzed that all the variables did not present normal distribution, with P < 0.10. Thus, a non-parametric Kruskal-Wallis analysis was performed, obtaining P > 0.05 in all analyses, that is, in all groups of causes of decompensation in CHF, there was no statistical difference in each group studied.

Conclusion

There is still no known influence of the efficacy of EN on increasing survival and reducing the morbidity of patients with CHF because there are few clinical trials that have evaluated this question; however, EN is very indicated in the attempt to mitigate the weight loss in these patients.

When timing and dose of nutrition support were examined, the modified Nutrition Risk in Critically Ill (mNUTRIC) score did not differentiate high-risk patients who would derive the most benefit from nutrition support: a prospective cohort study

BACKGROUND

The timing and dose of exclusive nutrition support (ENS) have not been investigated in previous studies aimed at validating the modified Nutrition Risk in Critically Ill (mNUTRIC) score. We therefore evaluated the mNUTRIC score by determining the association between dose of nutrition support and 28-day mortality in high-risk patients who received short- and longer-term ENS (≤ 6 days vs. ≥ 7 days).

METHODS

A prospective cohort study included data from 252 adult patients with > 48 h of mechanical ventilation in a tertiary care institution in Singapore. The dose of nutrition support (amount received ÷ goal: expressed in percentage) was calculated for a maximum of 14 days. Associations between the dose of energy (and protein) intake and 28-day mortality were evaluated with multivariable Cox regressions. Since patients have different durations of ENS, only the first 6 days of ENS in patients with short- and longer-term ENS were assessed in the Cox regressions to ensure a valid comparison of the associations between energy (and protein) intake and 28-day mortality.

RESULTS

In high-risk patients with short-term ENS (n = 106), each 10% increase in goal energy intake was associated with an increased hazard of 28-day mortality [adj-HR 1.37 (95% CI 1.17, 1.61)], and this was also observed for protein intake [adj-HR 1.31 (95% CI 1.10, 1.56)]. In contrast, each 10% increase in goal protein intake in high-risk patients with longer-term ENS (n = 146) was associated with a lower hazard of 28-day mortality [adj-HR 0.78 (95% CI 0.66, 0.93)]. The mean mNUTRIC scores in these two groups of patients were similar.

CONCLUSION

When timing and dose of nutrition support were examined, the mNUTRIC did not differentiate high-risk patients who would derive the most benefit from nutrition support.

ESPEN guideline on clinical nutrition in the intensive care unit

Following the new ESPEN Standard Operating Procedures, the previous guidelines to provide best medical nutritional therapy to critically ill patients have been updated. These guidelines define who are the patients at risk, how to assess nutritional status of an ICU patient, how to define the amount of energy to provide, the route to choose and how to adapt according to various clinical conditions. When to start and how to progress in the administration of adequate provision of nutrients is also described. The best determination of amount and nature of carbohydrates, fat and protein are suggested. Special attention is given to glutamine and omega-3 fatty acids. Particular conditions frequently observed in intensive care such as patients with dysphagia, frail patients, multiple trauma patients, abdominal surgery, sepsis, and obesity are discussed to guide the practitioner toward the best evidence based therapy. Monitoring of this nutritional therapy is discussed in a separate document.

Nutrition in the ICU: new trends versus old-fashioned standard enteral feeding?

PURPOSE OF REVIEW

The narrative review aims to summarize the relevant studies from the last 2 years and provide contextual information to understand findings.

RECENT FINDINGS

Recent ICU studies have provided insight in the pathophysiology and time course of catabolism, anabolic resistance, and metabolic and endocrine derangements interacting with the provision of calories and proteins.Early provision of high protein intake and caloric overfeeding may confer harm. Refeeding syndrome warrants caloric restriction and to identify patients at risk phosphate monitoring is mandatory.Infectious complications of parenteral nutrition are associated with overfeeding. In recent studies enteral nutrition is no longer superior over parenteral nutrition.Previously reported benefits of glutamine, selenium, and fish oil seem to have vanished in recent studies; however, studies on vitamin C, thiamine, and corticosteroid combinations show promising results.

SUMMARY

Studies from the last 2 years will have marked impact on future nutritional support strategies and practice guidelines for critical care nutrition as they challenge several old-fashioned concepts.

Parenteral nutrition in the ICU: Lessons learned over the past few years

Since the early 1990s enteral nutrition (EN) has been considered the optimal route of feeding rather than parenteral nutrition (PN), which was considered harmful in critically ill patients with intense inflammation. The aim of this review was to summarize recent developments and progress in PN, which have changed the view on this feeding technique. PubMed and personal databases were searched for studies and reviews reporting historical development of PN, and for clinical trials conducted after 2010 investigating PN in critical illness, comparing it to EN or not. Trials from the past decade have explored modalities and timing of artificial feeding. Trials based on equation-estimated energy targets and applying an early full feeding strategy have generally had negative results in terms of complications (infections, prolonged ventilation, and intestinal complications with EN). The few trials that based their targets on measured energy targets have achieved reduction of complications regardless of the route. Opposing enteral and parenteral feeding is no longer rational in the critical care setting. A pragmatic and reasonable approach offers better options for the individual patient. Although PN is simpler to deliver than EN, its metabolic consequences are more complicated to handle. A combination of both techniques may be a more reasonable approach in the sickest patients.

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.

Prescribed hypocaloric nutrition support for critically-ill adults

BACKGROUND

There are controversies about the amount of calories and the type of nutritional support that should be given to critically-ill people. Several authors advocate the potential benefits of hypocaloric nutrition support, but the evidence is inconclusive.

OBJECTIVES

To assess the effects of prescribed hypocaloric nutrition support in comparison with standard nutrition support for critically-ill adults SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Cochrane Library), MEDLINE, Embase and LILACS (from inception to 20 June 2017) with a specific strategy for each database. We also assessed three websites, conference proceedings and reference lists, and contacted leaders in the field and the pharmaceutical industry for undetected/unpublished studies. There was no restriction by date, language or publication status.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials comparing hypocaloric nutrition support to normo- or hypercaloric nutrition support or no nutrition support (e.g. fasting) in adults hospitalized in intensive care units (ICUs).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We meta-analysed data for comparisons in which clinical heterogeneity was low. We conducted prespecified subgroup and sensitivity analyses, and post hoc analyses, including meta-regression. Our primary outcomes were: mortality (death occurred during the ICU and hospital stay, or 28- to 30-day all-cause mortality); length of stay (days stayed in the ICU and in the hospital); and Infectious complications. Secondary outcomes included: length of mechanical ventilation. We assessed the quality of evidence with GRADE.

MAIN RESULTS

We identified 15 trials, with a total of 3129 ICU participants from university-associated hospitals in the USA, Colombia, Saudi Arabia, Canada, Greece, Germany and Iran. There are two ongoing studies. Participants suffered from medical and surgical conditions, with a variety of inclusion criteria. Four studies used parenteral nutrition and nine studies used only enteral nutrition; it was unclear whether the remaining two used parenteral nutrition. Most of them could not achieve the proposed caloric targets, resulting in small differences in the administered calories between intervention and control groups. Most studies were funded by the US government or non-governmental associations, but three studies received funding from industry. Five studies did not specify their funding sources.The included studies suffered from important clinical and statistical heterogeneity. This heterogeneity did not allow us to report pooled estimates of the primary and secondary outcomes, so we have described them narratively.When comparing hypocaloric nutrition support with a control nutrition support, for hospital mortality (9 studies, 1775 participants), the risk ratios ranged from 0.23 to 5.54; for ICU mortality (4 studies, 1291 participants) the risk ratios ranged from 0.81 to 5.54, and for mortality at 30 days (7 studies, 2611 participants) the risk ratios ranged from 0.79 to 3.00. Most of these estimates included the null value. The quality of the evidence was very low due to unclear or high risk of bias, inconsistency and imprecision.Participants who received hypocaloric nutrition support compared to control nutrition support had a range of mean hospital lengths of stay of 15.70 days lower to 10.70 days higher (10 studies, 1677 participants), a range of mean ICU lengths of stay 11.00 days lower to 5.40 days higher (11 studies, 2942 participants) and a range of mean lengths of mechanical ventilation of 13.20 days lower to 8.36 days higher (12 studies, 3000 participants). The quality of the evidence for this outcome was very low due to unclear or high risk of bias in most studies, inconsistency and imprecision.The risk ratios for infectious complications (10 studies, 2804 participants) of each individual study ranged from 0.54 to 2.54. The quality of the evidence for this outcome was very low due to unclear or high risk of bias, inconsistency and imprecisionWe were not able to explain the causes of the observed heterogeneity using subgroup and sensitivity analyses or meta-regression.

AUTHORS' CONCLUSIONS

The included studies had substantial clinical heterogeneity. We found very low-quality evidence about the effects of prescribed hypocaloric nutrition support on mortality in hospital, in the ICU and at 30 days, as well as in length of hospital and ICU stay, infectious complications and the length of mechanical ventilation. For these outcomes there is uncertainty about the effects of prescribed hypocaloric nutrition, since the range of estimates includes both appreciable benefits and harms.Given these limitations, results must be interpreted with caution in the clinical field, considering the unclear balance of the risks and harms of this intervention. Future research addressing the clinical heterogeneity of participants and interventions, study limitations and sample size could clarify the effects of this intervention.

Should we calculate or measure energy expenditure? practical aspects in the ICU

Indirect calorimetry is currently a gold standard of resting energy expenditure (REE) assessment in critically ill patients. Many predictive equations of energy expenditure have been proved to imprecisely predict REE and lead to under- or overfeeding. The benefits of indirect calorimetry-guided nutrition therapy rather than calculation-based strategy have been demonstrated in randomized controlled trials. To minimize energy debt in the intensive care unit, we support early enteral feeding. REE should be measured as soon as the patient's conditions allow and the target of delivered calorie should be around 0.7 to 1 of measured REE to avoid overfeeding. The supplemental parenteral nutrition should be prescribed to close the caloric gap if the goal is not reached by enteral nutrition alone.

Parenteral or enteral nutrition: do you have the choice?

PURPOSE OF REVIEW

The review focuses on the use of parenteral nutrition and enteral nutrition in critically ill patients to optimize the nutrition care throughout the ICU stay. The key message is: you have the choice!

RECENT FINDINGS

Enteral nutrition has been recommended for critically ill patients, whereas parenteral nutrition has been considered harmful and to be avoided. However, recent studies have challenged this theory. They demonstrated that enteral nutrition is frequently associated with energy and protein undernutrition, whereas parenteral nutrition becomes deleterious only if overfeeding is induced. Measuring energy expenditure by indirect calorimetry, in most cases, enables accurate determination of the energy needs to optimize the prescription of nutrition. Protein targets should also be considered for adequate feeding. Parenteral nutrition can be used as a supplement or as an alternative to enteral nutrition in case of gastrointestinal intolerance, to enable adequate energy, and protein provision.

SUMMARY

Parenteral nutrition is a powerful tool to optimize nutrition care of critically ill patients to improve clinical outcome, if prescribed according to the individual needs of the patients. After 3-4 days of attempt to feed enterally, enteral nutrition or parenteral nutrition can be used alternatively or combined, as long as the target is reached with special attention to avoid hypercaloric feeding.

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.

Effect of hypocaloric normoprotein or trophic feeding versus target full enteral feeding on patient outcomes in critically ill adults: a systematic review

Uncertainty surrounds the optimal approach to feeding the critically ill, with increasing interest in the concept of intentional underfeeding to reduce metabolic stress while maintaining gut integrity. Conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, this systematic review evaluates clinical outcomes reported in studies comparing hypocaloric normonitrogenous or trophic feeding (collectively 'intentional underfeeding') targeted full energy feeding administered via enteral nutrition to adult critically ill patients. Electronic databases including PubMed, CINAHL, EMBASE and CENTRAL were searched up to September 2017 for trials evaluating intentional underfeeding versus targeted energy feeding interventions on clinical outcomes (mortality, length of stay, duration of ventilation, infective complications, feeding intolerance and glycaemic control) among critically ill adult patients. Bias of included studies was assessed using the Cochrane risk of bias tool. Of the 595 articles identified, seven studies (six randomised controlled trials, one non-randomised trial) met the inclusion criteria, representing 2,684 patients (hypocaloric normonitrogenous n=668; trophic n=681; full energy feeding n=1335). Across the studies, there was considerable heterogeneity in study methodology, population, feeding strategy and outcomes and their timepoints. We observed no evidence that intentional underfeeding, when compared to targeting full energy feeding, reduced mortality or duration of ventilation or length of stay. However, limited trial evidence is available on the impact of intentional underfeeding on post-discharge functional and quality of life outcomes.

Permissive or Trophic Enteral Nutrition and Full Enteral Nutrition Had Similar Effects on Clinical Outcomes in Intensive Care: A Systematic Review of Randomized Clinical Trials

The aim of this study was to systematically review the effect of permissive underfeeding/trophic feeding on the clinical outcomes of critically ill patients. A systematic review of randomized clinical trials to evaluate the mortality, length of stay, and mechanical ventilation duration in patients randomized to either hypocaloric or full-energy enteral nutrition was performed. Data sources included PubMed and Scopus and the reference lists of the articles retrieved. Two independent reviewers participated in all phases of this systematic review as proposed by the Cochrane Handbook, and the review was reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 7 randomized clinical trials that included a total of 1,717 patients were reviewed. Intensive care unit length of stay and mechanical ventilation duration were not statistically different between the intervention and control groups in all randomized clinical trials, and mortality rate was also not different between the groups. In conclusion, hypocaloric enteral nutrition had no significantly different effects on morbidity and mortality in critically ill patients when compared with full-energy nutrition. It is still necessary to determine the safety of this intervention in this group of patients, the optimal amount of energy provided, and the duration of this therapy.

Nutrition therapy for critically ill patients across the Asia-Pacific and Middle East regions: A consensus statement

BACKGROUND & AIMS

Guidance on managing the nutritional requirements of critically ill patients in the intensive care unit (ICU) has been issued by several international bodies. While these guidelines are consulted in ICUs across the Asia-Pacific and Middle East regions, there is little guidance available that is tailored to the unique healthcare environments and demographics across these regions. Furthermore, the lack of consistent data from randomized controlled clinical trials, reliance on expert consensus, and differing recommendations in international guidelines necessitate further expert guidance on regional best practice when providing nutrition therapy for critically ill patients in ICUs in Asia-Pacific and the Middle East.

METHODS

The Asia-Pacific and Middle East Working Group on Nutrition in the ICU has identified major areas of uncertainty in clinical practice for healthcare professionals providing nutrition therapy in Asia-Pacific and the Middle East and developed a series of consensus statements to guide nutrition therapy in the ICU in these regions.

RESULTS

Accordingly, consensus statements have been provided on nutrition risk assessment and parenteral and enteral feeding strategies in the ICU, monitoring adequacy of, and tolerance to, nutrition in the ICU and institutional processes for nutrition therapy in the ICU. Furthermore, the Working Group has noted areas requiring additional research, including the most appropriate use of hypocaloric feeding in the ICU.

CONCLUSIONS

The objective of the Working Group in formulating these statements is to guide healthcare professionals in practicing appropriate clinical nutrition in the ICU, with a focus on improving quality of care, which will translate into improved patient outcomes.

Controversies Surrounding Critical Care Nutrition: An Appraisal of Permissive Underfeeding, Protein, and Outcomes

Over the past few years, numerous studies have called into question the optimal dose, timing, composition, and advancement rate of nutrition during the early acute phase of critical illness. These studies suggest permissive underfeeding with slow advancement may be more beneficial than aggressive full feeding. These counterintuitive results were possibly explained by enhanced autophagy, less hyperglycemia, or prevention of refeeding syndrome. This review underscores the controversies surrounding permissive underfeeding, aims to answer whether permissive underfeeding is appropriate for all critically ill patients, describes the impact of optimal protein delivery on critical care outcomes, discusses nutrition risk, and cogitates on the impact of nutrition on critical care outcomes.

Feeding During Phases of Altered Mitochondrial Activity: A Theory

Decisions surrounding the timing and dosing of nutrition support are made for thousands of ICU patients daily and yet remain a topic of controversy. Nutrition support designed to replenish resting energy expenditure (REE) early in critical illness has led to worse clinical outcomes in at least three recent prospective randomized clinical trials. Producing sufficient energy from nutrient substrates requires use of the mitochondrial electron transport chain (ETC). This process is functionally linked to the creation of a tightly regulated series of chemical messengers known as reactive oxygen species (ROS). In health, ROS are kept at low levels by a system of mitochondrial/cellular enzymes and antioxidants, allowing ROS to act as a signal for the redox health of the cell. In inflammatory conditions, however, this system is altered, leading to changes in the physiologic function of the ETC such that its usage produces greater ROS per unit of substrate. This increased ROS is capable of deactivating antioxidant systems, as well as activating further ROS-producing pathways and stimulating localized inflammatory activity. We propose that exacerbation of this process at this time by the forced influx of exogenously acquired nutrient substrates leads to mitochondrial damage, amplified ROS production, increased inflammation, decreased ATP-productive capacity, and, eventually, the death of the cell by either apoptosis or necrosis. Knowledge of this process is vital to determining the safe dosing and timing of nutrition support in the ICU. It is possible that the physiologic cost of meeting the REE under these conditions of mitochondrial stress may simply be too high. This paper details the proposed process by which inappropriately timed feeding in critically ill patients may damage the very mitochondria required for its utilization.

Early low-energy versus high-energy enteral nutrition support in patients with traumatic intracerebral haemorrhage: protocol for a randomised controlled trial

BACKGROUND

Early enteral nutrition (EN) is associated with shorter hospital stay and lower infection and mortality rates in patients with intracerebral haemorrhage. However, high-energy support always causes clinical complications, such as diarrhoea and aspiration pneumonia, and the true benefit of high-energy support in these patients has not been investigated. The appropriate amount of energy support still needs further investigation. Therefore, we are performing a randomised controlled trial to investigate whether early low-energy EN can decrease mortality and feeding-related complications and improve neurological outcomes as compared with high-energy EN in traumatic intracerebral haemorrhage (TICH) patients.

METHODS/ANALYSIS

This is a randomised, single-blind clinical trial performed in one teaching hospital. 220 TICH patients will be randomly allocated to one of two groups in a 1:1 ratio: an intervention group, and a control group. The intervention group will receive early low-energy EN (10 kcal/kg/day) and the control group will receive high-energy EN (25 kcal/kg/day) for 7 days. All these patients will be followed up for 90 days. The primary outcome is all-cause 90-day mortality. Secondary outcomes include the modified Rankin score, Glasgow Outcome Scale (GOS) and the National Institutes of Health Stroke Scale (NIHSS). Outcomes will be assessed at admission, 7, 30 and 90 days after onset of this trial. The safety of EN strategies will be assessed every day during hospitalisation.

ETHICS AND DISSEMINATION

The trial will be conducted in accordance with the Declaration of Helsinki and has been approved by the ethics committee of Dongyang People's Hospital. The findings will be published in peer-reviewed medical journals.

TRIAL REGISTRATION NUMBER

ChiCTR-INR-17011384; Pre-results.

Early or Late Feeding after ICU Admission?

The feeding of critically ill patients has recently become a controversial issue, as several studies have provided unexpected and contradictory results. Earlier beliefs regarding energy requirements in critical illness-especially during the initial phase-have been challenged. In the current review, we summarize existing evidence about fasting and the impact of early vs. late feeding on the sick organism's responses. The most important points are the non-nutritional advantages of using the intestine, and recognition that early endogenous energy production as an important player in the response must be integrated in the nutrient prescription. There is as of yet no bedside tool to monitor dynamics in metabolism and the magnitude of the endogenous energy production. Hence, an early "full-feeding strategy" exposes patients to involuntary overfeeding, due to the absence of an objective measure enabling the adjustment of the nutritional therapy. Suggestions for future research and clinical practice are proposed.

Current clinical nutrition practices in critically ill patients in Latin America: a multinational observational study

Background

Malnutrition in critically ill adults in the intensive care unit (ICU) is associated with a significantly elevated risk of mortality. Adequate nutrition therapy is crucial to optimise outcomes. Currently, there is a paucity of such data in Latin America. Our aims were to characterise current clinical nutrition practices in the ICU setting in Latin America and evaluate whether current practices meet caloric and protein requirements in critically ill patients receiving nutrition therapy.

Methods

We conducted a cross-sectional, retrospective, observational study in eight Latin American countries (Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Panama, and Peru). Eligible patients were critically ill adults hospitalised in the ICU and receiving enteral nutrition (EN) and/or parenteral nutrition (PN) on the Screening Day and the previous day (day −1). Caloric and protein balance on day –1, nutritional status, and prescribed nutrition therapy were recorded. Multivariable logistic regression analysis was performed to identify independent predictors of reaching daily caloric and protein targets.

Results

The analysis included 1053 patients from 116 hospitals. Evaluation of nutritional status showed that 74.1% of patients had suspected/moderate or severe malnutrition according to the Subjective Global Assessment. Prescribed nutrition therapy included EN alone (79.9%), PN alone (9.4%), and EN + PN (10.7%). Caloric intake met >90% of the daily target in 59.7% of patients on day –1; a caloric deficit was present in 40.3%, with a mean (±SD) daily caloric deficit of –688.8 ± 455.2 kcal. Multivariable logistic regression analysis showed that combined administration of EN + PN was associated with a statistically significant increase in the probability of meeting >90% of daily caloric and protein targets compared with EN alone (odds ratio, 1.56; 95% confidence interval, 1.02–2.39; p = 0.038).

Conclusions

In the ICU setting in Latin America, malnutrition was highly prevalent and caloric intake failed to meet targeted energy delivery in 40% of critically ill adults receiving nutrition therapy. Supplemental administration of PN was associated with improved energy and protein delivery; however, PN use was low. Collectively, these findings suggest an opportunity for more effective utilisation of supplemental PN in critically ill adults who fail to receive adequate nutrition from EN alone.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1805-z) contains supplementary material, which is available to authorized users.

Significant Published Articles for Pharmacy Nutrition Support Practice in 2016

Purpose: To assist the pharmacist engaged in nutrition support therapy in staying current with pertinent literature. Methods: Several clinical pharmacists engaged in nutrition support therapy compiled a list of articles published in 2016 considered important to their clinical practice. The citation list was compiled into a single spreadsheet where the author participants were asked to assess whether the paper was considered important to nutrition support pharmacy practice. A culled list of publications was then identified whereby the majority of author participants (at least 5 out of 8) considered the paper to be important. Guideline and consensus papers from professional organizations, important to practice but not scored, were also included. Results: A total of 103 articles were identified; 10 from the primary literature were voted by the group to be of high importance. An additional 11 organizational guidelines, position, recommendation, or consensus papers were also identified. The top-ranked articles from the primary literature were reviewed. Conclusion: It is recommended that pharmacists, engaged in nutrition support therapy, be familiar with the majority of these articles as it pertains to their practice.

Energy, Protein, Carbohydrate, and Lipid Intakes and Their Effects on Morbidity and Mortality in Critically Ill Adult Patients: A Systematic Review

The guidelines for nutritional support in critically ill adult patients differ in various aspects. The optimal amount of energy and nutritional substrates supplied is important for reducing morbidity and mortality, but unfortunately this is not well known, because the topic is complex and every patient is individual. The aim of this review was to gather recent pertinent information concerning the nutritional support of critically ill patients in the intensive care unit (ICU) with respect to the energy, protein, carbohydrate, and lipid intakes and the effect of their specific utilization on morbidity and mortality. Enteral nutrition (EN) is generally recommended over parenteral nutrition (PN) and is beneficial when administered within 24-48 h after ICU admission. In contrast, early PN does not provide substantial advantages in terms of morbidity and mortality, and the time when it is safe and beneficial remains unclear. The most advantageous recommendation seems to be administration of a hypocaloric (<20 kcal · kg^-1 · d^-1), high-protein diet (amino acids at doses of ≥2 g · kg^-1 · d^-1), at least during the first week of critical illness. Another important factor for reducing morbidity is the maintenance of blood glucose concentrations at 120-150 mg/dL, which is accomplished with the use of insulin and lower doses of glucose of 1-2 g · kg^-1 · d^-1, because this prevents the risk of hypoglycemia and is associated with a better prognosis according to recent studies. A fat emulsion is used as a source of required calories because of insulin resistance in the majority of patients. In addition, lipid oxidation in these patients is ∼25% higher than in healthy subjects.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012."

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Optimal Energy Delivery, Rather than the Implementation of a Feeding Protocol, May Benefit Clinical Outcomes in Critically Ill Patients

Malnutrition is common in intensive care units (ICU), and volume based feeding protocols have been proposed to increase nutrient delivery. However, the volume based approach compared to trophic feeding has not been proven entirely successful in critically ill patients. Our study aimed to compare the clinical outcomes both before and after the implementation of the feeding protocol, and to also evaluate the effects of total energy delivery on outcomes in these patients. We retrospectively collected all patient data, one year before and after the implementation of the volume-based feeding protocol, in the ICU at Taichung Veterans General Hospital. Daily actual energy intake from enteral nutritional support was recorded from the day of ICU admission until either the 7th day of ICU stay, or the day of discharge from the ICU. The energy achievement rate (%) was calculated as: (actual energy intake/estimated energy requirement) × 100%. Two-hundred fourteen patients were enrolled before the implementation of the volume-based feeding protocol (pre-FP group), while 198 patients were enrolled after the implementation of the volume-based feeding protocol (FP group). Although patients in the FP group had significantly higher actual energy intakes and achievement rates when compared with the patients in the pre-FP group, there was no significant difference in mortality rate between the two groups. Comparing survivors and non-survivors from both groups, an energy achievement rate of less than 65% was associated with an increased mortality rate after adjusting for potential confounders (odds ratio, 1.6, 95% confidence interval, 1.01-2.47). The implementation of the feeding protocol could improve energy intake for critically ill patients, however it had no beneficial effects on reducing the ICU mortality rate. Receiving at least 65% of their energy requirements is the main key point for improving clinical outcomes in patients.

Nutrition in the critically ill patient

PURPOSE OF REVIEW

To summarize recent relevant studies regarding nutrition during critical illness and provide recommendations for clinical practice.

RECENT FINDINGS

Recently acquired knowledge regarding nutritional status and risk assessment, body composition, gastric residual volume, prokinetics, tube positioning, enteral vs parenteral nutrition, nutritional dose and timing of initiation, pharmaconutrition, dysbiosis and probiotics are discussed.

SUMMARY

Body composition especially lean body mass is associated with clinical outcomes. The modified NUTrition Risk in the Critically ill score was validated for nutritional risk assessment and identifies patients that benefit from higher nutritional intake; however, caloric restriction decreases mortality in refeeding syndrome. Gastric residual volume monitoring is debated, as abandoning its application doesn't worsen outcome. There is no consensus regarding benefits of gastric vs postpyloric tube placement. Current prokinetics temporarily reduce feeding intolerance, new prokinetics are developed. Enteral remains preferable over parenteral nutrition, although no inferiority of parenteral nutrition is reported in recent studies. Studies imply no harm of hypocaloric feeding when protein requirements are met. Optimal protein provision may be more important than caloric adequacy. Pharmaconutrition confers no superior outcomes and may even confer harm. Dysbiosis is frequently encountered and associated with worse outcomes. Probiotics reduce infectious complications, but not mortality, and may contribute to earlier recovery of gut function.

Role of timing and dose of energy received in patients with acute lung injury on mortality in the Intensive Nutrition in Acute Lung Injury Trial (INTACT): a post hoc analysis

BACKGROUND

Our trial INTACT (Intensive Nutrition in Acute Lung Injury Trial) was designed to compare the impact of feeding from acute lung injury (ALI) diagnosis to hospital discharge, an interval that, to our knowledge, has not yet been explored. It was stopped early because participants who were randomly assigned to energy intakes at nationally recommended amounts via intensive medical nutrition therapy experienced significantly higher mortality hazards than did those assigned to standard nutrition support care that provided energy at 55% of recommended concentrations.

OBJECTIVE

We assessed the influence of dose and timing of feeding on hospital mortality.

DESIGN

Participants (n = 78) were dichotomized as died or discharged alive. Associations between the energy and protein received overall, early (days 1-7), and late (days ≥8) and the hazards of hospital mortality were evaluated between groups with multivariable analysis methods.

RESULTS

Higher overall energy intake predicted significantly higher mortality (OR: 1.14, 95% CI: 1.02, 1.27). Among participants enrolled for ≥8 d (n = 66), higher early energy intake significantly increased the HR for mortality (HR: 1.17, 95% CI: 1.07, 1.28), whereas higher late energy intake was significantly protective (HR: 0.91, 95% CI: 0.83, 1.0). Results were similar for early but not late protein (grams per kilogram) exposure (early-exposure HR: 8.9, 95% CI: 2.3, 34.3; late-exposure HR: 0.15, 95% CI: 0.02, 1.1). Threshold analyses indicated early mean intakes ≥18 kcal/kg significantly increased subsequent mortality.

CONCLUSIONS

Providing kilocalories per kilogram or grams of protein per kilogram early post-ALI diagnosis at recommended levels was associated with significantly higher hazards for mortality, whereas higher late energy intakes reduced mortality hazards. This time-varying effect violated the Cox proportionality assumption, indicating that feeding trials in similar populations should extend beyond 7 d and use time-varying statistical methods. Future trials are required for corroboration. INTACT was registered at clinicaltrials.gov as NCT01921101.

Supplemental parenteral nutrition in intensive care patients: A cost saving strategy

BACKGROUND & AIMS

The Swiss supplemental parenteral nutrition (SPN) study demonstrated that optimised energy provision combining enteral nutrition (EN) and SPN reduces nosocomial infections in critically ill adults who fail to achieve targeted energy delivery with EN alone. To assess the economic impact of this strategy, we performed a cost-effectiveness analysis using data from the SPN study.

METHODS

Multivariable regression analyses were performed to characterise the relationships between SPN, cumulative energy deficit, nosocomial infection, and resource consumption. The results were used as inputs for a deterministic simulation model evaluating the cost-effectiveness of SPN administered on days 4-8 in patients who fail to achieve ≥60% of targeted energy delivery with EN by day 3. Cost data were derived primarily from Swiss diagnosis-related case costs and official labour statistics.

RESULTS

Provision of SPN on days 4-8 was associated with a mean decrease of 2320 ± 338 kcal in cumulative energy deficit compared with EN alone (p < 0.001). Logistic regression analysis showed that each 1000 kcal decrease in cumulative energy deficit was associated with a 10% reduction in the risk of nosocomial infection (odds ratio 0.90; 95% confidence interval 0.83-0.99; p < 0.05). The incremental cost per avoided infection was -63,048 CHF, indicating that the reduction in infection was achieved at a lower cost.

CONCLUSION

Optimisation of energy provision using SPN is a cost-saving strategy in critically ill adults for whom EN is insufficient to meet energy requirements.

Can calculation of energy expenditure based on CO2 measurements replace indirect calorimetry?

BACKGROUND

Methods to calculate energy expenditure (EE) based on CO₂ measurements (EEVCO₂) have been proposed as a surrogate to indirect calorimetry. This study aimed at evaluating whether EEVCO₂ could be considered as an alternative to EE measured by indirect calorimetry.

METHODS

Indirect calorimetry measurements conducted for clinical purposes on 278 mechanically ventilated ICU patients were retrospectively analyzed. EEVCO₂ was calculated by a converted Weir's equation using CO₂ consumption (VCO₂) measured by indirect calorimetry and assumed respiratory quotients (RQ): 0.85 (EEVCO₂_0.85) and food quotient (FQ; EEVCO₂_FQ). Mean calculated EEVCO₂ and measured EE were compared by paired t test. Accuracy of EEVCO₂ was evaluated according to the clinically relevant standard of 5% accuracy rate to the measured EE, and the more general standard of 10% accuracy rate. The effects of the timing of measurement (before or after the 7th ICU day) and energy provision rates (<90 or ≥90% of EE) on 5% accuracy rates were also analyzed (chi-square tests).

RESULTS

Mean biases for EEVCO₂_0.85 and EEVCO₂_FQ were -21 and -48 kcal/d (p = 0.04 and 0.00, respectively), and 10% accuracy rates were 77.7 and 77.3%, respectively. However, 5% accuracy rates were 46.0 and 46.4%, respectively. Accuracy rates were not affected by the timing of the measurement, or the energy provision rates at the time of measurements.

CONCLUSIONS

Calculated EE based on CO₂ measurement was not sufficiently accurate to consider the results as an alternative to measured EE by indirect calorimetry. Therefore, EE measured by indirect calorimetry remains as the gold standard to guide nutrition therapy.

Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock: 2016

OBJECTIVE

To provide an update to "Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock: 2012".

DESIGN

A consensus committee of 55 international experts representing 25 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. A stand-alone meeting was held for all panel members in December 2015. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development.

METHODS

The panel consisted of five sections: hemodynamics, infection, adjunctive therapies, metabolic, and ventilation. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Each subgroup generated a list of questions, searched for best available evidence, and then followed the principles of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to assess the quality of evidence from high to very low, and to formulate recommendations as strong or weak, or best practice statement when applicable.

RESULTS

The Surviving Sepsis Guideline panel provided 93 statements on early management and resuscitation of patients with sepsis or septic shock. Overall, 32 were strong recommendations, 39 were weak recommendations, and 18 were best-practice statements. No recommendation was provided for four questions.

CONCLUSIONS

Substantial agreement exists among a large cohort of international experts regarding many strong recommendations for the best care of patients with sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for these critically ill patients with high mortality.

Effect of Calories Delivered on Clinical Outcomes in Critically Ill Patients: Systemic Review and Meta-analysis

Introduction:

International guidelines are promoting early enteral nutrition (EN) as a means of feeding critically ill adult patients to improve clinical outcomes. The question of how much calorie intake is enough to improve the outcomes still remained inconclusive. Therefore, we carried out a meta-analysis to evaluate the effect of low calorie (LC) versus high calorie (HC) delivery on critically ill patients' outcomes.

Methods:

We included randomized clinical trials (RCTs) that compared LC EN with or without supplemental parenteral nutrition with HC delivery in this meta-analysis irrespective of the site of nutritional delivery in the gastrointestinal tract. We searched PubMed, EMBASE, and Cochrane central register of controlled trials electronic databases to identify RCTs that compared the effects of initially different calorie intake in critical illness. The primary outcome was overall mortality.

Results:

This meta-analysis included 17 RCTs with a total of 3,593 participants. The result of analysis showed that there was no significant difference between the LC group and HC group in overall mortality (risk ratio [RR], 0.98; 95% confidence interval [CI], 0.87–1.10; P = 0.74; I² = 6%; P = 0.38), or new-onset pneumonia (RR, 0.92; 95% CI, 0.73–1.16, P = 0.46; I² = 38%, P = 0. 11).

Conclusion:

The current meta-analysis showed that there was no significant difference in mortality of critically ill patients initially between the two groups.

Resting energy expenditure, calorie and protein consumption in critically ill patients: a retrospective cohort study

Background

Intense debate exists regarding the optimal energy and protein intake for intensive care unit (ICU) patients. However, most studies use predictive equations, demonstrated to be inaccurate to target energy intake. We sought to examine the outcome of a large cohort of ICU patients in relation to the percent of administered calories divided by resting energy expenditure (% AdCal/REE) obtained by indirect calorimetry (IC) and to protein intake.

Methods

Included patients were hospitalized from 2003 to 2015 at a 16-bed ICU at a university affiliated, tertiary care hospital, and had IC measurement to assess caloric targets. Data were drawn from a computerized system and included the % AdCal/REE and protein intake and other variables. A Cox proportional hazards model for 60-day mortality was used, with the % AdCal/REE modeled to accommodate non-linearity. Length of stay (LOS) and length of ventilation (LOV) were also assessed.

Results

A total of 1171 patients were included. The % AdCal/REE had a significant non-linear (p < 0.01) association with mortality after adjusting for other variables (p < 0.01). Increasing the percentage from zero to 70 % resulted in a hazard ratio (HR) of 0.98 (CI 0.97–0.99) pointing to reduced mortality, while increases above 70 % suggested an increase in mortality with a HR of 1.01 (CI 1.01–1.02). Increasing protein intake was also associated with decreased mortality (HR 0.99, CI 0.98–0.99, p = 0.02). An AdCal/REE >70 % was associated with an increased LOS and LOV.

Conclusions

The findings of this study suggest that both underfeeding and overfeeding appear to be harmful to critically ill patients, such that achieving an Adcal/REE of 70 % had a survival advantage. A higher caloric intake may also be associated with harm in the form of increased LOS and LOV. The optimal way to define caloric goals therefore requires an exact estimate, which is ideally performed using indirect calorimetry. These findings may provide a basis for future randomized controlled trials comparing specific nutritional regimens based on indirect calorimetry measurements.

Lower versus higher dose of enteral caloric intake in adult critically ill patients: a systematic review and meta-analysis

BACKGROUND

There is conflicting evidence about the relationship between the dose of enteral caloric intake and survival in critically ill patients. The objective of this systematic review and meta-analysis is to compare the effect of lower versus higher dose of enteral caloric intake in adult critically ill patients on outcome.

METHODS

We reviewed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus from inception through November 2015. We included randomized and quasi-randomized studies in which there was a significant difference in the caloric intake in adult critically ill patients, including trials in which caloric restriction was the primary intervention (caloric restriction trials) and those with other interventions (non-caloric restriction trials). Two reviewers independently extracted data on study characteristics, caloric intake, and outcomes with hospital mortality being the primary outcome.

RESULTS

Twenty-one trials mostly with moderate bias risk were included (2365 patients in the lower caloric intake group and 2352 patients in the higher caloric group). Lower compared with higher caloric intake was not associated with difference in hospital mortality (risk ratio (RR) 0.953; 95 % confidence interval (CI) 0.838-1.083), ICU mortality (RR 0.885; 95 % CI 0.751-1.042), total nosocomial infections (RR 0.982; 95 % CI 0.878-1.077), mechanical ventilation duration, or length of ICU or hospital stay. Blood stream infections (11 trials; RR 0.718; 95 % CI 0.519-0.994) and incident renal replacement therapy (five trials; RR 0.711; 95 % CI 0.545-0.928) were lower with lower caloric intake. The associations between lower compared with higher caloric intake and primary and secondary outcomes, including pneumonia, were not different between caloric restriction and non-caloric restriction trials, except for the hospital stay which was longer with lower caloric intake in the caloric restriction trials.

CONCLUSIONS

We found no association between the dose of caloric intake in adult critically ill patients and hospital mortality. Lower caloric intake was associated with lower risk of blood stream infections and incident renal replacement therapy (five trials only). The heterogeneity in the design, feeding route and timing and caloric dose among the included trials could limit our interpretation. Further studies are needed to clarify our findings.

Gastrointestinal dysmotility in the critically ill: a role for nutrition

PURPOSE OF REVIEW

The role of enteral nutrition on gastrointestinal dysmotility in the critically ill remains controversial.

RECENT FINDINGS

The mechanisms of gastrointestinal dysmotility during critical illness remain poorly investigated. Low amounts of enteral feeding stimulate motility and have trophic effects. Therefore, enteral feeding is feasible even during gastrointestinal dysmotility as seen in the hemodynamically compromised patient. Rapid 'ramp-up' of administration rate of tube feeding bears the risk of overload and even detrimental ischemic bowel necrosis. The recent American Society for Parenteral and Enteral Nutrition guidelines do not recommend the measurement of gastric residual volume. The use of concentrated enteral solutions with 1.5 kcal/ml may result in greater calorie delivery. Biomarkers like plasma citrulline and plasma or urine intestinal fatty-acid-binding protein reflect the functional integrity of the bowel and may potentially support monitoring.

SUMMARY

To improve enteral nutrition protocols, the definitions of gastrointestinal dysfunction, gastric dysmotility, and feeding intolerance should be clearly defined in the future. In the concept of integrity of the gut, enteral nutrition should not be stopped completely during gastrointestinal dysfunction but restricted to a 'minimal' trophic feeding rate. In malnourished and high-risk patients intolerant to enteral feeding supplemental parenteral nutrition should be started on day 4 or earlier.

NutritionDay ICU: A 7 year worldwide prevalence study of nutrition practice in intensive care

INTRODUCTION

To determine the nutrition practice in intensive care units and the associated outcome across the world, a yearly 1 day cross sectional audit was performed from 2007 to 2013. The data of this initiative called "nutritionDay ICU" were analyzed.

MATERIAL AND METHODS

A questionnaire translated in 17 languages was used to determine the unit's characteristics, patient's condition, nutrition condition and therapy as well as outcome. All the patients present in the morning of the 1 day prevalence study were included from 2007 to 2013.

RESULTS

9777 patients from 46 countries and 880 units were included. Their SAPS 2 was median 38 (IQR 27-51), predicted mortality was 30.7% ± 26.9, and their SOFA score 4.5 ± 3.4 with median 4 (IQR 2-7). Administration of calories did not appear to be related to actual or ideal body weight within all BMI groups. Patients with a BMI <18.5 or >40 received slightly less calories than all other BMI groups. Two third of the patients were either ventilated or were in the ICU for longer than 24 h at nutritionDay. Routes of feeding used were the oral, enteral and parenteral routes. More than 40% of the patients were not fed during the first day. The mean energy administered using enteral route was 1286 ± 663 kcal/day and using parenteral nutrition 1440 ± 652 kcal/day. 60 days mortality was 26.0%.

DISCUSSION

This very large collaborative cohort study shows that most of the patients are underfed during according to actual recommendations their ICU stay. Prescribed calories appear to be ordered regardless to the ideal weight of the patient. Nutritional support is slow to start and never reaches the recommended targets. Parenteral nutrition prescription is increasing during the ICU stay but reaching only 20% of the population studied if ICU stay is one week or longer. The nutritional support worldwide does not seem to be guided by weight or disease but more to be standardized and limited to a certain level of calories. These observations are showing the poor observance to guidelines.

Indirect calorimetry in nutritional therapy. A position paper by the ICALIC study group

BACKGROUND & AIMS

This review aims to clarify the use of indirect calorimetry (IC) in nutritional therapy for critically ill and other patient populations. It features a comprehensive overview of the technical concepts, the practical application and current developments of IC.

METHODS

Pubmed-referenced publications were analyzed to generate an overview about the basic knowledge of IC, to describe advantages and disadvantages of the current technology, to clarify technical issues and provide pragmatic solutions for clinical practice and metabolic research. The International Multicentric Study Group for Indirect Calorimetry (ICALIC) has generated this position paper.

RESULTS

IC can be performed in in- and out-patients, including those in the intensive care unit, to measure energy expenditure (EE). Optimal nutritional therapy, defined as energy prescription based on measured EE by IC has been associated with better clinical outcome. Equations based on simple anthropometric measurements to predict EE are inaccurate when applied to individual patients. An ongoing international academic initiative to develop a new indirect calorimeter aims at providing innovative and affordable technical solutions for many of the current limitations of IC.

CONCLUSION

Indirect calorimetry is a tool of paramount importance, necessary to optimize the nutrition therapy of patients with various pathologies and conditions. Recent technical developments allow broader use of IC for in- and out-patients.