Overfeeding macronutrients to critically ill adults: metabolic complications

System for continuous metabolic monitoring of mechanically ventilated patients

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

Longitudinal analysis of caloric requirements in critically ill trauma patients: a retrospective cohort study

PURPOSE

Nutrition is of paramount importance in critically ill trauma patients. However, adequate supply is difficult to achieve, as caloric requirements are unknown. This study investigated caloric requirements over time, based on indirect calorimetry, in critically ill trauma patients.

METHODS

Retrospective cohort study at a tertiary trauma center including critically ill trauma patients who underwent indirect calorimetry 2012-2019. Caloric requirements were assessed as resting energy expenditure (REE) during the intensive care unit stay up to 28 days and analyzed in patient-clustered linear regression analysis.

RESULTS

A total of 129 patients were included. Median REE per day was 2376 kcal. The caloric intake did not meet REE at any time with a median daily deficit of 1167 kcal. In univariable analysis, ISS was not significantly associated with REE over time (RC 0.03, p = 0.600). Multivariable analysis revealed a significant REE increase (RC 0.62, p < 0.001) and subsequent decrease (RC - 0.03, p < 0.001) over time. Age < 65 years (RC 2.07, p = 0.018), male sex (RC 4.38, p < 0.001), and BMI ≥ 35 kg/m2 (RC 6.94, p < 0.001) were identified as independent predictors for higher REE over time. Severe head trauma was associated with lower REE over time (RC - 2.10, p = 0.030).

CONCLUSION

In critically ill trauma patients, caloric requirements significantly increased and subsequently decreased over time. Younger age, male sex and higher BMI were identified as independent predictors for higher caloric requirements, whereas severe head trauma was associated with lower caloric requirements over time. These results support the use of IC and will help to adjust nutritional support in critically ill trauma patients.

Effect of early enteral nutrition on short-term outcomes and survival in patients in the cardiothoracic intensive care unit: An inverse probability weighted retrospective study

OBJECTIVES

The merits of early enteral nutrition (EEN) in patients in the cardiothoracic intensive care unit (CTICU) remain unclear. This retrospective study aimed to address this issue.

METHODS

We analyzed data from the MIMIC IV v2.0 database, including patients with a CTICU stay of ≥4 d. Patients were divided into early and delayed enteral nutrition (EN) groups. Differences in baseline data were corrected using an inverse probability weighting (IPW) approach. Generalized linear models (GLMs) were used to compare trends over time between groups, and survival effects were evaluated with weighted logistic and Cox regression, supplemented by weighted Kaplan-Meier curves. Subgroup analysis facilitated the exploration of potential interactions.

RESULTS

The study included 720 CTICU patients. Following IPW, all baseline variables were balanced. EEN led to shorter hospital and CTICU stays, lower incidence of respiratory and blood infections, and reduced total insulin usage in the first week of CTICU admission, albeit with an increased total gastric residual volume. Mortality risk between the groups did not significantly differ at 28 d or at 1 y. Excessive early energy and protein intake elevated the risk of 28-d mortality, but the relationship may not be linear. Overweight patients or those with fewer comorbidities had a higher mortality risk with EEN.

CONCLUSIONS

EEN may improve short-term outcomes in CTICU patients without a clear survival benefit. Early high caloric and protein intake could lead to adverse outcomes, suggesting a careful evaluation for initiating EN in specific patients.

Association between energy surplus and intensive care unit length of stay in critically ill patients: A retrospective cohort study

BACKGROUND

Patients experiencing persistent critical illness have poor short-term and long-term outcomes and consume disproportionate amounts of health care resources. Nutrition optimization may improve outcomes, though few data exist on resting energy expenditure and nutrition requirements. We hypothesized that increased energy surplus per day is associated with increased intensive care unit (ICU) length of stay (LoS) in critically ill patients.

METHODS

Patients from a single ICU at Royal London Hospital were included in this retrospective cohort study.

EXPOSURE

energy surplus measured by serial indirect calorimetry (IC) and nutrition intake.

INCLUSION CRITERIA

mechanical ventilation of ≥3 days and expected to remain ventilated.

PRIMARY OUTCOME

ICU LoS.

RESULTS

Across 30 patients (median LoS 21 days), increased ICU LoS was associated with actual daily energy intake surplus to resting energy expenditure (REE) (R2 0.16; P < 0.005). Median REE was less than predicted energy requirements: 24 kcal per day per kilogram of ideal body weight (IBW) (interquartile range [IQR], 20-28) vs 28 kcal/day/kg IBW (IQR, 26-29) (P < 0.001). Patients with COVID-19 had a median energy surplus (actual intake- REE) + 344 kcal/day (IQR 35-517) vs -57 kcal/day (IQR -324 to 211) in other patients (P = 0.011); however, they had a median LoS of 44 days (IQR 26-58) vs 10 days (IQR 7-24), respectively (P < 0.001). Patients with obesity had a median energy deficit of -32 kcal/day (IQR -384 to 335) vs +234 kcal/day (IQR -79 to 499) for nonobese patients (P = 0.021).

CONCLUSION

Overfeeding represents an easily modifiable factor to improve outcomes in patients experiencing persistent critical illness, for which IC may be useful.

Enteral feeding strategies in patients with acute gastrointestinal injury: From limited to progressive to open feeding

Acute gastrointestinal injury (AGI) is very common in critically ill patients, and its severity is positively correlated with mortality. Critically ill patients with digestive and absorption dysfunction caused by AGI face higher nutritional risks, making nutritional support particularly important. Early enteral nutrition (EN) support is extremely important because it can promote the recovery of intestinal function, protect the intestinal mucosal barrier, reduce microbiota translocation, reduce postoperative complications, shorten hospital stay, and improve clinical prognosis. In recent years, many nutritional guidelines have been proposed for critically ill patients; however, there are few recommendations for the implementation of EN in patients with AGI, and their quality of evidence is low. The use of EN feeding strategies in critically ill patients with AGI remains controversial. The aim of this review was to elaborate on how EN feeding strategies should transition from limited to progressive to open feeding and explain the time window for this transition.

Energy Expenditure in Upper Gastrointestinal Cancers: a Scoping Review

Malnutrition is prevalent in people with upper gastrointestinal (GI) cancers and is associated with shorter survival and poor quality of life. In order to effectively prevent or treat malnutrition, nutrition interventions must ensure appropriate energy provision to meet daily metabolic demands. In practice, the energy needs of people with cancer are frequently estimated from predictive equations which are not cancer-specific and are demonstrated to be inaccurate in this population. The purpose of this scoping review was to synthesize the existing evidence regarding energy expenditure in people with upper GI cancer. Three databases (Ovid MEDLINE, Embase via Ovid, CINAHL plus) were systematically searched to identify studies reporting on resting energy expenditure using indirect calorimetry and total energy expenditure using doubly labeled water (DLW) in adults with any stage of upper GI cancer at any point from diagnosis. A total of 57 original research studies involving 2,125 individuals with cancer of the esophagus, stomach, pancreas, biliary tract, or liver were eligible for inclusion. All studies used indirect calorimetry, and one study used DLW to measure energy expenditure, which was reported unadjusted in 42 studies, adjusted for body weight in 32 studies, and adjusted for fat-free mass in 13 studies. Energy expenditure in upper GI cancer was compared with noncancer controls in 19 studies and measured compared with predicted energy expenditure reported in 31 studies. There was heterogeneity in study design and in reporting of important clinical characteristics between studies. There was also substantial variation in energy expenditure between studies and within and between cancer types. Given this heterogeneity and known inaccuracies of predictive equations in patients with cancer, energy expenditure should be measured in practice wherever feasible. Additional research in cohorts defined by cancer type, stage, and treatment is needed to further characterize energy expenditure in upper GI cancer.

A critical view of the use of predictive energy equations for the identification of hypermetabolism in motor neuron disease: A pilot study

BACKGROUND AND AIMS

People living with motor neuron disease (MND) frequently struggle to consume an optimal caloric intake. Often compounded by hypermetabolism, this can lead to dysregulated energy homeostasis, prompting the onset of malnutrition and associated weight loss. This is associated with a poorer prognosis and reduced survival. It is therefore important to establish appropriate nutritional goals to ensure adequate energy intake. This is best done by measuring resting energy expenditure (mREE) using indirect calorimetry. However, indirect calorimetry is not widely available in clinical practice, thus dietitians caring for people living with MND frequently use energy equations to predict resting energy expenditure (pREE) and estimate caloric requirements. Energy prediction equations have previously been shown to underestimate resting energy expenditure in over two-thirds of people living with MND. Hypermetabolism has previously been identified using the metabolic index. The metabolic index is a ratio of mREE to pREE, whereby an increase of mREE by ≥110% indicates hypermetabolism. We aim to critically reflect on the use of the Harris-Benedict (1919) and Henry (2005) energy prediction equations to inform a metabolic index to indicate hypermetabolism in people living with MND.

METHODS

mREE was derived using VO₂ and VCO₂ measurements from a GEMNutrition indirect calorimeter. pREE was estimated by Harris-Benedict (HB) (1919), Henry (2005) and kcal/kg/day predictive energy equations. The REE variation, described as the percentage difference between mREE and pREE, determined the accuracy of pREE ([pREE-mREE]/mREE) x 100), with accuracy defined as ≤ ± 10%. A metabolic index threshold of ≥110% was used to classify hypermetabolism. All resting energy expenditure data are presented as kcal/24hr.

RESULTS

Sixteen people living with MND were included in the analysis. The mean mREE was 1642 kcal/24hr ranging between 1110 and 2015 kcal/24hr. When REE variation was analysed for the entire cohort, the HB, Henry and kcal/kg/day equations all overestimated REE, but remained within the accuracy threshold (mean values were 2.81% for HB, 4.51% for Henry and 8.00% for kcal/kg/day). Conversely, inter-individual REE variation within the cohort revealed HB and Henry equations both inaccurately reflected mREE for 68.7% of participants, with kcal/kg/day inaccurately reflecting 41.7% of participants. Whilst the overall cohort was not classified as hypermetabolic (mean values were 101.04% for HB, 98.62% for Henry and 95.64% for kcal/kg/day), the metabolic index ranges within the cohort were 70.75%-141.58% for HB, 72.82%-127.69% for Henry and 66.09%-131.58% for kcal/kg/day, indicating both over- and under-estimation of REE by these equations. We have shown that pREE correlates with body weight (kg), whereby the lighter the individual, the greater the underprediction of REE. When applied to the metabolic index, this underprediction biases towards the classification of hypermetabolism in lighter individuals.

CONCLUSION

Whilst predicting resting energy expenditure using the HB, Henry or kcal/kg/day equations accurately reflects derived mREE at group level, these equations are not suitable for informing resting energy expenditure and classification of hypermetabolism when applied to individuals in clinical practice.

Metabolic impact of high lipid low dextrose parenteral nutrition

BACKGROUND

Parenteral nutrition (PN) containing 100% soybean oil lipids and high amounts of dextrose may lead to liver dysfunction and hyperglycemia. Mixed lipids have less pro-inflammatory components, so higher doses may be given to decrease the amount of dextrose provided. The purpose of this study is to provide a descriptive analysis of patients who received PN with high mixed lipid and low dextrose content versus PN with lower 100% soybean oil lipid and high dextrose content.

METHODS

We retrospectively reviewed 62 patients aged ≥18 years receiving PN ≥ 7 days from 2016 to 2021 in an acute care hospital. Participants were divided into two groups: high lipid low dextrose (HLLD) containing a four-oil lipid (>30% kcal or ≥1 g/kg) vs adequate lipid high dextrose (ALHD) containing a 100% soybean oil lipid (<30% kcal or <1 g/kg SO-ILE).

RESULTS

Patients in the HLLD group (n = 31) had 64.1% lower incidence of blood glucose levels >180 mg/dL, decreased insulin requirements, 52.7% lower alkaline phosphatase levels, 40.6% higher prealbumin levels, and 42.6% lower c-reactive protein levels while maintaining similar calorie targets compared to the ALHD group (n = 31).

CONCLUSION

Changing from 100% soybean oil to a mixed lipid in PN is helpful to reduce soybean oil intake. However, it is also important to increase the mixed lipid dose to decrease the amount of dextrose provided. PNs containing higher amounts of mixed lipids (40-45% kcal) with lower amounts of dextrose (20-30% kcal) may have clinical benefits that warrant further exploration.

High lipid, low dextrose parenteral nutrition allows patient to achieve nutritional autonomy: A case report

INTRODUCTION

Prolonged use of parenteral nutrition can eventually lead to liver abnormalities. Causative factors include decreased enteral stimulation, high intakes of intravenous dextrose, proinflammatory 100 % soybean oil-based lipids, and increased burden on liver through 24-h infusions. We present a case report of a patient who received parenteral nutrition modifications to address liver dysfunction.

PRESENTATION OF CASE

Our patient was a 37-year-old African American male with a past medical history including refractory Crohn's disease complicated by multiple small bowel obstructions, several bowel surgeries, left lower quadrant colostomy placement, short bowel syndrome, severe protein calorie malnutrition, parenteral nutrition dependence, and elevated liver function tests. He was admitted for nutritional optimization before a planned takedown of multiple chronic enterocutaneous and perianal fistulas. His home parenteral nutrition order contained high amounts of dextrose (69 % kcal), and low amounts of 100 % soybean oil (11 % kcal).

DISCUSSION

Due to an elevated alkaline phosphatase level at baseline (1746 U/L), the Registered Dietitian maximized protein, decreased the dextrose by 62.5 %, and changed to SMOFlipid (a fish-oil containing lipid) at >1 g/kg/day to address liver abnormalities. Within 1.5 months of changing parenteral nutrition to high SMOFlipid (>30 % kcal) with low dextrose (<30 % kcal) content, alkaline phosphatase levels declined by 62 %, prealbumin levels increased by 56 %, and c-reactive protein levels decreased by 62 %.

CONCLUSION

Parenteral nutrition modifications led to reversal of chronic liver dysfunction. This patient ultimately underwent a successful high-risk fistula takedown procedure, allowing for complete weaning of parenteral nutrition and achievement of sustained nutritional autonomy.

Metabolomic Profiles in Starved Light Breed Horses during the Refeeding Process

The large population of emaciated horses continues to be an issue troubling the equine industry. However, little is known regarding the collection of equine metabolites (metabolome) during a malnourished state and the changes that occur throughout nutritional rehabilitation. In this study, ten emaciated horses underwent a refeeding process, during which blood samples were collected for a blood chemistry panel and metabolomics analysis via ultrahigh performance liquid chromatography–high resolution mass spectrometry (UHPLC-HRMS). Significant differences among blood chemistry analytes and metabolite abundance during the critical care period (CCP; Days 1–10 of rehabilitation) and the recovery period (RP; the remainder of the rehabilitation process) were observed. Potentially toxic compounds, analytes related to liver, kidney, and muscle function, as well as energy-related metabolites were altered during the refeeding process. The combination of blood chemistry and metabolomics analyses on starved equine during rehabilitation provide vital biological insight and evidence that the refeeding process has a significant impact on the equine metabolome.

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

BACKGROUND

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

MATERIALS /METHODS

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

RESULTS

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

CONCLUSION

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

Estimated versus measured energy expenditure in ventilated surgical-trauma critically Ill patients

BACKGROUND

The American and European guidelines recommend measuring resting energy expenditure (REE) using indirect calorimetry (IC). Predictive equations (PEs) are used to estimate REE, but there is limited evidence for their use in critically ill patients. The aim of this study is to evaluate the degree of agreement and accuracy between IC-REE and ten different PEs in mechanically ventilated surgical-trauma critically ill patients who met their estimated caloric requirement.

METHODS

IC-REE was retrospectively compared to PE-REE by 10 PEs. Degree of agreement between REE-PE and REE-IC was analyzed by the Bland-Altman test (BAt) and the Concordance Correlation Coefficient (CCC). The accuracy was calculated by the percentage of patients whose REE-PE values differ by up to ±10% in relation to REE-IC. All analyses were stratified by gender and BMI (< 25 vs ≥ 25).

RESULTS

104 patients were analyzed and the closest estimate to IC-REE was the modified Harris-Benedict equation (mHB) by the BAt with a mean difference of 49.2 overall, 61.6 for males, 28.5 for females, 67.5 for BMI < 25 and 42.5 for BMI ≥ 25. The overall CCC between the IC-REE and mHB was 0.652; 0.560 for males; 0.496 for females; 0.570 for BMI < 25; and 0.598 for BMI ≥ 25. Modified HB equation was the most accurate with overall accuracy of 44.2%.

CONCLUSIONS

Effectiveness of PEs for estimating REE of mechanically ventilated surgical-trauma critically ill patients is limited. Nonetheless, of all the 10 equations examined, the closest to IC measured REE was the modified HB equation. This article is protected by copyright. All rights reserved.

Impact of an interdisciplinary nutrition support team (NST) on the clinical outcome of critically ill patients. A pre/post NST intervention study

BACKGROUND

Intensive care unit (ICU) patients are at particular risk for malnutrition with major impact for outcome and prognosis. Nutrition support teams (NST) have been proposed to improve nutrition care in ICU patients.

OBJECTIVE

To assess the effectiveness of an interdisciplinary NST on anthropometry and clinical outcome of ICU patients.

METHODS

Before NST implementation, we assessed 120 patients (before NST group; SAPS II score 44 ± 16), afterwards 60 patients (after NST group), of whom 29 received NST guidance (after NST + group; SAPS II 65 ± 19) and 31 not (after NST - group; SAPS II, 54 ± 16). The primary outcome parameter was length of stay in the hospital (hospital-LOS). Severity of disease was assessed by the APACHE II score and the nutritional risk (NUTRIC) score.

RESULTS

NST intervention resulted in a more pronounced improvement of disease severity (APACHE II, from 27 ± 8 to 18 ± 6, p < 0.001; NUTRIC, from 7 ± 2 to 4 ± 2, p < 0.001) compared to no NST intervention (APACHE II from 24 ± 7 to 21 ± 7, p < 0.05; NUTRIC from 6 ± 2 to 5 ± 2, p < 0.01). The mean hospital-LOS was not reduced, neither in the NST intervention group nor in the control group without NST intervention. NST intervention failed to improve nutritional status or mortality compared to no NST intervention.

CONCLUSION

In our study the NST intervention had a positive effect on disease severity, but failed to improve mortality, hospital-LOS or nutritional status in ICU patients, likely because of a large patient heterogeneity.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02200874).

Methods for Estimating Energy Expenditure in Critically Ill Adults

Energy expenditure (EE) is the sum of metabolic activity within the body at a given time and comprises basal EE, diet-induced thermogenesis, and physical activity. In the intensive care unit, EE is most often assessed to determine a patient's caloric requirements. Energy expenditure also may be useful to understand disease states and the metabolic impact of interventions. Several methods for estimating EE are relevant for clinical use, including indirect calorimetry, predictive equations, exhaled carbon dioxide volume, and the Fick method. Indirect calorimetry is the preferred method for evaluating EE and is considered the gold standard for estimating EE in hospitalized patients. However, use of indirect calorimetry is not always practical or possible. Therefore, other methods of estimating EE must be considered. In this review, methods of evaluating EE in critically ill adults are examined and the benefits and limitations of each method are discussed, with practical considerations for use.

Hyperemesis gravidarum induced refeeding syndrome causes blood cell destruction: a case report and literature review

Background

Hyperemesis gravidarum (HG) is a common complication during pregnancy, however, HG associated simultaneous onset of blood cell destruction due to electrolyte abnormalities is rare. In this case, a woman with refeeding syndrome (RFS) secondary to electrolyte abnormalities caused by severe HG was diagnosed and managed in our hospital.

Case presentation

A 29-year old woman was sent to the local hospitals because of severe HG with appetite loss, weight reduction, general fatigue, and she was identified to have severe electrolyte abnormalities. However, the electrolyte abnormalities were not corrected promptly, and then she had the symptoms of stillbirth, altered mental status, visual hallucination, hemolytic anemia and thrombocytopenia. After transferred to our hospital, we continued to correct the electrolyte abnormalities and the labor induction was performed as soon as possible. The symptoms of blood cell destruction were relieved obviously, and the patient discharged four days later. The electrolyte disturbances and physio-metabolic abnormalities caused by HG helped us diagnose this case as RFS.

Conclusions

This case emphasizes that patients with RFS should be diagnosed appropriately and intervened promptly in order to prevent electrolyte imbalance induced blood cell destruction.

Effect of an intensified individual nutrition therapy on serum metabolites in critically ill patients - A targeted metabolomics analysis of the ONCA study

PURPOSE

The effect of medical nutrition on serum metabolomics has been poorly explored. The aim of the study was to investigate the relation between energy supply and metabolic profiles in critically ill patients.

MATERIALS AND METHODS

Twenty mechanically ventilated patients on enteral nutrition (EN) or enteral/parenteral nutrition (EN/PN) were randomized into two groups. One group received an individual energy supply based on indirect calorimetry (IC group, n = 9), the other group received a standard energy supply based on a formula, the standard care group (SC group, n = 11). Targeted metabolomics was performed in early-, late- and post-acute metabolic phase.

RESULTS

Individual versus standard care energy supply resulted in a metabolite class separation between the IC and the SC group (P < 0.001). In the SC group concentrations of four glucogenic amino acids and three biogenic amines increased between the early- and late-acute metabolic phase (P < 0.05). The metabolomics pattern differed between the routes of nutrition administration (P < 0.01).

CONCLUSIONS

The amount of energy supply by EN or PN, besides other factors, seems to modulate serum metabolites. Nutrition therapy based on individualized energy supply is associated with a reduction of metabolites reflecting catabolism. Therefore, metabolomics could be a new tool to determine metabolic phases in critically ill patients.

Utilization of indirect calorimetry to assist in determining undiagnosed hypothyroidism in a patient on mechanical ventilation

Published predictive equations are required when indirect calorimetry (IC) is unavailable in the clinical setting. Several medical conditions that are not accounted for by published predictive equations can impact a patient's resting energy expenditure, such as adrenal changes or alterations in thyroid-stimulating hormone (TSH). TSH levels significantly impact a patient's resting energy expenditure, with hypothyroidism decreasing and hyperthyroidism increasing energy requirements. Clinical hypothyroidism has been correlated with increased ventilator dependency in patients with critical illness and malnutrition. The following case study describes the utilization of IC to trigger a full evaluation for the diagnosis of hypothyroidism in an adult patient with multiple myeloma who was mechanically ventilated. IC results for this patient were 39% lower than estimated by predictive energy equations. TSH, thyroxine, and triiodothyronine serum assays were obtained to rule out hypothyroidism. Based on elevated TSH and low thyroxine, the patient was found to have undiagnosed hypothyroidism. Appropriate pharmaceutical and nutrition interventions were made based upon these results. This case demonstrates the impact hormonal changes can have on resting energy expenditure and how the utilization of IC can provide additional information other than energy requirements.

Perioperative Management of Gastric Cancer Patients Treated With (Sub)Total Gastrectomy, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy (HIPEC): Lessons Learned

BACKGROUND

The PERISCOPE I study was designed to assess the safety and feasibility of (sub)total gastrectomy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin and docetaxel for gastric cancer patients who have limited peritoneal dissemination. The current analysis investigated changes in perioperative management together with their impact on postoperative outcomes.

METHODS

Patients with resectable gastric cancer and limited peritoneal dissemination were administered (sub)total gastrectomy, CRS, and HIPEC with oxaliplatin (460 mg/m²) and docetaxel (escalating scheme: 0, 50, 75 mg/m²). Of the 25 patients who completed the study protocol, 14 were treated in the dose-escalation cohort and 11 were treated in the expansion cohort (to optimize perioperative management).

RESULTS

A significant proportion of the patients in the dose-escalation cohort (n = 7, 50%) had ileus-related complications. In this cohort, enteral nutrition was started immediately after surgery at 20 ml/h, which was increased on day 1 to meet nutritional needs. In the expansion cohort, enteral nutrition was administered at 10 ml/h until day 3, then restricted to 20 ml/h until day 6, supplemented with total parenteral nutrition to meet nutritional needs. Ileus-related complications occurred for two patients (18%) of the expansion cohort. The intensive care unit (ICU) readmission rate decreased from 50 (n = 7) to 9% (n = 1; p = 0.04).

CONCLUSION

The implementation of a strict nutritional protocol during the PERISCOPE I study was associated with a decrease in postoperative complications. Based on these results, a perioperative care path was described for the gastric cancer HIPEC patients in the PERISCOPE II study.

Oral Nutrition during and after Critical Illness: SPICES for Quality of Care!

Malnutrition is associated to poor outcomes in critically ill patients. Oral nutrition is the route of feeding in less than half of the patients during the intensive care unit (ICU) stay and in the majority of ICU survivors. There are growing data indicating that insufficient and/or inadequate intakes in macronutrients and micronutrients are prevalent within these populations. The present narrative review focuses on barriers to food intakes and considers the different points that should be addressed in order to optimize oral intakes, both during and after ICU stay. They are gathered in the SPICES concept, which should help ICU teams improve the quality of nutrition care following 5 themes: swallowing disorders screening and management, patient global status overview, involvement of dieticians and nutritionists, clinical evaluation of nutritional intakes and outcomes, and finally, supplementation in macro-or micronutrients.

Improvement in Protein Delivery for Critically Ill Patients Requiring High-Dose Propofol Therapy and Enteral Nutrition

BACKGROUND

Patients with traumatic brain (TBI) injury often require a high dosage of propofol, which can provide an excessive caloric intake. We evaluated our strategy of using liquid protein supplement boluses concurrently with high protein-containing enteral nutrition (EN) formulas and formula rate reduction to avoid caloric overfeeding and inadequate protein intake.

METHODS

Adult patients (aged >17 years) with TBI admitted to the trauma intensive care unit (TICU) who received concurrent propofol and EN were retrospectively reviewed. Caloric intakes from propofol and EN were obtained. Actual protein intake was compared with projected protein intakes from high protein content and standard protein content enteral formulas when given at an isocaloric intake.

RESULTS

Fifty-one patients were enrolled. Average caloric intake from propofol was 356 ± 243 kcal/d or 5 ± 3 kcal/kg/d (range, <1-15 kcal/kg/d). Daily EN caloric intake ranged from 7 ± 4 kcal/kg/d (day 2) to 16 ± 9 kcal/kg/d (day 5; P < .001). Average protein intake ranged from 0.6 ± 0.4 g/kg/d (day 2) to 1.5 ± 0.7 g/kg/d (day 5; P < .001). The modified EN strategy resulted in daily delivery of 24%-38% more protein than an isocaloric regimen with a high protein-content formula and twice as much protein than the standard protein-content formula (P < .001).

CONCLUSION

The strategy of providing an EN regimen comprised liquid protein boluses, and high and very high protein-containing EN formulas at a reduced rate improved protein delivery without caloric overfeeding.

The epidemiology of overfeeding in mechanically ventilated intensive care patients

BACKGROUND AND AIMS

Nutrition research in the Intensive Care Unit (ICU) typically focusses on the epidemiology of underfeeding, particularly early in the ICU admission. Once the acute phase of critical illness has resolved, patients may be at risk of overfeeding. We assessed for the frequency and consequences of potential overfeeding in ICU patients mechanically ventilated (MV) for at least 10 days.

METHODS

Retrospective analysis of 105 MV patients including caloric input, estimated caloric requirements using the Schofield equation, and association between caloric input and several pre-defined clinical outcomes. To increase likelihood of detecting overfeeding, we conducted a post-hoc sensitivity analysis for sub-groups of patients who received on average < 25 kcal/kg/day (N = 55) and >30 kcal/kg/day (N = 17) between day 7-10 and performed repeat ANOVA.

RESULTS

There were no differences in the pre-defined outcomes for those given over, and below 25 kcal/kg/day. On each study day, approximately 25% of patients received >30 kcal/kg/day. Higher caloric delivery was statistically associated with increased minute ventilation on each study day (Spearman Rho approx 0.27;p ≤ 0.007) and also in sub-group analysis (p< 0.001). Higher caloric delivery was also associated with more frequent diarrhoea (p= 0.02) and greater insulin requirement. However, these differences did not translate into increased duration of mechanical ventilation, length of stay, or increased mortality. Higher caloric intake was less strongly associated with serum urea and creatinine, but not associated with agitation, abnormal liver function tests, fever, or antibiotic prescription.

CONCLUSIONS

Delivery of more than 25 kcal/kg/day was not associated with adverse outcomes. On post-hoc analysis, delivery of more than 30 kcal/kg/day was associated with increased minute ventilation, diarrhoea and insulin requirements but no differences in length of ventilation or in-hospital mortality.

Metabolic and Immunological Effects of Intermittent Fasting on a Ketogenic Diet Containing Medium-Chain Triglycerides in Healthy Dogs

In several species, intermittent fasting (IF) has been shown to have beneficial effects, including delayed aging, increased lifespan, increased insulin sensitivity, reduced ischemic tissue damage, delayed onset of neurodegenerative disease and improved neuronal repair following injury. However, the metabolic and immunological effects of IF have not been well-established in dogs. The aim of this study was to examine the effects of a 48 h IF regimen using a low fat and a high fat diet in healthy dogs by quantifying the metabolic, hormonal, and immunological changes. We hypothesized that IF dogs would have higher blood ketone and ghrelin concentrations, lower blood leptin, insulin and glucose concentrations, and signs of immunosuppression compared to dogs eating daily. Ten healthy adult dogs were randomized into three group and underwent three feeding regimes in a 3 × 3 Latin square design: twice a day feeding on a low fat (23% energy from fat; LF) diet, 48 h fasting on a low fat diet, and 48 h fasting on a high fat enriched with medium-chain triglycerides (68% energy from fat; HF) diet. Body weight, food intake, activity, blood glucose, β-hydroxybutyrate, leptin, ghrelin, and insulin were measured. Lymphocyte proliferation and neutrophil/macrophage phagocytosis and respiratory burst were measured as markers of immune function. Nuclear magnetic resonance spectroscopy was used to relatively quantify plasma metabolites. When the dogs were IF on a HF diet, they had the highest concentration of blood ketones (mean 0.061 mmol/L, SD 0.024), whereas they had the lowest concentration (mean 0.018 mmol/L, SD 0.004) when fed daily. Blood glucose and insulin concentrations were lower in IF dogs on a HF diet compared to daily feeding or IF on a LF diet. There was an increase in plasma β-hydroxybutyrate concentrations, and a reduction in glucose and insulin concentrations when dogs were IF on a HF diet. There was only a decline in the immune parameters studied when the dogs were IF on a LF diet, which was not seen when on the HF diet. The results of this study indicate the potential of IF to be further investigated as a potential beneficial feeding regime for dogs.

Clinical Sequelae From Overfeeding in Enterally Fed Critically Ill Adults: Where Is the Evidence?

Enteral energy delivery above requirements (overfeeding) is believed to cause adverse effects during critical illness, but the literature supporting this is limited. We aimed to quantify the reported frequency and clinical sequelae of energy overfeeding with enterally delivered nutrition in critically ill adult patients. A systematic search of MEDLINE, EMBASE, and CINAHL from conception to November 28, 2018, identified clinical studies of nutrition interventions in enterally fed critically ill adults that reported overfeeding in 1 or more study arms. Overfeeding was defined as energy delivery > 2000 kcal/d, > 25 kcal/kg/d, or ≥ 110% of energy prescription. Data were extracted on methodology, demographics, prescribed and delivered nutrition, clinical variables, and predefined outcomes. Cochrane "Risk of Bias" tool was used to assess the quality of randomized controlled trials (RCTs). Eighteen studies were included, of which 10 were randomized (n = 4386 patients) and 8 were nonrandomized (n = 223). Only 4 studies reported a separation in energy delivery between treatment groups whereby 1 arm met the definition of overfeeding, which reported no between-group differences in mortality, infectious complications, or ventilatory support. Overfeeding was associated with increased insulin administration (median 3 [interquartile range: 0-41.8] vs 0 [0-30.6] units/d) and upper-gastrointestinal intolerance in 1 large RCT and with duration of antimicrobial therapy in a small RCT. There are limited high-quality data to determine the impact of energy overfeeding of critically ill patients by the enteral route; however, based on available evidence, overfeeding does not appear to affect mortality or other important clinical outcomes.

Seven Deadly Sins of Nutrition Therapy in Critically Ill Patients

This article presents 7 nutrition steps that, if not followed by the clinical staff, may be metaphorically considered as "7 deadly sins" of nutrition therapy. In this review, we suggest approaches that must be avoided or accomplished to increase compliance with the "Ten Commandments" of good nutrition practice in the intensive care setting. Multiple aggressive and simultaneous sets of therapies are implemented in the intensive care setting, which include nutrition and metabolic support as important components in these therapies. "Sins" should be remembered as a mnemonic device for nutrition standard care in the intensive care unit; this incorporates nutrition adequacy and protocol adherence.

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

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

Association of PROtein and CAloric Intake and Clinical Outcomes in Adult SEPTic and Non-Septic ICU Patients on Prolonged Mechanical Ventilation: The PROCASEPT Retrospective Study

Background

The optimal nutritional support for critically ill septic patients remains unknown. This study evaluates the associations of macronutrient intake during the first week of intensive care unit (ICU) admission and long‐term clinical outcomes in septic and non‐septic patients.

Methods

Prolonged mechanically ventilated patients were retrospectively studied. The association of protein (low: <0.8 g/kg/d, medium: 0.8–1.2 g/kg/d, high >1.2 g/kg/d) and energy intake (<80%, 80%–110%, 110% of target) during days 1–3 and 4–7 after ICU admission and 6‐month mortality was analyzed for septic and non‐septic patients separately.

Results

A total of 423 patients were investigated. Of these, 297 had sepsis. In the sepsis group, medium protein intake at days 4–7 was associated with lower 6‐month mortality (hazard ratio [HR]: 0.646, 95% confidence interval [CI]: 0.418‐0.996, P=0.048) compared with high intake. In the non‐sepsis group, early high and late low protein intake were associated with higher 6‐month mortality (HR: 3.902, 95% CI: 1.505‐10.115, P=0.005; HR: 2.642, 95% CI: 1.128‐6.189, P=0.025) compared with low and high protein intake, respectively. For energy intake, late energy intake of >110% was associated with decreased mortality in septic patients (HR: 0.400, 95% CI: 0.222‐0.721, P=0.002), whereas in non‐septic patients, late medium energy intake (80%–110%) was associated with better survival (HR: 0.379, 95% CI: 0.175‐0.820, P=0.014), both compared with low energy intake.

Conclusion

Divergent associations of macronutrient intake were found; early high protein intake in non‐septic patients, but not in septic patients, was found to be associated with higher 6‐month mortality.

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.

Hypophosphatemia before endoscopic gastrostomy predicts higher mortality during the first week and first month post-gastrostomy: a risk marker of refeeding syndrome in gastrostomy-fed patients

Introduction

Introduction: starvation is usual in patients referred for endoscopic gastrostomy (PEG). A high risk of refeeding syndrome (RS) may contribute to poor prognosis. Objectives: this study aims to: a) evaluate serum phosphorus and magnesium when patients underwent PEG; b) determine the mortality rate during the first week and first month of enteral nutrition; and c) assess if hypophosphatemia or hypomagnesemia are associated with early mortality. Material and methods: retrospective study with patients followed in the Artificial Nutrition Clinic and died under PEG feeding. General nutritional assessment included NRS 2002, anthropometry and serum proteins. Serum phosphorus and magnesium were measured immediately before gastrostomy. Survival was recorded and compared to electrolyte and nutritional status. Results: one hundred and ninety-seven patients (137 men/60 women) aged 26-100 years. Most underwent PEG due to neurologic disorders (60.9%) and were malnourished according to body mass index (BMI) and serum proteins. Low phosphorus and magnesium were found in 6.6% and 4.6%, respectively. Hypophosphatemia was associated with malnutrition (p < 0.05). Mean survival was 13.7 ± 15.4 months. Mortality was 4.6% in the first week and 13.2% in the first month post-gastrostomy. Overall survival was shorter in malnourished patients but malnutrition did not directly influence early mortality (p > 0.05). Hypophosphatemia was associated with mortality during the first week (p = 0.02) and the first month of PEG feeding (p = 0.02). Conclusions: hypophosphatemia was uncommon but predicted early mortality after PEG. Although RS may be less frequent than expected, hypophosphatemia may be used as a RS marker and RS is the probable cause of increase early mortality in hypophosphatemic PEG-fed patients.

Gut rest strategy and trophic feeding in the acute phase of critical illness with acute gastrointestinal injury

Critically ill patients frequently suffer from gastrointestinal dysfunction as the intestine is a vulnerable organ. In critically ill patients who require nutritional support, the current guidelines recommend the use of enteral nutrition within 24-48 h and advancing towards optimal nutritional goals over the next 48-72 h; however, this may be contraindicated in patients with acute gastrointestinal injury because overuse of the gut in the acute phase of critical illness may have an adverse effect on the prognosis. We propose that trophic feeding after 72 h, as a partial gut rest strategy, should be provided to critically ill patients during the acute phase of illness as an organ-protective strategy, especially for those with acute gastrointestinal injury.

The effect of a low carbohydrate formula on glycaemia in critically ill enterally-fed adult patients with hyperglycaemia: A blinded randomised feasibility trial

BACKGROUND

Enteral nutrition is a source of carbohydrate that may exacerbate hyperglycaemia. Its treatment, insulin, potentially exacerbates glycaemic variability.

METHODS

This was a prospective, parallel group, blinded, randomised feasibility trial. Patients were eligible if 18 years or over when admitted to the intensive care unit and receiving enteral nutrition (EN) exclusively with two consecutive blood glucose > 10 mmol/L. A standardized glucose management protocol determined administration of insulin. Key outcome measures were insulin administered and glycaemic variability (coefficient of variation) over the first 48 h.

RESULTS

41 patients were randomized to either standard EN (14.1 g/100 mL carbohydrate; n = 20) or intervention EN (7.4 g/100 mL carbohydrate; n = 21). Overall 59% were male, mean (±SD) age of 62.3 years ± 10.4, APACHE II score of 16.5 ± 7.8 and a median (IQR) Body Mass Index 29.0 kg/m² (25.2-35.5). Most patients (73%) were mechanically ventilated. Approximately half (51%) were identified as having diabetes prior to ICU admission. Patients in the intervention arm received less insulin over the 48 h study period than those in the control group (mean insulin units over study period (95% CI) 45.0 (24.4-68.7) vs. 107 (56.1-157.9) units; p = 0.02) and had lower mean glycaemic variability (12.6 vs. 15.9%, p = 0.01). There was a small difference in the mean percentage of energy requirements met (intervention: 72.9 vs. control: 79.1%; p = 0.4) or protein delivered (78.2 vs. 85.4%; p = 0.3).

CONCLUSIONS

A low carbohydrate formula was associated with reduced insulin use and glycaemic variability in enterally-fed critically ill patients with hyperglycaemia. Further large trials are required to determine the impact of this formula on clinical outcomes. Registered under Australian and New Zealand Clinical Trials Registry, ANZCTR number: 12614000166673.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Refeeding syndrome in the gastroenterology practice: how concerned should we be?

Clinical nutrition is emerging as a major area in gastroenterology practice. Most gastrointestinal disorders interfere with digestive physiology and compromise nutritional status. Refeeding syndrome (RS) may increase morbidity and mortality in gastroenterology patients. Literature search using the keywords "Refeeding Syndrome", "Hypophosphatemia", "Hypomagnesemia" and "Hypokalemia". Data regarding definition, pathophysiology, clinical manifestations, risk factors, management and prevention of RS were collected. Most evidence comes from case reports, narrative reviews and scarse observational trials. RS results from the potentially fatal shifts in fluid and electrolytes that may occur in malnourished patients receiving nutritional therapy. No standard definition is established and epidemiologic data is lacking. RS is characterized by hypophosphatemia, hypomagnesemia, hypokalemia, vitamin deficiency and abnormal glucose metabolism. Oral, enteral and parenteral nutrition may precipitate RS. Awareness and risk stratification using NICE criteria is essential to prevent and manage malnourished patients. Nutritional support should be started using low energy replacement and thiamine supplementation. Correction of electrolytes and fluid imbalances must be started before feeding. Malnourished patients with inflammatory bowel disease, liver cirrhosis, chronic intestinal failure and patients referred for endoscopic gastrostomy due to prolonged dysphagia present high risk of RS, in the gastroenterology practice. RS should be considered before starting nutritional support. Preventive measures are crucial, including fluid and electrolyte replacement therapy, vitamin supplementation and use of hypocaloric regimens. Gastroenterology patients must be viewed as high risk patients but the impact of RS in the outcome is not clearly defined in current literature.

Optimization of Nutrition Therapy with the Use of Calorimetry to Determine and Control Energy Needs in Mechanically Ventilated Critically Ill Patients: The ONCA Study, a Randomized, Prospective Pilot Study

BACKGROUND

Adequate nutrition therapy in critically ill patients poses a challenge because of the variable energy and substrate needs. The objective was to investigate whether nutrition therapy involving indirect calorimetry (IC), instead of equations for assessment of energy needs, could improve the nutrition status of critically ill patients.

METHODS

Forty mechanically ventilated patients were randomized into a group in which energy needs were controlled by calorimetry (IC group) and a group treated with a formula-based approach reflecting standard care (SC group). The primary outcome was change in the phase angle (PhA), a bioelectrical impedance parameter related to nutrition status and prognosis.

RESULTS

The mean IC-based energy requirement was lower than the formula-based estimate (21.1 ± 6.4 versus [vs] 25 kcal/kg/d, P < .01). The IC group reached 98% ± 8% of the energy goal, whereas the SC group reached only 79% ± 29% (P < 0.05), although mean intake was similar in both groups. The protein intake goal was better met in the IC group (91% ± 24%) than the SC group (73% ± 33%). The PhA of the IC group did not change during treatment, whereas that of the SC group tended to decrease by 0.36° ± 0.86° (P = .077). A shorter length of stay in intensive care was observed in the IC than in the SC group (13 ± 8 vs 24 ± 20 days, P < .05).

CONCLUSION

Intensified individual nutrition therapy involving IC appears to be useful for improving nutrition status in critically ill patients.

Energy Demands of Early Life Drive a Disease Tolerant Phenotype and Dictate Outcome in Neonatal Bacterial Sepsis

Bacterial sepsis is one of the leading causes of death in newborns. In the face of growing antibiotic resistance, it is crucial to understand the pathology behind the disease in order to develop effective interventions. Neonatal susceptibility to sepsis can no longer be attributed to simple immune immaturity in the face of mounting evidence that the neonatal immune system is tightly regulated and well controlled. The neonatal immune response is consistent with a "disease tolerance" defense strategy (minimizing harm from immunopathology) whereas adults tend toward a "disease resistance" strategy (minimizing harm from pathogens). One major advantage of disease tolerance is that is less energetically demanding than disease resistance, consistent with the energetic limitations of early life. Immune effector cells enacting disease resistance responses switch to aerobic glycolysis upon TLR stimulation and require steady glycolytic flux to maintain the inflammatory phenotype. Rapid and intense upregulation of glucose uptake by immune cells necessitates an increased reliance on fatty acid metabolism to (a) fuel vital tissue function and (b) produce immunoregulatory intermediates which help control the magnitude of inflammation. Increasing disease resistance requires more energy: while adults have fat and protein stores to catabolize, neonates must reallocate resources away from critical growth and development. This understanding of sepsis pathology helps to explain many of the differences between neonatal and adult immune responses. Taking into account the central role of metabolism in the host response to infection and the severe metabolic demands of early life, it emerges that the striking clinical susceptibility to bacterial infection of the newborn is at its core a problem of metabolism. The evidence supporting this novel hypothesis, which has profound implications for interventions, is presented in this review.

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.

The science and art of pediatric critical care nutrition

PURPOSE OF REVIEW

Nutritional status and nutrient delivery during critical illness impact clinical outcomes. We have reviewed recent studies that may guide best practices regarding nutrition therapy in critically ill children.

RECENT FINDINGS

Malnutrition is prevalent in the pediatric ICU population, and is associated with worse outcomes. Nutrition support teams, dedicated dietitians, and educational programs facilitate surveillance for existing malnutrition and nutrition risk, but specific tools for the pediatric ICU population are lacking. Estimation of macronutrient requirements is often inaccurate; novel strategies to accurately determine energy expenditure are being explored. Indirect calorimetry remains the reference method for measuring energy expenditure. Enteral nutrition is the preferred route for nutrition in patients with a functioning gut. Early enteral nutrition and delivery of adequate macronutrients, particularly protein, have been associated with improved clinical outcomes. Delivery of enteral nutrition is often interrupted because of fasting around procedures and perceived intolerance. Objective measures for detection and management of intolerance to nutrient intake are required. In low-risk patients who are able to tolerate enteral nutrition, supplemental parenteral nutrition may be delayed during the first week of critical illness.

SUMMARY

Systematic research and consensus-based practices are expected to promote optimal nutritional practices in critically ill children with the potential to improve clinical outcomes.

Energy Requirements in Critically Ill Patients

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

Diabetes-Specific Formulae Versus Standard Formulae as Enteral Nutrition to Treat Hyperglycemia in Critically Ill Patients: Protocol for a Randomized Controlled Feasibility Trial

Background

During critical illness, hyperglycemia is prevalent and is associated with adverse outcomes. While treating hyperglycemia with insulin reduces morbidity and mortality, it increases glycemic variability and hypoglycemia risk, both of which have been associated with an increase in mortality. Therefore, other interventions which improve glycemic control, without these complications should be explored. Nutrition forms part of standard care, but the carbohydrate load of these formulations has the potential to exacerbate hyperglycemia. Specific diabetic-formulae with a lesser proportion of carbohydrate are available, and these formulae are postulated to limit glycemic excursions and reduce patients’ requirements for exogenous insulin.

Objective

The primary outcome of this prospective, blinded, single center, randomized controlled trial is to determine whether a diabetes-specific formula reduces exogenous insulin administration. Key secondary outcomes include the feasibility of study processes as well as glycemic variability.

Methods

Critically ill patients will be eligible if insulin is administered whilst receiving exclusively liquid enteral nutrition. Participants will be randomized to receive a control formula, or a diabetes-specific, low glycemic index, low in carbohydrate study formula. Additionally, a third group of patients will receive a second diabetes-specific, low glycemic index study formula, as part of a sub-study to evaluate its effect on biomarkers. This intervention group (n=12) will form part of recruitment to a nested cohort study with blood and urine samples collected at randomization and 48 hours later for the first 12 participants in each group with a secondary objective of exploring the metabolic implications of a change in nutrition formula. Data on relevant medication and infusions, nutrition provision and glucose control will be collected to a maximum of 48 hours post randomization. Baseline patient characteristics and anthropometric measures will be recorded. A 28-day phone follow-up will explore weight and appetite changes as well as blood glucose control pre and post intensive care unit (ICU) discharge.

Results

Recruitment commenced in February 2015 with an estimated completion date for data collection by May 2018. Results are expected to be available late 2018.

Conclusions

This feasibility study of the effect of diabetes-specific formulae on the administration of insulin in critically ill patients and will inform the design of a larger, multi-center trial.

Trial Registration

Australian New Zealand Clinical Trial Registry (ANZCTR):12614000166673; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12614000166673 (Archived by WebCite at http://www.webcitation.org/6xs0phrVu)

What a Trainee Surgeon Should Know About Refeeding Syndrome: A Literature Review

Refeeding syndrome (RFS) is potentially fatal, yet there is limited understanding regarding its management among general surgeons due in part to a lack of universally accepted guidelines for RFS diagnosis. The aim of this review is to equip general surgery trainees with the essentials of RFS including a review of the National Institute for Health and Care Excellence (NICE) best practice guidelines for RFS. We used the keywords "refeeding", "syndrome", and "hypophosphatemia" to search PubMed, Embase, and Medline databases. We reviewed approximately 130 indexed papers for relevance. Having profound knowledge of nutritional needs in critically ill patients will help trainee surgeons prevent illnesses in the spectrum of RFS, and, over time, this would immensely contribute to reducing the morbidity and mortality associated with RFS.