Predicted estimates of resting energy expenditure have limited clinical utility in patients with cirrhosis

BACKGROUND & AIMS

Malnutrition is associated with adverse clinical outcomes in patients with cirrhosis. Accurate assessment of energy requirements is needed to optimize dietary intake. Resting energy expenditure (REE), the major component of total energy expenditure, can be measured using indirect calorimetry (mREE) or estimated using prediction equations (pREE). This study assessed the usefulness of predicted estimates of REE in this patient population.

METHODS

Individual mREE data were available for 900 patients with cirrhosis (mean [±1 SD] age 55.7±11.6 years-old; 70% men; 52% south-east Asian) and 282 healthy controls (mean age 36.0±12.8 years-old; 52% men; 18% south-east Asian). Metabolic status was classified using thresholds based on the mean ± 1 SD of the mREE in the healthy controls. Comparisons were made between mREE and pREE estimates obtained using the Harris-Benedict, Mifflin, Schofield and Henry equations. Stepwise regression was used to build 3 new prediction models which included sex, ethnicity, body composition measures, and model for end-stage liver disease scores.

RESULTS

The mean mREE was significantly higher in patients than controls when referenced to dry body weight (22.4±3.8 cf. 20.8±2.6 kcal/kg/24 hr; p <0.001); there were no significant sex differences. The mean mREE was significantly higher in Caucasian than Asian patients (23.1±4.4 cf. 21.7±2.9 kcal/kg/24 hr; p <0.001). Overall, 37.1% of Caucasian and 25.3% of Asian patients were classified as hypermetabolic. The differences between mREE and pREE were both statistically and clinically relevant; in the total patient population, pREE estimates ranged from 501 kcal/24 hr less to 548 kcal/24 hr more than the mREE. Newly derived prediction equations provided better estimates of mREE but still had limited clinical utility.

CONCLUSIONS

Prediction equations do not provide useful estimates of REE in patients with cirrhosis. REE should be directly measured.

LAY SUMMARY

People with cirrhosis are often malnourished and this has a detrimental effect on outcome. Provision of an adequate diet is very important and is best achieved by measuring daily energy requirements and adjusting dietary intake accordingly. Prediction equations, which use information on age, sex, weight, and height can be used to estimate energy requirements; however, the results they provide are not accurate enough for clinical use, particularly as they vary according to sex and ethnicity.

Achieving Protein Targets in the ICU Using a Specialized High-Protein Enteral Formula: A Quality Improvement Project

BACKGROUND

To meet protein needs in critical illness (CI), guidelines suggest ≥1.2-2.5 g protein/kg/d; however, most intensive care unit (ICU) patients receive ≤0.7 g/kg/d. Higher protein enteral nutrition (EN) formulas may be part of the solution to provide prescribed protein. Our objective was to demonstrate that an EN formula with 37% protein can deliver ≥80% of prescribed protein, without overfeeding calories within the first 5 days of feeding and to describe ICU clinicians' experience.

METHODS

This quality improvement (QI) project included patients requiring exclusive EN for up to 5 days from 6 Canadian ICUs. Rationale for choosing formula, patient's BMI (kg/m² ), nutrition targets, daily protein and energy delivered, feeding interruptions, and general tolerance were recorded.

RESULTS

Forty-four of 49 patients received the formula ≥2 days. Average protein prescribed was 137.5 g/d (82.5-200) or 1.9 g/kg/d (1.5-2.5). Average protein delivered was 116.9 g/d (33.5-180) or 1.6 g/kg/d (0.4-2.4). Seventy-five percent to 83% of patients received ≥80% prescribed protein on days 2-5. Average energy prescribed was 1638.6 kcal/d (990-2500) or 17.8 kcal/kg (11-26). Average energy delivered was 1523.9 kcal/d (693.0-2557.5) or 17.3 kcal/kg/d (1.35-64.7). The formula was well tolerated with no gastrointestinal symptoms reported in 38 (86%) patients. The most common reasons to prescribe the formula were obesity and use of fat-based medications.

CONCLUSIONS

We demonstrated in a QI study that a high-protein EN formula was tolerated in a small, heterogeneous group of ICU patients and effective in meeting protein targets without overfeeding.

Feasibility of a Lactobacillus casei Drink in the Intensive Care Unit for Prevention of Antibiotic Associated Diarrhea and Clostridium difficile

Background: Over 70% of patients are prescribed antibiotics during their intensive care (ICU) admission. The gut microbiome is dramatically altered early in an ICU stay, increasing the risk for antibiotic associated diarrhea (AAD) and Clostridium difficile infections (CDI). Evidence suggests that some probiotics are effective in the primary prevention of AAD and CDI. Aim: To demonstrate safety and feasibility of a probiotic drink in ICU patients. Methods: ICU patients initiated on antibiotics were recruited, and matched with contemporary controls. Study patients received two bottles daily of a drink containing 10 billion Lactobacillus casei which was bolused via feeding tube. Tolerance to probiotics and enteral nutrition, development of adverse events, and incidence of AAD was recorded. CDI rates were followed for 30 days post antibiotic treatment. Results: Thirty-two patients participated in the trial. There were no serious adverse events in the probiotic group, compared to three in the control group. AAD was documented in 12.5% of the probiotic group and 31.3% in the control group. One patient in the probiotic group developed CDI compared to three in the control group. Discussion: A probiotic containing drink can safely be delivered via feeding tube and should be considered as a preventative measure for AAD and CDI in ICU.

Energy Requirements in Critically Ill Patients: How Close Are Our Estimates?

A retrospective analysis of 55 mechanically ventilated critically ill patients was conducted to determine adequacy of nutritional support (total parenteral nutrition or enteral nutrition) according to requirements established by indirect calorimetry. Patients who received 90% to 110% of the established energy requirements as measured by indirect calorimetry were defined as adequately fed. At the time of the indirect calorimetry measurements, all patients were receiving their targeted nutritional support, as assessed by the unit dietitian, who used predictive formulas to assess patients. Indirect calorimetry results showed that 25% of the patients were overfed (receiving >110% of energy requirements), 35% were underfed (receiving <90% of energy requirements), and 40% were adequately fed (receiving 90% to 110% of energy requirements). We determined that critically ill patients with a body mass index <20 kg/m2 were the most likely group to be assessed inappropriately by available regression equations. If indirect calorimetry measurement is unavailable, we suggest using an empiric formula of 37 kcal/kg for critically ill patients with a body mass index <20 kg/m2.

Essential Fatty Acid Deficiency in 2015: The Impact of Novel Intravenous Lipid Emulsions

The fatty acids, linoleic acid (18:2ω-6) and α-linolenic acid (18:3ω-3), are essential to the human diet. When these essential fatty acids are not provided in sufficient quantities, essential fatty acid deficiency (EFAD) develops. This can be suggested clinically by abnormal liver function tests or biochemically by an elevated Mead acid and reduced linoleic acid and arachidonic acid level, which is manifested as an elevated triene/tetraene ratio of Mead acid/arachidonic acid. Clinical features of EFAD may present later. With the introduction of novel intravenous (IV) lipid emulsions in North America, the proportion of fatty acids provided, particularly the essential fatty acids, varies substantially. We describe a case series of 3 complicated obese patients who were administered parenteral nutrition (PN), primarily using ClinOleic 20%, an olive oil-based lipid emulsion with reduced amounts of the essential fatty acids, linoleic and α-linolenic, compared with more conventional soybean oil emulsions throughout their hospital admission. Essential fatty acid profiles were obtained for each of these patients to investigate EFAD as a potential cause of abnormal liver enzymes. Although the profiles revealed reduced linoleic acid and elevated Mead acid levels, this was not indicative of the development of essential fatty acid deficiency, as reflected in the more definitive measure of triene/tetraene ratio. Instead, although the serum fatty acid panel reflected the markedly lower but still adequate dietary linoleic acid content and greatly increased oleic acid content in the parenteral lipid emulsion, the triene/tetraene ratio remained well below the level, indicating EFAD in each of these patients. The availability and use of new IV lipid emulsions in PN should encourage the clinician to review lipid metabolism based on the quantity of fatty acids provided in specific parenteral lipid emulsions and the expected impact of these lipid emulsions (with quite different fatty acid composition) on measured fatty acid profiles.

Energy requirements and the use of predictive equations versus indirect calorimetry in critically ill patients

Nutrition support has been shown to have a positive impact on critically ill patients who meet their defined goals of nutrition therapy. However, inappropriate energy assessment can contribute to under- or overfeeding resulting in deleterious effects. Thus, assessment of energy expenditure in critically ill patients is crucial to prevent negative impacts from inappropriate feeding. Currently, the optimal energy requirement and appropriate energy assessment in these patients is controversial. Indirect calorimetry or predictive equations have been suggested to evaluate energy expenditure in critically ill patients. Indirect calorimetry is a gold standard for evaluating energy expenditure, but it is not always available and has some limitations. Many predictive equations, therefore, have been developed to predict energy expenditure in critically ill patients. However, these equations cannot be used generally in these patients since they were developed in a unique patient population. Many studies compared measured energy expenditure with predictive energy expenditure, but the data regarding accuracy is not robust. Therefore, clinicians should consider using these equations carefully based on the current supporting data. Indirect calorimetry is recommended for use in evaluating energy expenditure in critically ill patients if it is available.

Optimizing nutrition in intensive care units: empowering critical care nurses to be effective agents of change

Observational studies have consistently revealed wide variation in nutritional practices across intensive care units and indicated that the provision of adequate nutrition to critically ill patients is suboptimal. To date, the potential role of critical care nurses in implementing nutritional guideline recommendations and improving nutritional therapy has received little consideration. Factors that influence nurses' nutritional practices include the lack of guidelines or conflicting evidence-based recommendations pertaining to nurses' practice, strategies for implementing guidelines that are not tailored to barriers nurses face when feeding patients, strategies to communicate best evidence that do not capitalize on nurses' preference for seeking information through social interaction, prioritization of nutrition in initial and continuing nursing education, and a lack of interdisciplinary team collaboration in the intensive care unit when decisions on how to feed patients are made. Future research and quality improvement strategies are required to correct these deficits and successfully empower nurses to become nutritional champions at the bedside. Using nurses as agents of change will help standardize nutritional practices and ensure that critically ill patients are optimally fed.

Effects of probiotic therapy in critically ill patients: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is a major cause of mortality in intensive care units. A breakdown in gut barrier function and immune dysfunction are associated with the onset of MODS. Probiotic bacteria have been shown to modulate intestinal barrier and immune function.

OBJECTIVE

This study assessed the efficacy of a probiotic compound in a viable and nonviable formulation in modulating intestinal permeability and immune function and preventing the onset of MODS in patients in the intensive care unit.

DESIGN

A double-blind, randomized controlled trial was conducted in the intensive care unit of a tertiary care teaching hospital. Twenty-eight critically ill patients admitted to the intensive care unit were randomly assigned to receive 1 of 3 treatments daily for 7 d: 1) placebo, 2) viable probiotics, or 3) equivalent probiotic sonicates. MODS scores and systemic concentrations of immunoglobulin (Ig) A and IgG were measured on days -1, 4, and 7, and intestinal permeability measurements were taken daily.

RESULTS

The patients responded to viable probiotics with a significantly larger increase in systemic IgA and IgG concentrations than in the patients who received placebo or sonicates (P < 0.05). MODS scores were not significantly affected by probiotic treatment. Over the study period, intestinal permeability decreased in most patients.

CONCLUSION

Patients receiving viable probiotics show a greater enhancement in immune activity than do patients receiving either placebo or probiotic bacterial sonicates.

Malnutrition: etiology, consequences, and assessment of a patient at risk

Malnutrition results from the imbalance of nutrients and energy provided to the body (too low), relative to its needs (too high). These needs increase dramatically with illness. This is certainly the case for patients with gastrointestinal diseases. Sub-optimal dietary intake, metabolic stress, malabsorption and increased nutrient demands, put a patient with gastrointestinal disease, at high-risk for malnutrition. The causes, consequences and assessment and monitoring indicators of malnutrition are reviewed herein.

Patients' perceptions of outcomes of a Canadian hospitalization

Notes that with health care reform moving at tremendous speed throughout Canada, a great deal of interest in outcomes research has been generated. States that the research team consisted of 17 professional practice leaders from eight disciplines. Proposes, through the research, to identify from the perspective of former patients what results they hoped to achieve prior to discharge from hospital and what facilitated and hindered them in achieving these results. Reports that a representative sample was selected for the study. Forty-one former patients each participated in up to two focus groups, with a total of 16 focus groups conducted. Hierarchical analysis revealed themes that fell within the framework of structure, process and outcomes. The findings will assist in ensuring that more appropriate and effective care is offered to patients by a variety of disciplines.