Permissive Underfeeding of the Critically Ill Patient

Estimating Enhanced Endogenous Glucose Production in Intensive Care Unit Patients with Severe Insulin Resistance

BACKGROUND

Critically ill ICU patients frequently experience acute insulin resistance and increased endogenous glucose production, manifesting as stress-induced hyperglycemia and hyperinsulinemia. STAR (Stochastic TARgeted) is a glycemic control protocol, which directly manages inter- and intra- patient variability using model-based insulin sensitivity (SI). The model behind STAR assumes a population constant for endogenous glucose production (EGP), which is not otherwise identifiable.

OBJECTIVE

This study analyses the effect of estimating EGP for ICU patients with very low SI (severe insulin resistance) and its impact on identified, model-based insulin sensitivity identification, modeling accuracy, and model-based glycemic clinical control.

METHODS

Using clinical data from 717 STAR patients in 3 independent cohorts (Hungary, New Zealand, and Malaysia), insulin sensitivity, time of insulin resistance, and EGP values are analyzed. A method is presented to estimate EGP in the presence of non-physiologically low SI. Performance is assessed via model accuracy.

RESULTS

Results show 22%-62% of patients experience 1+ episodes of severe insulin resistance, representing 0.87%-9.00% of hours. Episodes primarily occur in the first 24 h, matching clinical expectations. The Malaysian cohort is most affected. In this subset of hours, constant model-based EGP values can bias identified SI and increase blood glucose (BG) fitting error. Using the EGP estimation method presented in these constrained hours significantly reduced BG fitting errors.

CONCLUSIONS

Patients early in ICU stay may have significantly increased EGP. Increasing modeled EGP in model-based glycemic control can improve control accuracy in these hours. The results provide new insight into the frequency and level of significantly increased EGP in critical illness.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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

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

Critical Care Nutrition: Where's the Evidence?

The surgical critically ill patient is subject to a variable and complex metabolic response, which has detrimental effects on immunity, wound healing, and preservation of lean body muscle. The concept of nutrition support has evolved into nutrition therapy, whereby the primary objectives are to prevent oxidative cell injury, modulate the immune response, and attenuate the metabolic response. This review outlines the metabolic response to critical illness, describes nutritional risk; reviews the evidence for the role, dose, and timing of enteral and parenteral nutrition, and reviews the evidence for immunonutrition in the surgical intensive care unit.

Nutritional support for critically ill children

BACKGROUND

Nutritional support in the critically ill child has not been well investigated and is a controversial topic within paediatric intensive care. There are no clear guidelines as to the best form or timing of nutrition in critically ill infants and children. This is an update of a review that was originally published in 2009. .

OBJECTIVES

The objective of this review was to assess the impact of enteral and parenteral nutrition given in the first week of illness on clinically important outcomes in critically ill children. There were two primary hypotheses:1. the mortality rate of critically ill children fed enterally or parenterally is different to that of children who are given no nutrition;2. the mortality rate of critically ill children fed enterally is different to that of children fed parenterally.We planned to conduct subgroup analyses, pending available data, to examine whether the treatment effect was altered by:a. age (infants less than one year versus children greater than or equal to one year old);b. type of patient (medical, where purpose of admission to intensive care unit (ICU) is for medical illness (without surgical intervention immediately prior to admission), versus surgical, where purpose of admission to ICU is for postoperative care or care after trauma).We also proposed the following secondary hypotheses (a priori), pending other clinical trials becoming available, to examine nutrition more distinctly:3. the mortality rate is different in children who are given enteral nutrition alone versus enteral and parenteral combined;4. the mortality rate is different in children who are given both enteral feeds and parenteral nutrition versus no nutrition.

SEARCH METHODS

In this updated review we searched: the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2); Ovid MEDLINE (1966 to February 2016); Ovid EMBASE (1988 to February 2016); OVID Evidence-Based Medicine Reviews; ISI Web of Science - Science Citation Index Expanded (1965 to February 2016); WebSPIRS Biological Abstracts (1969 to February 2016); and WebSPIRS CAB Abstracts (1972 to February 2016). We also searched trial registries, reviewed reference lists of all potentially relevant studies, handsearched relevant conference proceedings, and contacted experts in the area and manufacturers of enteral and parenteral nutrition products. We did not limit the search by language or publication status.

SELECTION CRITERIA

We included studies if they were randomized controlled trials; involved paediatric patients, aged one day to 18 years of age, who were cared for in a paediatric intensive care unit setting (PICU) and had received nutrition within the first seven days of admission; and reported data for at least one of the pre-specified outcomes (30-day or PICU mortality; length of stay in PICU or hospital; number of ventilator days; and morbid complications, such as nosocomial infections). We excluded studies if they only reported nutritional outcomes, quality of life assessments, or economic implications. Furthermore, we did not address other areas of paediatric nutrition, such as immunonutrition and different routes of delivering enteral nutrition, in this review.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the searches, applied the inclusion criteria, and performed 'Risk of bias' assessments. We resolved discrepancies through discussion and consensus. One author extracted data and a second checked data for accuracy and completeness. We graded the evidence based on the following domains: study limitations, consistency of effect, imprecision, indirectness, and publication bias.

MAIN RESULTS

We identified only one trial as relevant. Seventy-seven children in intensive care with burns involving more than 25% of the total body surface area were randomized to either enteral nutrition within 24 hours or after at least 48 hours. No statistically significant differences were observed for mortality, sepsis, ventilator days, length of stay, unexpected adverse events, resting energy expenditure, nitrogen balance, or albumin levels. We assessed the trial as having unclear risk of bias. We consider the quality of the evidence to be very low due to there being only one small trial. In the most recent search update we identified a protocol for a relevant randomized controlled trial examining the impact of withholding early parenteral nutrition completing enteral nutrition in pediatric critically ill patients; no results have been published.

AUTHORS' CONCLUSIONS

There was only one randomized trial relevant to the review question. Research is urgently needed to identify best practices regarding the timing and forms of nutrition for critically ill infants and children.

Feeding the gut: how, when and with what -- the metabolic issue

PURPOSE OF REVIEW

To review the literature on feeding critically ill patients with special emphasis on the intestine.

RECENT FINDINGS

Many dogmas have been questioned in the past few years. In particular, the absence of evidence for impact on outcomes in critically ill patients has been highlighted. So 'early enteral feeding', the trophic effect on intestinal mucosa in humans, 'pharmaco-nutrition', postpyloric feeding and prokinetic drugs have all been found to lack proper evidence to affect outcomes.

SUMMARY

The use of gastric feeding in critical illness is recommended. Successful gastric feeding is indicative of a functional gastrointestinal tract. Pharmacological effects of nutrients are questionable, but supplementation of deficits (glutamine, selenium, etc.) may be in the patient's best interest. A more individualized prescription of nutrition in the critically ill is advocated.

Nutritional care of the obese adult burn patient: a U.K. Survey and literature review

Obesity is an emerging healthcare problem and affects an increasing number of burn patients worldwide. An email survey questionnaire was constructed and distributed among the 16 U.K. burn services providing adult inpatient facilities to investigate nutritional practices in obese thermally injured patients. Responses received from all dieticians invited to participate in the study were analyzed, and a relevant literature review of key aspects of nutritional care is presented. The majority of services believe that obese patients warrant a different nutritional approach with specific emphasis to avoid overfeeding. The most common algebraic formulae used to calculate calorific requirements include the Schofield, Henry, and modified Penn State equations. Indirect calorimetry despite being considered the "criterion standard" tool to calculate energy requirements is not currently used by any of the U.K. burn services. Gastric/enteral nutrition is initiated within 24 hours of admission in the services surveyed, and a variety of different practices were noted in terms of fasting protocols before procedures requiring general anesthesia/sedation. Hypocaloric regimens for obese patients are not supported by the majority of U.K. facilities, given the limited evidence base supporting their use. The results of this survey outline the wide diversity of dietetic practices adopted in the care of obese burn patients and reveal the need for further study to determine optimal nutritional strategies.

A single-blinded randomised clinical trial of permissive underfeeding in patients requiring parenteral nutrition

BACKGROUND & AIMS

The importance of adequate nutritional support is well established, but characterising what 'adequate nutrition' represents remains contentious. In recent years there has been increasing interest in the concept of 'permissive underfeeding' where patients are intentionally prescribed less nutrition than their calculated requirements. The aim of this study was to evaluate the effect of permissive underfeeding on septic and nutrition related morbidity in patients requiring short term parenteral nutrition (PN).

METHODS

This was a single-blinded randomised clinical trial of 50 consecutive patients requiring parenteral nutritional support. Patients were randomized to receive either normocaloric or hypocaloric feeding (respectively 100% vs. 60% of estimated requirements). The primary end point was septic complications. Secondary end points included the metabolic, physiological and clinical outcomes to the two feeding protocols.

RESULTS

Permissive underfeeding was associated with fewer septic complications (3 vs. 12 patients; p = 0.003), and a lower incidence of the systemic inflammatory response syndrome (9 vs. 16 patients; p = 0.017). Permissively underfed patients had fewer feed related complications (2 vs. 9 patients; p = 0.016).

CONCLUSION

Permissive underfeeding in patients requiring short term PN appears to be safe and may results in reduced septic and feed-related complications.

TRIAL REGISTRATION

NCT01154179 TRIAL REGISTRY: http://clinicaltrials.gov/ct2/show/NCT01154179.

Nutrition support in the intensive care patient

Nutrition intervention plays a significant role in changing patient clinical outcomes in the intensive care unit. Identifying patients at nutrition risk with a validated tool is essential. The decision to use enteral or parenteral nutrition is patient dependent and should include an assessment of the patient's gastrointestinal function. Protein is a critical component of the nutrition prescription, and prescribed levels may need to be higher than current guidelines recommend. Alternative lipids, such as olive oil and fish oil, are still being evaluated for their potential clinical impact. Avoiding nutrition therapy-associated complications, such as catheter infection and hyperglycemia, are important factors in being able to maximize the effectiveness of a nutritional intervention.

Enteral nutrition in critical care

There is a consensus that nutritional support, which must be provided to patients in intensive care, influences their clinical outcome. Malnutrition is associated in critically ill patients with impaired immune function and impaired ventilator drive, leading to prolonged ventilator dependence and increased infectious morbidity and mortality. Enteral nutrition is an active therapy that attenuates the metabolic response of the organism to stress and favorably modulates the immune system. It is less expensive than parenteral nutrition and is preferred in most cases because of less severe complications and better patient outcomes, including infections, and hospital cost and length of stay. The aim of this work was to perform a review of the use of enteral nutrition in critically ill patients.

Pilot study of the SPRINT glycemic control protocol in a Hungarian medical intensive care unit

INTRODUCTION

Stress-induced hyperglycemia increases morbidity and mortality. Tight control can reduce mortality but has proven difficult to achieve. The SPRINT (Specialized Relative Insulin and Nutrition Tables) protocol is the only protocol that reduced both mortality and hypoglycemia by modulating both insulin and nutrition, but it has not been tested in independent hospitals.

METHODS

SPRINT was used for 12 adult intensive care unit patients (949 h) at Kálmán Pándy Hospital (Gyula, Hungary) as a clinical practice assessment. Insulin recommendations (0-6 U/h) were administered via constant infusion rather than bolus delivery. Nutrition was administered per local standard protocol, weaning parenteral to enteral nutrition, but was modulated per SPRINT recommendations. Measurement was every 1 to 2 h, per protocol. Glycemic performance is assessed by percentage of blood glucose (BG) measurements in glycemic bands for the cohort and per patient. Safety from hypoglycemia is assessed by numbers of patients with BG < 2.2 (severe) and %BG < 3.0 and < 4.0 mmol/liter (moderate and light). Clinical effort is assessed by measurements per day. Results are median (interquartile range).

RESULTS

There were 742 measurements over 1088 h of control (16.4 measurements/day), which is similar to clinical SPRINT results (16.2/day). Per-patient hours of control were 65 (50-95) h. Initial per-patient BG was 10.5 (7.9-11.2) mmol/liter. All patients (100%) reached 6.1 mmol/liter. Cohort BG was 6.3 (5.5-7.5) mmol/liter, with 42.2%, 65.1% and 77.6% of BG in the 4.0-6.1, 4.0-7.0, and 4.0-8.0 mmol/liter bands. Per-patient, median percentage time in these bands was 40.2 (26.7-51.5)%, 62.5 (46.0-75.7)%, and 74.7 (61.6.8-87.8)%, respectively. No patients had BG < 2.2 mmol/liter, and the %BG < 4.0 mmol/liter was 1.9%. These results were achieved using 3.0 (3.0-5.0) U/h of insulin with 7.4 (4.4-10.2) g/h of dextrose administration (all sources) for the cohort. Per-patient median insulin administration was 3.0 (3.0-3.0) U/h and 7.1 (3.4-9.6) g/h dextrose. Higher carbohydrate nutrition formulas than were used in SPRINT are offset by slightly higher insulin administration in this study.

CONCLUSIONS

The glycemic performance shows that using the SPRINT protocol to guide insulin infusions and nutrition administration provided very good glycemic control in initial pilot testing, with no severe hypoglycemia. The overall design of the protocol was able to be generalized with good compliance and outcomes across geographically distinct clinical units, patients, and clinical practice.

[Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): macro-and micronutrient requirements]

Energy requirements are altered in critically-ill patients and are influenced by the clinical situation, treatment, and phase of the process. Therefore, the most appropriate method to calculate calorie intake is indirect calorimetry. In the absence of this technique, fixed calorie intake (between 25 and 35 kcal/kg/day) or predictive equations such as the Penn State formula can be used to obtain a more accurate evaluation of metabolic rate. Carbohydrate administration should be limited to a maximum of 4 g/kg/day and a minimum of 2g/kg/day. Plasma glycemia should be controlled to avoid hyperglycemia. Fat intake should be between 1 and 1.5 g/kg/day. The recommended protein intake is 1-1.5 g/kg/day but can vary according to the patient's clinical status. Particular attention should be paid to micronutrient intake. Consensus is lacking on micronutrient requirements. Some vitamins (A, B, C, E) are highly important in critically-ill patients, especially those undergoing continuous renal replacement techniques, patients with severe burns and alcoholics, although the specific requirements in each of these types of patient have not yet been established. Energy and protein intake in critically-ill patients is complex, since both clinical factors and the stage of the process must be taken into account. The first step is to calculate each patient's energy requirements and then proceed to distribute calorie intake among its three components: proteins, carbohydrates and fat. Micronutrient requirements must also be considered.

A prospective randomised study comparing oral 13C-bicarbonate tracer technique versus indirect calorimetry for measurement of energy expenditure in adults

BACKGROUND AND AIMS

Accurate assessment of energy expenditure (EE) is important in guiding nutritional therapy but current methods are unsatisfactory. This study compared the oral ¹³C-bicarbonate tracer (BT) technique using the IRIS® system (Wagner, Germany) against indirect calorimetry (IC, ventilated-hood) to measure CO₂ output (VCO₂) and thus estimate EE.

METHODS

Ten overnight-fasted healthy male volunteers were randomised to studies at rest or mild exercise in a crossover manner. During each study BT-IRIS® and IC were used simultaneously to measure VCO₂ and thus EE. Participants ingested a drink labelled with 50mg ¹³C-bicarbonate and breath samples were collected every 5 min for 180 min and analysed using IRIS®. Bland-Altman plots were used to assess agreement between the two techniques in measurements of VCO₂ (L/day) and estimates of EE (kJ/day).

RESULTS

Mean ± SE age and BMI of participants were 21.1 ± 1.1 yrs and 23.6 ± 0.6 kg/m². Both at rest and exercise, there was small bias but overall poor agreement between the two techniques as evident by the wide 95% limits of agreement in measurements of VCO₂ and EE: rest VCO₂ (bias 1.4, SD 93, 95% limits of agreement -180 to 183), rest EE (-8.3, 1830, -3595 to 3578), exercise VCO₂ (49.3, 66.1, -80.4 to 178.9) and exercise EE (1083, 1944, -2727 to 4893). Furthermore, there was also evidence of systematic error in these measurements.

CONCLUSION

Prior to clinical application, further optimisation of the BT-IRIS® system should be undertaken, given the poor agreement with IC in measuring VCO₂ and estimating EE.

Current strategies of critical care assessment and therapy of the obese patient (hypocaloric feeding): what are we doing and what do we need to do?

Two of the most challenging issues in the clinical management of the obese patient are assessing energy requirements and whether hypocaloric (permissive) underfeeding should be employed. Multiple predictive equations have been used in the literature to estimate resting metabolic rate, although no consensus has emerged regarding which prediction equation is most accurate and precise in the obese population. Hypocaloric, or permissive underfeeding, specifically refers to the intentional administration of calories that are less than predicted energy expenditure. Thus far, very few studies performed have been performed to assess the efficacy of hypocaloric feeding in the obese hospitalized patient. It is concluded that the optimal caloric intake of obese patients in the intensive care unit remains unclear given the limitation of the existing data.

Allometric Prediction of Energy Expenditure in Infants and Children

Predicting energy needs in children is complicated by the wide range of patient sizes, confusing traditional estimation equations, nonobjective stress-activity factors, and so on. These complications promote errors in bedside estimates of nutritional needs by rendering the estimation methods functionally unavailable to bedside clinicians. Here, the authors develop a simple heuristic energy prediction equation that requires only body mass (not height, age, or sex) as input. Expert estimation of energy expenditure suggested a power-law relationship between mass and energy. A similar mass-energy expenditure relationship was derived from published pediatric echocardiographic data using a Monte Carlo model of energy expenditure based on oxygen delivery and consumption. A simplified form of the equation was compared with energy required for normal growth in a cohort of historical patients weighing 2 to 70 kg. All 3 methods demonstrate that variation in energy expenditure in children is dominated by mass and can be estimated by the following equation: Power(kcal/kg/d) = 200 × [Mass(kg)^(−0.4)]. This relationship explains 85% of the variability in energy required to maintain expected growth over a broad range of surgical clinical contexts. A simplified power-law equation predicts real-world energy needs for growth in patients over a wide range of body sizes and clinical contexts, providing a more useful bedside tool than traditional estimators.

Effect of enteral versus parenteral nutrition on outcome of medical patients requiring mechanical ventilation

BACKGROUND

Early enteral nutrition (EN) in patients receiving mechanical ventilation commonly has been advocated, based mainly on studies conducted in mixed populations of trauma and surgery patients. In this study, ventilator-associated pneumonia rates and outcomes were compared in mechanically ventilated medical intensive care unit (ICU) patients receiving enteral versus parenteral nutrition.

METHODS

Patients fulfilling inclusion criteria between February 1, 2004, and January 31, 2006, were included. Patients were randomized to enteral or parenteral nutrition (PN) within 48 hours of intubation. Development of ventilator-associated pneumonia, assessment as to whether day feeding goal was attained, duration of mechanical ventilation, ICU and hospital length of stay (LOS), and mortality rates were recorded.

RESULTS

Of 249 consecutive patients receiving mechanical ventilation, 71 patients were included. Thirty (42.3%) patients received EN, and 41 (57.7%) received PN. There was no difference between groups for age, sex, body mass index, and scores on the Acute Physiology and Chronic Health Evaluation II. Ventilator-associated pneumonia rate, ICU and hospital LOS, and mortality rates were similar for both groups. In the parenterally fed group, duration of mechanical ventilation was longer (p = .023), but the feeding goal was attained earlier (p = .012).

CONCLUSIONS

In mechanically ventilated patients in the medical ICU, ventilator-associated pneumonia rates, ICU and hospital lengths of stay, and ICU and hospital mortality rates of patients receiving PN are not significantly different than those in patients receiving EN, and feeding goals can more effectively be attained by PN. Yet, duration of mechanical ventilation is slightly longer in patients receiving PN.

Providing optimal nutritional support on the intensive care unit: key challenges and practical solutions

Many patients in the intensive care unit are malnourished or unable to eat. Feeding them correctly has the potential to reduce morbidity and even mortality but is a very complex procedure. The inflammatory response induced by surgery, trauma or sepsis will alter metabolism, change the ability to utilise nutrients and can lead to rapid loss of lean mass. Both overfeeding and underfeeding macronutrients can be harmful but generally it would seem optimal to give less during metabolic stress and immobility and increase in recovery. Physical intolerance of feeding such as diarrhoea or delayed gastric emptying is common in the intensive care unit. Diarrhoea can be treated with fibre or peptide feeds and anti-diarrhoeal drugs; however, the use of probiotics is controversial. Gastric dysfunction problems can often be overcome with prokinetic drugs or small bowel feeding tubes. New feeds with nutrients such as n-3 fatty acids that have the potential to attenuate excessive inflammatory responses show great promise in favourably improving metabolism and substrate utilisation. The importance of changing nutrient provision according to metabolic and physical tolerance cannot be understated and although expert groups have produced many guidelines on nutritional support of the critically ill, correct interpretation and implementation can be difficult without a dedicated nutrition health care professional such as a dietitian or a multidisciplinary nutritional support team.

Review article: permissive underfeeding in short-term nutritional support

BACKGROUND

The importance of adequate nutritional support in selected patient groups is well established. Traditionally, the amounts of macronutrients provided have been based on a perceived need to achieve, if not exceed, energy and protein balance. In recent years, there has been increasing interest in the concept of 'permissive underfeeding'.

AIM

To determine whether or not there is evidence of benefit for permissive underfeeding in selected groups.

METHODS

Studies were identified from MEDLINE, Embase and PubMed databases and the Cochrane collaboration. The search was limited from January 1950 to January 2010. Further searches were made from the references of original articles. The literature search revealed 591 abstracts of relevant studies. All abstracts were initially reviewed by the primary author (AO) and those that did not fulfil the inclusion criteria were discarded. The remaining articles were requested and were reviewed independently by two authors (AO, JM).

RESULTS

Twelve studies were included in the final analysis. Eight of these were randomized interventional trials. Three were prospective cohort studies and one was a retrospective analysis.

CONCLUSION

This review suggests that permissive underfeeding may be associated with improved outcomes and reduced morbidity in patients requiring short-term nutritional support.

The Glucosafe system for tight glycemic control in critical care: a pilot evaluation study

PURPOSE

"Glucosafe' is a new model-based decision support system for glycemic control in critical care. Safety and achievement of glycemic goals using the system are tested prospectively.

METHODS

Four penalty functions were developed to balance regimens of nutrition and insulin therapy against model-predicted glycemic outcome. The system advises the regimen where the penalty sum is minimal. An interactive interface allows advice alterations. Ten hyperglycemic patients (median Acute Physiology and Chronic Health Evaluation II, 12.5; interquartile range, 7.5-16.3) from a neuro and trauma intensive care unit were included for pilot testing using Glucosafe for 12 to 14 hours. Glycemic outcomes were compared to the 24-hour intervals before and after intervention.

RESULTS

Hypoglycemia (blood glucose [BG] <3.5 mmol/L) was not observed. Mean log-normal BG +/- standard deviation was reduced from 8.6 +/- 2.4 mmol/L preintervention to 7.0 +/- 1.1 mmol/L during the intervention. Nine patients reached the 4.4- to 6.1-mmol/L band after a mean 5 hours. At 5 hours intervention, mean log-normal BG was 6.7 mmol/L, 40% of measurements were in the 4.4- to 6.1-mmol/L band, and 84% were in the 4.4- to 7.75-mmol/L band.

CONCLUSIONS

Safety was demonstrated with the developed penalty functions. The low BG variance achieved may permit minor adjustments of the penalty function values to reduce average BG if desired.

A multi-center, randomized, controlled trial of parenteral nutrition titrated to resting energy expenditure in children undergoing hematopoietic stem cell transplantation ("PNTREE"): rationale and design

BACKGROUND

Children undergoing hematopoietic stem cell transplantation (HSCT) frequently require prolonged courses of parenteral nutrition (PN) as a consequence of gastrointestinal dysfunction related to preparative chemotherapy and radiation. PN has been associated with shorter engraftment time and decreased mortality during HSCT, however, it is also linked with complications, including infections, liver disease, and metabolic disturbances. Some of these complications may be a result of providing PN in excess of nutrient requirements. We previously described significant reductions in resting energy expenditure (REE), as measured by indirect calorimetry, over the course of HSCT. We also documented a decline in mid-arm muscle area, suggesting depletion of muscle mass, while triceps skinfold, a marker of fat stores, was unchanged. These results suggested the need for further study of energy expenditure, body composition and nutritional intake in this group of high risk patients.

DESIGN AND HYPOTHESIS

We hypothesize that changes in body composition affect REE during HSCT, and that standard nutritional support may lead to overfeeding. We are performing a randomized controlled trial of parenteral nutrition among children undergoing allogeneic HSCT. Subjects are randomized to receive PN designed to provide 100% of measured REE, or standard PN, i.e., 140% of estimated energy expenditure. The primary outcome variable is change in percent body fat. Secondary outcomes include glycemic control and frequency of infections, changes in REE and body composition.

CONCLUSION

This study will provide unique and comprehensive nutritional data and its results will guide nutritional therapy for children undergoing HSCT and possibly other catabolic patients.

Blood glucose control among critically ill patients with brain injury

OBJECTIVE

To evaluate the incidence of hypoglycemia, hyperglycemia and blood glucose (BG) variability in brain-injured patients and their association with clinical outcomes.

METHODS

Retrospective cohort study of brain-injured patients admitted to an 11-bed neurosciences intensive care unit (ICU) from January 1 to December 31, 2003.

RESULTS

We included 606 patients. Mean age was 52.3 years, 60.6% were male, 11.9% had diabetes mellitus, and 64% were post-operative. Seventy-five (12.4%) received intensive insulin therapy (IIT) for a median (IQR) 72 (24-154) hours. Hypoglycemia and hyperglycemia occurred in 4.6% (96.4% receiving IIT) and 9.6% (77.6% receiving IIT). Median number of episodes per patient was 3 (75% with > or = 2) and 4 (81% with > or = 2) for hypoglycemia and hyperglycemia. Variable glycemic control occurred in 3.8% (100% receiving IIT) with median number of 13 episodes per patient. In-hospital mortality was 16.7%, median (IQR) ICU and hospital lengths of stay were 2 (1-5) and 8 (3-19) days. Hypoglycemia, hyperglycemia and BG variability showed non-significant but consistent associations with hospital mortality and prolonged lengths of ICU and hospital stay. The rate of recurrence of episodes showed stronger and significant associations with outcome, in particular for BG variability and hyperglycemia.

CONCLUSIONS

Hypoglycemia, hyperglycemia and BG variability are relatively common in brain-injured patients and are associated with IIT. An increased frequency of episodes, in particular for BG variability and hyperglycemia, was associated with greater risk of both hospital death and prolonged duration of stay.

The relationship between nutritional intake and clinical outcomes in critically ill patients: results of an international multicenter observational study

PURPOSE

The objective of this study was to examine the relationship between the amount of energy and protein administered and clinical outcomes, and the extent to which pre-morbid nutritional status influenced this relationship.

METHODS

We conducted an observational cohort study of nutrition practices in 167 intensive care units (ICUs) across 21 [corrected] countries. Patient demographics were collected, and the type and amount of nutrition received were recorded daily for a maximum of 12 days. Patients were followed prospectively to determine 60-day mortality and ventilator-free days (VFDs). We used body mass index (BMI, kg/m2) as a marker of nutritional status prior to ICU admission. Regression models were developed to evaluate the relationship between nutrition received and 60-day mortality and VFDs, and to examine how BMI modifies this relationship.

RESULTS

Data were collected on 2,772 mechanically ventilated patients who received an average of 1,034 kcal/day and 47 g protein/day. An increase of 1,000 cal per day was associated with reduced mortality [odds ratio for 60-day mortality 0.76; 95% confidence intervals (CI) 0.61-0.95, p = 0.014] and an increased number of VFDs (3.5 VFD, 95% CI 1.2-5.9, p = 0.003). The effect of increased calories associated with lower mortality was observed in patients with a BMI <25 and > or =35 with no benefit for patients with a BMI 25 to <35. Similar results were observed when comparing increasing protein intake and its effect on mortality.

CONCLUSIONS

Increased intakes of energy and protein appear to be associated with improved clinical outcomes in critically ill patients, particularly when BMI is <25 or > or =35.

Nutritional support for critically ill children

BACKGROUND

Nutritional support in the critically ill child has not been well investigated and is a controversial topic within paediatric intensive care. There are no clear guidelines as to the best form or timing of nutrition in critically ill infants and children.

OBJECTIVES

To assess the impact of enteral and total parenteral nutrition on clinically important outcomes for critically ill children.

SEARCH STRATEGY

We searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); Ovid MEDLINE (1966 to February 2007); Ovid EMBASE (1988 to February 2007); OVID Evidence-Based Medicine Reviews; ISI Web of Science - Science Citation Index Expanded (1965 to February 2007); WebSPIRS Biological Abstracts (1969 to February 2007); and WebSPIRS CAB Abstracts (1972 to February 2007). We also searched trial registries; reviewed reference lists of all potentially relevant studies; handsearched relevant conference proceedings; and contacted experts in the area and manufacturers of enteral and parenteral nutrition products. We did not limit the search by language or publication status.

SELECTION CRITERIA

We included studies if they were randomized controlled trials; involved paediatric patients, aged one day to 18 years of age, cared for in a paediatric intensive care unit setting (PICU) and received nutrition within the first seven days of admission; and reported data for at least one of the pre-specified outcomes (30-day or PICU mortality; length of stay in PICU or hospital; number of ventilator days; and morbid complications, such as nosocomial infections). We excluded studies if they only reported nutritional outcomes, quality of life assessments, or economic implications. Furthermore, other areas of paediatric nutrition, such as immunonutrition and different routes of delivering enteral nutrition, were not addressed in this review.

DATA COLLECTION AND ANALYSIS

Two authors independently screened searches, applied inclusion criteria, and performed quality assessments. We resolved discrepancies through discussion and consensus. One author extracted data and a second checked data for accuracy and completeness.

MAIN RESULTS

Only one trial was identified as relevant. Seventy-seven children in intensive care with burns involving > 25% of the total body surface area were randomized to either enteral nutrition within 24 hours or after at least 48 hours. No statistically significant differences were observed for mortality, sepsis, ventilator days, length of stay, unexpected adverse events, resting energy expenditure, nitrogen balance, or albumin levels. The trial was assessed as of low methodological quality (based on the Jadad scale) with an unclear risk of bias.

AUTHORS' CONCLUSIONS

There was only one randomized trial relevant to the review question. Research is urgently needed to identify best practices regarding the timing and forms of nutrition for critically ill infants and children.

The risk for bloodstream infections is associated with increased parenteral caloric intake in patients receiving parenteral nutrition

Background

Patients receiving total parenteral nutrition (TPN) are at high risk for bloodstream infections (BSI). The notion that intravenous calories and glucose lead to hyperglycemia, which in turn contributes to BSI risk, is widely held but is unproven. We therefore sought to determine the role that hyperglycemia and parenteral calories play in the development of BSI in hospitalized patients receiving TPN.

Methods

Two hundred consecutive patients initiated on TPN between June 2004 and August 2005 were prospectively studied. Information was collected on patient age, sex, admission diagnosis, baseline laboratory values, intensive care unit (ICU) status and indication for TPN. Patients in the ICU were managed with strict glycemic control, whereas control on the general ward was more liberal. The maximum blood glucose level over each 8-hour period was recorded, as were parenteral daily intake, enteral daily intake and total daily caloric intake. The primary outcome measure was the incidence of BSI. Additional endpoints were ICU length of stay, hospital length of stay and mortality.

Results

A total of 78 patients (39%) developed at least one BSI, which were more common in ICU patients than in other hospitalized patients (60/122 patients versus 18/78 patients; P < 0.001). Maximum daily blood glucose concentrations were similar in patients with BSI and in patients without BSI (197 mg/dl versus 196 mg/dl, respectively). Patients with BSI received more calories parenterally than patients without BSI (36 kcal/kg/day versus 31 kcal/kg/day, P = 0.003). Increased maximum parenteral calories, increased average parenteral calories, and treatment in the ICU were strong risk factors for developing BSI. There was no difference in mortality between patients with and without BSI.

Conclusion

Increased parenteral caloric intake is an independent risk factor for BSI in patients receiving TPN. This association appears unrelated to hyperglycemia. Based upon our observations, we suggest that parenteral caloric intake be prescribed and adjusted judiciously with care taken to account for all intravenous caloric sources and to avoid even short periods of increased intake.

Evaluation of Delivery of Enteral Nutrition in Critically Ill Patients Receiving Mechanical Ventilation

Background Published reports consistently describe incomplete delivery of prescribed enteral nutrition. Which specific step in the process delays or interferes with the administration of a full dose of nutrients is unclear.

Objectives To assess factors associated with interruptions in enteral nutrition in critically ill patients receiving mechanical ventilation.

Methods An observational prospective study of 59 consecutive patients who required mechanical ventilation and were receiving enteral nutrition was done in an 18-bed medical intensive care unit of an academic center. Data were collected prospectively on standardized forms. Steps involved in the feeding process from admission to discharge were recorded, each step was timed, and delivery of nutrition was quantified.

Results Patients received approximately 50% (mean, 1106.3; SD, 885.9 Cal) of the prescribed caloric needs. Enteral nutrition was interrupted 27.3% of the available time. A mean of 1.13 interruptions occurred per patient per day; enteral nutrition was interrupted a mean of 6 (SD, 0.9) hours per patient each day. Prolonged interruptions were mainly associated with problems related to small-bore feeding tubes (25.5%), increased residual volumes (13.3%), weaning (11.7%), and other reasons (22.8%). Placement and confirmation of placement of the small-bore feeding tube were significant causes of incomplete delivery of nutrients on the day of admission.

Conclusions Delivery of enteral nutrition in critically ill patients receiving mechanical ventilation is interrupted by practices embedded in the care of these patients. Evaluation of the process reveals areas to improve the delivery of enteral nutrition.

Feeding critically ill patients: what is the optimal amount of energy?

Hypermetabolism and malnourishment are common in the intensive care unit. Malnutrition is associated with increased morbidity and mortality, and most intensive care unit patients receive specialized nutrition therapy to attenuate the effects of malnourishment. However, the optimal amount of energy to deliver is unknown, with some studies suggesting that full calorie feeding improves clinical outcomes but other studies concluding that caloric intake may not be important in determining outcome. In this narrative review, we discuss the studies of critically ill patients that examine the relationship between dose of nutrition and clinically important outcomes. Observational studies suggest that achieving targeted caloric intake might not be necessary since provision of approximately 25% to 66% of goal calories may be sufficient. Randomized controlled trials comparing early aggressive use of enteral nutrition compared with delayed, less aggressive use of enteral nutrition suggest that providing increased calories with early, aggressive enteral nutrition is associated with improved clinical outcomes. However, energy provision with parenteral nutrition, either instead of or supplemental to enteral nutrition, does not offer additional benefits. In summary, the optimal amount of calories to provide critically ill patients is unclear given the limitations of the existing data. However, evidence suggests that improving adequacy of enteral nutrition by moving intake closer to goal calories might be associated with a clinical benefit. There is no role for supplemental parenteral nutrition to increase caloric delivery in the early phase of critical illness. Further high-quality evidence from randomized trials investigating the optimal amount of energy intake in intensive care unit patients is needed.

How many calories are necessary during critical illness?

Several nutritional alternatives exist to provide critically ill patients sufficient calories to meet metabolic demands. Intuitively, investigators, nutritionists, and clinicians have pursued the goal of providing high-calorie nutrition support, believing that this would improve outcomes. There is little evidence, however, that meeting caloric goals is of significant benefit. In fact, accumulating data suggest that feeding patients below previously described caloric goals is associated with better outcomes, including decreases in hospital stay, ventilator dependence, use of antibiotics, and even mortality. This suggests that permissive underfeeding could replace the paradigm of meeting measured caloric goals. Prospective evidence to support adoption of permissive underfeeding is lacking, however. Appropriate clinical studies are necessary to prove its safety and efficacy.

24-hour indirect calorimetry in mechanically ventilated critically ill patients

BACKGROUND

Energy imbalance in critically ill, mechanically ventilated patients may lead to medical complications. The nutrition care team needs accurate, noninvasive, rapid methods to estimate energy requirements. We investigated whether brief measurements of indirect calorimetry at any time of the day would give valid estimates of 24-hour energy expenditure (EE).

METHODS

EE of 12 mechanically ventilated critically ill patients (6 men, 6 women, mean +/- SD age 67 +/- 18 years, weight 70.2 +/- 8.8 kg) was recorded every minute during 24 hours by indirect calorimetry. All patients were continuously fed enteral nutrition.

RESULTS

Mean +/- SD EE was 1658 +/- 279 kcal/d (6941 +/- 1167 kJ/d). Within patients, EE during the day fluctuated by 234 kcal in the most constant patient to 1190 kcal in the least constant patient, with a mean fluctuation of 521 kcal (12 patients). No statistically significant difference (p = .53) in mean EE between morning (6-12 hours, 1676 kcal), afternoon (12-18 hours, 1642 kcal), evening (18-24 hours, 1658 kcal), and night (0-6 hours, 1655 kcal) was found. A 2-hour instead of a 24-hour measurement resulted in a maximal error of 128 kcal (536 kJ), which was <10% of the average EE. The maximal error decreased with longer time intervals.

CONCLUSIONS

In mechanically ventilated critically ill patients, 24-hour indirect calorimetry measurements can be replaced by shorter (>/=2 hours) measurements. Time of day did not affect EE.

Advances in Surgical Nutrition

Dr. Stanley Dudrick invented total parenteral nutrition in 1968, providing a desperately needed therapy to those patients who could not eat. It has since saved thousands of patients worldwide. Nutrition interventions (NI) in surgical/trauma and critically ill patients have evolved dramatically during the last 20 years from a supportive therapy to a clear therapeutic role. Like any other form of therapy, NI will benefit patients when adequately indicated and prescribed. NI, however, may cause significant side effects and harm when poorly ordered. This article reviews the indications for the prescription of the different forms of NI available to the clinician caring for the surgical patient.

A pilot study of the SPRINT protocol for tight glycemic control in critically Ill patients

BACKGROUND

Stress-induced hyperglycemia is prevalent in critical care, even in patients with no history of diabetes. Increased counter-regulatory hormone response increases gluconeogenesis and effective insulin resistance, which can be exacerbated by drug therapy. Control of blood glucose levels to the 4.0-6.1 mmol/L range has been shown to reduce mortality and improve clinical outcomes. The Specialized Relative Insulin and Nutrition Tables (SPRINT) protocol is a simple alternative intensive care unit protocol for modulating insulin and nutritional input to gain tight blood glucose control in the 4.0-6.1 mmol/L target band. The look-up tables, implemented in a wheel-based format, are used by nurses to determine glycemic control actions based on hourly or 2-hourly blood glucose measurements and nutrition and insulin administration rates.

METHODS

An 11 patient pilot study was conducted comprising 2,152 hours of blood glucose level control using the SPRINT protocol. The patient cohort average Acute Physiology and Chronic Health Evaluation II score was 22, which was higher than previous intensive insulin clinical studies.

RESULTS

Overall, 64% of measurements were in the 4.0-6.1 mmol/L band, 89% in the 4.0-7.0 mmol/L band, and 96% of all measurements in the 4.0-7.75 mmol/L band. The average value was 5.8 +/- 0.9 mmol/L. Only 1.4% of all measurements were below 4 mmol/L, with a minimum of 3.2 mmol/L. The maximum value recorded was 11.8 mmol/L.

CONCLUSIONS

Control of blood glucose level was achieved using a protocol implemented by the nursing staff without the need for physician intervention or interpretation, where control is defined as maximizing time within a desired band. The results led to a high level of support for the SPRINT protocol among clinical staff and acceptance of the frequent measurement requirement for effective control. The ease-of-use of the protocol resulted in minimal noncompliance by clinical staff.

A novel, model-based insulin and nutrition delivery controller for glycemic regulation in critically ill patients

BACKGROUND

Critically ill patients are often hyperglycemic and insulin resistant, as well as highly dynamic. Tight glucose control has been shown to significantly reduce mortality in critical care. A physiological model of the glucose-insulin regulatory system is improved and used to develop an adaptive control protocol utilizing both nutritional and insulin inputs to control hyperglycemia. The approach is clinically verified in a critical care patient cohort.

METHODS

A simple two-compartment model for glucose rate of appearance in plasma due to stepwise enteral glucose fluxes is developed and incorporated into a previously validated system model. A control protocol modulating intravenous insulin infusion and bolus, with an enteral feed rate, is developed, enabling tight and predictive glycemic regulation to preset targets. The control protocol is adaptive to patient time-variant effective insulin resistance. The model and protocol are verified in seven 10-h and one 24-h proof-of-concept clinical trials. Ethics approval was granted by the Canterbury Ethics Committee.

RESULTS

Insulin requirements varied widely following acute changes in patient physiology. The algorithm developed successfully adapted to patient metabolic status and insulin sensitivity, achieving an average target acquisition error of 9.3% with 90.7% of all targets achieved within +/-20%. Prediction errors may not be distinguishable from sensor measurement errors. Large errors (>20%) are attributable to highly dynamic and unpredictable changes in patient condition.

CONCLUSIONS

Tight, targeted stepwise regulation was exhibited in all trials. Overall, tight glycemic regulation is achieved in a broad critical care cohort with optimized insulin and nutrition delivery, effectively managing glycemia even with high effective insulin resistance.

Diabetes and Stroke: Part two—Treating diabetes and stress hyperglycemia in hospitalized stroke patients

It is well established that strict glycemic control for the hospitalized stroke patient is associated with improved outcome compared with poor control. This is particularly true for the stroke patients because hyperglycemia can adversely affect ischemic damage. A blood sugar level of less than 110 mg/dL is recommended for critically ill patients and should be achieved by intravenous insulin administration in an intensive care unit setting. Many stroke patients are unable to swallow, and insulin requirement must be readjusted carefully to conform to the nutritional state of the patient. The transition from intravenous insulin to subcutaneous insulin or oral antihyperglycemic agents must be carefully monitored. Careful discharge planning of diabetic care for the stroke patient is necessary to prevent long-term sequelae of inadequate control.

Nutritional support of the obese patient

Overweight and obesity is the most common chronic disease in the United States and is associated with an increased risk for morbidity and mortality. For the hospitalized patient, the mechanical, metabolic, and inflammatory physiologic changes induced by obesity necessitate additional considerations for care. Calculation of nutritional requirements is problematic and challenging due to difficulty in measuring body composition and energy expenditure. Provision of selective hypocaloric feeding in this population may be particularly beneficial in reducing complications of hyperglycemia, fluid overload, and reduction in fat mass. Clinical care should incorporate a team approach that addresses the special nutritional and metabolic needs of this population.