Journal of Parenteral and Enteral Nutrition

The nutrition support practitioner may be called upon to help coordinate care at home for a patient who requires prolonged intravenous nutrition after he or she becomes stable enough to leave the hospital. This tutorial reviews the many concepts that must be considered to manage this type of care successfully.

Clostridium difficile is the leading cause of healthcare-associated infectious diarrhea. Although C difficile is part of normal flora in some healthy individuals, patients with selective risk factors are often vulnerable to the toxigenic potential of this virulent healthcare pathogen. The spectrum of C difficile infection (CDI) is highly variable, ranging from mild to severe illness, presenting with single to multiple disease recurrences. Current approaches to treatment are based on severity of illness, number of recurrences, and clinical presentation. Oral vancomycin and metronidazole have formed the foundation for treatment of CDI, but therapeutic failures are commonly reported, especially involving hypervirulent clones. Alternative therapies, including newer antimicrobials, probiotics, immunotherapy, and fecal transplantation, have all met with varying degrees of efficacy. Although toxigenic culture (TC) testing from anaerobic culture remains the gold standard, newer technologies, including enzyme immunoassay, common antigen (glutamate dehydrogenase) testing, and real-time polymerase chain reaction (PCR) are less time-consuming and rapid. However, TC and PCR have reported high specificity and sensitivity when compared with other laboratory tests. Because of the significant morbidity and mortality associated with CDI, a high index of suspicion is warranted. Prevention and eradication of CDI require a multidisciplinary approach, including early disease recognition through appropriate surveillance, implementation of effective contact isolation strategies, adherence to environmental controls, judicious hand hygiene, evidence-based treatment, and management that includes antibiotic stewardship, continuous education of healthcare workers, and administrative support.

Background: The National Board of Nutrition Support Certification (NBNSC) is an independent credentialing board responsible for administering the multidisciplinary certification examination in nutrition support. For an exam to be legally and practically defensible, it must represent practice. Validation is by practice audit, the highest level of supporting evidence. Objectives: To define the role of the nutrition support professional (NSP) and the current elements (knowledge and functions) required for competent NSP practice. Methods: A survey instrument was constructed using a content validation strategy to establish the link between job tasks and the content of the examination. Internet-based surveys were made available to 5100 NSPs. NSP duties performed and knowledge required for patient safety and welfare were analyzed for the group as a whole and for each profession separately. Results: A total of 765 surveys were completed (return rate of 15%). The results of the practice audit demonstrate a common core of practice across the nutrition support disciplines as well as a universal core of elements believed to be important for competent nutrition support practice. Conclusion: The results of this survey continue to support a common core of practice across nutrition support disciplines as well as a common core of elements believed to be important for competent nutrition support practice. Accordingly, the NBNSC will continue to offer one examination to all disciplines both nationally and internationally and confer the Certified Nutrition Support Clinician (CNSC) credential to all individuals who successfully pass this validated examination.

The present review aims at highlighting the use of a recently developed medium-chain triacylglycerol:fish oil (MCT:FO) emulsion for the rapid and sustained enrichment of long-chain polyunsaturated ω-3 fatty acids in cell phospholipids. Preclinical in vitro, in vivo, and ex vivo experiments are briefly considered with emphasis on the changes in the fatty acid pattern of cell phospholipids in several organs, the partial correction of liver steatosis, and the cardiovascular modification of cationic and functional variables observed in ω-3-depleted rats examined 60–120 minutes after a bolus intravenous (IV) injection (1.0 mL) of the MCT:FO emulsion. The clinical findings collected in healthy male volunteers before or after the bolus IV injection (50.0 mL) of either the MCT:FO emulsion or a control medium-chain triacylglycerol:long-chain triacylglycerol emulsion are also reviewed, with emphasis on the rapid (within 60 minutes) and sustained (up to 2–3 days) enrichment of platelet and white blood cell phospholipids in long-chain polyunsaturated ω-3 fatty acids and hemostatic safety of the present procedure proposed as a tool for the rapid prevention or correction of metabolic and functional disturbances in humans with a relative deficiency in such ω-3 fatty acids.

Background: Parenteral lipid emulsions (LEs) can influence leukocyte functions. The authors investigated the effect of 2 LEs on leukocyte death in surgical patients with gastrointestinal cancer. Material and Methods: Twenty-five patients from a randomized, double-blind clinical trial (ID: NCT01218841) were randomly included to evaluate leukocyte death after 3 days of preoperative infusion (0.2 g fat/kg/d) of an LE composed equally of medium/long-chain triglycerides and soybean oil (MCTs/LCTs) or pure fish oil (FO). Blood samples were collected before (t0) and after LE infusion (t1) and on the third postoperative day (t2). Results: After LE infusion (t1 vs t0), MCTs/LCTs did not influence cell death; FO slightly increased the proportion of necrotic lymphocytes (5%). At the postoperative period (t2 vs t0), MCTs/LCTs tripled the proportion of apoptotic lymphocytes; FO maintained the slightly increased proportion of necrotic lymphocytes (7%) and reduced the percentage of apoptotic lymphocytes by 74%. In the postoperative period, MCT/LCT emulsion increased the proportion of apoptotic neutrophils, and FO emulsion did not change any parameter of apoptosis in the neutrophil population. There were no differences in lymphocyte or neutrophil death when MCT/LCT and FO treatments were compared during either preoperative or postoperative periods. MCT/LCTs altered the expression of 12 of 108 genes related to cell death, with both pro- and antiapoptotic effects; FO modulated the expression of 7 genes, demonstrating an antiapoptotic effect. Conclusion: In patients with gastrointestinal cancer, preoperative MCT/LCT infusion was associated with postoperative lymphocyte and neutrophil apoptosis. FO has a protective effect on postoperative lymphocyte apoptosis.

Background: Data on resting energy expenditure (REE) and oxygen consumption (VO₂) after pediatric cardiopulmonary bypass (CPB) will facilitate optimal nutrient prescription. Methods: The authors measured continuous REE and VO₂, using an in-line indirect calorimetery (IC) in 30 consecutive children with single-ventricle physiology immediately after Fontan surgery. REE during steady state at 8 hours after surgery was compared with standard equation-estimated energy expenditure (EEE). Patients were classified into 3 groups: hypermetabolic (measured REE [MREE]/EEE ratio >1.2), hypometabolic (MREE/EEE ratio <0.8), and normometabolic (MREE/EEE ratio 0.8–1.2). Demographic, anthropometric, and perioperative clinical characteristics were examined for their correlation with metabolic status. Results: In 26 of 30 patients with completed IC, mean REE at 8 hours after surgery was 57 ± 20 kcal/kg/d, and mean VO₂ was 110 ± 35 mL/min. Mean values of VO₂ and REE did not change within the first 24 hours after surgery. There was poor correlation between MREE at 8 hours and the EEE using the World Health Organization equation (r = 0.32, P = .11). Most patients (n = 19, 73%) were either normometabolic or hypometabolic. Lack of hypermetabolism was significantly associated with higher intraoperative serum lactate level and positive fluid balance compared with the rest of the group. Conclusions: The authors report a low prevalence of hypermetabolism in children with single-ventricle defects after Fontan surgery. Measured REE had poor correlation with equation-estimated energy expenditure in a majority of the cohort. The absence of increased energy expenditure after CPB will influence energy prescription in this group.

Background: Accurate measurement of resting energy expenditure (REE) using indirect calorimetry (IC) facilitates optimal energy prescription. Steady-state (SS) REE obtained using a 5-minute protocol (SS5) has been used as a surrogate for 24-hour REE measurement. However, SS5 conditions are difficult to achieve in critically ill children on mechanical ventilatory support. Methods: The authors prospectively examined factors associated with successful IC testing using the standard SS5 protocol in mechanically ventilated children. They examined the agreement of REE between SS5 and 2 abbreviated SS protocols: 4-minute (SS4) and 3-minute (SS3) protocols as well as the Schofield prediction equation, using Bland-Altman analysis. Results: IC testing (n = 45) was completed in 34 children. SS was achieved during 25 (56%), 31 (69%), and 42 (93%) tests, using the SS5, SS4, and SS3 protocols, respectively. Intratest variability in respiratory rate, endotracheal tube leak, and inspiratory time was associated with failed IC by the SS5 protocol. The mean bias (limits of agreement) for REE was 2.8 (–47 to 65), 5.8 (–71 to 72), and −127 (–418 to 1176) kcal/d using SS4, SS3, and Schofield, respectively. A stronger agreement was observed when means of all abbreviated SS REE values during a 30-minute test were used. Conclusion: In mechanically ventilated children, 4-minute and 3-minute SS protocols allowed REE measurements to be obtained in most patients with reasonable accuracy. Abbreviated protocols may decrease the need to rely on inaccurate equations when assessing energy expenditure in children who fail IC testing by standard SS criteria.

Background: Indirect calorimetry is the criterion method for assessment of energy expenditure in critically ill patients but is decidedly uncommon. Thus, calculation methods proliferate. Even if indirect calorimetry is available, it usually is not repeated more than weekly on the same patient, creating potential for error. The purpose of the current study was to quantify estimation errors against indirect calorimetry measurements in critically ill patients over time. Methods: In mechanically ventilated, critical care patients, indirect calorimetry was used to measure resting metabolic rate for 7 days. Three estimation methods were compared with the cumulative measurement: the Penn State equations, the American College of Chest Physicians (ACCP) standard (25 kcal/kg body weight), and an extrapolated value based on the first measurement multiplied by 7 days. Results: The cumulative difference between measured resting metabolic rate and the rate predicted by the Penn State equations was −468 ± 642 kcal (–3.7% ± 5.1% of the measured value). The difference for the ACCP was smaller, but variation was much wider (–387 ± 1597 kcal or −2.2% ± 11.9% of the measured value). The extrapolated value was −684 ± 1731 kcal (–4.1% ± 11.4% of measured expenditure). Conclusion: On average, the Penn State equations predict resting metabolic rate over time within 5% of the measured value. This performance is similar to the practice of making 1 measurement and extrapolating it over 1 week. The ACCP method has an unacceptably wide limit of agreement.

Background: Despite the numerous disease conditions associated with vitamin D deficiency in the general population, the relationship of this deficiency to outcome in critically ill patients remains unclear. The objective of this study is to determine the burden of vitamin D deficiency in intensive care unit (ICU) patients and determine if it is associated with poor patient outcomes. Methods: The authors conducted an analysis of samples collected from a prospective study of 196 patients admitted to a medical/surgical ICU in a tertiary care hospital. They measured serum 25-hydroxyvitamin D at admission and up to 10 days following admission and followed patients prospectively for 28-day outcomes. Results: Of analyzable patients, 50 (26%) were deficient (≤30 nmol/L) and 109 (56%) were insufficient (>30 and ≤60 nmol/L). Baseline 25(OH)D levels decreased significantly in all patients after 3 days in the ICU and remained significantly lower through 10 days (P < .001). 25(OH)D status was not significantly associated with 28-day all-cause mortality (hazard ratio [HR], 0.89; 95% confidence interval, [CI] 0.37–2.24). Higher levels of 25(OH)D were associated with a shorter time-to-alive ICU discharge (HR, 2.11; 95% CI, 1.27–3.51). 25(OH)D-deficient patients showed a nonstatistically significant trend toward a higher infection rate (odds ratio [OR], 3.20; 95% CI, 0.784–13.07; P = .11) compared with patients with sufficient levels of 25(OH)D. Conclusions: This study demonstrates significant decreases in vitamin D status over the duration of the patient’s ICU stay. Low levels of vitamin D are associated with longer time to ICU discharge alive and a trend toward increased risk of ICU-acquired infection.

Use of acid-suppressive therapy (AST) to prevent stress gastropathy in the intensive care unit has grown rapidly over the past 20 years. The primary indications for such use of AST include need for mechanical ventilation, overt gastrointestinal bleeding, severe burn, and head trauma. Despite this limited list of indications, proton pump inhibitors (PPIs) often are overprescribed for purposes of stress prophylaxis. Decreased mucosal blood flow with subsequent tissue ischemia is thought to be the mechanism responsible for stress-induced gastropathy. Subsequent activation of inflammatory and vasoconstrictive mediators determines the severity of the gastropathy. Numerous basic science studies suggest that enteral nutrition (EN) can improve mucosal blood flow and reverse the generation of these inflammatory mediators. Clinical studies evaluating the effectiveness of EN vs acid-suppressive medications, however, have shown variable results (and there are no randomized controlled trials to date). In hypersecretory states (such as head trauma and burns), AST should be given, even in patients who are tolerating EN. In the absence of a hypersecretory state, pharmacologic AST may be avoided or discontinued in patients who are tolerating EN. Stress prophylaxis medications also should be discontinued in patients who do not have a clear indication for their use. Overt bleeding in a patient receiving EN for stress prophylaxis should prompt the initiation of a PPI. Randomized controlled studies investigating the efficacy of EN for stress ulcer prophylaxis are needed. Protocols should be developed to alert healthcare teams to consider discontinuation of AST, especially when tolerance of EN is achieved.

Background: Although enteral nutrition (EN) is provided to most mechanically ventilated patients, the effect of specific feeding strategies on circulating markers of coagulation and inflammation is unknown. Methods: Markers of inflammation (tumor necrosis factor [TNF]-α, interleukin [IL]-1β, interferon [IFN]-γ, IL-6, IL-8, IL-10, IL-12) and coagulation (tissue factor [TF], plasminogen activator inhibitor-1) were measured at baseline (n = 185) and 6 days (n = 103) in mechanically ventilated intensive care unit patients enrolled in a randomized controlled study of trophic vs full-energy feeds to test the hypothesis that trophic enteral feeds would be associated with decreases in markers of inflammation and coagulation compared to full-energy feeds. Results: There were no differences in any of the biomarkers measured at day 6 between patients who were randomized to receive trophic feeds compared to full-energy feeds. However, TF levels decreased modestly in patients from baseline to day 6 in the trophic feeding group (343.3 vs 247.8 pg/mL, P = .061) but increased slightly in the full-calorie group (314.3 vs 331.8 pg/mL). Lower levels of TF at day 6 were associated with a lower mortality, and patients who died had increasing TF levels between days 0 and 6 (median increase of 39.7) compared to decreasing TF levels in patients who lived (median decrease of 95.0, P = .033). Conclusions: EN strategy in critically ill patients with acute respiratory failure does not significantly modify inflammation and coagulation by day 6, but trophic feeds may have some modest effects in attenuating inflammation and coagulation.

Background: Arginine deficiency and chronic inflammation may cause immune dysfunction. The authors previously showed that a pharmacological dose of parenteral arginine facilitates ornithine rather than nitric oxide production in subacute peritonitis. Herein, they investigated the effects of different doses of parenteral arginine supplementation on immunocytic subpopulation distribution and function. Materials: Male Wistar rats that underwent cecal punctures for induction of subacute peritonitis were infused with conventional parenteral nutrition solution (1.61% of total calories as arginine) or solutions supplemented with low-, medium-, or high-dose arginine (2.85%, 4.08%, and 6.54% of total calories, respectively) for 7 days. Distributions of T cells, B cells, and monocytes/macrophages and cytokine productions of peripheral blood lymphocytes (PBLs) and splenocytes were analyzed. Results: There were no significant differences in circulating white blood cell numbers and serum tumor necrosis factor (TNF)–α and interferon (IFN)–γ concentrations among groups. Serum nitrate/nitrite (NOx) and interleukin (IL)–2 levels were significantly decreased by arginine in a dose-dependent manner. Animals supplemented with parenteral arginine had significantly decreased productions of concanavalin (Con) A– and lipopolysaccharide (LPS)–stimulated TNF-α in PBLs and splenocytes, spontaneous IL-6 and LPS-stimulated IFN-γ in PBLs, and LPS-stimulated IL-6 in splenocytes. In addition, low-dose arginine significantly increased production of spontaneous IFN-γ in PBLs and splenocytes. High-dose arginine significantly increased spontaneous TNF-α, and Con A stimulated IL-4 and IL-6 in PBLs. Conclusion: Parenteral arginine administration at approximately 4% of total calories may alter PBLs and splenocytic immunity, and >6% of total calories might not be of benefit in rats with subacute peritonitis.

Introduction: Early nutrition support is an integral part of the care of critically ill children. Early enteral nutrition (EN) improves nitrogen balance and prevents bacterial translocation and gut mucosal atrophy. Adequate EN is often not achieved as gastric feeds are not tolerated and placing postpyloric feeding tubes can be difficult. Spontaneous transpyloric passage of standard feeding tubes without endoscopic intervention or use of anesthesia can range from 30%−80%. The authors report on their experience with a 14Fr polyurethane self-advancing jejunal feeding tube in a pediatric population. These tubes have been used in the adult population with success, but to the authors’ knowledge, there have been no reports of its use in the pediatric age group. Case Series: The authors present 7 critically ill patients 8–19 years old, admitted to the pediatric intensive care unit, in whom prolonged recovery, inability to tolerate gastric feeds, and dependence on ventilator were predicted at the outset. The jejunal feeding tube was successfully placed on first attempt at the bedside in all 7 patients within the first 24 hours without the use of a promotility agent or endoscopic intervention. Nutrition goal achieved within 48 hours of feeding tube placement was reported for each patient. This case series demonstrates that children fed via the small bowel reached their nutrition goal earlier and did not require parenteral nutrition. Conclusion: The self-advancing jejunal feeding tube can be used effectively to establish early EN in critically ill children.

A 5-year-old boy with autism developed dry eye and xerophthalmia. Serum vitamin A was undetectable. Dietary history revealed a markedly altered intake consisting of only fried potatoes and rice balls for 2 years. Fried potatoes contain no vitamin A. Autism is a multifaceted developmental disorder infrequently accompanied by abnormal eating practices. To the authors’ knowledge, most children with autism who develop dietary vitamin A deficiency have consumed an excess of fried potatoes. Attention to possible vitamin A deficiency is essential when fried potatoes are consumed exclusively.