Rupinder Dhaliwal

Canadian clinical practice guidelines for nutrition support in mechanically ventilated, critically ill adult patients

OBJECTIVE This study was conducted to develop evidence-based clinical practice guidelines for nutrition support (ie, enteral and parenteral nutrition) in mechanically ventilated critically ill adults. OPTIONS The following interventions were systematically reviewed for inclusion in the guidelines: enteral nutrition (EN) versus parenteral nutrition (PN), early versus late EN, dose of EN, composition of EN (protein, carbohydrates, lipids, immune-enhancing additives), strategies to optimize delivery of EN and minimize risks (ie, rate of advancement, checking residuals, use of bedside algorithms, motility agents, small bowel versus gastric feedings, elevation of the head of the bed, closed delivery systems, probiotics, bolus administration), enteral nutrition in combination with supplemental PN, use of PN versus standard care in patients with an intact gastrointestinal tract, dose of PN and composition of PN (protein, carbohydrates, IV lipids, additives, vitamins, trace elements, immune enhancing substances), and the use of intensive insulin therapy. OUTCOMES The outcomes considered were mortality (intensive care unit [ICU], hospital, and long-term), length of stay (ICU and hospital), quality of life, and specific complications. EVIDENCE We systematically searched MEDLINE and CINAHL (cumulative index to nursing and allied health), EMBASE, and the Cochrane Library for randomized controlled trials and meta-analyses of randomized controlled trials that evaluated any form of nutrition support in critically ill adults. We also searched reference lists and personal files, considering all articles published or unpublished available by August 2002. Each included study was critically appraised in duplicate using a standard scoring system. VALUES For each intervention, we considered the validity of the randomized trials or meta-analyses, the effect size and its associated confidence intervals, the homogeneity of trial results, safety, feasibility, and the economic consequences. The context for discussion was mechanically ventilated patients in Canadian ICUs. BENEFITS, HARMS, AND COSTS The major potential benefit from implementing these guidelines is improved clinical outcomes of critically ill patients (reduced mortality and ICU stay). Potential harms of implementing these guidelines include increased complications and costs related to the suggested interventions. SUMMARIES OF EVIDENCE AND RECOMMENDATIONS: When considering nutrition support in critically ill patients, we strongly recommend that EN be used in preference to PN. We recommend the use of a standard, polymeric enteral formula that is initiated within 24 to 48 hours after admission to ICU, that patients be cared for in the semirecumbent position, and that arginine-containing enteral products not be used. Strategies to optimize delivery of EN (starting at the target rate, use of a feeding protocol using a higher threshold of gastric residuals volumes, use of motility agents, and use of small bowel feeding) and minimize the risks of EN (elevation of the head of the bed) should be considered. Use of products with fish oils, borage oils, and antioxidants should be considered for patients with acute respiratory distress syndrome. A glutamine-enriched formula should be considered for patients with severe burns and trauma. When initiating EN, we strongly recommend that PN not be used in combination with EN. When PN is used, we recommend that it be supplemented with glutamine, where available. Strategies that maximize the benefit and minimize the risks of PN (hypocaloric dose, withholding lipids, and the use of intensive insulin therapy to achieve tight glycemic control) should be considered. There are insufficient data to generate recommendations in the following areas: use of indirect calorimetry; optimal pH of EN; supplementation with trace elements, antioxidants, or fiber; optimal mix of fats and carbohydrates; use of closed feeding systems; continuous versus bolus feedings; use of probiotics; type of lipids; and mode of lipid delivery. VALIDATION This guideline was peer-reviewed and endorsed by official representatives of the Canadian Critical Care Society, Canadian Critical Care Trials Group, Dietitians of Canada, Canadian Association of Critical Care Nurses, and the Canadian Society for Clinical Nutrition. SPONSORS This guideline is a joint venture of the Canadian Critical Care Society, the Canadian Critical Trials Group, the Canadian Society for Clinical Nutrition, and Dietitians of Canada. The Canadian Critical Care Society and the Institute of Nutrition, Metabolism, and Diabetes of the Canadian Institutes of Health Research provided funding for development of this guideline.

Intensive insulin therapy and mortality among critically ill patients: a meta-analysis including NICE-SUGAR study data

Background: Hyperglycemia is associated with increased mortality in critically ill patients. Randomized trials of intensive insulin therapy have reported inconsistent effects on mortality and increased rates of severe hypoglycemia. We conducted a meta-analysis to update the totality of evidence regarding the influence of intensive insulin therapy compared with conventional insulin therapy on mortality and severe hypoglycemia in the intensive care unit (ICU). Methods: We conducted searches of electronic databases, abstracts from scientific conferences and bibliographies of relevant articles. We included published randomized controlled trials conducted in the ICU that directly compared intensive insulin therapy with conventional glucose management and that documented mortality. We included in our meta-analysis the data from the recent NICE-SUGAR (Normoglycemia in Intensive Care Evaluation — Survival Using Glucose Algorithm Regulation) study. Results: We included 26 trials involving a total of 13 567 patients in our meta-analysis. Among the 26 trials that reported mortality, the pooled relative risk (RR) of death with intensive insulin therapy compared with conventional therapy was 0.93 (95% confidence interval [CI] 0.83–1.04). Among the 14 trials that reported hypoglycemia, the pooled RR with intensive insulin therapy was 6.0 (95% CI 4.5–8.0). The ICU setting was a contributing factor, with patients in surgical ICUs appearing to benefit from intensive insulin therapy (RR 0.63, 95% CI 0.44–0.91); patients in the other ICU settings did not (medical ICU: RR 1.0, 95% CI 0.78–1.28; mixed ICU: RR 0.99, 95% CI 0.86–1.12). The different targets of intensive insulin therapy (glucose level ≤ 6.1 mmol/L v. ≤ 8.3 mmol/L) did not influence either mortality or risk of hypoglycemia. Interpretation: Intensive insulin therapy significantly increased the risk of hypoglycemia and conferred no overall mortality benefit among critically ill patients. However, this therapy may be beneficial to patients admitted to a surgical ICU.

Antioxidant nutrients: a systematic review of trace elements and vitamins in the critically ill patient

ObjectiveCritical illness is associated with the generation of oxygen free radicals and low endogenous antioxidant capacity leading to a condition of oxidative stress. We investigated whether supplementing critically ill patients with antioxidants, trace elements, and vitamins improves their survival.MethodsWe searched four bibliographic databases from 1980 to 2003 and included studies that were randomized, reported clinically important endpoints in critically ill patients, and compared various trace elements and vitamins to placebo.ResultsEleven articles met the inclusion criteria. When the results of all the trials were aggregated, overall antioxidants were associated with a significant reduction in mortality [Risk Ratio (RR) 0.65, 95% confidence intervals (CI) 0.44–0.97, p=0.03] but had no effect on infectious complications. Studies that utilized a single trace element were associated with a significant reduction in mortality [RR 0.52, 95% CI 0.27–0.98, p=0.04] whereas combined antioxidants had no effect. Studies using parenteral antioxidants were associated with a significant reduction in mortality [RR 0.56, 95% CI 0.34–0,92, p=0.02] whereas studies of enteral antioxidants were not. Selenium supplementation (alone and in combination with other antioxidants) may be associated with a reduction in mortality [RR 0.59, 95% CI 0.32–1.08, p=0.09] while nonselenium antioxidants had no effect on mortality.ConclusionsTrace elements and vitamins that support antioxidant function, particularly high-dose parenteral selenium either alone or in combination with other antioxidants, are safe and may be associated with a reduction in mortality in critically ill patients.

Nutrition therapy in the critical care setting: What is "best achievable" practice? An international multicenter observational study*

Objective: To describe current nutrition practices in intensive care units and determine “best achievable” practice relative to evidence-based Critical Care Nutrition Clinical Practice Guidelines. Design: An international, prospective, observational, cohort study conducted January to June 2007. Setting: One hundred fifty-eight adult intensive care units from 20 countries. Patients: Two-thousand nine-hundred forty-six consecutively enrolled mechanically ventilated adult patients (mean, 18.6 per site) who stayed in the intensive care unit for at least 72 hrs. Interventions: Data on nutrition practices were collected from intensive care unit admission to intensive care unit discharge or a maximum of 12 days. Measurements and Main Results: Relative to recommendations of the Clinical Practice Guidelines, we report average, best, and worst site performance on key nutrition practices. Adherence to Clinical Practice Guideline recommendations was high for some recommendations: use of enteral nutrition in preference to parenteral nutrition, glycemic control, lack of utilization of arginine-enriched enteral formulas, delivery of hypocaloric parenteral nutrition, and the presence of a feeding protocol. However, significant practice gaps were identified for other recommendations. Average time to start of enteral nutrition was 46.5 hrs (site average range, 8.2–149.1 hrs). The average use of motility agents and small bowel feeding in patients who had high gastric residual volumes was 58.7% (site average range, 0%–100%) and 14.7% (site average range, 0%–100%), respectively. There was poor adherence to recommendations for the use of enteral formulas enriched with fish oils, glutamine supplementation, timing of supplemental parenteral nutrition, and avoidance of soybean oil-based parenteral lipids. Average nutritional adequacy was 59% (site average range, 20.5%–94.4%) for energy and 60.3% (site average range, 18.6%–152.5%) for protein. Conclusions: Despite high adherence to some recommendations, large gaps exist between many recommendations and actual practice in intensive care units, and consequently nutrition therapy is suboptimal. We have identified “best achievable” practice that can serve as targets for future quality improvement initiatives.

Nutrition support in the critical care setting: current practice in canadian ICUs--opportunities for improvement?

BACKGROUND The purpose of this project was to describe current nutrition support practice in the critical care setting and to identify interventions to target for quality improvement initiatives. METHODS We conducted a cross-sectional national survey of dietitians working in intensive care units (ICUs) across Canada to document various aspects of nutrition support practice. RESULTS Of the 79 dietitians sent study materials, 66 responded (83%). Sixteen of 66 sites (24.2%) reported the presence of a nutrition support team, and 35 of 66 (53%) used a standard enteral feeding protocol. Dietitians retrospectively abstracted data from charts of all patients in the ICU on April 18, 2001. Of 702 patients, 313 (44.6%) received enteral nutrition only, 50 (7.1%) received parenteral nutrition only, 60 (8.5%) received both, and 279 (39.7%) received no form of nutrition support. Enteral nutrition was initiated on 1.6 days (median) after admission to ICU; 10.7% of patients were initiated on day 1. Of those receiving any form of nutrition support, on average, patients received 58% of their prescribed amounts of calories and protein over the first 12 days in the ICU. Of all days on enteral feeds, patients received feeds into the small bowel on 381 of 2321 (16.4%) days. The mean head of the bed elevation for all patients was 30 degrees. Controlling for differences in patient characteristics, site factors contributing the most successful application of nutrition support included the amount of funded dietitians per ICU bed, size of ICU, and the fact that the ICU was located in an academic setting. CONCLUSIONS A significant number of critically ill patients did not receive any form of nutrition support for the study period. Those that did receive nutrition support did not meet their prescribed energy or protein needs, especially earlier in the course of their illness. Significant opportunities to improve provision of nutrition support to critically ill patients exist.

Identifying critically ill patients who benefit the most from nutrition therapy: the development and initial validation of a novel risk assessment tool

IntroductionTo develop a scoring method for quantifying nutrition risk in the intensive care unit (ICU).MethodsA prospective, observational study of patients expected to stay > 24 hours. We collected data for key variables considered for inclusion in the score which included: age, baseline APACHE II, baseline SOFA score, number of comorbidities, days from hospital admission to ICU admission, Body Mass Index (BMI) < 20, estimated % oral intake in the week prior, weight loss in the last 3 months and serum interleukin-6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) levels. Approximate quintiles of each variable were assigned points based on the strength of their association with 28 day mortality.ResultsA total of 597 patients were enrolled in this study. Based on the statistical significance in the multivariable model, the final score used all candidate variables except BMI, CRP, PCT, estimated percentage oral intake and weight loss. As the score increased, so did mortality rate and duration of mechanical ventilation. Logistic regression demonstrated that nutritional adequacy modifies the association between the score and 28 day mortality (p = 0.01).ConclusionsThis scoring algorithm may be helpful in identifying critically ill patients most likely to benefit from aggressive nutrition therapy.

Validation of the Canadian clinical practice guidelines for nutrition support in mechanically ventilated, critically ill adult patients: Results of a prospective observational study*

Objective:Recently, evidence-based clinical practice guidelines for the provision of nutrition support in the critical care setting have been developed. To validate these guidelines, we hypothesized that intensive care units whose practice, on average, was more consistent with the guidelines would have greater success in providing enteral nutrition. Design:Prospective observational study. Setting:Fifty-nine intensive care units across Canada. Patients:Consecutive cohort of mechanically ventilated patients. Interventions:In May 2003, participating intensive care units recorded nutrition support practices on a consecutive cohort of mechanically ventilated patients who stayed for a minimum of 72 hrs. Sites enrolled an average of 10.8 (range, 4–18) patients for a total of 638. Patients were observed for an average of 10.7 days. Measurements and Main Results:We examined the association between five recommendations from the clinical practice guidelines most directly related to the provision of nutrition support (use of parenteral nutrition, feeding protocol, early enteral nutrition, small bowel feedings, and motility agents) and adequacy of enteral nutrition. We defined adequacy of enteral nutrition as the percent of prescribed calories that patients actually received. Across sites, the average adequacy of enteral nutrition over the observed stay in intensive care unit ranged from 1.8% to 76.6% (average 43.0%). Intensive care units with a greater than median utilization of parenteral nutrition (>17.5% patient days) had a much lower adequacy of enteral nutrition (32.9 vs. 52.7%, p < .0001). Intensive care units that used a feeding protocol tended to have a higher adequacy of enteral nutrition than those that did not (44.9 vs. 38.5%, p = .03). Intensive care units that initiated enteral nutrition on >50% of their patients within the first 48 hrs had a higher adequacy of enteral nutrition than those that did not (48.1 vs. 34.4%, p < .0001). Intensive care units that had a >50% utilization of motility agents and/or any small bowel feedings in patients with high gastric residuals tended to have a higher adequacy of enteral nutrition than those intensive care units that did not (45.6 vs. 39.2%, p = .04, and 48.4 vs. 41.8%, p = .16, respectively). Conclusions:Intensive care units that were more consistent with the Canadian clinical practice guidelines were more likely to successfully feed patients via enteral nutrition. Adoption of the Canadian clinical practice guidelines should lead to improved nutrition support practice in intensive care units. This may translate into better outcomes for critically ill patients receiving nutrition support.

Perioperative Use of Arginine-supplemented Diets: A Systematic Review of the Evidence

g p t t c d A d Infections are the most frequent cause of morbidity after surgery and up to 54% of all hospital-acquired infections occur in high-risk surgical populations. Infections result in rolongation of hospital stay and increased health care osts by up to

Optimizing the benefits and minimizing the risks of enteral nutrition in the critically ill: Role of small bowel feeding

10 billion per year in the United States lone. Multifaceted efforts to prevent infection are an essential component of any surgical practice. Surgical stress predisposes patients to immune dysfunction, placing them at higher risk of infection, risks that are increased even more if the patient is malnourished before surgical insult. Various nutrient and nutritional strategies ave been studied to evaluate their effect on immune function nd clinical outcomes. One pharmaconutrient that has been he center of much debate in the literature is arginine and rginine-supplemented nutritional formulas. Arginine is an mino acid involved in multiple metabolic processes. It is a recursor of the formation of polyamines and hydroxyproine, which is important for connective tissue repair, and is he precursor for the formation of nitric oxide, an imporant signaling molecule. In addition to these vital roles, arginine is an essential metabolic substrate for immune cells and required for normal lymphocyte function. Arginine deficiency after surgical stress was reported more than 30 years ago, although the mechanisms behind this have until recently remained unknown. More than 20 years ago, supraphysiologic concentrations of arginine were added to the diets of critically ill and surgical patients. These diets were aimed at “enhancing immune function” and also contained increased amounts of omega-3 fatty acids, nucleotides, and other nutrients. These nutrients

The Canadian Critical Care Nutrition Guidelines in 2013 An Update on Current Recommendations and Implementation Strategies

BACKGROUND Strategies that maximize the delivery of enteral nutrition while minimizing the associated risks have the potential to improve the outcomes of critically ill patients. By delivering enteral feeds in the small bowel, beyond the pylorus, the frequency of regurgitation and the risk of aspiration is thought to be decreased while at the same time, nutrient delivery is maximized. The purpose of this paper is to systematically review those studies that compare gastric with small bowel feeding. METHODS We searched computerized bibliographic databases, personal files, and relevant reference lists to identify eligible studies. Only randomized, clinical trials of critically ill patients that compared small bowel and gastric feedings were included in this review. In an independent fashion, relevant data on the methodology and outcomes of primary studies were abstracted in duplicate. RESULTS There were 10 studies that met the inclusion criteria for this review. In 1 study, small bowel feeding was associated with a reduction in gastroesophageal regurgitation and a trend toward reduced pulmonary aspiration. Several studies document that small bowel feeding was associated with an increase in protein and calories delivered and a shorter time to target dose of nutrition. Compared with gastric feeding, when the results of 7 randomized trials were aggregated statistically, small bowel feeding was associated with a reduction in pneumonia (relative risk, 0.76; 95% confidence intervals, 0.59, 0.99). There was no difference in mortality rates between the 2 groups. CONCLUSIONS Small bowel feeding may be associated with a reduction in gastroesophageal regurgitation, an increase in nutrient delivery, a shorter time to achieve desired target nutrition, and a lower rate of ventilator-associated pneumonia.