Naomi E. Cahill

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.

Nutritional practices and their relationship to clinical outcomes in critically ill children—An international multicenter cohort study*

Objectives:To examine factors influencing the adequacy of energy and protein intake in the pediatric intensive care unit and to describe their relationship to clinical outcomes in mechanically ventilated children. Design, Setting, Patients:We conducted an international prospective cohort study of consecutive children (ages 1 month to 18 yrs) requiring mechanical ventilation longer than 48 hrs in the pediatric intensive care unit. Nutritional practices were recorded during the pediatric intensive care unit stay for a maximum of 10 days, and patients were followed up for 60 days or until hospital discharge. Multivariate analysis, accounting for pediatric intensive care unit clustering and important confounding variables, was used to examine the impact of nutritional variables and pediatric intensive care unit characteristics on 60-day mortality and the prevalence of acquired infections. Main Results:31 pediatric intensive care units in academic hospitals in eight countries participated in this study. Five hundred patients with mean (SD) age 4.5 (5.1) yrs were enrolled and included in the analysis. Mortality at 60 days was 8.4%, and 107 of 500 (22%) patients acquired at least one infection during their pediatric intensive care unit stay. Over 30% of patients had severe malnutrition on admission, with body mass index z-score >2 (13.2%) or <−2 (17.1%) on admission. Mean prescribed goals for daily energy and protein intake were 64 kcals/kg and 1.7 g/kg respectively. Enteral nutrition was used in 67% of the patients and was initiated within 48 hrs of admission in the majority of patients. Enteral nutrition was subsequently interrupted on average for at least 2 days in 357 of 500 (71%) patients. Mean (SD) percentage daily nutritional intake (enteral nutrition) compared to prescribed goals was 38% (34) for energy and 43% (44) for protein. A higher percentage of goal energy intake via enteral nutrition route was significantly associated with lower 60-day mortality (Odds ratio for increasing energy intake from 33.3% to 66.6% is 0.27 [0.11, 0.67], p = .002). Mortality was higher in patients who received parenteral nutrition (odds ratio 2.61 [1.3, 5.3], p = .008). Patients admitted to units that utilized a feeding protocol had a lower prevalence of acquired infections (odds ratio 0.18 [0.05, 0.64], p = .008), and this association was independent of the amount of energy or protein intake. Conclusions:Nutrition delivery is generally inadequate in mechanically ventilated children across the world. Intake of a higher percentage of prescribed dietary energy goal via enteral route was associated with improved 60-day survival; conversely, parenteral nutrition use was associated with higher mortality. Pediatric intensive care units that utilized protocols for the initiation and advancement of enteral nutrient intake had a lower prevalence of acquired infections. Optimizing nutrition therapy is a potential avenue for improving clinical outcomes in critically ill children.

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

Clinical practice guidelines (CPGs) are systematically developed statements to assist practitioners and patient decisions about appropriate healthcare for specific clinical circumstances, and are designed to minimize practice variation, improve costs, and improve clinical outcomes. The Canadian Critical Care Practice Guidelines (CCPGs) were first published in 2003 and most recently updated in 2013. A total of 68 new randomized controlled trials were identified since the last version in 2009, 50 of them published between 2009 and 2013. The remaining articles were trials published before 2009 but were not identified in previous iterations of the CCPGs. For clinical practice guidelines to be useful to practitioners, they need to be up-to-date and be reflective of the current body of evidence. Herein we describe the process by which the CCPGs were updated. This process resulted in 10 new sections or clinical topics. Of the old clinical topics, 3 recommendations were upgraded, 4 were downgraded, and 27 remained the same. To influence decision making at the bedside, these updated guidelines need to be accompanied by active guideline implementation strategies. Optimal implementation strategies should be guided by local contextual factors including barriers and facilitators to best practice recommendations. Moreover, evaluating and monitoring performance, such as participating in the International Nutrition Survey of practice, should be part of any intensive care units performance improvement strategy. The active implementation of the updated CCPGs may lead to better nutrition care and improved patient outcomes in the critical care setting.

Optimal amount of calories for critically ill patients: Depends on how you slice the cake!*

Objective:The optimal amount of calories required by critically ill patients continues to be controversial. The objective of this study is to examine the relationship between the amount of calories administered and mortality. Design:Prospective, multi-institutional audit. Setting:Three hundred fifty-two intensive care units from 33 countries. Patients:A total of 7,872 mechanically ventilated, critically ill patients who remained in the intensive care unit for at least 96 hrs. Interventions:None. Measurements and Main Results:We evaluated the association between the amount of calories received and 60-day hospital mortality using various sample restriction and statistical adjustment techniques and demonstrate the influence of the analytic approach on the results. In the initial unadjusted analysis, we observe a significant association between increased caloric intake and increased mortality (odds ratio 1.28; 95% confidence interval 1.12–1.48 for patients receiving more than two-thirds of their caloric prescription vs. those receiving less than one-third of their prescription). Excluding days after permanent progression to oral intake attenuated the estimates of harm (unadjusted analysis: odds ratio 1.04; 95% confidence interval 0.90–1.20). Restricting the analysis to patients with at least 4 days in the intensive care unit before progression to oral intake and excluding days of observation after progression to oral intake resulted in a significant benefit to increased caloric intake (unadjusted odds ratio 0.73; 95% confidence interval 0.63–0.85). When further adjusting for both evaluable days and other important covariates, patients who received more than two-thirds of their caloric prescription are much less likely to die than those receiving less than one-third of their prescription (odds ratio 0.67; 95% confidence interval 0.56–0.79; p < .0001). When treated as a continuous variable, the overall association between the percent of the caloric prescription received and mortality is highly statistically significant with increasing calories associated with decreasing mortality (p < .0001). Conclusions:The estimated association between the amount of calories and mortality is significantly influenced by the statistical methodology used. The most appropriate available analyses suggest that attempting to meet caloric targets may be associated with improved clinical outcomes in critically ill patients.

Enhanced protein-energy provision via the enteral route feeding protocol in critically ill patients: results of a cluster randomized trial.

Objectives:To determine the effect of the enhanced protein-energy provision via the enteral route feeding protocol, combined with a nursing educational intervention on nutritional intake, compared to usual care. Design:Prospective, cluster randomized trial. Setting:Eighteen ICUs from United States and Canada with low baseline nutritional adequacy. Patients:One thousand fifty-nine mechanically ventilated, critically ill patients. Interventions:A novel feeding protocol combined with a nursing educational intervention. Measurements and Main Results:The two primary efficacy outcomes were the proportion of the protein and energy prescriptions received by study patients via the enteral route over the first 12 days in the ICU. Safety outcomes were the prevalence of vomiting, witnessed aspiration, and ICU-acquired pneumonia. The proportion of prescribed protein and energy delivered by enteral nutrition was greater in the intervention sites compared to the control sites. Adjusted absolute mean difference between groups in the protein and energy increases were 14% (95% CI, 5–23%; p = 0.005) and 12% (95% CI, 5–20%; p = 0.004), respectively. The intervention sites had a similar improvement in protein and calories when appropriate parenteral nutrition was added to enteral sources. Use of the enhanced protein-energy provision via the enteral route feeding protocol was associated with a decrease in the average time from ICU admission to start of enteral nutrition compared to the control group (40.7–29.7 hr vs 33.6–35.2 hr, p = 0.10). Complication rates were no different between the two groups. Conclusions:In ICUs with low baseline nutritional adequacy, use of the enhanced protein-energy provision via the enteral route feeding protocol is safe and results in modest but statistically significant increases in protein and calorie intake.

Extreme Obesity and Outcomes in Critically Ill Patients

BACKGROUND Recent literature suggests that obese critically ill patients do not have worse outcomes than patients who are normal weight. However, outcomes in extreme obesity (BMI ≥ 40 kg/m(2)) are unclear. We sought to determine the association between extreme obesity and ICU outcomes. METHODS We analyzed data from a multicenter international observational study of ICU nutrition practices that occurred in 355 ICUs in 33 countries from 2007 to 2009. Included patients were mechanically ventilated adults ≥ 18 years old who remained in the ICU for > 72 h. Using generalized estimating equations and Cox proportional hazard modeling with clustering by ICU and adjusting for potential confounders, we compared extremely obese to normal-weight patients in terms of duration of mechanical ventilation (DMV), ICU length of stay (LOS), hospital LOS, and 60-day mortality. RESULTS Of the 8,813 patients included in this analysis, 3,490 were normal weight (BMI 18.5-24.9 kg/m(2)), 348 had BMI 40 to 49.9 kg/m(2), 118 had BMI 50 to 59.9 kg/m(2), and 58 had BMI ≥ 60 kg/m(2). Unadjusted analyses suggested that extremely obese critically ill patients have improved mortality (OR for death, 0.77; 95% CI, 0.62-0.94), but this association was not significant after adjustment for confounders. However, an adjusted analysis of survivors found that extremely obese patients have a longer DMV and ICU LOS, with the most obese patients (BMI ≥ 60 kg/m(2)) also having longer hospital LOS. CONCLUSIONS During critical illness, extreme obesity is not associated with a worse survival advantage compared with normal weight. However, among survivors, BMI ≥ 40 kg/m(2) is associated with longer time on mechanical ventilation and in the ICU. These results may have prognostic implications for extremely obese critically ill patients.

Early use of supplemental parenteral nutrition in critically ill patients: results of an international multicenter observational study.

Objective:To evaluate the effect of using supplemental parenteral nutrition compared to early enteral nutrition alone on nutritional and clinical outcomes. Design:A multicenter, observational study. Setting:Two hundred twenty-six intensive care units from 29 Countries. Patients:Mechanically ventilated critically ill adult patients that remained in the intensive care unit for >72 hrs and received early enteral nutrition within 48 hrs from admission. Interventions:Data were collected on patient characteristics and daily nutrition practices for up to 12 days. Patient outcomes were recorded after 60 days. Measurements and Main Results:We compared the outcomes of patients who received early enteral nutrition alone, early enteral nutrition + early parenteral nutrition, and early enteral nutrition + late parenteral nutrition (after 48 hrs of admission). Cox regression analyses were conducted to determine the effect of feeding strategy, adjusted for other confounding variables, on time to being discharged alive from hospital. A total of 2,920 patients were included in this study; 2562 (87.7%) in the early enteral nutrition group, 188 (6.4%) in the early parenteral nutrition group, and 170 (5.8%) in the late parenteral nutrition group. Adequacy of calories and protein was highest in the early parenteral nutrition group (81.2% and 80.1%, respectively) and lowest in the early enteral nutrition group (63.4% and 59.3%) (p < .0001). The 60-day mortality rate was 27.8% in the early enteral nutrition group, 34.6% in the early parenteral nutrition group, and 35.3% in the late parenteral nutrition group (p = .02). The rate of patients discharged alive from hospital was slower in the group that received early parenteral nutrition (unadjusted hazard ratio 0.75, 95% confidence interval 0.59–0.96) and late parenteral nutrition (hazard ratio 0.64, 95% confidence interval 0.51–0.81) (p = .0003) compared to early enteral nutrition. These findings persisted after adjusting for known confounders. Conclusions:The supplemental use of parenteral nutrition may improve provision of calories and protein but is not associated with any clinical benefit.

Nutrition therapy for the critically ill surgical patient: we need to do better!

BACKGROUND To identify opportunities for quality improvement, the nutrition adequacy of critically ill surgical patients, in contrast to medical patients, is described. METHODS International, prospective, and observational studies conducted in 2007 and 2008 in 269 intensive care units (ICUs) were combined for purposes of this analysis. Sites provided institutional and patient characteristics and nutrition data from ICU admission to ICU discharge for maximum of 12 days. Medical and surgical patients staying in ICU at least 3 days were compared. RESULTS A total of 5497 mechanically ventilated adult patients were enrolled; 37.7% had surgical ICU admission diagnosis. Surgical patients were less likely to receive enteral nutrition (EN) (54.6% vs 77.8%) and more likely to receive parenteral nutrition (PN) (13.9% vs 4.4%) (P < .0001). Among patients initiating EN in ICU, surgical patients started EN 21.0 hours later on average (57.8 vs 36.8 hours, P < .0001). Consequently, surgical patients received less of their prescribed calories from EN (33.4% vs 49.6%, P < .0001) or from all nutrition sources (45.8% vs 56.1%, P < .0001). These differences remained after adjustment for patient and site characteristics. Patients undergoing cardiovascular and gastrointestinal surgery were more likely to use PN, were less likely to use EN, started EN later, and had lower total nutrition and EN adequacy rates compared with other surgical patients. Use of feeding and/or glycemic control protocols was associated with increased nutrition adequacy. CONCLUSIONS Surgical patients receive less nutrition than medical patients. Cardiovascular and gastrointestinal surgery patients are at highest risk of iatrogenic malnutrition. Strategies to improve nutrition performance, including use of protocols, are needed.

Understanding Adherence to Guidelines in the Intensive Care Unit Development of a Comprehensive Framework

BACKGROUND Clinical practice guidelines (CPGs) have been hailed as a useful method of translating evidence into practice. Several CPGs have been published that provide recommendations for feeding patients in the intensive care unit (ICU). Despite a rigorous development process and active dissemination of these guidelines, their impact on nutrition practice has been modest. The purpose of this study was to develop a comprehensive framework for understanding adherence to nutrition CPGs in the critical care setting. METHODS Multiple case studies were completed at 4 Canadian ICUs. Semistructured interviews were conducted with 7 key informants at each ICU site who were asked about their perceptions and attitudes toward guidelines in general and the Canadian Critical Care Nutrition CPGs specifically. Interview transcripts and related documents were analyzed qualitatively using a framework approach. RESULTS The 5 key components of the developed framework were characteristics of the CPGs, the implementation process, institutional factors, provider intent, and the clinical condition of the patient. These key themes encapsulate numerous itemized factors that contribute to guideline adherence either as barriers or enablers. CONCLUSIONS Adherence to nutrition CPGs is determined by a complex interaction of multiple factors that act as barriers or enablers. The comprehensive framework for adherence to CPGs in the ICU attempts to elucidate this process and provides a useful template for future research. Future quality improvement initiatives should assess local barriers to change and design interventions to overcome these barriers.

When Early Enteral Feeding Is Not Possible in Critically Ill Patients Results of a Multicenter Observational Study

BACKGROUND Early enteral nutrition (EN) is the preferred strategy for feeding the critically ill; however, it is not always possible to initiate EN within the recommended 24 to 48 hours. When these situations arise, controversy exists whether to start feeding early via the parenteral route or to delay feeding until EN can be provided. METHODS A multicenter, international, observational study examined nutrition practices in intensive care units (ICUs). Eligible patients were critically ill patients with a medical diagnosis who remained in the ICU for >72 hours and received EN >48 hours after admission. Data were collected on site, including patient characteristics, daily nutrition practices, and outcomes at 60 days. Nutrition and clinical outcomes were compared between 3 groups of patients: (1) early parenteral nutrition (PN) (<48 hours after admission) and late EN (>48 hours after admission), (2) late PN and late EN, and (3) late EN and no PN. RESULTS Of the 703 patients who met our inclusion criteria, 541 (77.0%) medical patients received late EN and no PN. In patients receiving late EN and PN, 83 (11.8%) received early PN and 79 (11.2%) received late PN. Adequacy of calories and protein from total nutrition was highest in the early PN group (74.1% ± 21.2% and 71.5% ± 24.9%, respectively) and lowest in the late EN group (42.9% ± 21.2% and 38.7% ± 21.6%) (P < .001). The proportion of patients dead or remaining in hospital was significantly higher for early PN compared with late EN and PN (unadjusted hazard ratio for early PN = 0.55; 95% confidence interval, 0.37-0.83, P = .015). However, this difference did not remain significant (P = .65) after adjustment for baseline characteristics. CONCLUSIONS The results suggest that initiating PN early, when it is not possible to feed enterally early, may improve provision of calories and protein but is not associated with better clinical outcomes compared with late EN or PN.