Emma J. Ridley

Comparisons between intragastric and small intestinal delivery of enteral nutrition in the critically ill: a systematic review and meta-analysis.

INTRODUCTION The largest cohort of critically ill patients evaluating intragastric and small intestinal delivery of nutrients was recently reported. This systematic review included recent data to compare the effects of small bowel and intragastric delivery of enteral nutrients in adult critically ill patients. METHODS This is a systematic review of all randomised controlled studies published between 1990 and March 2013 that reported the effects of the route of enteral feeding in the critically ill on clinically important outcomes. RESULTS Data from 15 level-2 studies were included. Small bowel feeding was associated with a reduced risk of pneumonia (Relative Risk, RR, small intestinal vs. intragastric: 0.75 (95% confidence interval 0.60 to 0.93); P=0.01; I2=11%). The point estimate was similar when only studies using microbiological data were included. Duration of ventilation (weighted mean difference: -0.36 days (-2.02 to 1.30); P=0.65; I2=42%), length of ICU stay (WMD: 0.49 days, (-1.36 to 2.33); P=0.60; I2=81%) and mortality (RR 1.01 (0.83 to 1.24); P=0.92; I2=0%) were unaffected by the route of feeding. While data were limited, and there was substantial statistical heterogeneity, there was significantly improved nutrient intake via the small intestinal route (% goal rate received: 11% (5 to 16%); P=0.0004; I2=88%). CONCLUSIONS Use of small intestinal feeding may improve nutritional intake and reduce the incidence of ICU-acquired pneumonia. In unselected critically ill patients other clinically important outcomes were unaffected by the site of the feeding tube.

Use of a concentrated enteral nutrition solution to increase calorie delivery to critically ill patients: a randomized, double-blind, clinical trial

BACKGROUND Critically ill patients typically receive ∼60% of estimated calorie requirements. OBJECTIVES We aimed to determine whether the substitution of a 1.5-kcal/mL enteral nutrition solution for a 1.0-kcal/mL solution resulted in greater calorie delivery to critically ill patients and establish the feasibility of conducting a multicenter, double-blind, randomized trial to evaluate the effect of an increased calorie delivery on clinical outcomes. DESIGN A prospective, randomized, double-blind, parallel-group, multicenter study was conducted in 5 Australian intensive care units. One hundred twelve mechanically ventilated patients expected to receive enteral nutrition for ≥2 d were randomly assigned to receive 1.5 (n = 57) or 1.0 (n = 55) kcal/mL enteral nutrition solution at a rate of 1 mL/kg ideal body weight per hour for 10 d. Protein and fiber contents in the 2 solutions were equivalent. RESULTS The 2 groups had similar baseline characteristics (1.5 compared with 1.0 kcal/mL). The mean (±SD) age was 56.4 ± 16.8 compared with 56.5 ± 16.1 y, 74% compared with 75% were men, and the Acute Physiology and Chronic Health Evaluation II score was 23 ± 9.1 compared with 22 ± 8.9. The groups received similar volumes of enteral nutrition solution [1221 mL/d (95% CI: 1120, 1322 mL/d) compared with 1259 mL/d (95% CI: 1143, 1374 mL/d); P = 0.628], which led to a 46% increase in daily calories in the group given the 1.5-kcal/mL solution [1832 kcal/d (95% CI: 1681, 1984 kcal/d) compared with 1259 kcal/d (95% CI: 1143, 1374 kcal/d); P < 0.001]. The 1.5-kcal/mL solution was not associated with larger gastric residual volumes or diarrhea. In this feasibility study, there was a trend to a reduced 90-d mortality in patients given 1.5 kcal/mL [11 patients (20%) compared with 20 patients (37%); P = 0.057]. CONCLUSIONS The substitution of a 1.0- with a 1.5-kcal/mL enteral nutrition solution administered at the same rate resulted in a 46% greater calorie delivery without adverse effects. The results support the conduct of a large-scale trial to evaluate the effect of increased calorie delivery on clinically important outcomes in the critically ill.

Practicalities of nutrition support in the intensive care unit: The usefulness of gastric residual volume and prokinetic agents with enteral nutrition

The provision of early nutrition therapy to critically ill patients is established as the standard of care in most intensive care units around the world. Despite the known benefits, tolerance of enteral nutrition in the critically ill varies and delivery is often interrupted. Observational research has demonstrated that clinicians deliver little more than half of the enteral nutrition they plan to provide. The main clinical tool for assessing gastric tolerance is gastric residual volume; however, its usefulness in this setting is debated. There are several strategies employed to improve the tolerance and hence adequacy of enteral nutrition delivery in the critically ill. One of the most widely used strategies is that of prokinetic drug administration, most commonly metoclopramide and erythromycin. Although there are new agents being investigated, none are ready for routine application in the critically ill and the benefits are still being established. This review investigates current practice and considers the literature on assessment of enteral tolerance and optimization of enteral nutrition in the critically ill.

Prevalence of Underprescription or Overprescription of Energy Needs in Critically Ill Mechanically Ventilated Adults as Determined by Indirect Calorimetry: A Systematic Literature Review.

BACKGROUND Underfeeding and overfeeding has been associated with adverse patient outcomes. Resting energy expenditure can be measured using indirect calorimetry. In its absence, predictive equations are used. A systematic literature review was conducted to determine the prevalence of underprescription and overprescription of energy needs in adult mechanically ventilated critically ill patients by comparing predictive equations to indirect calorimetry measurements. METHODS Ovid MEDLINE, CINAHL Plus, Scopus, and EMBASE databases were searched in May 2013 to identify studies that used both predictive equations and indirect calorimetry to determine energy expenditure. Reference lists of included publications were also searched. The number of predictive equations that underestimated or overestimated energy expenditure by ±10% when compared to indirect calorimetry measurements were noted at both an individual and group level. RESULTS In total, 2349 publications were retrieved, with 18 studies included. Of the 160 variations of 13 predictive equations reviewed at a group level, 38% underestimated and 12% overestimated energy expenditure by more than 10%. The remaining 50% of equations estimated energy expenditure to within ±10 of indirect calorimetry measurements. On an individual patient level, predictive equations underestimated and overestimated energy expenditure in 13-90% and 0-88% of patients, respectively. Differences of up to 43% below and 66% above indirect calorimetry values were observed. CONCLUSIONS Large discrepancies exist between predictive equation estimates and indirect calorimetry measurements in individuals and groups. Further research is needed to determine the influence of indirect calorimetry and predictive equation limitations in contributing to these observed differences.

Nutrition therapy in critically ill patients- a review of current evidence for clinicians

The provision of nutrition to critically ill patients is internationally accepted as standard of care in intensive care units (ICU). Nutrition has the potential to positively impact patient outcomes, is relatively inexpensive compared to other commonly used treatments, and is increasingly identified as a marker of quality ICU care. Furthermore, we are beginning to understand its true potential, with positive and deleterious consequences when it is delivered inappropriately. As with many areas of medicine the evidence is rapidly changing and often conflicting, making interpretation and application difficult for the individual clinician. This narrative review aims to provide an overview of the major evidence base on nutrition therapy in critically ill patients and provide practical suggestions.

Changes in the prevalence of lipodystrophy, metabolic syndrome and cardiovascular disease risk in HIV-infected men*

UNLABELLED Background Although it significantly improves HIV-related outcomes, some components of combination antiretroviral therapy (ART) cause lipodystrophy syndrome. The composition of combination ART has changed over time but the impact on lipodystrophy prevalence is unknown. METHODS One hundred HIV-infected males underwent dual-energy X-ray absorptiometry scanning, serum lipid testing and completed a questionnaire in a cross-sectional study in 2010. Thirty-four participants of a 1998 study cohort were re-evaluated in 2010. The same parameters were used to define and compare lipodystrophy, metabolic syndrome and cardiovascular disease (CVD) risk in the two time periods. RESULTS In 2010, the prevalence of lipodystrophy was lower when compared with 1998 (53% v. 69%, P=0.012), despite higher mean age (51.8 v. 42.1 years, P<0.0001), duration of HIV (165 v. 86 months, P<0.0001), ART exposure (129 v. 38 months, P<0.0001), CD4+ cell count (601 v. 374 cells µL(-1), P<0.0001) and waist circumference (95.5 v. 89.9cm P<0.0001). Cholesterol (5.0 v. 5.6mmolL(-1), P=0.0001) and triglycerides (1.9 v. 3.7mmolL(-1), P<0.0001) were significantly lower in 2010. Factors associated with an increased risk of lipodystrophy in 2010 were duration of HIV infection and low-density lipoprotein cholesterol, whereas current tenofovir or abacavir use was associated with a decreased risk of lipodystrophy. On multivariate analysis low-density lipoprotein cholesterol (OR, 2.65; CI, 1.4-4.9) remained significant for an increased risk and current tenofovir or abacavir use with reduced risk of lipodystrophy (OR, 0.096; CI, 0.011-0.83). In 2010 there was a higher prevalence of metabolic syndrome (33 v. 28%) and higher median Framingham CVD risk (9.9% (5.7-14.6) v. 8.2% (4.5-12.9). CONCLUSION Despite ageing and longer duration of HIV infection and ART exposure, the prevalence of lipodystrophy in HIV-infected men significantly declined over a 12-year period. However, a trend exists toward a higher prevalence of metabolic syndrome and increased CVD risk.

Nutritional therapy in patients with acute pancreatitis requiring critical care unit management: a prospective observational study in Australia and New Zealand.

Objective:To determine nutritional therapy practices of patients with severe acute pancreatitis (defined as those receiving critical care management in an intensive care unit or high-dependency unit) in Australia and New Zealand with focus on the choice of enteral nutrition or parenteral nutrition. Design:Prospective observational multicentered study performed at 40 sites in Australia and New Zealand over 6 months. Setting:Intensive care units or high-dependency units within Australia and New Zealand. Patients:Those with severe acute pancreatitis diagnosed by elevated lipase and/or amylase. Patients with chronic pancreatitis were excluded. Measurements:The primary outcome was the proportion of patients who received enteral nutrition, parenteral nutrition, or concurrent enteral nutrition/parenteral nutrition. Secondary outcomes included other aspects of nutritional therapy and the severity and clinical outcomes of acute pancreatitis. Measurements and Main Results:We enrolled 121 patients and 117 were analyzed. The mean age was 61 (sd 17) years and 53% were men. Enteral nutrition was delivered to 58 (50%; 95% confidence interval [CI], 41–59%) and parenteral nutrition to 49 (42%; 95% CI, 33–51%) patients. Parenteral nutrition was more frequently used as the initial therapy (58%; 95% CI, 49–67%) than enteral nutrition (42%; 95% CI, 33–51%). The most common reason for parenteral nutrition prescription was the treating doctors preference (60%). Enteral nutrition (74%) was more often used than parenteral nutrition (40%) on any individual study day. Concurrent enteral nutrition and parenteral nutrition occurred in 28 (24%) patients on 14% of days. Complications of acute pancreatitis requiring critical care unit management were observed in 45 (39%) patients. The median (interquartile range) duration of intensive care unit and hospital stay were 5 (2–10) and 19 (9–31) days, respectively. The hospital mortality rate was 15% (95% CI, 8–21%), and there was a tendency toward higher mortality for patients who only received parenteral nutrition than for those who only received enteral nutrition (28% vs. 7%, p = .06). Conclusions:For patients with acute pancreatitis requiring critical care unit management in Australian and New Zealand intensive care units, enteral nutrition is used most commonly, but parenteral nutrition is more often used as the initial route of nutritional therapy. Given that clinical practice guidelines currently recommend enteral nutrition as the initial route of nutritional therapy in severe acute pancreatitis, improved education about and dissemination of these guidelines seems warranted.

Energy Goals in the Critically Ill Adult: Annual Update in Intensive Care and Emergency Medicine 2011

The introduction of the mechanical ventilator in the 1950s and the development of intensive care in the 1960s permitted many patients to sustain their vegetative functions and survive severe injuries. Despite such advances, in many cases patients were found to suffer from altered states of consciousness which had never been encountered before as these patients would normally have died from apnea [1]. The imminent ethical impact of these profound states of unconsciousness was reflected in the composition of the first bioethical committees discussing the redefinition of life and the concept of therapeutic obstinacy. In 1968, the Ad Hoc Committee of Harvard Medical School published a milestone paper for the redefinition of death as irreversible coma and brain failure [2]. The committee was comprised of ten physicians, a theologian, a lawyer and a historian of science, betokening the medical, legal and societal debates that were to follow. We will here give a brief overview of some ethical issues related to the concept of consciousness and the medical management of patients with disorders of consciousness, such as comatose, vegetative and minimally conscious states that may be encountered in the intensive care setting. We will emphasize the problem of pain management and end-of life decision-making.

Identification of Malnutrition in Critically Ill Patients via the Subjective Global Assessment Tool: More Consideration Needed?

We read with interest the article by Bector and colleagues, ‘‘Does the Subjective Global Assessment Predict Outcome in Critically Ill Medical Patients?’’ We agree that identification of malnutrition and associated clinical outcomes in critically ill patients is important, but we would like to comment on the validity and feasibility of the Subjective Global Assessment (SGA) tool in this setting. First, conducting an SGA on a patient involves gathering (1) current weight and height, (2) a history of weight, diet, and gastrointestinal and functional status, and (3) assessment of muscle and fat stores. The authors stated that the dietitian in their study utilized a variety of techniques to deal with some of the challenges associated with obtaining an appropriate history from a mechanically ventilated patient to complete the tool. This included obtaining a history from family members. Although we understand that it is possible to attain an estimated weight, height, and weight history from a family member, we question the accuracy of obtaining detailed information regarding a history of dietary intake and gastrointestinal and functional status using this method. Could the authors please comment on the percentage of data that was provided by family members and discuss how obtaining a history in this way might affect the reliability of their results? Furthermore, were these data confirmed by the patient(s) when/if they were awake and able to communicate? And to what extent did the third-party data match the patients’ later reporting? This has important implications for the application by others of the approach to use the SGA proposed by the authors. Second, as highlighted by the authors, critically ill patients experience large fluid shifts, making it extremely challenging to measure actual weight and body composition or to identify physical signs of muscle and/or fat wasting. Furthermore, weight loss is masked by fluid retention. Sheean et al measured skeletal muscle cross-sectional area via computed tomography (containing third lumbar area) in a group of respiratory failure patients where nutrition status was assessed by the SGA tool. In this study, patients classified as normally nourished using SGA were found to have low muscularity, indicating that the SGA failed to accurately detect muscle wasting. Bector and colleagues do not appear to have validated the physical examination for muscle and fat stores in edematous patients. Third, the reported associations between SGA category and clinical outcomes were not adjusted for potential confounders including severity of illness. This is important to demonstrate the independence of the observed association between malnutrition assessed by SGA and clinical outcomes. We suggest that given the concerns about the inability of the SGA to quantify changes in nutritional status in the intensive care setting, there is a critical need for the development of valid objective tools to assess nutritional status and measure changes in body composition over the typical time frame of an intensive care unit stay.

What Happens to Nutrition Intake in the Post-Intensive Care Unit Hospitalization Period? An Observational Cohort Study in Critically Ill Adults.

BACKGROUND Little is currently known about nutrition intake and energy requirements in the post-intensive care unit (ICU) hospitalization period in critically ill patients. We aimed to describe energy and protein intake, and determine the feasibility of measuring energy expenditure during the post-ICU hospitalization period in critically ill adults. METHODS This is a nested cohort study within a randomized controlled trial in critically ill patients. After discharge from ICU, energy and protein intake was quantified periodically and indirect calorimetry attempted. Data are presented as n (%), mean (SD), and median (interquartile range [IQR]). RESULTS Thirty-two patients were studied in the post-ICU hospitalization period, and 12 had indirect calorimetry. Mean age and BMI was 56 (18) years and 30 (8) kg/m2 , respectively, 75% were male, and the median estimated energy and protein requirement were 2000 [1650-2550] kcal and 112 [84-129] g, respectively. Oral nutrition either alone (n = 124 days, 55%) or in combination with enteral nutrition (n = 96 days, 42%) was the predominant mode. Over 227 total days in the post-ICU hospitalization period, a median [IQR] of 1238 [869-1813] kcal and 60 [35-89.5] g of protein was received from nutrition therapy. In the 12 patients who had indirect calorimetry, the median measured daily energy requirement was 1982 [1843-2345] kcal and daily energy deficit was -95 [-1050 to 347] kcal compared with the measured energy requirement. CONCLUSIONS Energy and protein intake in the post-ICU hospitalization period was less than estimated and measured energy requirements. Oral nutrition provided alone was the most common mode of nutrition therapy.