Stephen A. McClave

Guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient: Society of critical care medicine (SCCM) and American society for parenteral and enteral nutrition (A.S.P.E.N.)

This document represents the first collaboration between 2 organizations-the American Society for Parenteral and Enteral Nutrition and the Society of Critical Care Medicine-to describe best practices in nutrition therapy in critically ill children. The target of these guidelines is intended to be the pediatric critically ill patient (>1 month and 2-3 days in a PICU admitting medical, surgical, and cardiac patients. In total, 2032 citations were scanned for relevance. The PubMed/MEDLINE search resulted in 960 citations for clinical trials and 925 citations for cohort studies. The EMBASE search for clinical trials culled 1661 citations. In total, the search for clinical trials yielded 1107 citations, whereas the cohort search yielded 925. After careful review, 16 randomized controlled trials and 37 cohort studies appeared to answer 1 of the 8 preidentified question groups for this guideline. We used the GRADE criteria (Grading of Recommendations, Assessment, Development, and Evaluation) to adjust the evidence grade based on assessment of the quality of study design and execution. These guidelines are not intended for neonates or adult patients. The guidelines reiterate the importance of nutrition assessment-particularly, the detection of malnourished patients who are most vulnerable and therefore may benefit from timely intervention. There is a need for renewed focus on accurate estimation of energy needs and attention to optimizing protein intake. Indirect calorimetry, where feasible, and cautious use of estimating equations and increased surveillance for unintended caloric underfeeding and overfeeding are recommended. Optimal protein intake and its correlation with clinical outcomes are areas of great interest. The optimal route and timing of nutrient delivery are areas of intense debate and investigations. Enteral nutrition remains the preferred route for nutrient delivery. Several strategies to optimize enteral nutrition during critical illness have emerged. The role of supplemental parenteral nutrition has been highlighted, and a delayed approach appears to be beneficial. Immunonutrition cannot be currently recommended. Overall, the pediatric critical care population is heterogeneous, and a nuanced approach to individualizing nutrition support with the aim of improving clinical outcomes is necessary.

Enteral tube feeding in the intensive care unit: factors impeding adequate delivery.

OBJECTIVE To evaluate those factors that impact on the delivery of enteral tube feeding. DESIGN Prospective study. SETTING Medical intensive care units (ICU) and coronary care units at two university-based hospitals. PATIENTS Forty-four medical ICU/coronary care unit patients (mean age, 57.8 yrs; 70% male) who were to receive nothing by mouth and were placed on enteral tube feeding. INTERVENTIONS Rate of enteral tube feeding ordered, actual volume delivered, patient position, residual volume, flush volume, presence of blue food coloring in oropharynx, and stool frequency were recorded every 4 hrs. Duration and reason for cessation of enteral tube feeding were documented. MEASUREMENTS AND MAIN RESULTS Physicians ordered a daily mean volume of enteral tube feeding that was 65.6% of goal requirements, but an average of only 78.1% of the volume ordered was actually infused. Thus, patients received a mean volume of enteral tube feeding for all 339 days of infusion that was 51.6% of goal (range, 15.1% to 87.1%). Only 14% of patients reached > or = 90% of goal feeding (for a single day) within 72 hrs of the start of enteral tube feeding infusion. Of 24 patients weighed before and after, 54% were noted to lose weight on enteral tube feeding. Declining albumin levels through the enteral tube feeding period correlated significantly with decreasing percent of goal calories infused (p = .042; r2 = .13). Diarrhea occurred in 23 patients (52.3%) for a mean 38.2% of enteral tube feeding days. In >1490 bedside evaluations, patients were observed to be in the supine position only 0.45%, residual volume of >200 mL was found 2.8%, and blue food coloring was found in the oropharynx 5.1% of the time. Despite this, cessation of enteral tube feeding occurred in 83.7% of patients for a mean 19.6% of the potential infusion time. Sixty-six percent of the enteral tube feeding cessations was judged to be attributable to avoidable causes. CONCLUSIONS The current manner in which enteral tube feeding is delivered in the ICU results in grossly inadequate nutritional support. Barely one half of patient caloric requirements are met because of underordering by physicians and reduced delivery through frequent and often inappropriate cessation of feedings.

Comparison of the safety of early enteral vs parenteral nutrition in mild acute pancreatitis.

BACKGROUND This prospective study was designed to compare the safety, efficacy, cost, and impact on patient outcome of early total enteral nutrition (TEN) vs total parenteral nutrition (TPN) in acute pancreatitis. METHODS Patients admitted with acute pancreatitis or an acute flare of chronic pancreatitis, characterized by abdominal pain and elevated serum amylase and lipase, were randomized to receive either isocaloric and isonitrogenous TEN (via a nasojejunal feeding tube placed endoscopically) or TPN (via a central or peripheral line) started within 48 hours of admission. RESULTS Thirty patients were studied over 32 admissions (TEN given on 16 and TPN on 16) for acute pancreatitis. There were no differences on admission in mean age, Ranson criteria, multiple organ failure score (MOF), or APACHE III score between TEN and TPN groups. Although slower to approach goal feeding over the first 72 hours of admission, TEN patients received 71.3% goal calories by day 4 vs 85.2% for TPN patients (not significant). There were no deaths and no differences between groups in serial pain scores, days to normalization of amylase, days to diet by mouth, serum albumin levels, or percent nosocomial infection. However, the mean cost of TPN per patient was over four times greater than that for TEN (

Guidelines for the Provision and Assessment of Nutrition Support Therapy in the Adult Critically Ill Patient: Society of Critical Care Medicine (sccm) and American Society for Parenteral and Enteral Nutrition (a.s.p.e.n.)

3294 vs

Poor validity of residual volumes as a marker for risk of aspiration in critically ill patients.

761, respectively, p < .001). Mean serial Ranson criteria, APACHE III, and MOF scores recorded every 2 to 3 days decreased in the TEN group, whereas those in the TPN group increased. Only the difference in the third Ranson criteria (mean 6.3 days after admission) for the TEN and TPN groups (0.5 vs 2.8, respectively) reached statistical significance (p = .002). Stress-induced hyperglycemia was worse in the TPN group, as serum glucose levels increased significantly over the first 5 days of hospitalization (p < .02), whereas those in the TEN group showed no significant change. An exacerbation of pancreatitis, occurring in one TEN patient when the nasojejunal tube was dislodged into the stomach, resolved after placement back in the jejunum. Three patients who became asymptomatic and normalized amylase on TEN flared upon advancing to diet by mouth. CONCLUSIONS TEN for acute pancreatitis is as safe and effective, but is significantly less costly than TPN. Compared with TPN, TEN may promote more rapid resolution of the toxicity and stress response to pancreatitis. TEN via jejunal feeding should be used preferentially in this disease setting.

North American Summit on Aspiration in the Critically Ill Patient: Consensus Statement

A.S.P.E.N. and SCCM are both nonprofit organizations composed of multidisciplinary healthcare professionals. The mission of A.S.P.E.N. is to improve patient care by advancing the science and practice of clinical nutrition and metabolism. The mission of SCCM is to secure the highest quality care for all critically ill and injured patients. Guideline Limitations: These A.S.P.E.N.−SCCM Clinical Guidelines are based on general conclusions of health professionals who, in developing such guidelines, have balanced potential benefits to be derived from a particular mode of medical therapy against certain risks inherent with such therapy. However, practice guidelines are not intended as absolute requirements. The use of these practice guidelines does not in any way project or guarantee any specific benefit in outcome or survival. The judgment of the healthcare professional based on individual circumstances of the patient must always take precedence over the recommendations in these guidelines. The guidelines offer basic recommendations that are supported by review and analysis of the current literature, other national and international guidelines, and a blend of expert opinion and clinical practicality. The population of critically ill patients in an intensive care unit (ICU) is not homogeneous. Many of the studies on which the guidelines are based are limited by sample size, patient heterogeneity, variability in disease severity, lack of baseline nutritional status, and insufficient statistical power for analysis. Periodic Guideline Review and Update: This particular report is an update and expansion of guidelines published by A.S.P.E.N. and SCCM in 2009 (1). Governing bodies of both A.S.P.E.N. and SCCM have mandated that these guidelines be updated every three to five years. The database of randomized controlled trials (RCTs) that served as the platform for the analysis of the literature was assembled in a joint “harmonization process” with the Canadian Clinical Guidelines group. Once completed, each group operated separately in their interpretation of the studies and derivation of guideline recommendations (2). The current A.S.P.E.N. and SCCM guidelines included in this paper were derived from data obtained via literature searches by the authors through December 31, 2013. Although the committee was aware of landmark studies published after this date, these data were not included in this manuscript. The process by which the literature was evaluated necessitated a common end date for the search review. Adding a last-minute landmark trial would have introduced bias unless a formalized literature search was re-conducted for all sections of the manuscript. Target Patient Population for Guideline: The target of these guidelines is intended to be the adult (≥ 18 years) critically ill patient expected to require a length of stay (LOS) greater than 2 or 3 days in a medical ICU (MICU) or surgical ICU (SICU). The current guidelines were expanded to include a number of additional subsets of patients who met the above criteria, but were not included in the previous 2009 guidelines. Specific patient populations addressed by these expanded and updated guidelines include organ failure (pulmonary, renal, and liver), acute pancreatitis, surgical subsets (trauma, traumatic brain injury [TBI], open abdomen [OA], and burns), sepsis, postoperative major surgery, chronic critically ill, and critically ill obese. These guidelines are directed toward generalized patient populations but, like any other management strategy in the ICU, nutrition therapy should be tailored to the individual patient. Target Audience: The intended use of these guidelines is for all healthcare providers involved in nutrition therapy of the critically ill, primarily physicians, nurses, dietitians, and pharmacists. Methodology: The authors compiled clinical questions reflecting key management issues in nutrition therapy. A committee of multidisciplinary experts in clinical nutrition composed of physicians, nurses, pharmacists, and dietitians was jointly convened by the two societies.

Early diagnosis of columnar-lined esophagus: a new endoscopic diagnostic criterion

Background and Aims:Elevated residual volumes (RV), considered a marker for the risk of aspiration, are used to regulate the delivery of enteral tube feeding. We designed this prospective study to validate such use. Methods:Critically ill patients undergoing mechanical ventilation in the medical, coronary, or surgical intensive care units in a university-based tertiary care hospital, placed on intragastric enteral tube feeding through nasogastric or percutaneous endoscopic gastrostomy tubes, were included in this study. Patients were fed Probalance (Nestlé USA) to provide 25 kcal/kg per day (to which 109 yellow microscopic beads and 4.5 mL of blue food coloring per 1,500 mL was added). Patients were randomized to one of two groups based on management of RV: cessation of enteral tube feeding for RV >400 mL in study patients or for RV >200 mL in controls. Acute Physiology and Chronic Health Evaluation (APACHE) III, bowel function score, and aspiration risk score were determined. Bedside evaluations were done every 4 hrs for 3 days to measure RV, to detect blue food coloring, to check patient position, and to collect secretions from the trachea and oropharynx. Aspiration/regurgitation events were defined by the detection of yellow color in tracheal/oropharyngeal samples by fluorometry. Analysis was done by analysis of variance, Spearman’s correlation, Student’s t-test, Tukey’s method, and Cochran-Armitage test. Results:Forty patients (mean age, 44.6 yrs; range, 18–88 yrs; 70% male; mean APACHE III score, 40.9 [range, 12–85]) were evaluated (21 on nasogastric, 19 on percutaneous endoscopic gastrostomy feeds) and entered into the study. Based on 1,118 samples (531 oral, 587 tracheal), the mean frequency of regurgitation per patient was 31.3% (range, 0% to 94%), with a mean RV for all regurgitation events of 35.1 mL (range, 0–700 mL). The mean frequency of aspiration per patient was 22.1% (range, 0% to 94%), with a mean RV for all aspiration events of 30.6 mL (range, 0–700 mL). The median RV for both regurgitation and aspiration events was 5 mL. Over a wide range of RV, increasing from 0 mL to >400 mL, the frequency of regurgitation and aspiration did not change appreciably. Aspiration risk and bowel function scores did not correlate with the incidence of aspiration or regurgitation. Blue food coloring was detected on only three of the 1,118 (0.27%) samples. RV was ≤50 mL on 84.1% and >400 mL on 1.4% of bedside evaluations. Sensitivities for detecting aspiration per designated RV were as follows: 400 mL = 1.5%; 300 mL = 2.3%; 200 mL = 3.0%; and 150 mL = 4.5%. Low RV did not assure the absence of events, because the frequency of aspiration was 23.0% when RV was <150 mL. Raising the designated RV for cessation of enteral tube feeding from 200 mL to 400 mL did not increase the risk, because the frequency of aspiration was no different between controls (21.6%) and study patients (22.6%). The frequency of regurgitation was significantly less for patients with percutaneous endoscopic gastrostomy tubes compared with those with nasogastric tubes (20.3% vs. 40.7%, respectively; p = .046). There was no correlation between the incidence of pneumonia and the frequency of regurgitation or aspiration. Conclusions:Blue food coloring should not be used as a clinical monitor. Converting nasogastric tubes to percutaneous endoscopic gastrostomy tubes may be a successful strategy to reduce the risk of aspiration. No appropriate designated RV level to identify aspiration could be derived as a result of poor sensitivity over a wide range of RV. Study results do not support the conventional use of RV as a marker for the risk of aspiration.

Use of residual volume as a marker for enteral feeding intolerance: prospective blinded comparison with physical examination and radiographic findings.

Aspiration is the leading cause of pneumonia in the intensive care unit and the most serious complication of enteral tube feeding (ETF). Although aspiration is common, the clinical consequences are variable because of differences in nature of the aspirated material and individual host responses. A number of defense mechanisms normally present in the upper aerodigestive system that protect against aspiration become compromised by clinical events that occur frequently in the critical care setting, subjecting the patient to increased risk. The true incidence of aspiration has been difficult to determine in the past because of vague definitions, poor assessment monitors, and varying levels of clinical recognition. Standardization of terminology is an important step in helping to define the problem, design appropriate research studies, and develop strategies to reduce risk. Traditional clinical monitors of glucose oxidase strips and blue food coloring (BFC) should no longer be used. A modified approach to use of gastric residual volumes and identification of clinical factors that predispose to aspiration allow for risk stratification and an algorhythm approach to the management of the critically ill patient on ETF. Although the patient with confirmed aspiration should be monitored for clinical consequences and receive supportive pulmonary care, ETF may be continued when accompanied by appropriate steps to reduce risk of further aspiration. Management strategies for treating aspiration pneumonia are based on degree of diagnostic certainty, time of onset, and host factors.

Complications of enteral access

The relationship between the proximal margins of the gastric mucosal folds and the squamocolumnar mucosal junction (SCMJ) in normal subjects and in patients with columnar-lined esophagus (CLE) was studied. Results indicate that in the normal esophagus, the SCMJ is located within 2 cm of the proximal margin of the gastric folds. The proximal margin of the gastric folds in a hiatal hernia pouch provide a fixed, reproducible, anatomic landmark at endoscopy, which designates the junction of the muscular wall of the esophagus and stomach and permits one to predict the expected normal location of the SCMJ. The diagnosis of CLE should be considered at endoscopy when either the SCMJ is located or columnar epithelium is obtained by biopsy at a site greater than 2 cm above the proximal margin of the gastric folds located within a hiatal hernia pouch. This study provides an endoscopic criterion to permit a more accurate diagnosis of CLE in its earliest stages and may permit a better assessment of its prevalence.

Invited Review: Use of Indirect Calorimetry in Clinical Nutrition

High gastric residual volumes (RVs) are a frequent cause for cessation of total enteral nutrition (TEN). This study was designed to determine the RV that indicates intolerance or inadequate gastric emptying and to compare the RV findings in a blinded fashion with those findings obtained on physical examination and radiography. Twenty healthy normal volunteers (HNV), 8 stable patients with gastrostomy tubes (GTP), and 10 critically ill patients (CIP) were evaluated prospectively for 8 hours while receiving TEN. No subjects were clearly intolerant (ie, vomiting, aspiration). Of the total RVs recorded, 13.1% were greater than or equal to 150 mL in the CIP group, whereas only 2.4% of the RVs were greater than or equal to 150 mL in the HNV group. None of the RVs in the GTP group were greater than or equal to 150 mL. Objective scores on physical examination failed to correlate with RV (p = .397), as did objective scores on radiography (p = .742). However, objective scores on physical examination were significantly related to scores on radiography (p = .016). Abnormal physical examination findings were found in 4 out of 11 patients (GTP + CIP) with RVs less than 100 mL and in 6 out of 7 with RVs greater than or equal to 100 mL. Abnormal radiographic results were found in 6 out of 11 patients with RVs less than 100 mL, in 7 out of 7 patients with RVs greater than or equal to 100 mL, and in 4 out of 20 HNVs. There was no difference in RVs obtained from the supine or right lateral decubitus positions.(ABSTRACT TRUNCATED AT 250 WORDS)