Enteral Nutrition Administration
By Jennifer Doley, MBA, RD, CNSC, FAND
Today’s Dietitian
Vol. 26 No. 3 P. 30

Clearing Up Common Misconceptions for Optimal Patient Care

Enteral nutrition (EN) can supplement oral intake for individuals who can’t eat enough food to meet their nutritional needs, or it may be the sole source of nutrition for those who are nothing by mouth. Dysphagia is the most common condition that necessitates the use of EN, which may be caused by medical conditions such as stroke, Parkinson’s disease, amyotrophic lateral sclerosis, head and neck cancer, and multiple sclerosis. Other conditions that may require the use of EN include reduced level of consciousness and mechanical ventilation.

When sufficient oral intake isn’t possible, EN is preferred over parenteral nutrition (PN), as it helps maintain gut integrity by preventing gastrointestinal (GI) mucosal atrophy and permeability, supports immune function, and lowers costs of care. It’s therefore important that evidence-based practice is used to ensure EN tolerance is monitored appropriately and that withholding EN is limited as much as possible.

Although EN is a commonly used nutritional therapy, especially in the hospital setting, many misconceptions exist regarding when it should be started, how and when to advance to goal rate, and when it should be held. These misconceptions can result in prolonged inadequate nutritional intake and lead to malnutrition. Dispelling these misconceptions can ensure that patients receive sufficient EN to meet their nutritional needs to support healing and recovery.

This article discusses the most common misconceptions surrounding EN administration and provides evidence-based practice guidance for better patient outcomes.

Common Misconceptions
1. EN shouldn’t be started postoperatively until bowel sounds are present. This misconception arises from the concern that lack of bowel sounds indicates an ileus, a condition in which GI peristalsis is reduced or absent. However, lack of bowel sounds doesn’t necessarily indicate an ileus. Bowel sounds often may be sporadic or faint; one may need to listen to all four quadrants of the abdomen for several minutes before bowel sounds are heard. Bowel sounds are a result of motility only and aren’t indicative of gut permeability or absorption.

Regardless, even if bowel sounds are absent, early EN (or oral feeding) postoperatively has been shown to reduce the incidence of ileus, as gut motility returns more rapidly when stimulated by the presence of nutrients. Enteral feeding helps maintain immune function and gut integrity, which decreases the risk of bacterial translocation. Early feeding can enhance healing and, with presurgery carbohydrate loading, modulate insulin resistance postoperatively.1,2

EN or oral feeding may be withheld after GI surgery because of concerns for the integrity of the GI anastomosis following a resection; however, research has shown that early postoperative EN is safe. Studies have demonstrated either no difference or improved outcomes in surgical patients receiving EN vs PN. These benefits include fewer infectious and noninfectious complications, decreased length of stay, and reduced costs of care. However, EN should be withheld if anastomotic leaks occur.1,2

Early postoperative EN or oral feeding also has been shown to improve patient outcomes especially when included with other perioperative practices, often referred to as enhanced recovery after surgery (ERAS). Studies have confirmed that ERAS protocols should be the standard of care for many types of surgery patients, including GI, orthopedic, gynecologic, bariatric, and cardiac, among many others.1

2. EN shouldn’t be started in critically ill patients on vasopressor medications. Some critically ill patients experience septic shock resulting in hypotension, which often requires the use of vasopressor medications. In hypotensive states, the body prioritizes blood flow for the more vital organs like the heart and brain, thereby reducing vascular perfusion of the gut, which inhibits the gut’s ability to digest and absorb nutrients. Case reports have been published on patients with hypotension who suffered severe ischemia and necrosis of the bowel following EN administration. While this condition has a high mortality rate, studies have found bowel ischemia and necrosis to be rare in patients with septic shock receiving early EN, with a rate of 0.2 to 0.3%.3,4

Risk of bowel ischemia is much lower if blood pressure remains normal with the use of low-dose vasopressor medications, and the benefits of EN may outweigh those risks if EN isn’t otherwise contraindicated. Professional guidelines for nutrition support in critical care recommend initiation of EN when patients are hemodynamically stable: adequate blood perfusion, low and stable or decreasing doses of vasopressors, and stable or decreasing lactate levels. When EN is initiated, patients should be closely observed for signs that may indicate intolerance, such as pain, distension, decreased stooling, and bowel sounds. These recommendations are largely based on expert consensus, and further research on the safety and potential benefits of EN in patients with septic shock is needed.3

3. EN causes diarrhea in hospitalized patients. Diarrhea is a common GI symptom in many hospitalized patients and often is attributed to EN administration. However, diarrhea can occur for several reasons. Medications such as prokinetics, proton pump inhibitors, and those containing magnesium are common culprits. Medications in liquid form also can be problematic. Many in tablet and capsule form can’t or shouldn’t be crushed and dissolved with water and, therefore, can’t be administered via a feeding tube. Therefore, patients on EN are more likely to receive a liquid form of some medications, many of which contain sugar alcohols, such as sorbitol and mannitol, and are known to cause secretory diarrhea.5,6

Antibiotics are another common medication culprit; they can cause diarrhea directly as well as indirectly via altered GI flora. Long-term antibiotic use can increase the risk of Clostridium difficile infection, a primary symptom of which is diarrhea. Other causes include medical conditions or disease processes, such as small intestinal bacterial overgrowth and inflammatory bowel diseases, including Crohn’s disease and ulcerative colitis.6

EN doesn’t need to be held if patients experience diarrhea. Doing so can cause or worsen nutritional deficits. A common misconception is that diarrhea is an indication that patients aren’t absorbing the EN nutrients; however, GI losses from diarrhea are largely limited to water and electrolytes. The GI tract has tremendous absorptive capacity, and significant malabsorption is unlikely unless patients have short bowel syndrome, untreated pancreatic insufficiency, or other malabsorptive issues. If patients are at high risk of malabsorption, tests can be conducted while they continue to receive EN.6

If diarrhea occurs, an immediate change in the EN formula generally isn’t necessary. Changing the EN formula to one without fiber isn’t the best course of action, as fiber in the formula is unlikely to be the cause. Furthermore, the fiber in most EN formulas is a mix of soluble and insoluble; soluble fiber helps treat diarrhea as it absorbs water, making stool less liquid. Changing the EN formula to one that’s less concentrated also is unlikely to be beneficial. A common misconception is that hyperosmolar formulas draw fluid into the intestines, resulting in diarrhea. However, by the time the formula reaches the intestines, it already has been diluted by gastric and other GI secretions.5,6

If diarrhea occurs, EN should be continued while the cause is investigated. Treatment will be dependent on the reason and may include discontinuing or changing the form of the offending medication, treating infections, and/or the underlying disease. Antidiarrheal medications can be used if treatment of the primary suspected cause is insufficient to alleviate symptoms.6

4. EN should be held for high gastric residual volumes. Gastric residual volumes (GRVs) have long been considered a measure of EN tolerance; however, research has shown little correlation between GRVs and abdominal distention, as well as rates of pneumonia and aspiration. There’s no standard practice on how to measure GRVs nor an accepted definition of what’s considered “high.” Measured GRVs can vary depending on the patient’s position, as well as the position of the tube in the stomach. Stopping EN for an arbitrarily high GRV can lead to delays in reaching EN goal rates and result in an overall calorie and protein deficit. In addition, frequent GRV monitoring takes up valuable nursing time and can increase the risk of clogged feeding tubes.3,5,6

To monitor EN tolerance, other GI signs and symptoms should be assessed, including vomiting, abdominal distention, pain, and bloating. Just as it isn’t an indication of ileus, lack of bowel sounds without any other abdominal symptoms isn’t considered a sign of EN intolerance. Bowel function should be monitored closely, and efforts should be made to prevent and treat constipation or diarrhea.3,5,6

5. EN should be held if patients are in the prone position. Prone positioning, or placing patients on their stomachs, is a common treatment for acute respiratory distress syndrome and is now widely used to treat hospitalized patients with respiratory failure related to COVID-19 infection. Pronation schedules involve alternating periods of supination and pronation with periods of up to 16 hours in the prone position. Since a feeding tube can’t be placed while in the prone position, it should be inserted before positioning the patient. Once inserted, care should be taken to avoid dislodgment when repositioning.5,7,8

Considering the patient’s position and inability to raise the head of the bed greater than 30 degrees (as is recommended in gastric feeding), administering EN in prone patients raises concerns for poor GI tolerance and aspiration. Some studies have reported higher GRVs and more episodes of vomiting in enterally fed prone vs supine patients; however, others have reported minimal or no differences between these groups. Postpyloric feeding can help mitigate these concerns in high-risk patients. Prokinetic medications may be used to facilitate gastric emptying, and more concentrated EN formulas can be given to further reduce gastric volumes. Tilting the bed up to 25 to 30 degrees may help lessen the risk of aspiration.5,7,8

In high-risk patients unable to have a postpyloric feeding tube placed successfully, gastric EN may be held while they’re prone and resumed while supine, even if this results in patients not receiving their daily goal volume of formula. Research has shown that outcomes are similar in patients with acute respiratory distress syndrome who receive EN that meets full nutritional needs compared with EN at a lower rate in the first week of critical illness. If the full volume of EN can’t be given due to GI intolerance or inability to place a postpyloric feeding tube in high-risk patients, low-rate “trophic” EN feeding still provides the benefit of supporting gut integrity and immune function. There’s no standard definition of trophic feeding; however, it’s usually described as providing EN at 10 to 20 mL/hr. After the first week, if the patient can’t tolerate EN that provides 100% of their estimated energy needs, supplemental PN can be considered.5,7,8

6. EN should be held for 24 hours after PEG tube placement. Percutaneous endoscopic gastrostomy (PEG) tubes are used for long-term EN access and are frequently placed in hospitalized patients who are going home or to a lower level of care (eg, skilled nursing facility) with continued EN support. PEG tubes are placed endoscopically, so there are no concerns regarding a possible ileus or surgical incisions, as may be the case if a tube was placed during surgery. However, EN often is held for up to 24 hours after placement of a PEG tube, which can delay discharge or transfer to another facility. Research has demonstrated that earlier EN initiation of ≤4 hours after PEG tube placement is safe and isn’t associated with greater rates of complications such as vomiting and leakage. Some studies have shown that EN can be safely administered immediately after the patient has recovered from sedation that was given during the PEG placement procedure.5,9 Nutrition support guidelines now state that EN may be started within four hours after PEG tube placement.9

Evidence-Based Practice
Many individuals can’t safely consume food and therefore rely on EN to meet their nutritional needs. In the hospital setting, EN may be temporary but often necessary to give patients the best chance to heal and recover. Nevertheless, despite EN’s benefits over PN (or no nutrition), administration of EN often may be limited by misconceptions surrounding its assumed risks. EN administration should be informed by evidence and not based on outdated practices.

— Jennifer Doley, MBA, RD, CNSC, FAND, worked as a critical care dietitian specializing in nutrition support for many years. She’s currently a corporate malnutrition program manager with Morrison Healthcare. Previous roles include dietetic internship director and regional clinical nutrition manager.


1. Scott MJ, Baldini G, Fearon KC, et al. Enhanced recovery after surgery (ERAS) for gastrointestinal surgery, part 1: pathophysiological considerations. Acta Anaesthesiol Scand. 2015;59(10):1212-1231.

2. Weimann A, Braga M, Harsanyi L, et al. ESPEN guidelines on EN: surgery including organ transplantation. Clin Nutr. 2006;25(2):224-244.

3. McClave SA, Taylor BE, Martindale RG, et al. 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 of Parenteral and Enteral Nutrition (ASPEN). JPEN J Parenter Enteral Nutr. 2016;40(2):159-211.

4. Patel JJ, Shukla A, Heyland DK. Enteral nutrition in septic shock: a pathophysiological conundrum. JPEN J Parenter Enteral Nutr. 2021;45(S2):74-S78.

5. Zoeller S, Bechtold ML, Burns B, et al. Dispelling myths and unfounded practices about enteral nutrition. Nutr Clin Pract. 2020;35(2):196-204.

6. Parrish CR, McCray S. Enteral feeding myths and truths. Clin Nutr Pract. 2021;40(2):2-9.

7. Al-Dorzi HM, Arabi YM. Enteral nutrition safety with advanced treatments: extracorporeal membrane oxygenation, prone positioning, and infusion of neuromuscular blockers. Nutr Clin Pract. 2021;36(1):88-97.

8. Behrens S, Kozeniecki M, Knapp N, Martindale RG. Nutrition support during prone positioning: an old technique reawakened by COVID-19. Nutr Clin Pract. 2021;36(1):105-109.

9. Boullata JI, Carrera AL, Harvey L, et al. ASPEN safe practices for enteral nutrition therapy. JPEN J Parenter Enteral Nutr. 2017;41(1):15-103.