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Enteral nutrition is nutrition delivered using the gut. This can refer to oral, gastric, or postpyloric feeds. There are many indications requiring a feeding tube to deliver nutrition or hydration. This is known as tube feeding, enteral feeding, or gavage. Advantages of enteral nutrition over parenteral nutrition include safety, effectiveness, decreased risk of infection, decreased cost, prevention of gut atrophy, and preservation of the gut's barrier function. Enteral tube feeding is indicated in patients who cannot maintain adequate oral intake of food or nutrition to meet their metabolic demands. This activity reviews the indications, contraindications, and methodology of enteral feedings and highlights the interprofessional team's role in caring for patients requiring enteral nutrition. Objectives: Identify the anatomical importance of enteric feeding. Determine the equipment required for enteric feeding. Assess the potential complications of enteric feeding. Communicate a structured interprofessional team approach to provide effective care and appropriate surveillance for patients requiring enteral nutrition. Access free multiple choice questions on this topic.

Enteral nutrition uses the gastrointestinal tract to supply nutrients. This can be accomplished by feeding by mouth or through a feeding tube. Advantages of enteral nutrition over parenteral nutrition include safety, effectiveness, decreased risk of infection, decreased cost, prevention of gut atrophy, and preservation of the gut's barrier function. Artificial nutrition refers to providing or supplementing daily metabolic nutrition requirements in patients with contraindications to feeding through the mouth or those with inadequate oral intake. Artificial nutrition is provided through parental or enteral access. Parenteral nutrition is provided through a large vein in the central venous system. Enteral nutrition uses the gastrointestinal (GI) tract to provide nutrition. Enteral access can be obtained by passing a feeding tube through the nose (nasogastric and nasojejunal) and mouth (orogastric) at the bedside. It can also be achieved by surgically implanting a feeding tube into the gut, such as a feeding gastrostomy (stomach) or a feeding jejunostomy (jejunum). Historically, enteral nutrition has not been as well emphasized as parenteral nutrition because of the belief that many disease states prevent the gut from normal absorptive function. However, enteral nutrition is well tolerated even in severe disease states in critically ill patients. Moreover, enteral nutrition has been associated with reduced infectious complications, lower costs, and reduced length of hospital stay.[1]

Tube-Related Mechanical Complication Tube placement for enteral feeding might cause mechanical complications. Some mechanical complications from tube feeding are listed below. Tube malposition Tube obstruction Accidental dislodgment of tube Breakage of the feeding tube Leakage of the feeding tube Erosion and ulceration near the site of insertion Intestinal obstruction Bleeding Tube for enteral feeding can be inserted nasally through the guided percutaneous application or surgical technique. Nasoenteral insertion is mostly done blindly by the bedside, with about 0.5% to 16% mispositioning in the pleura, trachea, or bronchial trees. This can cause the infusion of enteral feeds in the tracheobronchial tree, causing a pulmonary abscess or pneumothorax.[29] Installing air or auscultation is not an accurate method for determining proper tube placement. The best confirmation is with radiography.[30][30] The failure of bedside nasoenteral tube placement indicates fluoroscopy or endoscopy-guided tube insertion. Infectious Complications Infection at the site of tube insertion Aspiration pneumonia Ear and nasopharyngeal infection Infective gastroenteritis with diarrhea Peritonitis Tube placement in enteral feeding is sometimes associated with the abovementioned infectious processes. Aspiration pneumonia is reported in 89% of patients on enteral feeding with no clear benefit of gastroenteric feeding over nasogastric. Distal duodenal or jejunal feeding might prevent the regurgitation of enteral feeds.[30] Complications from the enteral feeding tube also depend on the following: The size of the tube The tube material The diameter of the tube Spark et al. critically reviewed pulmonary complications from gastroenteric tube placement. In 9931 cases of tube placement, there was 1.9% (187) malposition in the tracheobronchial tree. The 187 misplaced tubes resulted in 35 pneumothoraxes (18.7%) with at least 5 mortalities.[31] Gastrointestinal Complications Enteral feeding is associated with several GI complications Nausea and vomiting Diarrhea Constipation Cramps and bloating Regurgitation and aspiration Nausea Nausea and vomiting are common after the initiation of enteral feeding, about 20% to 30%. Non-occlusive bowel necrosis and aspiration can also occur. This is associated with high mortality.[32][33] Diarrhea

Enteral feeding is associated with several GI complications Nausea and vomiting Diarrhea Constipation Cramps and bloating Regurgitation and aspiration Nausea Nausea and vomiting are common after the initiation of enteral feeding, about 20% to 30%. Non-occlusive bowel necrosis and aspiration can also occur. This is associated with high mortality.[32][33] Diarrhea This is the most gastrointestinal complication seen in enteral feeding. Diarrhea occurs in about 30% of patients admitted to the medical or surgical wards and about 80% of patients in the ICU.[28][34][35] Diarrhea in enteral feeding is a result of many factors. Using antibiotics and other medications in enteral feeding is a common cause of diarrhea—medications like antacids, oral magnesium or phosphate, antacids, and prokinetic agents. Oral and intravenous antibiotics can also favor the growth of Clostridium difficile, Escherichia coli, and Klebsiella. The sorbitol-containing solution can also trigger profuse diarrhea in patients on enteral feeding. Using fiber based on the meta-analysis result can significantly reduce the incidence of enteral feeding-associated diarrhea, especially in high-risk, post-surgically, and critically ill patients. Constipation This is a less common complication associated with enteral feeding. Constipation is more common in patients on long-term enteral feeds. Some studies suggest that fiber supplementation might help reduce the percentage of patients reporting constipation in enteral feeding. Aspiration Pneumonia This is a potentially life-threatening complication from enteral feeding. It occurs because of the aspiration of oral secretion or gastric secretions with enteric secretions. Aspiration is more common when patients are fed via a nasogastric tube in a supine position.[36][37] The cause of aspiration pneumonia in enteral feeding is multifactorial. Gravitational backflow Lower esophageal sphincter impairment Infrequent contract of the esophagus The presence of a tube near the gastric cardia Impaired level of consciousness Poor gag and cough reflexes are seen in neurologically impaired patients with stroke or dementia [38] To prevent aspiration, place the enteral feeding tube about 40 cm distal to the ligament of Treitz. This applies to patients with a higher risk of aspiration.[39][40] Metabolic Complications

The presence of a tube near the gastric cardia Impaired level of consciousness Poor gag and cough reflexes are seen in neurologically impaired patients with stroke or dementia [38] To prevent aspiration, place the enteral feeding tube about 40 cm distal to the ligament of Treitz. This applies to patients with a higher risk of aspiration.[39][40] Metabolic Complications Enteral feeding is associated with metabolic complications. A common complication seen in malnourished patients is refeeding syndrome. This phenomenon was first described in Far East prisoners during the Second World War.[41][42][43] Patients with anorexia nervosa, hyperemesis, alcoholism, and malabsorption syndrome like short bowel syndrome who are started on enteral feeding are prone to refeeding syndrome. The pathophysiology of the refeeding syndrome is still poorly understood. In starvation, the cellular membrane system downregulates with the loss of intracellular potassium, phosphorus, magnesium, and calcium. The total body content of these ions is depleted. The cell's intake of sodium and water is also increased. The sudden reversal of malnutrition with enteral feeding is due to the cell's uptake of potassium, phosphorus, magnesium, and calcium back with the simultaneous movement of water and sodium out of the cells. The undernourished kidney is also impaired and cannot handle the sodium and water load. Hypophosphataemia is the hallmark of refeeding syndrome. Hypophosphatemia can cause rhabdomyolysis, cardiac failure, arrhythmia, muscular weakness, leukocyte dysfunction, seizure, coma, and sudden death.[44] The phenomenon is more common in enteral than parenteral feeding.[45] Awareness of the syndrome is the key to treatment and prevention. Patients at Risk for Re-feeding Syndrome Chronic alcoholism Anorexia nervosa Postoperative patients Elderly patients Prolonged fasting Morbid obesity associated with profound weight loss Malabsorption syndrome: Cystic fibrosis, inflammatory bowel disease, and short bowel syndrome[46] To manage refeeding syndrome, the patient's cardiovascular status should be monitored closely, preferably in the ICU. Judicious monitoring of electrolytes and micronutrients should also be implemented. Goal caloric intake should target about 50% to 75% of daily requirements. Body Weight Less than 7 years: 80 to 100kcal/kg body weight per day Seven to 10 years: 80 to 100kcal/kg body weight per day

To manage refeeding syndrome, the patient's cardiovascular status should be monitored closely, preferably in the ICU. Judicious monitoring of electrolytes and micronutrients should also be implemented. Goal caloric intake should target about 50% to 75% of daily requirements. Body Weight Less than 7 years: 80 to 100kcal/kg body weight per day Seven to 10 years: 80 to 100kcal/kg body weight per day Eleven to 14 years: 60 kcal/kg body weight per day Fifteen to 18 years: 50kcal/kg body weight per day Older than 18 years: 25 kcal/kg body weight per day, an average of 1000 kcal per day initially Thiamine, riboflavin, folic acid, and pyridoxine should be supplemented, including fat-soluble vitamins A, D, E, and K. Minerals Sodium should be restricted, I mmol/kg of body weight per day or 1.5 g per day, but an adequate amount of phosphorus, magnesium, and potassium should be given. Magnesium (0.8 to 1.6mmol/L) For hypomagnesemia, start at 0.5 mmol/kg per day over 24 hours, then 0.25 mmol/kg of body weight per day for 5 days Maintenance 0.2 mmol/kg per day intravenous or 0.5 mmol/kg per day oral Hypophosphatemia A normal range is 0.85 per 1.40mmol/L For mild hypophosphatemia (0.6 to 0.85 mmol/L), start at 0.3 to 0.6 mmol/kg of body weight per day For moderate hypophosphatemia (0.3 to 0.6 mmol/L), start at 0.3 to 0.6 mmol/kg of body weight per day In less than 0.3 mmol/L of severe hypophosphatemia, give IV sodium or potassium phosphate 0.8 mmol/kg of body weight in half normal saline over 12 to 24 hours.[47][48] Complications Associated with PEG Placement Peristomal Wound Infection Wound infection occurs after PEG placement with an incidence of about 3 to 70%. The technique of placement, obesity, malnutrition, steroid, or immunosuppressive therapy can cause wound site infection. Prophylactic antimicrobial therapy has been shown to reduce the incidence of wound infection after placement of PEG. First-generation cephalosporins or penicillin give adequate coverage.[49][50][51] Clogged Feeding Tube

Wound infection occurs after PEG placement with an incidence of about 3 to 70%. The technique of placement, obesity, malnutrition, steroid, or immunosuppressive therapy can cause wound site infection. Prophylactic antimicrobial therapy has been shown to reduce the incidence of wound infection after placement of PEG. First-generation cephalosporins or penicillin give adequate coverage.[49][50][51] Clogged Feeding Tube The clogging of feeding tubes can be as high as 25%. Clogging occurs when very thick feeds and medications are delivered through a relatively thin tube. Repeated gastric aspiration is discouraged since the low pH of gastric fluid can promote protein coagulation.[52] After delivering thick feeds or medications, the feeding tube should be flushed with about 40 to 50 mL of water. A clogged feeding tube can also be cleared mechanically using various endoscopic catheters, braided quid wires, or plastic brushes. Peristomal Leakage This is also a complication of PEG tube placement for enteral feeding. Several factors can contribute to leakage. Excessive pulling, tugging, and increased gastric secretion inhibit wound healing, like malnutrition, diabetes, and immunodeficiency. This can be prevented using antisecretory agents like proton pump inhibitors (PPI). Skin protectants and barrier creams can also be used. Bleeding The incidence of bleeding is about 2.5% after placement of PEG.[53][54] This might be secondary to mucosal tears or damage to a local vessel. Risk factor for bleeding includes the use of antiplatelet or anticoagulation therapy. Based on the current recommendations, aspirin can be continued in high-risk patients. Warfarin is recommended to be discontinued, and unfractionated heparin can be used as a bridge.[54] Colonic Fistulae Misplacement of PEG for enteral feeding might lead to the formation of gastrocolic, colocutaneous, and gastro colocutaneous fistulae. A gastrocolic fistula connects the wall of the stomach and the colon. Gastro colocutaneous fistula is an epithelial connection between the wall of the stomach, colon, and skin that can occur because of iatrogenic puncture or direct erosion of the PEG into the colon wall and the skin.[55][32][56][57][58]

Misplacement of PEG for enteral feeding might lead to the formation of gastrocolic, colocutaneous, and gastro colocutaneous fistulae. A gastrocolic fistula connects the wall of the stomach and the colon. Gastro colocutaneous fistula is an epithelial connection between the wall of the stomach, colon, and skin that can occur because of iatrogenic puncture or direct erosion of the PEG into the colon wall and the skin.[55][32][56][57][58] The gastroscope should be transilluminated through the anterior abdominal wall to prevent colonic misplacement. The endoscopically visible imprint of a finger or needle is considered a “condition sine qua non” before introducing the needle through the stomach.[59] Clinically, a fistula is associated with watery diarrhea around the site of the PEG or stool around the site of insertion of the PEG. In rare instances, fistulae formation can cause peritonitis, infection, or fasciitis. Injection of contrast into the PEG can establish the diagnosis. Management can be conservative with removing PEG and awaiting the spontaneous fistulae closure. For more severe cases, endoscopic intervention or invasive laparotomy with colonic exploration might be necessary. Pneumoperitoneum This can occur in 8% to 18% of PEG tube placements.[60][61][62][27] This is a relatively benign condition that does not warrant any intervention.

Improving the outcome of enteral feeding requires an interprofessional approach. Enteral feeding involves coordination among the nutritional support team. The nutrition support team is made up of the following: Clinician Nutrition nurse specialist Dietician Pharmacist The clinician coordinates and directs the care related to enteral feeding. The clinician determines the optimal feeding regimen for the patient. A nutrition nurse specialist is primarily responsible for educating the patient on using the feeding tube. The nurse also supervises the tube care and notifies the clinician if any complications develop. The dietician manages the evaluation of the nutritional requirements, including the calculation of the daily caloric need and the optimal fluid requirements. The pharmacist provides the enteral feed and can mix and compound parenteral nutrition. The pharmacist advises on the compatibility of nutrients and interaction. Other ancillary staff include the social worker, physical, occupational, and speech therapists, as well as a case manager, who helps arrange home supplies.[64] Care coordination, open communication, and accurate patient record-keeping are all aspects of the interprofessional care model that drive optimal patient outcomes.