Tube feeding positionVolumeOsmolalityFractionationAdministration timeStomachAllows high-volume supplyHyperosmolar solutions are tolerated, but the higher solution osmolality the slower stomach emptyingDepends on the total volume/day and patient tolerance. Lower fractionation (four to six times per day) and higher volume in each supply may be usedAbout 120 drops per min (or time (min) = total volume (ml)/6) from the beginning of therapyPostpyloricDuring intermittent supply, the volume should not exceed 300 ml h− 1 in adapted patientsBetter tolerance for formulations with less than 550 mOsm l− 1; dripping of hyperosmolar solutions should be strictly controlled by using infusion pumpContinuous or intermittent fractionation, generally between six and eight supplies per day in each 3 hInitial phase: 60 drops/min (or time (min) = total volume (ml)/3); ‘adapted’ phase: 120 drops per min (or time (min) = total volume (ml)/6) Show
Enteral formulations should be nutritionally complete when used as exclusive nutrition or as a supplement to patients with normal oral ingestion; or nutritionally incomplete when used only as a supplement nutrition. The evaluation of the digestive and absorptive capacity of the patient should be performed for better enteral formula selection (Scheme 2).  Scheme 2. Planning for selection of enteral diets. Several enteral formulations are based on fresh food, processed food, or both fresh and processed food. Therefore, nutrients comprising EN are generally the same constituents of a normal diet, consumed by the oral route, including carbohydrate (40–60% total energy needs), protein (14–20% total energy needs), fat (15–30% energy needs), and fiber (40–20 g l− 1). Different factors should be considered to facilitate the choice of the most appropriate enteral formulation for patients with EN indication, such as caloric density, osmolarity and osmolality, administration pathway, source and complexity of nutrients, and disease. The EN caloric density (kcal ml− 1) should be based on the patient’s total calorie needs versus the volume of enteral diets to be administered per day. Enteral diets with higher energy density have a lower amount of water, which can range from 690 to 860 ml l− 1 diet. The categorization of enteral formulas, according to its energy density, is shown in Table 3. Table 3. Categorization of enteral formulas according to its energy density Energy densityValue (kcal ml− 1)FormulaVery low< 0.6Sharply hypocaloricLow0.6–0.8HypocaloricStandard0.9–1.2NormocaloricHigh1.3–1.5HypercaloricVery high> 1.5Sharply hypercaloric Vitamin and mineral supply varies according to the specific needs of the patients and their disease. In the specific nutritional needs, you should evaluate the indication of additional micronutrient supplementation, even when the formulation, per se, achieves those values recommended by the Recommended Dietary Allowance (RDA). Clinical nutritional patient evaluation should include objective and/or subjective indicators to identify, as early as possible, any risk of specific micronutrient deficiency for it to be immediately corrected and/or prevented. Some specialized and very specific formulations to particular clinical situation (e.g., renal failure) are insufficient in some vitamin and mineral supply. Therefore, EN dietary planning attends to the need for supplementation or not of these micronutrients. For the long-term use of incomplete enteral feeding, the supplemental vitamins and minerals should be indicated. In patients with malabsorption syndromes, investigate the possible fat soluble vitamins (A, D, E, and K) deficiency to correct it shortly. There is a lack of specific vitamin and mineral recommendations for critically ill patients. However, in such a condition, the needs of antioxidant nutrients are increased due the oxidative stress, and it is recommended to supplement vitamins A, C, and E, zinc, and selenium. EN osmolality (mmol l− 1 solution) and osmolality (mOsm kg− 1 water) are associated with its digestive tolerance. Although the stomach tolerates diets with higher osmolality, more distal portions of the gastrointestinal tract respond better to isosmolares formulations. Therefore, hyperosmolar diets infused by gastrostomy or nasogastric feeding tube have better digestive tolerance when compared with administration by postpyloric or jejunal probes. The nutrients that most affect the osmolality of a solution are simple carbohydrates (mono- and disaccharides), which have greater osmotic effect than the higher molecular weight carbohydrates (starch); minerals and electrolytes, due the property of its dissociation into smaller particles (e.g., sodium, potassium, and chloride); hydrolyzed proteins; crystalline amino acids; as well as medium-chain triglycerides, because they are more soluble than long-chain triglycerides. The more hydrolysates components contains the formulation, the higher its osmolality. Enteral diets should not exceed the value of the renal solute load tolerated by the kidneys (800–1200 mOsm, in normal situation). Renal solute load can be calculated by adding 1 mOsm for each mEq of sodium/potassium/chloride, and 5.7 mOsm (adults) or 4 mOsm (children) for each gram of protein from its formula. Special attention should be given to critical clinical situations, such as sepsis, postoperative, polytrauma, and severe burn, where the urine becomes very dense, with high osmolality (around 500–1000 mOsm kg− 1), even under appropriate hydration. Importantly, the influence of the medication osmolality is usually neglected. The mean osmolality of liquid medications administered orally or by feeding tube ranges from 450 to 10 950 mOsm kg− 1 water. Certain manifestations of gastrointestinal intolerance may be related to the medication, although it is often attributed to enteral formulation. In specific clinical situations, there may be demands for change in the types of nutrients used; the quantity and/or form these should be presented. In such cases, nutritional therapy becomes more specialized. These adaptations involve changes from simple source of nutrients used until its physicochemical and structural modifications. Thus, specialized formulations for enteral use may provide different sources of vitamins, minerals, carbohydrates, lipids, and proteins, and these nutrients may be presented in their entirety or hydrolyzed (wholly or partly) structure. Some specialized EN formulations are part of immunonutrition. The immunonutrition is a nutritional intervention that explores the particular activity of various nutrients in alleviating inflammation and modulating the immune system, in which are included the omega-3 fatty acids, arginine, glutamine, nucleotides, and antioxidants. There is a current consensus that perioperative immunonutrition can beneficiate elective surgical patients, especially those malnourished patients submitted to major gastrointestinal surgery. In these patients, administration of enteral diets containing n-3 PUFA, nucleotides and arginine contributes to decrease postoperative infectious and noninfectious complications and must be initiated 5–7 days preop (500–1000 ml day− 1) and maintained in the postoperative period. Although the benefit of using this enteral formula combining different nutrients with immunomodulatory functions is well established in surgical patients, data are lacking to confirm or guide the effective and safe use of enteral diets containing isolated immunonutrients in different clinical populations, including arginine and glutamine. In hemodynamically stable condition, arginine may offer immunologic and metabolic benefits, but its participation in the synthesis of nitric oxide may constitute a potential risk for septic patients. Enteral glutamine should be considered to treat burn patients and trauma victims, but there is not sufficient evidence for its use in critically ill patients with failure of multiple systems. Other nutrients that may compose specialized EN formulations include the branched chain amino acids (BCAAs). BCAAs provide primary fuel for skeletal muscle during stress and sepsis. Therefore, leucine, isoleucine, and valine may be added to specialized EN formulas as supplemental metabolic sources to attend the metabolic needs of skeletal muscle during hypermetabolic conditions. View chapterPurchase book Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780123849472002555 Nutrition and Cystic FibrosisZhumin Zhang, ... HuiChuan J. Lai, in Nutrition in the Prevention and Treatment of Disease (Fourth Edition), 2017 b Enteral FeedingsEnteral feeding can be initiated when oral supplementation does not improve growth and nutritional status significantly. The goals of enteral feeding should be explained to the patient and family, that is, as a supportive therapy to improve quality of life and outcome, and their acceptance and commitment to this intervention should be realistically assessed. Enteral feeding can be delivered via nasogastric tubes, gastrostomy tubes, and jejunostomy tubes. The choice of enterostomy tube and technique for its placement should be based on the expertise of the CF center. Nasogastric tubes are appropriate for short-term nutritional support in highly motivated patients. Gastrostomy tubes are more appropriate for patients who need long-term enteral nutrition. Jejunostomy tubes may be indicated in patients with severe GERD; use of predigested or elemental formula may be needed with jejunostomy feeding. Standard enteral feeding formulas (complete protein, long-chain fat) are typically well tolerated. Calorically dense formulas (1.5–2.0 kcal/mL) are usually required to provide adequate energy. Nocturnal infusion is encouraged to promote normal eating patterns during the day. Initially, 30–50% of EER may be provided overnight. Pancreatic enzymes should be given with enteral feeding. However, optimal dosing regimen is unclear with overnight feeding. View chapterPurchase book Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780128029282000424 NUTRITIONAL SUPPORT | Adults, EnteralK.N. Jeejeebhoy, in Encyclopedia of Human Nutrition (Second Edition), 2005 Optimizing Enteral Nutrition and Reducing Risk of Aspiration PneumoniaEnteral feeding is associated with several factors that may result in reflux of gastric contents and aspiration: the supine position of the patient, the presence of a nasogastric tube, gastric contents, and delayed emptying of the stomach. Intuitively, placing the tip of the feeding tube into the intestine rather than the stomach should reduce aspiration, and the Canadian clinical practice guidelines recommend postpyloric feeding. On the other hand, a meta-analysis comparing gastric and postpyloric feeding did not show any significant difference in the incidence of pneumonia between patients fed into the stomach and those fed beyond the pylorus. Although enteral feeding is widely practiced as the route of choice, in a study of 103 patients admitted to an ICU who were observed prospectively for the development of nosocomial pneumonia, there was evidence that feeding contributed to pneumonia. In that study, a multivariate analysis concluded that continuous enteral feeding, but not the nasogastric tube, was an independent risk factor for nosocomial pneumonia and patients who developed pneumonia had a significantly higher mortality of 43.5% compared to 18.8% for those who did not develop pneumonia. Clearly, more studies need to be done to determine the best approach to prevent pneumonia. The use of prokinetics is another way of promoting gastric emptying. In a placebo controlled randomized trial of 305 patients receiving enteral feeding, giving metoclopramide did not reduce the incidence of pneumonia. Erythromycin, a motilin receptor agonist, is another powerful prokinetic agent. In a randomized controlled trial the benefit of erythromycin was questionable. There was no difference in the rate of pneumonia between the placebo and erythromycin-treated patients. The previous studies unfortunately involved small numbers of patients, and there is a need for larger trials of small bowel feeding and prokinetics to establish their role in promoting enteral feeding and reducing the risk of aspiration. View chapterPurchase book Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B0122266943002283 Nutritional Support: Adults, EnteralA.K. Fischer, ... G.E. Mullin, in Encyclopedia of Human Nutrition (Third Edition), 2013 Adults, EnteralDefinitionEnteral feeding is a method of providing nutrients directly into the gastrointestinal (GI) tract when a person cannot receive food orally. It is used in patients who have an adequate functional GI tract and can digest and absorb food but in whom oral intake is inadequate to maintain or restore optimal nutritional status. Also known as tube feeding, enteral nutrition (EN) delivers nutrients directly to the stomach or intestines through a thin flexible tube. It is administered through a nasogastric tube placed via the nose, or a percutaneous tube placed into the stomach (gastrostomy) or the small intestine (jejunostomy). EN is generally considered safer and the preferred method of delivering nutritional support over parenteral nutrition. In this article, the use of enteral feeding is reviewed. View chapterPurchase book Read full chapter URL: https://www.sciencedirect.com/science/article/pii/B9780123750839002038 LUNG DISEASESA. MacDonald, in Encyclopedia of Human Nutrition (Second Edition), 2005 Enteral nutritionEnteral feeding is more commonly used in teenagers and adults, reflecting their deterioration in nutritional status. It is considered if the patient is less than 85% expected weight for height, the patient's weight has declined by two centile positions, the patient has failed to gain weight over a 6-month period, or the patient has a BMI less than 19. Enteral feeding is associated with improvements in body fat, height, lean body mass, muscle mass, increased total body nitrogen, improved strength, and development of secondary sexual characteristics. To produce lasting benefit, numerous studies have demonstrated that enteral feeding should be continued long term. The choice of route used is influenced by the duration of feeding and the preference of the patient and family, but gastrostomies, sited by endoscopic placement, are usually chosen for long-term feeding (Table 4). Table 4. Advantages and disadvantages of enteral feeding routes MethodAdvantagesDisadvantagesNasogastricShort-term feedingTube reinsertion may beDistressing to patient/caregiver/nurseEasily removedRisk of aspirationDiscomfort to nasopharynxPsychosocial implicationsNasojejunalLess risk of aspirationDifficulty of insertionShort-term feedingRadiographic check of positionEasily removedRisk of perforationAbdominal pain and diarrhoea unless continuous infusion of feedDiscomfort in nasopharynxReflux of bile is facilitatedGastrostomyCosmetically more acceptableIncrease reflux if presentLong-term feedingLocal skin irritationInfectionGranulation tissueLeakageGastric distensionStoma closes within a few hours if accidentally removedJejunostomyReduced risk of aspirationSurgical/radiology procedureLong-term feedingRisk of perforationMust be constant infusion of feedBacterial overgrowthDumping syndrome can occur Adapted from MacDonald A, Holden C, and Johnston T (2001) Paediatric enteral nutrition. In Payne-James J, Grimble G, and Silk D (eds.) Artificial Nutrition Support in Clinical Practice, pp. 347–366. London: Greenwich Medical Media. It is common practice to give enteral feeding for 8–10 h overnight, with at least 40–50% of the estimated energy requirement given via the feed. Most patients tolerate an energy-dense polymeric feed providing at least 1.5 kcal/ml with additional pancreatic enzymes. However, there is some support for the use of chemically defined elemental or short-chain peptide feeds. These are generally low in fat and are administered without the use of pancreatic enzymes, although there is little evidence to support this practice and it is disputed by some. Monitoring for glucose intolerance is important. Patients receiving supplemental feeds who demonstrate repeated blood sugar levels higher than 11.1 mmol/l during the feed may benefit from insulin given before the feed. Which type of enteral feeding should be avoided in patients at high risk of aspiration?Patients at high risk of aspiration should never be considered for nasoenteric tube feeding due to the high risk of complications.
Can G tube feeding cause aspiration?Recent findings: There is evidence in the literature showing that the presence of a nasogastric feeding tube is associated with colonization and aspiration of pharyngeal secretions and gastric contents leading to a high incidence of Gram-negative pneumonia in patients on enteral nutrition.
Does NGT increase risk of aspiration?NGT feeding is known to be a significant cause of aspiration pneumonia in stroke patients [10]. Since the NGT bypasses the small amount of gastric contents through to the oropharynx, the materials can be easily aspirated into lower airways in dysphagic patients with stroke.
Which types of tube feeding delivery systems have lower risk of aspiration into the lungs?Jejunal Tube Feeding
The jejunal tube bypasses the stomach decreasing the risk of gastric reflux and aspiration.
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