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Early Enteral Nutrition

1INTRODUCTIONSurgical and accidental trauma is well known to cause a transient suppression of the immune system, that increases the infection risk. There is consensus that nutritional support is an essential component of the multidisciplinary treatment of surgical and critically ill patients, especially when the illness is associated with prolonged catabolism and with the inability to use the GI tract. 2INTRODUCTIONIn the second half of the last century several studies underscored the importance of feeding surgical patients adequately, to reduce the severity and duration of the catabolic phase, thus decreasing the postoperative infection risk. 3Postoperative nutritional support benefits the high risk surgical patients, by decreasing surgical morbidity, maintaining immunocompetence and improving wound healing4Why Enteral Nutrition?Without enteral nutrition gut atrophy because no nutrients for enterocyte & colonocyteInadequate enteral nutrition barrier function failure endotoxin&bacteria translocationsGOAL: To maintain intestinal mucosal integrity (normal microvilli and intestinal barrier, intestinel mucosal immunity)

5The EN has a specific trophic effect on the GI tract; such effect is potentially valuable in preventing microbial translocation from the gut to the blood stream and subsequent gut derived infection. 6Time of EN ?Early enteral feeding is well tolerated and it reduces significantly the rate of postoperative complications . As a consequence, there is now consensus that critically ill patients are candidates to enteral feeding if they have a functioning GI tract

7Time of EN ?The EN usually can begin postoperatively as soon as the patient is haemodinamically stable. Preferably it should start within 24 hours after surgery, and no later than 48 hours. As long as there is no significant abdominal distension, enteral feeding is not contraindicated, even with markedly diminished bowel sounds. Most patients can be fed enterally without waiting for flatus.8Why sould be Early ?Immediate or early postoperative EN stimulates the splanchnic and hepatic circulation; it improves intestinal mucosa blood flow, it prevents intramucosal acidosis and permeability disturbances and it eliminates the need for stress ulcer prophylaxis9Definitiondelivery of nutrients directly into the stomach, duodenum or jejunum. Called also enteral nutrition10Enteral Tube Feeding

Nutritional support via tube placement through the nose, esophagus, stomach, or intestines (duodenum or jejunum)Must have functioning GI tractIF THE GUT WORKS, USE IT!Exhaust all oral diet methods first.11Diagram of enteral tube placement.Fig. 22-2. p. 468.

Copyright 2000 by W. B. Saunders Company. All rights reserved.12INDICATIONMalnourished patient who unable to eat >5-7 daysNormally nourished patient who unable to eat >7-9 daysAdaptive phase of short bowel syndromeIncreased needs that cannot be met through oral intake (burns, trauma)Inadequate oral intake resulting in deterioration of nutritional status or delayed recovery from illness

CONTRAINDICATIONSevere acute pancreatitisHigh output proximal fistulaInability to gain accessIntractable vomiting or diarrheaAggressive therapy not warranted

ASPEN. The science and practice of nutrition support. A case-Based Core curriculum. 2001; 14313Contraindications for ENInadequate resuscitation or hypotension; hemodynamic instabilityIleusIntestinal obstructionSevere G.I. BleedExpected need less than 5-7 days if malnourished or 7-9 days if normally nourished

14Choosing the Feeding Site Can the GI tract be used?NoYesTube feeding for more than 6 weeks?NoYesNasoenteric TubeRisk for pulmonary aspiration?YesNoYesNoNasogastric TubeJejunostomyParenteral NutritionEnterostomy Tube Nasoduodenalor nasojejunal tubeGastrostomy15After determining if a patient is a candidate for enteral nutrition, a physician must determine what enteral access routes are most appropriate. The level of GI functionality should first be considered, as this will be the determining factor for tube placement either the stomach or the small intestine. If the patient has gastroparesis, has aspirated in the past, or is presently at risk for aspiration, the physician should feed into the small bowel. If there are fistulas, it is imperative to feed distal to them. The second consideration is the time required by enteral nutrition. If required for 4-6 weeks, a nasogastric or nasoenteric feeding tube should be considered. If nutrition therapy will be required for more than 6 weeks, a more permanent type of feeding tube should be used: gastrostomy or jejunostomy. Placement method should also be evaluated blind, endoscopic, fluoroscopic or surgical.

Gastric AccessGastric Route Preferred Adequate gastric motilityMinimum risk of aspirationGastric Route ContraindicatedDelayed gastric emptying (gastroparesis)High risk for aspiration

16Gastric access is indicated when there is adequate gastric motility and minimal risk of aspiration.Gastric feeding is contraindicated with delayed gastric emptying, as seen in gastroparesis, and with high aspiration risk such as when the gag reflex is impaired or absent.

Gastric Feeding Techniques Nasogastric TubeShort term

Manual or radiologic placement GastrostomyLong term

Endoscopic,radiologic, orsurgical placementRugeles S, et al. Universitas Medica 1993;34(I):19-2317Gastric access may be obtained for short-term feeding via the nasogastric route using blind or manual placement at the bedside or with the use of radiologic guidance.For long-term use, gastric access may be obtained via a gastrostomy placement using endoscopic, radiologic, or surgical techniques.The technique used for gastric access is based on the expertise of the physician placing the tube as well as the patients condition. For example, if the patient has an esophageal tumor, the narrowed esophagus may prevent passage of the endoscope.

Rugeles S et al. Universitas Medica 1993;34(I):19-23. Nasogastric Tube: DisadvantagesShort-term use onlyHigher risk for aspirationDifficult to confirm positionSmall boreNasopharyngeal trauma/irritationAccidental tube displacement

18The disadvantages of nasogastric tubes are:Indicated only for short term usageGreater risk for aspirationConfirming placement can be difficultSmall bore, which can lead to tube obstructionCan cause nasopharyngeal trauma/irritation Accidental displacement by patient

Percutaneous Endoscopic Gastrostomy: PEG Tubes RigidFlexible Minard G. Nutr Clin Prac 1994;9:172-182

19If a permanent feeding tube is needed, or if nutrition therapy is required for more than 4-6 weeks, a gastrostomy may be the enteral access route of choice.Since the introduction of PEG (percutaneous endoscopic gastrostomy) in 1980 by Ponski/Gauderer, it has been the most utilized technique for placing gastrostomy feeding tubes. PEG tubes are normally made of silicone, a biocompatible material, and are either rigid (as seen in the left picture) or flexible (as seen in the right picture). Rigid PEG tubes should be removed using a second endoscopy, while flexible ones can be removed by applying external traction. All PEG tubes should have some type of external skin disc as well as a Y-port for easy tube cleaning or administration of medications without having to disconnect the feeding port.

Minard G. Nutr Clin Prac 1994;9:172-182. Percutaneous Endoscopic Gastrostomy: AdvantagesThe same as for surgical gastrostomyNo surgery / less invasiveMinimal sedationDirect visualization< 30 minutes to place tubeLower costs20PEG offers the same advantages as an open surgical gastrostomy, but is less invasive, does not require general anesthesia and, therefore, the patient has a shorter recovery time after the procedure.Endoscopy allows for direct visualization of the inside of the esophagus and stomach to evaluate any condition before placing the tube.PEG placement is less costly than an open surgical technique, unless the feeding tube is placed during an already-scheduled surgical procedure.

Percutaneous Endoscopic Gastrostomy: Placement CriteriaAdequate passage for endoscopeEase in identifying safe siteEase in determining a safe tractFunctioning GI tractAbsence of ascites / morbid obesity

Stellato TA, et al. Ann Surg 1984;200:46-50Lee M, et al. Clin Radiol 1991;44:332-33421To perform a PEG, there should be no anomaly in the upper GI tract that might prevent performing an endoscopy. Once the endoscopy is done, the physician should be able to identify a safe site by using translumination of the abdominal wall, and a safe tract by determining that the needle is in the stomach.If, after the endoscopy, the physician is not able to identify a safe site and tract, the procedure should be aborted. Ascites and morbid obesity are relative contraindications that interfere with the determination of a safe site and tract for PEG tube placement. Ascites can cause leakage around the tube and exert excessive pressure on the internal bumper or skin disc, leading to tissue necrosis.

Stellato TA, et al. Ann Surg 1984;200:46-50Lee M, et al. Clin Radiol 1991;44:332-334 Surgical Gastrostomy Performed in operating roomIndicated when PEG is contraindicated or during other surgical proceduresRequires general anesthesia and full surgical teamIn observation during recoveryMore expensive than PEG

22Surgical gastrostomies are performed in an operating room and normally require general anesthesia and an entire surgical team. These procedures are therefore more costly than a PEG placement and require additional hospitalization for the patient to recover.Surgical gastrostomies can be done in conjunction with another surgical procedure or when the PEG technique is not an option. Gastrostomy: Low-Profile Tube

23This slide shows a low-profile gastrostomy feeding tube. This tube is not indicated as a primary feeding tube, but rather as a replacement device because it requires a healed stoma tract. The low-profile device is useful for active people who do not want a traditional gastrostomy tube. It is also appropriate for pediatric patients.

Post-pyloric AccessIndications for post-pyloric routePatient at risk for bronchial aspiration, gastric refluxGastric feeding contraindicated Gastric motility disorders; e.g., gastroparesis Upper GI tract condition; e.g., carcinoma, stricture, fistula

24Postpyloric access is the route of choice for enteral nutrition when gastric access is not appropriate or when early feeding is required. Postpyloric feeding indications include:Risk of aspiration/gastric reflux.When gastric feeding is contraindicated as in gastroparesis or upper GI tract abnormalities.

Post-pyloric Access Montecalvo MA, et al. Crit Care Med 1992;20:1377-1387Advantages

Allows earlier post-op feedingLower risk of aspirationDisadvantages

Small bore tubes, prone to obstructionTubes can be dislodged into stomachDifficult to maintain long termPotential for dumping syndromeRequires infusion pump

25Postpyloric access enables earlier enteral feeding, which can occur more quickly after an operation if small bowel motility returns sooner than the stomach. Theoretically, there is a lower risk of aspiration due to the barriers created by the various sphincters. The risk of aspiration probably decreases if the feeding tube goes beyond the ligament of Treitz. If the tube is only a short distance beyond the pylorus, it can migrate back into the stomach.Though postpyloric access is beneficial in many cases, there are disadvantages:Small-bore tubes become easily blocked.A problem with postpyloric feeding is the possibility of tube migration into the stomach, which can lead to aspiration.Postpyloric feeding tubes are frequently more difficult to place and maintain than gastric feeding tubes.Postpyloric feeding requires a continuous nutritional regimen and an enteral feeding pump in order to avoid dumping syndrome.

Monteclavo MA, et al. Crit Care Med 1992; 20: 1377-1387.

Post-pyloric Feeding Techniques Gauderer MW, et al. J Pediatr Surg 1980;15:872-875Short Term

Nasoenteric Nasoduodenal NasojejunalLong Term

Jejunostomy Percutaneous endoscopic jejunostomy or through the PEG tube Surgical jejunostomy

26A nasoenteric tube is used for short-term post-pyloric feeding. Nasal feeding tubes can be placed in the duodenum or jejunum depending on how far from the pylorus they need to be placed. The belief is that the farther the tube is located from the pylorus, the lower the risk of aspiration. Nasal tubes used for jejunal feeding vary in size from 8 to 12 French and 45 to 60 inches long.A jejunostomy tube is used for long-term post-pyloric feeding. It may be placed through an existing PEG tube or by a surgical approach.

Gauderer MW, et al. J Pediatr Surg 1980;15:872-875. Nasal Access: Tubes NasogastricNasoduodenal / JejunalEasyShort termY-PortSmall boreWeighted tipMetal guidewire

27This slide compares nasogastric and nasoduodenal/jejunal tubes. As you can see, there is not much difference except in feeding tube length.Post-pyloric Enteral Nutrition: IndicationsHistory / risk of reflux or aspirationGastric motility disordersUpper GI tract fistulaeAcute pancreatitis

28Postpyloric nasoenteric feeding tubes are indicated only when there is a history of gastroesophageal reflux/aspiration or gastric motility disorders.They can also be used to bypass an upper enterocutaneous fistulae (esophageal, gastric or duodenal) or to bypass the duodenum in acute pancreatitis in order to reduce pancreatic stimulation.

Post-pyloric Enteral Nutrition:AdvantagesEasily accessibleLess invasiveLower risk of aspirationManual, fluoroscopic, or endoscopic placement29Post-pyloric nasoenteric feeding tubes can normally be blindly or manually placed at bedside.With manual placement, the tube is often placed in the stomach and passes through the pylorus on its own, unless prokinetic medication is given to accelerate its passage.However, depending on the physicians level of experience and the degree of placement difficulty, it may be necessary to use fluoroscopy or endoscopy to guide feeding tube placement.

Post-pyloric Enteral Nutrition:DisadvantagesPlacement can be difficult to achieve and maintain Requires x-ray confirmationShort term use onlyNasopharyngeal trauma / irritationSmall bore tube

30The disadvantages of using nasoenteric feeding tubes are:Placement can be difficult to achieve and maintain. However, some physicians have developed a highly successful technique to place tubes blindly at bedside.X-rays are required for confirmation of tube placement.Indicated only for short-term use.Patients may experience nasopharyngeal trauma or irritation.Small bore tubes need regular maintenance to prevent problems.

Jejunostomy Feeding: Indications Feeding contraindicated for upper GI tractGastric motility disordersHistory / risk of reflux or aspiration

31When long-term post-pyloric enteral feeding is the treatment of choice, a jejunostomy is performed.Jejunostomy feeding is indicated when the gastric access is contraindicated (e.g., gastroparesis), and when there is a history of increased risk of gastroesophageal reflux or aspiration.

Nutrition by Jejunostomy: DisadvantagesSmall bore tubePlacement can be difficult to achieve and maintainDifficult to maintain for long term32Disadvantages of jejunostomy are:These tubes are small in caliber, ranging from 5 to 10 French. Obstruction can be a problem if the tube is not meticulously cared for.Correct placement can be more difficult and costly than gastrostomy. It is difficult to maintain for long term.

Percutaneous Endoscopic JejunostomyTube placed with or without existing PEGRequires endoscopyPlaced distal to Ligament of TreitzBumpers HL, et al. Surg Endosc 1994;8:121-12333A jejunostomy tube placed in an existing gastrostomy tube can be called a PEJ. In reality, it is a PEG-J since it is threaded through a gastric tube. Endoscopy is normally required for this process, but fluoroscopy can also be used. The advantage of a PEG-J is that it is placed beyond the Ligament of Treitz, lowering the probability of migration to the stomach and subsequent aspiration. A jejunostomy tube may also be placed by direct percutaneous endoscopy, but the technique is very laborious and requires a highly-skilled endoscopist.

Bumpers HL, et al. Surg Endosc 1994;8:121-123. Nasal Access: Multilumen Tubes

34Multilumen tubes are used in patients suffering from gastric motility problems or stasis. They contain a lumen for gastric aspiration and another lumen to enable duodenal or jejunal feeding. ENTERAL FORMULASFactors that influence the choice of enteral formula:Functional status of the GI tract,The extent of organ dysfunction (e.g., renal, pulmonary, hepatic, or gastrointestinal)The nutrients needed to restore optimal function and healingThe cost of specific products

35Low-Residue Isotonic FormulasThis low-osmolarity compositions Provide a caloric density of 1.0 kcal/mL and need 1500-1800 mL to meet daily requirementsProvide baseline carbohydrates, protein, electrolytes, water, fat, and fat-soluble vitamins (some do not have vitamin K) Standard or first-line formulas for stable patients with an intact gastrointestinal tract

36Isotonic Formulas with FiberContain soluble and insoluble fiber, which is most often soy basedFiber-based solutions delay intestinal transit time and reduce the incidence of diarrheaFiber stimulates pancreatic lipase activity and is degraded by gut bacteria into short-chain fatty acids (as fuel for colonocytes)No contraindications for using fiber-containing formulas in critically ill patients

37Immune-Enhancing FormulasFortified with special nutrients to enhance immune or solid organ functionIncluding glutamine, arginine, branched-chain amino acids, omega-3 fatty acids, nucleotides, and beta caroteneThe addition of amino acids to these formulas generally doubles the amount of protein (nitrogen) found in standard formula; however, their cost can be prohibitive

38Calorie-Dense FormulasHave greater caloric value for the same volumeProvide 1.5 to 2 kcal/mL suitable for patients requiring fluid restriction or those unable to tolerate large-volume infusions39High-Protein FormulasAvailable in isotonic and nonisotonic mixturesProposed for critically ill or trauma patientsNonprotein-calorie:nitrogen ratios between 80:1 and 120:1.

40Elemental FormulasAdvantage ease of absorptionNot indicated for long term use as a primary source of nutrients because of the inherent scarcity of fat, associated vitamins, and trace elementsHigh osmolarity, dilution or slow infusion ratesUsed frequently in patients with malabsorption, gut impairment, and pancreatitisHigher cost than standard formulas.

41Renal-Failure FormulasBenefits lower fluid volume and concentrations of K, P, and Mg needed to meet daily calorie requirementsContains essential amino acids Has high nonprotein-calorie:nitrogen ratioNot contain trace elements or vitamins42Pulmonary-Failure FormulaIncreased fat content to 50% of the total calories and reduction in carbohydrate contentGoal to reduce carbon dioxide production and alleviate ventilation burden for failing lungs

43Hepatic-Failure Formulas50% of the proteins are branched-chain amino acids (e.g., leucine, isoleucine, and valine)Goalreduce aromatic amino acid levels and increase the levels of branched-chain amino acids to reverse encephalopathyProtein restriction should be avoided because patients have significant protein energy malnutrition predisposition of additional morbidity and mortality44MONITORINGPARAMETERDURING INITIATIONSTABLE ACUTE PATIENTLONG TERM PATIENTBlood chemistry2 - 3 times/week Every 1 - 2 weeks Every 6 months Lytes, BUN, CreatinineDaily 2 - 3 times/week Every 6 months TriglyceridesWeeklyEvery 1 - 2 weeks Every 6 months Glucose2 - 3 times/week Every 1 - 2 weeks Every 6 months Serum proteinsWeeklyMonthlyEvery 6 months WeightDaily2 - 3 times/week WeeklyI & ODaily2 - 3 times/week WeeklyNitrogen balancePRNPRNPRN45COMPLICATIONSTube feeding diarrhea, aspiration, vomiting, distension, metabolic abnormalities, and tube dislodgmentAspiration minimized by elevation of the head 30, use prokinetic agents, feedings beyond the ligament of TreitzAbdominal distention and cramps corrected by temporarily discontinuing feedings and resuming at a lower infusion rate

46COMPLICATIONSDiarrhea usually is not caused by the tube feedings but by other therapiesCaused by use of medications via the tube (sorbitol, antibiotics, prokinetic agents, magnesium antacids) reversed by discontinuation of these medicationsReduce diarrhea by fiber-containing diet to provide substrate for the colonocytes47Metabolic ComplicationsPROBLEM CAUSETREATMENTHyponatremiaOverhydration Change formula Restrict fluids HypernatremiaInadequate fluid intake Increase free water DehydrationDiarrhea Inadequate fluid intake Evaluate causes of diarrhea Increase free water HyperglycemiaToo many calories Lack of adequate insulinEvaluate caloric intake Adjust insulin HypokalemiaRefeeding syndrome Diarrhea Replace K Evaluate causes of diarrhea HyperkalemiaExcess K intake Renal insufficiency Change formula 48COMPLICATIONSJejunal tube feedings pneumatosis intestinalis and small-bowel necrosisPathophysiology: bowel distention and consequent reduction in bowel wall perfusion (inadequate splanchnic perfusion)Factors: hyperosmolarity of solutions, bacterial overgrowth, fermentation, and accumulation of metabolic breakdown productsEnteral feedings in the critically ill patient should be delayed until adequate resuscitation has been achieved

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