Download - 36- Parenteral & Enteral Feeding
Parenteral & Enteral Feeding
Aim of Nutritional Support
To ensure that the nutritional requirements are met in patients at risk of malnutrition, by the most appropriate route in a way that minimizes complications
Definition
Parenteral feeding: the provision of all nutritional requirements by means of IV route without the use of the GIT
Enteral feeding: delivery of nutrients into the GIT; either by standard oral intake or by direct administration into the stomach or a small intestine via a feeding tube
[Nutritional requirements: macronutrients, carbohydrates, fat, proteins, vitamins, trace elements, electrolytes & water]
Enteral Feeding
When possible, enteral feeding is preferred as a nutritional support, why?
Because it maintains gut mucosal integrity, protects against mucosal atrophy & reduces complications.
Enteral Feeding
Types:1. Sip feeding2. Nasogastric tube3. Gastrostomy4. Jujenostomy
1. Sip Feeding
By using small amounts of special formula Indicated in patients who can take fluids only (in
case of weakness in the mouth or the mastication muscles)
2. Nasogastric Tube
Fine bore tube (1mm) inserted into the stomach via the nose
Indicated in patients:1. Unable to swallow2. With CVA3. In coma4. In ICU
2. Nasogastric Tube[cont]
Intact gag reflex is a must in case of using this type of feeding
Good gastric peristalsis is a must (to prevent gastric stasis which can lead to gastric ulceration)
• How to check for peristalsis? By motility study; where a specific amount of
normal saline is administered into the stomach. After 2 hours, suction from the stomach is done, to compare both amounts.
(if the amount after suction was the same as the administered one, then there’s gastric stasis)
2. Nasogastric Tube[cont]
Disadvantages:• Nose irritation, ulceration & pressure necrosis• Offensive in conscious or semi-conscious patients• Duration limited; used for maximum of 2 months• Gastroesophageal reflux & aspiration (due to the
incomplete closure of esophageal sphincter in the presence of NG tube)
3. Gastrostomy
Tube inserted directly to the stomach through the abdominal wall
PEG [percutaneous endoscopic gastrostomy]: insertion of the tube by endoscope, used nowadays instead of open surgery
Good evacuation (good peristalsis) is also needed here, which can be confirmed by motility study
2. Gastrostomy[cont]
Indicated in:• Obstructed GI tract before the stomach (tumors in
oropharynx or lower esophagus)• Loss of peristalsis due to neuromuscular disorder• Need for nutritional support for long time (e.g: head
trauma, coma)
4. Jujenostomy
Post-pyloric feeding decreases risk of aspiration but difficult to place
Over distention could result from flooding of GIT by feeding
Indicated in:• Gastric obstruction (advanced gastric CA)• Major resection of upper GIT, like whipple procedure
(pancreaticoduodenectomy & gastrojejunostomy)
Complications of Enteral Feeding Tube-related: malposition, displacement, blockage,.. GI: diarrhea, nausea, vomiting, abdominal cramps,.. Metabolic: electrolyte disorders, drug interactions,.. Infective: handling contamination, endogenous,..
Total Parenteral Nutrition
Indications:1. Obstruction2. Short bowel syndrome3. Inflammation4. Fistula5. Inability to cope
Total Parenteral Nutrition
Indications:1. Obstruction• Irremovable advanced tumors; e.g lymphoma• Pancreatic tumor: causes malabsorption &
obstruction
Total Parenteral Nutrition
2. Short bowel syndrome (<1m of small intestine) A disorder clinically defined by malabsorption, diarrhea,
steatorrhea, fluid & electrolyte disturbances and malnutrition caused by loss of large segment of small intestine
Causes :- Mesenteric ischemia: superior mesenteric embolism
if left untreated for 5 hrs may lead to gangrene & resection.
- Volvulus neonatorum: bowel twisted around itself, which is treated by resection
- Crohn’s disease: recurrent surgical resection of the bowel
Total Parenteral Nutrition
3. Inflammation Ulcerative colitis & crohn’s disease; TPN used to rest
the bowel
Total Parenteral Nutrition
4. Fistula Fistula in the upper GIT Causes leak of pus, feces or bowel contents (gastric
juice, bile, enzymes, etc..) Managed conservatively & need 6 wks to improve
by using TPN to rest the bowel
Total Parenteral Nutrition
5. Inability to copeIn cases of increased catabolic rate where the bowel can’t compensate the body demand, especially proteins:
- Sever sepsis.- Extensive burning.
Total Parenteral Nutrition
How to perform TPN?Through the central line access:
1- Femoral V: rarely used, because it’s low and away from the heart
2- Internal jugular V: commonly used in anesthesia3- Subclavian V: commonly used
Total Parenteral Nutrition
Why central not peripheral? Because the nutrition used is hyperosmolar, so:
- If peripheral access causes irritation, inflammation & thrombosis due to poor flow If complicated, it can’t be easily washed by saline because of the narrow lumen of peripheral veins
If central access Does not cause irritation due to high blood flow If complicated, can be easily washed out by saline
Total Parenteral Nutrition
How to insert an IV central line?1. Supine position & head down (to congest neck
veins)2. Local anesthesia below the clavicle3. By a wide bore needle (1mm) make incision in the
inferior surface of clavicle4. Insert a cannula (backward medially & downward)
until blood comes out5. Introduce a catheter to reach SVC6. Fix the line by stitch
Total Parenteral Nutrition
During the procedure: patient is asked to hold their breath to decrease risk of pneumothorax & air embolism
After the procedure: CXR is done to confirm the site of the catheter & to exclude pneumothorax
Total Parenteral Nutrition
Complications of the procedure; injury of:1) Brachial plexus2) Subclavian artery (hematoma)3) Thoracic duct4) Phrenic nerve5) Superior vena cava6) Lungs (pneumothorax)7) Cardiac muscles
Total Parenteral Nutrition
Complications of TPN:1) Line infection2) Fatty infiltration to the liver3) Hyper-osmolarity4) Re-feeding syndrome: metabolic disturbances that
occur as a result of reinstitution of nutrition to patients who are malnourished
5) Insulin rebound phenomenon (somogyi syndrome)
Infection TPN requires a chronic IV access for the solution to run through,
and the most common complication is infection of this catheter. Infection is a common cause of death in these patients, with a mortality rate of approximately 15% per infection, and death usually results from septic shock]
Blood clots Chronic IV access leaves a foreign body in the vascular system, and
blood clots on this IV line are common.] Death can result from pulmonary embolism wherein a clot that starts on the IV line but breaks off goes into the lungs.
Patients under long-term TPN will typically receive a periodic heparin flush to dissolve such clots before they become dangerous.
Fatty liver and liver failure Fatty liver is usually a more long term complication of TPN, though
over a long enough course it is fairly common. The pathogenesis is due to using linoleic acid (an omega-6 fatty acid component of soybean oil) as a major source of calories.
Hunger Because patients are being fed intravenously, the subject does
not physically eat, resulting in intense hunger pangs. The brain uses signals from the mouth (taste and smell), the stomach/G.I. Tract (fullness) and blood (nutrient levels) to determine conscious feelings of hunger. In cases of TPN, the taste, smell and physical fullness requirements are not met, and so the patient experiences hunger, despite the fact that the body is being fully nourished. In cases where the patient eats food despite the inability, they can experience a wide range of complications.
Total Parenteral Nutrition
How to give nutrition by TPN?Normal body need: Fluid: 30-40 mL/kg/day Calories: 30-40 kcal/kg/day Nitrogen: 0.15-0.2 g/kg/day Na: 100mmol/day K: 80mmol/day
Total Parenteral Nutrition
Example A patient who weighs 70 Kg with fistula & fever 10
days post-op.. How to calculate the need?
Total Parenteral Nutrition
Fluids70x40 = 2800 mL/day- An amount of fluid is lost by the fistula; so we add an
amount of fluid in order to compensate +1000 mL/day- Another amount must be added because of fluids lost in
sweating (he’s feverish) +200 mL/day
2800+1000+200=4000 mL/day
[sweating, fistula, diarrhea, vomiting & drain all cause fluid loss]
Total Parenteral Nutrition
Calories:70x40 = 2800 kcal/day- He has sepsis & post-op stress, which causes a loss of
more calories, so to compensate +1200 kcal/day
2800+1200 = 4000 kcal/day
Total Parenteral Nutrition
Nitrogen:70x0.2 = 14 g- Due to increased catabolism (due to sepsis), this
needs to be compensated + 7 g
14+7 = 21 g
Total Parenteral Nutrition
How to give those nutrients as a source of energy? Carbohydrates 50% Protein 15% Fat 35%
Total Parenteral Nutrition
Glucose WaterWe have many forms: 5%, 10%, 25%, 50%, 75%(1 g 4 kcal)
- 5% form contains 50 g/L so 200 kcal/L- 50% form contains 500 g/L so 2000 kcal/L
Our patient needs 4000kcal/day, this can be achieved by:20 L/day of 5% form or 2 L/day of 50% formSo 50% is better to be used in this case
Total Parenteral Nutrition
NitrogenDifferent forms: 3%, 5%, 10%, 14% 14% form contains 14 g/L
Our patient needs 21g, so 1.5 L of 14% form can be given in this case
Total Parenteral Nutrition
LipidDifferent forms:(1g 9kcal) - 10% form contains 100 g, so 900kcal/L[Not given daily, because it causes allergic reaction & interference with coagulation factor and it’s expensive]
ElectrolytesNormal saline or ringer lactate
Total Parenteral Nutrition
General instructions: TPN must be given by drips, one bottle with fixed gradual rate(1st day 2.5.. 2nd day 3.5L.. 3rd day 4.5L..) Nutrients must not be given at once, this may cause
hyperglycemia & rebound insulin phenomena Pt must be weighed daily, increment of 300 g or more this is
over feeding, so decrease doses KFT & LFT weekly Electrolytes & glucose level daily (for metabolic complication) In case of sepsis: drain the cath, culture, & change site of cath
Thank You