Uploaded by Cassy Highland

Nutrition Support

Nutrition Support: Enteral Nutrition
Feeding through the GI tract via a tube, catheter, or stoma (opening) that delivers
nutrients distally (below) the oral cavity
Patients with a functioning GI tract that
Patient has serious medical
can’t feed themselves adequately such
conditions that affect the GI tract
as those with
such as
o Altered mental status
o Diffuse peritonitis –
o Swallowing dysfunction
inflammation of the
o Disorders of the upper GI
peritoneal lining of the
tract – can be bypassed by
inserting the tip of the
abdominal cavity
o Intestinal obstruction that
feeding tube below the area
prevents intestinal contents
of dysfunction
from passing through the
o Intractable vomiting not
responsive to medical
o Paralytic ileus – prevents
GI contents from passing
through the GI tract
o Intractable diarrhea that is
not controlled by
o Gastrointestinal ischemia –
insufficient blood flow to GI
 Cost effective
 Reduced rate of infections in
critically ill patients
 Improved wound healing
 Reduced surgical intervention
 Maintenance of GI tract functions
 Difficult to administer
 Poor tolerance
 Difficulty of meeting nutritional
requirements of some patients
 Discomfort of the patient
GI Access
1. Nasogastric Feeding tube  A tube that is inserted through the nose into the
o Most common
o Easiest to achieve
o Easiest to maintain
o Least expensive
o Can be used in various conditions
o Can be easily dislodged
o May need to be replaced frequently
2. Orogastric Feeding tube
o Tube that is inserted through the mouth to the stomach
3. Nasointestinal Feeding tube
o Tube that is inserted through the nose into the intestine bypassing the
stomach to reside in the duodenum or jejunum used in cases of
Gastroparesis – delayed gastric emptying
Gastric outlet obstruction
Previous gastric surgery preventing feeding into the stomach
o Minimizes risk of accidental aspiration of formula into lungs
Tubes entering through the nose or mouth are used for short term therapy (<6 weeks)
More permanent feeding tube methods
4. Gastrostomy
o Tube delivering feeds to the stomach
5. Jejunostomy
o Tube delivering feeds through the abdominal wall into the jejunum
Both methods involve placement of the tube by the following procedures:
Surgical Gastrostomy
o Physician places permanent feeding tubes when the patient is sedated
Percutaneous Gastrostomy
o Feeding tubes placed through the skin without a surgical incision
Percutaneous Endoscopic Gastrostomy (PEG)
o Inserting a feeding tube through the skin into the stomach using an
Depends on where the tip of the tube is and on osmolality – number of water attracting
particles per kg.
1. Protein
Derived from soy or casein
Most formulas require enzymes to split intact proteins into peptides before
absorption – standard formulas
Some contain proteins from peptides used in patients with enzyme deficiency or
other conditions resulting in maldigestion – elemental or hydrolyzed formulas
Specialized amino acid formulas – elemental formulas - are used for
o Renal failure
o Hepatic failure
o Stress
o Inborn errors of metabolism
2. CHO
Large molecules (monosaccharides, oligosaccharides, dextrin, maltodextrins)
Most have insoluble fibres (i.e. soy polysaccharides)
o Less hydrophilic
Some have soluble fibre added to improve bowel functions
o Only small amounts as these formulas are hydrophilic – attracts water
Causes formula to thicken and form a gel when added
3. Lipids
Derived from corn and soy oil – long and medium chain fatty acids
4. Vitamins/Minerals
Most provide DRIs for vitamins and minerals for adults within a specified volume (i.e.
1500 mL in 24 hours)
5. Fluid/Nutrient Density
Some patients are unable to tolerate large volumes of fluid as they have impaired
o Cardiac
o Renal
o Pulmonary
Nutrient density determined by kcal/mL
o Standard is 1 kcal/mL
EN may be the sole source of fluid intake – monitor patient’s ins and outs to check
for dehydration
Precise water content of formulas are determined by the free water content
o 80% water for 1 kcal/mL
o 65 % water for 2 kcal/mL
Partially hydrolyzed formulas have higher Osmolality
o Number of water attracting particles per weight of water in kgs (mOsm/kg)
Iso-osmolar – formulas that have the same osmolality of body fluids (300 mOsm/kg)
o Was used to minimize the effects of dumping syndrome – diarrhea resulting
from rapid movement of fluids into the GI tract to dilute hyperosmolar or
concentrated fluids
Typically most formulas have moderate osmolality (300 – 600 mOsm/kg)
Feeding Techniques
1. Bolus Feeds
Rapid administration of 250 – 500 mL of formula several times daily using a syringe
2. Intermittent Feeds
Administered several times daily over 20 – 30 minutes
Typically requires a pump to control flow rate or can use gravity feeds if container is
suspended above the patient
3. Continuous Feeds
Administered over 10 – 24 hours daily using a pump to control feeding rate preferred method in hospitals or nursing homes
o May improve tolerance
Can be restrictive on mobility
Most polymeric, isotonic formulas can be initiated at 10 – 40mL/ hour
Rate is advanced in increments of 10 – 25mL/ hour every 4 - 8 hours until goal rate
is reached
Clogged, twisted or kinked tubes – flush with water
most common is diarrhea
o abnormal looseness of stool with increased liquidity or decreased consistency
o output > 200 g/day for adults and 20 kg/day for children
can be caused by medications – antibiotics containing sorbitol
also due to infections by bacteria or viruses
fluid is inspired into the lungs
common in patients who are
o sedated
o have endotracheal tubes – tube allowing oxygen into the lungs of patients
receiving mechanical ventilation
o have swallowing difficulties
elevate patient’s head about 45 during feeding
determine GI emptying by calculating residual volumes of liquid in stomach
o stop EN if residual > 400 mL
Tube Feeding Syndrome
hyperosmolar-nonketotic dehydration over a short 2 to 4 day period caused by
insufficient fluid intake in patients with EN
Electrolyte Imbalances
patients with organ failure require lower levels of electrolytes
IV supplementation of electrolytes are preferred
Delays nutritional repletion and wound healing
May assist in preventing acute and respiratory complications in some patients
o Inability to clear by-products of protein breakdown resulting in toxicity
o Impaired wound healing
Hepatic Steatosis – fatty liver
o Due to an increase of liver enzymes that promotes increased storage of fatty
o Congestion of the reticular endothelial system – increased serum tryglycerides
Prolonged mechanical ventilation
o Increased CO2 production due to increased metabolism of CHO
Refeeding Syndrome
Metabolic alterations that occur during the nutritional repletion of starved patients
o In starved patients, major energy source is from fatty acids used to produce
ketones resulting in decreased BMR
Reintroduction of CHO results in shift of energy source from ketones to glucose
Glucose requires large quantities of phosphorus to be metabolized
o Magnesium, potassium and thiamin needs may increase as well
Serum phosphate decreases (hypophosphatemia) resulting in
o Hemolysis
o Impaired cardiac function
o Impaired respiratory function
o Death
Serum potassium decreases (hypokalemia) resulting in
o Cardiac abnormalities
Serum magnesium decreases (hypomagnesemia) results in
o Tremors
o Twitching muscles
o Cardiac arrythmias
o Paralysis
Patients at highest risk are:
Have a history of long-term inadequate oral intake
Have had minimal intake for several day
Parenteral Nutrition
Administration of nutrition directly into the circulatory system via IV – intravenously
Central Parenteral Nutrition
Administration of concentrated macronutrients, vitamins, minerals and electrolytes
into a large central vein so that the volume of blood flow is sufficient to immediately
dilute the concentrated PN solution
Peripheral Parenteral Nutrition
Administration of large volumes of dilute solutions of nutrients into a vein in the arm
or the back of the hand
Usually used for short-term
Patient unable to meet needs by EN or oral intake
Inability to digest and absorb nutrients – malabsorption
o Massive bowel resection
o Short bowel syndrome
o Intractable vomiting
o GI tract obstruction
o Impaired GI motility
o Abdominal trauma, injury or infection
Venous Access
Short Term:
1. Central Venous Catheter
o IV access inserted into large veins at the centre of the body such as the
Femoral veins
2. Peripherally inserted central catheter (PICC)
o IV access inserted into the arm and threaded into a subclavian vein to the
vena cava
o Threaded from smaller veins to larger veins
o Inserted bedside – doesn’t need surgical placement
Long Term
1. Tunneled Catheters
o IV access placed in a vein on the upper chest wall and exits the body near the
xyphoid process, axilla or abdominal wall
o Surgically inserted directly into the superior vena cava
o Better suited for long-term support
Patient can use both hands to access it
Less chance of displacement as it is sutured in place
2. Implantable Ports
o IV access that is completely under the skin
o Placed in the vein on the upper chest wall and exits the body near the xyphoid
process, axilla or abdominal wall