Section 5b - Feeding Tubes Flashcards
What are feeding tubes used for?
To provide nutritional support to patients who cannot eat by mouth
How are parenteral and enteral feeding different?
- Enteral feeding maintains both structural and functional integrity of the GI tract by preventing changes due to atrophy
- Enteral feeding is less expensive and risky
- Enteral feeding voids possible bacterial translocation and development of cholestasis is avoided since bile flow is maintained
What determines the type of feeding tube that is used?
- Why the patient requires tube feeding
- Expected duration of treatment
Where can a feeding tube be placed?
- Stomach
- Jejunum
- Occasionally duodenum
What are the locations of dual lumens?
- One in stomach for passive decompression
- Other in the small bowel for nutrition
What is a tube placed through the mouth called?
Orogastric
What is a tube placed through the nose called?
Nasogastric
Tubes that are placed surgically are called _____
Percutaneous
When would a tube be placed in the stomach?
For patients who have a normal functioning GI tract from lower esophagus down
When would a tube be placed in the upper duodenum or jejunum?
For patients w/
- Gastric emptying problems (gastroparesis)
- Non-functional upper GI tract
- Pancreatitis
- Severe gastroesophageal reflux disease
- At significant risk of aspiration
What is important to note if the patient has a tube in their jejunum?
Need to provide food that is partly digested already
What is the most common location for a feeding tube and why?
Stomach b/c more convenient and is able to tolerate enteral formulas which are hypertonic
What is a side effect of jejunal feedings?
Abdominal cramping and diarrhea
Which type of feeding tubes are used for short-term nutritional support?
Oral or nasal (percutaneous when these options are not possible)
Which type of feeding tubes are used for long-term nutritional support?
Percutaneous
What determines the size of feeding tube that is used?
- Nature of access
- Feeding supplement
- Patient
What is the size of a small-bore?
Outer diameter is 5-12 French units
What does 1 French unit equal?
0.33 mm
What is the size of a large-bore?
Outer diameter is greater than 12 French units
Which size of feeding tube is more common?
Small-bore, but has a greater risk of clogging
What is the advantage to commercial products over home-prepared?
Commercial products contain vitamin and mineral supplementation and are sterile
When should elemental (pre-digested) formulations be used?
Patients w/ severe small bowel absorptive dysfunction
What determines feeding schedule?
Condition of the patient
What are the 3 types of administration?
- Feeding syringe
- Gravity bag system
- Pump
Can medications be given through enteral feeding tubes?
Yes if alternative drug delivery routes are not possible
Should medication be mixed with formula?
No
Should feeding and medication administration occur together?
No, feeding should be interrupted for medication administration and tube should be flushed w/ 15-30 mL of water before and after medication administration
Is absorption better on an empty stomach?
Yes
What should be done if medication needs to be taken on an empty stomach?
- Stop feeding 30 mins before administering drug to allow gastric emptying
- Wait 30 mins after medication is given to allow time for drug absorption
- *Only applicable to gastric feeding
Can placement site affect drug absorption?
Yes
What will occur if an opioid is given through a jejunal tube?
Will undergo extensive first-pass hepatic metabolism, and may show greater systemic effects
Is gastric or jejunal access preferred?
Gastric
Stomach is more tolerant than jejunum of ____ medications
Hypertonic
Are liquid dose forms or enteral administration preferred and why?
- Liquid dose forms
- Readily absorbed and less likely to cause tube occlusion
Drugs should be drawn up and dispensed only in ____ syringes
Oral (not parenteral)
What are disadvantages to liquid dose forms?
- Usually made for children, so large volumes of product are needed for adult dosage and volume may not be tolerated by patient
- Adjustments in dose and frequency may be necessary especially when switching from extended or controlled-release product to liquid preparation which is usually immediate release
Many liquid preparations are _____ or contain large amounts of ______
- Hypertonic
- Sorbitol
Why are hypertonic medications better tolerated in stomach?
- Stomach can dilute hypertonic substances w/ gastric juices before transferring contents into duodenum
- If given too rapidly may be “dumped” into small intestine resulting in osmotic diarrhea
When can hypertonic medications be administered into the small intestine?
When diluted w/ 10-30 mL STERILE water
What are some side effects to adminstration of hypertonic medication into small intestine?
- Bloating
- Nausea
- Cramping
- Diarrhea
What is sorbitol used for and what are some side effects?
- Sweetening agent
- 10-20 g daily may cause an osmotic laxative effect => cramping and diarrhea
Why aren’t syrup dose forms frequently used w/ feeding tubes?
Usually acidic, and most enteral feeding formulas will coagulate if exposed to acidic environment
When can syrup dose forms be used w/ feeding tubes?
If the feeding formula and syrup do not come into contact b/c tube may become clogged or blocked
What can be done w/ immediate-release tablets that need to be administered through a feeding tube?
May be crushed, including those that are sugar or film coated, then mixed w/ 15-30 mL water
What can be done w/ hard gelatin capsules that need to be administered through a feeding tube?
Opened and contents are dispersed in 10-15 mL of water
What can be done w/ liquid-filled soft gelatin capsules that need to be administered through a feeding tube?
- Pierced w/ needle and contents squeezed out
- May result in under-dosing
Can enteric-coated products be crushed and why?
No b/c adverse effects may occur or drugs effectiveness may be reduced
What happens if extended or controlled-release tablets are crushed?
It destroys delivery mechanism and may result in potentially toxic peaks and low troughs
What happens if a sublingual preparation is administered enterally?
May result in reduced drug absorption and lack of efficacy
Can injectable formulations be used orally?
Yes, but must consider stability in gastric acid (hypertonic products may induce osmotic diarrhea and cost is usually high)
What are some side effects to adding medication directly to an enteral formula?
- Physical incompatibilities
- Decreased drug absorption
- Increased risk of tube occlusions
- Potential microbial contamination
Which type of formulas will be more affected if medication is added?
Formulas containing protein will be more affected than those containing free aa’s or hydrolyzed protein
What should be done if multiple medications need to be given through a feeding tube?
- Give each separately
- Feeding tube should be irrigated w/ 5-10 mL of water (sterile if into jejunum) btwn each medication
Why should the tube be flushed?
- To reduce risk of tube occlusion
- Ensures total drug delivery and avoidance of contact btwn feeding formula and medication
Should liquid medications that are highly concentrated or viscous by diluted and why?
Yes to reduce medication osmolality and prevent tube occlusions
What is an example of a drug that is not very compatible w/ enteral feeding?
- Phenytoin
- Showed a 70% decrease in bioavailability when administered w/ enteral feeding
- Drug may bind w/ components in the feeding and avoid absorption
What can be done if phenytoin must be administered through a feeding tube?
Hold feeding formulas for 1 hour before and 2 hours after medication dosing
Why are proton-pump inhibitors prolembatic to feeding tubes?
Are highly unstable in acidic environments and are inactivated by gastric acid
What should capsule contents be mixed w/?
- Apple or orange juice b/c they protect the enteric-coated granules so they remain intact in stomach until reaching the small intestine
- Mixing w/ water causes clumping
What are some problems associated w/ bedside modification?
- Taste
- Acid stability
- Over-dosing when controlled-release products are used
