Chapter 10: Overview of EN

Question 1

Name 6 benefits in EN feeding.

Answer 1

Nutrients provided via the enteral route undergo first-pass metabolism, 1. promoting efficient nutrient utilization. The presence of nutrients in the SI maintains normal gallbladder function by stimulating the release of cholecystokinin, 2. reducing the risk of cholecystitis that may occur if patients are kept NPO.

3. Luminal nutrients provide GI structural support and
4. help maintain the gut-associated and mucosa-associated lymphoid tissues vital to immune function
   ((this is via: IgA, which is secreted within the GI tract when there are nutrients, can prevent bacterial adherence and translocation))
5. EN reduces infectious complications
6. less expensive than PN

Question 2

Name 8 contraindications for EN.

Answer 2

1. Severe Short Bowel Syndrome (<100-150 cm remaining small bowel in the absence of the colon, OR 50-70 cm remaining small bowel in the presence of the colon).
2. Other severe malabsorptive conditions
3. Severe GI bleed
4. Distal high-output GI fistula
5. Paralytic ileus
6. Intractable vomiting and/or diarrhea that does not improve with medical mgmt
7. Inoperative mechanical obstruction
8. When the GI tract cannot be accessed – ie: when upper GI obstruction prevent feeding tube placement

Question 3

Placement of long-term feeding tubes is indicated if EN is expected to last longer than..?

Answer 3

4-6 weeks

Question 4

Define standard EN formulas

Answer 4

meet normal requirements for most patients; energy density of 1-2 kcal/ML; may or may not contain fiber

Question 5

Define disease-specific EN formulas

Answer 5

Designed for patients with renal/hepatic disease, diabetes, pulmonary (COPD, ARDS) disease, and immunocompromised patients; elemental and semi-elemental options available

Question 6

Define modular components.

Answer 6

Can be co-administered via feeding tube to provide additional:

1. Energy (maltodextrin, hydrolyzed corn starch)
2. Fat (fish oils, MCTs, etc)
3. Protein (powdered calcium caseinates, whey protein concentrates)
4. Individual AA (glutamine, arginine)

Note these are not mixed directly with EN formulas because they may clog the feeding tube.

Question 7

What is the typical dose for thiamin supplementation?

Answer 7

100 mg thiamin daily for 5-7 days

Question 8

(True or False) Aspiration of gastric contents is less likely to result in bacterial colonization of the respiratory tract than oral secretions.

Answer 8

TRUE

Question 9

What type of EN route of delivery reduces risk of aspiration?

Answer 9

Post-pyloric; which reduces the volume of stomach contents; shown to have a 30% lower rate of aspiration than gastric feeding

Question 10

(True or False) Gastric feeding is considered safe for most patients.

Answer 10

TRUE

Question 11

(T/F) Gastric feeding is preferable if waiting for migration of a feeding tube tip past the pylorus will delay the early initiation of EN.

Answer 11

TRUE

Question 12

**What is the ASPEN recommendation for when EN needs to be initiated in a well-nourished patient?

Answer 12

**NPO/Inadequate oral intake x 7-14 days

Question 13

**What is the ASPEN recommendation for when EN needs to be initiated in a high-risk critically ill patient?

Answer 13

***Within 24 - 48 hours of initial insult (mechanical ventilation, surgery, neurologic injury) (“Early EN initiation”

Question 14

Pump-assisted continuous drip infusions

Answer 14

Preferred method for critically ill patients, who are vented (using oro-tracheal method), at risk for refeeding, have poor glycemic control, have jejunostomy tube, or have an intolerance to intermittent gravity or bolus feeding

Question 15

Gravity drip method

Answer 15

(Without use of a pump), may be used to provide continuous drip feedings to the non-critically ill patient living at home or outside the hospital setting

Question 16

Cyclic feedings

Answer 16

Uses pump or gravity drip, over a time period that is less than 24 hours. Minimum infusion time per day is 8 hours, depending on volume tolerance

Question 17

Intermittent feedings

Answer 17

Uses infusion pump or gravity drip; selected for patients with feeding tubes that terminate in the stomach to accommodate the larger volumes administered in a shorter time period

Volumes range from 240 - 720 mls (1 - 3 cups)
Administered time period ranges from 20 - 60 mins
Can be provided from 4 - 6 times / day, depending on volume required

Question 18

Bolus feedings

Answer 18

Provide a set volume of formula at specified time intervals over a VERY SHORT period of time, usually with a feeding syringe.

Typical feeding: 240 mL of formula over a 4 - 10 min. period, with infusions 3 - 6 times/day, with at least 3 hours between feedings

These can also be administered with the gravity drip method, which the rate of formula is regulated by adjusting a roller clamp.

Question 19

What is the recommended EN initiation for critically-ill patients?

Answer 19

Start at 10 - 40 mL/hr, increasing by 10 - 20 mL/hr Q 8 - 12 hours to goal rate.

Many critically-ill patients can tolerate rapid advancement of EN to goal rate within 24 - 48 hours, minimizing energy and protein deficits.

Question 20

Volume-Based feeding

Answer 20

prescribed in terms of the goal volume per day, rather than goal volume per hour; more recent feeding method used in the critically-ill patient population

EN formulas are typically started at goal rate, or rapidly advancing to the goal

Question 21

Define hemodynamically unstable.

Answer 21

Defined as those with a mean arterial BP of less than 150 mmHg, or those who are starting vasopressor meds, or require increasing doses to maintain BP

Ischemia bowel may occur as a result of reduced blood flow to the gut, a potential consequence of low BP

Question 22

Hypocaloric feeding

Answer 22

Defined as 65 - 70% of energy needs as estimated by IC (or calculations); provided as high-protein hypocaloric EN, designed for critically-ill obese patients to minimize the metabolic complications of feeding, preserve LBM and mobilize fat stores

Question 23

What are the energy recommendations for critically-ill patients w/ sepsis, starting EN?

Answer 23

Provide 60 - 70% of energy needs (with 100% estimated protein needs), during the first week of EN. Then advance to more than 80% of estimated energy needs after the first week.

Question 24

Define trophic feeding. When is it indicated, and for which patients?

Answer 24

10 - 20 mL/hr or up to 500 kcal/day; indicated for patients with ARDS or acute lung injury who are expected to be vented for more than 72 hours AND not high nutrition risk or malnourished.

Question 25

List factors that increase the risk for clogging of the feeding tube.

Answer 25

1. Use of fiber-containing formulas
2. Use of small-diameter tubes
3. Use of silicone, rather than polyurethane tubes
4. Checking GRVs
5. Improper medication admin via the tube

Question 26

**What is the ASPEN recommendation for flushing feeding tubes?

Answer 26

**At least 30 mL water Q 4 hours during continuous feeding

OR, before and after intermittent or bolus feedings in adult patients

AND, 30 ml of water, before and after GRV checks

Question 27

What is the #1 method for preventing contamination of open feeding systems?

Answer 27

Hand-washing

Question 28

Contamination of TF formula, can cause, what?

Answer 28

Abdominal distention, diarrhea, and bacteremia

Sepsis, PNA, infectious enterocolitis

Question 29

What is the ENfit Connector?

Answer 29

A newly designed EN connector, made to help prevent enteral tubing misconnections

Question 30

**What is ASPEN/SCCM recommendations for checking GRVs in critically-ill patients?

Answer 30

• **It is not recommended, because a number of factors can compromise the accuracy of GRV checks:
  
  • feeding tube type, diameter and position
  • viscosity of GRVs
  • technique, including size of syringe and time and effot spent
  • position of the patient

*GRVs have not been found to correlate with incidence of PNA or aspiration, and checking them increases episodes of feeding tube occlusion, reduce the total volume of EN delivered, and take up RN time

Question 31

**If GRVs are checked, what are the ASPEN/SCCM recommendations?

Answer 31

**In the absence of other signs of intolerance (vomiting or abdominal distention), EN should not be held for GRVs of less than 500 mL.

Question 32

In what patient populations, is checking GRVs helpful?

Answer 32

Patients that are high risk for GI dysfunction, in the surgical ICU and the most severely ill patients

Question 33

What methods should be used routinely for checking GI function?

Answer 33

1. Passage of flatus and stool
2. Stool frequency and consistency
3. Physical exam to assess bowel sounds, abdominal girth, and abdominal radiographs

Question 34

What methods are used to assess for dehydration?

Answer 34

• Poor skin turgor
• Dry mucous membranes
• Elevated [BUN], [Cr], and [Na2+]

Question 35

What are causes for hyperglycemia in the ICU?

Answer 35

Causes are multifactorial and include:

• Increased release of counterregulatory hormones that stimulate gluconeogenesis
• Proinflammatory cytokines that result in IR
• Provision of steroid and adrenergic meds
• Excess dextrose admin via IV fluids and meds

Question 36

**What are SCCM/ASPEN guidelines for acceptable blood glucose control in hospitalized patients?

Answer 36

**140 - 180 mg/dL

BG levels should be checked every 4 - 6 hours for patients with diabetes OR in patients with BG over 180 mg/dL

Question 37

How should optimal BG control be achieved in the hospital setting?

Answer 37

Continuous insulin drip; hyperglycemia is not an indication to delay initiation of EN

Note: oral meds and SSI should not be used because they can delay the achievement of BG control and are associated with a higher incidence of renal dysfunction

Question 38

If an MD recommends switching the EN formula to a higher-fat content formula, what would you say?

Answer 38

It is not recommended because the higher fat content may delay gastric emptying, affecting tolerance and thereby limiting the ability to achieve goal volumes.

Question 39

If an MD notes serum albumin and prealbumin as indicators of nutrition status, what would you say?

Answer 39

They are now known as indicative of inflammatory status and not nutrition intake. No serum lab values indication nutrition status or adequacy of nutrition provision.