Fluids, Electrolytes, Acid-Base Disorders, and Nutrition Support

Indications for EN: If the patient is unable to eat adequate amounts to achieve goal nutritional intake.

EN is preferred to PN because EN helps maintain the integrity of the GI tract, has fewer infectious

complications, is associated with decreased ICU length of stay, and is more cost-effective (JPEN J

Clin Nutr 2017;36:623-50) indicating a reduction in infectious complications with PN as compared

with the past literature (likely because of improvements in catheter care, PN formula management

and compounding practices, and glycemic control standards over the past several decades). In fact,

the 2022 ASPEN guidelines for critically ill patients recommends that either PN or EN is acceptable

as the primary feeding modality in the first week of critical illness (evidence GRADE: high; strength

of GRADE recommendation: strong) (JPEN J Parenter Enteral Nutr 2022;46:12-41). This is based on

findings that similar energy intake provided as PN is not superior to EN and no differences in harm

were shown. Patient-specific factors and clinical judgment should guide the choice between PN versus

EN.

Lack of bowel sounds, flatus, or bowel movement is not a contraindication for EN because these

are nonspecific indicators of GI function (JPEN J Parenter Enteral Nutr 2009;33:277-316; SCCM/

ASPEN 2009).Evidence of ileus (e.g., dilated loops of bowel on abdominal radiography) is, however,

a relative contraindication for EN.

High NG output (greater than around 800 mL NG output) in a 24-hour period may indicate delayed

gastric emptying, and the patient may not be ready for EN when fed into the stomach and post-

pyloric feeding is not possible. High NG output may also indicate an ongoing ileus or obstruction,

in which case, PN may be indicated, especially if at high nutrition risk.

Refusal to eat/anorexia is not an absolute contraindication for EN. Ensure appropriate dietary

preferences, and add high-calorie/protein liquid supplements to meals and bedtime snack first.

Product Category

Indication

Macronutrients

Additional

Comments

Examples

Standard tube

feeding

Minimal stress

1–1.2 kcal/mL

Protein 40–50 g/L

Polymeric, 300–500

mOsm/kg, fiber

Jevity, Nutren 1.0,

Fibersource HN

Volume restricted

Congestive heart

failure, fluid-restricted

patients

2 kcal/mL

Protein 60–80 g/L

Polymeric, 700–800

mOsm/kg, fiber

Nutren 2.0,

Resource 2.0,

TwoCal HN

Renal

AKI (predialysis),

renal dysfunction

with increased serum

potassium, phosphorus,

magnesium

2 kcal/mL

Protein 30–40 g/L

High calorie, low

protein, no or low

electrolytes, 600

mOsm/kg, volume

restricted, fiber

Renalcal, Suplena

Renal

Renal failure with

hemodialysis

1.8–2 kcal/mL

Protein 80–90 g/L

High calorie, modest

electrolytes, volume

restricted, 1000

mOsm/kg, fiber

Novasource

Renal, Nepro