Parenteral Nutrition

Question 1

What is the max osmolarity tolerated by a peripheral vein?

Answer 1

900 mOsm/L

Question 2

What time period indicates Central parenteral nutrition and peripheral parenteral nutrition?

Answer 2

PN support longer than 7 to 14 days indicates CPN. While PPN is recommended for periods < 2wks.

Question 3

What 2 criteria that pt must meet to be considered for PPN?

Answer 3

1. To have good peripheral venous access

2. To be able to tolerate large volume (2.5 - 3 L) of fluid.

Question 4

What are the contraindications of PPN?

Answer 4

1. Significan malnutrition
2. Severe metabolic stress
3. Large nutrient or electrolytes needs
4. Fluid restriction
5. Need for prolong parenteral nutrition (>2wks)
6. Renal or liver compromise

Question 5

Describe 2 ways to improve tolerance to PPN.

Answer 5

1. In addition to increasing the caloric density of PPN, adding IVFE doesn’t increase osmolarity which improve peripheral vein tolerance.
2. Using mid-line catheters improve peripheral vein tolerance because they are longer and more likely to have the tip in a larger vein.

Question 6

Which conditions/circumstances has PN shown beneficial?

Answer 6

1. Perioperative support of pt with moderate to severe malnutrition
2. Acute exacerbation of Crohn’s disease
3. GI fistulas
4. Extreme short bowel syndrome
5. Critical care pt who will be NPO for prolong periods of time.
6. Severe acute necrotizing pancreatitis

Question 7

List the indication for PN?

Answer 7

1. Pts who cannot or will not eat adequately to maintain their nutrient stores. They are or have potential to be malnourish
2. Pt has failed EN trial w/ appropriate tube placement (postpyloric).
3. EN is contraindicated or the intestinal tract has severely diminished fnx due to underlying disease/treatment.
4. In postoperative nutrition support. It’s suggested that wound healing is impaired if PN is not started w/in 5-10 days postoperatively for pts unable to eat or tolerate EN feeding.

Question 8

List some conditions where nutrition support should be withheld until the condition improves?

Answer 8

1. Hyperglycemia
2. Azotemia
3. Encephalopathy
   4.Hyperosmolality
4. Severe fluid and electrolyte disturbances
   NB: PN should only be given in patients who are hemodynamically stable.

Question 9

List some clinical conditions that warrants cautious use of PN.

Answer 9

1. Hyperglycemia (glu >300mg/dl)
2. Azotemia BUN >100mg/dl
3. Hyperosmolality >350mOsm/kg
4. Hypernametria: Na >150mEq/L
5. Hypokalemia: K < 3mEq/L
6. Hyperchloremic metabolic acidosis: Cl >115mEq/L
7. Hypophosphatemia: P < 2mg/dl
8. Hypochloremic metabolic alkalosis: Cl <85 mEq/L

Question 10

NB: Critically ill patients requiring PN are those who are hemodynamically stable and have a paralytic ileus, acute GI bleeding, or complete bowel obstruction.

Answer 10

NB: Moderately to severly malnourished pts who are expected to have a prolonged period of GI problems precluding the use of GI tract are likely to benefit from PN.