TPN Flashcards
1
Q
Advantages of nutrition support therapy
A
*Reduce disease severity
*Diminish complications
*Decrease length of hospital stay
*Increase patient’s qualify of life
*Decrease costs of medical care
*Severe chronic intestinal failure
*Neonates who cannot be fed by mouth
Goal is to provide adequate calories to prevent malnutrition and associated complications
2
Q
Classification of Malnutrition
A
- Weight and recent weight loss
- Actual body weight vs. ideal body weight vs.
adjusted body weight - Weight dynamics
- Body mass index (BMI)
- Albumin (half-life 18-21 days)
- Transferrin (half-life 8-10 days)
- Prealbumin (half-life 2-3 days)
- Retinol-binding protein (half-life 0.5 day)
3
Q
Enteral Nutrition (EN) vs. PN
A
- If the gut works, use it
- Enteral feeding:
-EN maintains gut integrity
-Fewer infections
-Lower costs & shorter hospital stays - Parenteral feeding:
-Useful if enteral access is not feasible, inadequate,
or not tolerated
-PN has less risk of gastric retention, emesis, and
aspiration
4
Q
Options for tube feeding
A
*Nasal vs. ostomy
*Sites for formula delivery
-Gastric (preferred)
-Duodenal
-Jejunal
5
Q
Indications for PN:
A
- Short bowel
- Radiation enteritis
- Distal high output fistulas
- Persistent ileus
- Pseudo obstruction
- Mechanical obstruction
6
Q
IV Access for PN therapy
A
- Peripheral IV (PIV aka PPN)
-Limited use (<7days) - Central Line (TPN) - PICC: Peripherally inserted central catheter
- CVC triple lumen
- Port a Cath
7
Q
Maximum Dextrose Concentrations and Osmolarity Limits
A
- Peripheral line (PPN):
-Max Concentration: Dextrose 10%
-Osm: 900 mOsm/L - Central line (TPN):
-Max Concentration: Dextrose 25%
-Osm: 1500 mOsm/L
8
Q
Estimated Energy Requirement Examples
A
- Healthy, maintenance: 20-25 kcal/kg/day
- Malnourished or stressed: 25-30 kcal/kg/day
- Severe stress: 30-35 kcal/kg/day
9
Q
Protein requirements
A
- Based on body weight, degree of stress and disease state
- Estimated protein needs:
-Maintenance: 0.8-1.2 g/kg/day
-Mild catabolism: 1.2-1.5
-Moderate cat: 1.5-2.0
-Severe cat: 2.0-2.5 - Note: Protein and amino acids are restricted in patients with renal and hepatic dysfunction
-Require only 0.6-0.8 g/kg daily
10
Q
Protein
A
- Protein in PN is supplied as an amino acid mixture
- Protein provides 4 kcal/g
- Notated as “AA” and various percentages
- Ex: AA 10% = 10g/100mL
- Max AA% in PN = 8%
11
Q
Carbohydrates
A
- Dextrose is the most common carbohydrate for IV use
- Dextrose provides 3.4 kcal/g
- Carbohydrates to meet 70-85% of nonprotein calories
12
Q
Fat
A
- Lipid or fat provides 9 kcal/g
- IV formulas supplied as 10% and 20% lipid
emulsion - 10% lipids provide 1.1 kcal/mL
- 20% lipids provide 2 kcal/mL
- Fat to provide 15-30% of nonprotein calories
13
Q
Why include lipids in PN?
A
- Required for cell membrane synthesis and production of immune response mediators
- Used to prevent EFAD
- Essential fatty acid deficiency (EFAD) occurs
after 1 week-1 month of no fat intake - Monitor triglycerides weekly
- Note: Lipids are held if the patient is on Propofol or if TG ≥ 400 mg/dLq
14
Q
Daily fluid requirements
A
*1500 mL + 20 mL/kg in excess of 20 kg
* Range 20-40 mL/kg/day
* Can also estimate 1 mL/kcal
* Replacing fluid losses in patient on PN
14
Q
Other ingredients in PN
A
- Electrolytes :
-Na, K, Mg, Phos, Ca - Multivitamin :
-ADEK + B1/B2/B6/B12/C + Folic Acid - Trace elements: Zinc, Chromium, Selenium, Copper, & Manganese
-Renal trace elements contain all trace elements at a reduced amount
-Hepatic trace elements only contain zinc, chromium, and selenium
14
Q
Nutritional Requirements
A
- Total calories: 20-35 kcal/kg/d
- Protein: 0.8-2.5 g/kg/d
- Carbohydrates to meet 70-85% of non-protein calories
- Fat to provide 15-30% of non-protein calories
- Fluids: 20-40 mL/kg/d
- Vitamins, trace elements, electrolytes
14
Q
Calcium and Phosphate
A
- Avoid mixing in close sequence
- Add phosphate before calcium
- Avoid excess Calcium/Phosphate
- Utilize the Calcium/Phosphate Curve
14
Q
Monitoring patients on PN
A
- Body weight
- Intake (PO, IVF, IV medications, PN)
- Output (Drainage, fistula, diarrhea)
- Blood glucose & metabolic panel
- Hepatic panel & triglycerides
- Signs and symptoms of line infection
15
Q
Tips for Adjusting Electrolytes
A
- Sodium: 136-145 mmol/L
-Avoid too rapid a correction of serum [Na+] to
avoid serious neurological complications - Calcium: 8.6 -10.2 mg/dL
-Calculate corrected calcium first - Potassium*: 3.5-5.1 mmol/L
- Magnesium*: 1.7-2.6 mg/dL
- Phosphorous*: 2.7-4.5 mg/dL
- Use with caution if adding to PN in AKI/IHD/CRRT patients and discuss with nephrology
16
Q
Renal Impairment
A
- AKI/IHD/CRRT
- Very conservative if barely any electrolytes in PN
- Watch K, Mg, & Phos
- Discuss with Nephrology
- Renal adjustments for amino acid (protein requirement reduced to 0.6-0.8 g/kg daily) and trace elements
17
Q
Hepatic Impairment
A
- Monitor liver function tests (LFTs)
- Adjust trace elements if total bilirubin >1.2 mg/dL
- Adjustments for amino acids
18
Q
Potential Complications of PN
A
- Mechanical (catheter occlusion = use heparin or sodium citrate)
- Infectious (maintain access)
- Metabolic:
-Hyperglycemia (limit dextrose rate <4, insulin)
-Electrolyte disturbances (monitor daily BMP/Mg/Phos, weekly TG/Liver)
-Refeeding syndrome (start slow, advance slow)
-Liver (steatosis, cholestasis)
-Bone (ca deficiency, osteos, Al/Vit D tox)
19
Q
Insulin in PN
A
- Only regular insulin can be used in PN
- Discuss with Endocrinology
- Monitor closely and use with caution
- Reasonable starting point is 0.05-0.1 units/g of dextrose if warranted
- If patient becomes hypoglycemic, all sources of insulin would stop (including PN)
