PN

Definition: Administration of nutrients directly into the bloodstream when the gastrointestinal (GI) tract cannot be used for ingestion, digestion, and absorption of essential nutrients.

Customization: PN is tailored to meet each patient's needs and is reformulated as the patient’s condition changes.
- Collaboration: Involves an interprofessional team to ensure proper delivery of PN.
Commercially Prepared Solutions:
- Base solutions contain dextrose and protein in the form of amino acids.
- Pharmacy adds prescribed electrolytes, vitamins, and trace elements to meet individual needs.
- 3-in-1 Total Nutrient Admixture: Combination of IV fat emulsion, dextrose, and amino acids is commonly used.
- Premixed Solutions: Require mixing dextrose and amino acid chambers before use; may have standard electrolytes and multivitamins added before administration.

Source of Calories: Primarily from carbohydrates (dextrose) and fats (fat emulsions).
- Dextrose provides 100 to 150 g/day (1 g yields approximately 3.4 calories).
- Oral carbohydrates yield 4 calories per gram.
Protein-Sparing Effect: Adequate nonprotein calories allow amino acids to be used for functions such as wound healing instead of energy.
Risks of Overfeeding: Overfeeding can result in metabolic complications, thus recommended energy intake is 25 to 30 cal/kg/day for nonobese patients.
Fat Emulsions: Available in 10%, 20%, and 30% concentrations, comparable caloric values:
- 10% solution: approximately 1 cal/mL
- 20% solution: approximately 2 cal/mL
Composition: Mainly contain soybean or safflower triglycerides and egg phospholipids as emulsifiers. Useful for patients at risk for fluid overload.
Lipid Dose Recommendations: General guideline is up to 20%-30% of total calories from fat. Most stable patients typically receive 1 g/kg/day; maximum is 2.5 g/kg/day. Critically ill patients may receive less, monitored closely with serum triglyceride levels.

Quantity: Provided at 1 to 1.5 g/kg/day; can exceed 150 g/day (or 2 g/kg/day) for nutritionally depleted patients.
- Patients with burns or multiple traumas may need over 2 g/kg protein.
- Lower protein needs (below 1 g/kg) may be indicated for patients with end-stage renal disease who are not on dialysis.

Assessment: Individual electrolyte needs depend on the patient's condition and serum levels, evaluated daily to several times weekly.
Average Daily Requirements for Adults (without renal or liver impairment):
- Sodium: 1 to 2 mEq/kg
- Potassium: 1 to 2 mEq/kg
- Magnesium: 8 to 20 mEq
- Calcium: 10 to 15 mEq
- Phosphate: 20 to 40 mmol

Addition: Zinc, copper, selenium, manganese, and chromium are added based on specific patient conditions.
Monitoring: Levels of these elements should be monitored.
Multivitamins: Commonly added to generally meet vitamin requirements; additional amounts may be ordered by the healthcare provider (HCP).

Types of PN: Central PN and Peripheral Parenteral Nutrition (PPN).
- Central PN: Indicated for long-term support requiring high protein and caloric levels, delivered via central venous catheter or peripherally inserted central catheter (PICC); solutions are hypertonic (at least 1600 mOsm/L).
- PPN: Administered via a peripheral catheter; appropriate for short-term needs and lower nutrient requirements; creates risks of phlebitis and fluid overload due to high-volume requirements. E.g., osmolality may reach up to 800 mOsm/L.

Solutions must be prepared by pharmacy professionals using strict aseptic techniques under laminar flow hood.
No additional substances should be added post-preparation.
Limit personnel involved in PN preparation and delivery to minimize infection risks.
PN solutions are customized daily to align with patient needs, labeled with nutrient content, additives, and expiration.
Solutions unstable after 24 hours; refrigeration required until 30 minutes pre-use.

Adhere to aseptic techniques to mitigate infection risk.
Use filtration: 0.22-micron for non-fat emulsions; 1.2-micron for fat emulsions.
Change filters and IV tubing per fresh PN containers or every 24 hours.
Label tubing and filters with initiation date and time.
Use a dedicated line for PN in multi-lumen catheters and avoid blood draws unless necessary.
Infuse PN using an infusion pump to control rates; check infusion volumes periodically to prevent discrepancies due to malfunctions.

Verification of PN solution with HCP orders before initiation; cross-check infusion pump settings with a second RN.
Tracking administration tubing is critical to ensure proper connections and prevent errors.
Conduct visual checks for leaks, color changes, particulate matter, and emulsification issues; report and replace solutions with any discrepancies.
After 24 hours, replace any PN solution that isn’t entirely used to prevent microbial growth, especially if fat emulsions are present.
Fat Emulsions: Administer separately, ideally via continuous low volume over 12 hours.

Hyperglycemia: Regular monitoring of glucose at bedside every 4-6 hours; aim for range 140-180 mg/dL, using insulin as needed.
Hypoglycemia: If PN formula empties prematurely, administer appropriate dextrose solutions to avoid hypoglycemia, evaluating based on the PN formula's sugar concentration.

Regular assessment of catheter sites for signs of infection or inflammation, noting manifestations such as erythema or tenderness.
Monitor systemic signs: fever, chills, nausea, and malaise, being cautious with immunosuppressed individuals.
Employ antibiotic or antiseptic-treated catheters for infection mitigation.
Agency protocols must be followed for dressing changes and infection control measures; cultures should be taken upon suspected infection and HCP notified.

Encourage gradual oral intake, recommending that at least 60% of caloric needs be met orally or through enteral nutrition (EN) before PN can be discontinued.
Begin with clear liquids, advancing to soft diet as tolerated.

Regular monitoring includes vital signs every 4-8 hours and daily weight checks to evaluate patients' hydration status.
Maintain meticulous intake and output records, looking for significant weight fluctuations and correlating with other parameters, like serum glucose, electrolytes, and urea nitrogen levels.
Conduct comprehensive blood tests — complete blood count (CBC) and hepatic enzyme studies — at least three times weekly until stable, then weekly as necessary depending on clinical status.