Parenteral Nutrition


Step 3: Implement

Interdisciplinary Team

There are many healthcare professionals involved in the interdisciplinary team. Depending on the patients medical plan and condition, there may be other team members involved. However, the list below represents a usual inpatient team. Their roles are discussed as it pertains to enteral nutrition.

  • Registered Dietitian: primarily responsible for enteral nutrition, transition to oral diet.
  • Speech Language Pathologist (SLP): assess safety of oral diet & texture recommendation.
  • Pharmacist (RPh): drug and nutrient interactions, medication dosing/ indications.
  • Registered Nurse (RN): implement nutrition care plan, provide clinical information.
  • Physiotherapist (PT): ambulation, positioning, assist with obtaining weights.
  • Occupational therapist (OT): cognitive assessment to determine if patient can provide accurate information, modified eating equipment, positioning.
  • Medical Doctor (MD) or Nurse Practitioner (NP): medical update, enter orders for IVF, labs, imaging, medications, consults.
  • Social Worker (SW): provide counselling, disposition planning and identify sources of emotional support for patients and their families.

Depending on your institution, you may have a dedicated PN team. PN is a complex form of nutritional care which involves multiple disciplines: RD, MD, NP, RN, RPh, and pharmacy technicians. A multidisciplinary approach is more cost-effective, efficient and may be associated with a reduction in infectious complications and more appropriate use of parenteral nutrition (communication, training, and consensual approach).

Dedicated PN team members include:

  • Dietitian: performs nutritional assessment to determine estimated nutrition requirements; chooses formula, quantity, rate and concentrations; monitors clinical/metabolic response; manages transition to EN/oral intake; monitors and manages some side effects, liaises with all team members.
  • Doctor or Nurse Practitioner: oversees/consults on medical management of the patient, may insert vascular access device, responsible for signing off all nutrition prescriptions including additives.
  • Nurse: oversees care of the vascular access site, physical management of the parenteral nutrition infusion and related equipment, training for home parenteral nutrition.
  • Pharmacist: oversees/consults on the choice of formulation and additives, may be involved with nutrition prescription and compounding of solutions and/or loading of parenteral additives.

Implementing Parenteral Nutrition

When monitoring for refeeding syndrome or when generally initiating PN in a critically ill patient, it is important to take a “step-wise” approach. Conservative initiation allows you to monitor, replace, and adjust the PN as required.

Protocols vary by institution & unit (ICU vs. ward):

  1. Monitor for refeeding syndrome
  2. On day 1, feed ≤50% of energy requirements and follow with monitoring and replacing
  3. On day 3, feed ~75% of energy requirements and follow with monitoring and replacing
  4. On day 4/5, feed 100% of energy requirements and follow with monitoring and replacing
  5. Long-term PN: Continue to revise energy and protein goals, cycle PN, monitoring and replacing

Monitoring Parenteral Nutrition

Patients who are receiving PN require monitoring to ensure safe deliver of their nutrition care plan. Frequency of monitoring depends on your patient’s clinical condition, past medical history and tolerance of PN regime.

During implementation of the PN feeding plan, consider monitoring the following.

  • Bloodwork: Typically monitored more frequently (daily) when starting PN and less frequently (1-2 times per week) when stable on PN. Typical labs that are ordered and monitored include: electrolytes, renal profile, calcium profile, LFTs, amylase, blood glucose, CBC, lactate, triglycerides (TG).
  • Weight: Patients receiving PN should be weighed prior to initiation and then weekly (or bi-weekly) while receiving PN to monitor weight changes.
  • Daily intake and output: to assess your patient’s fluid balance and actual volume of PN received.

Continuously reassess your patient’s need for PN and nutrition provision based on their clinical course.

The tables below represent the monitoring parameters mentioned above.

Anthropometric parameters, by monitoring frequency
[*] denotes: daily until stable, then once or twice weekly
Initial Daily Weekly
Weight X X X
Height X
Intake & Output X X*
Metabolic assessment parameters, by monitoring frequency
[*] denotes: daily until stable, then once or twice weekly
[**] denotes: not routinely ordered
[***] denotes: Initially and before each advancement of IV fat emulsions (IVFE), then once weekly. If septic, more frequent monitoring is required.
Initial Daily Weekly
Na, K, Cl, CO2 X X* X
Ca, Phos, Mg X X* X
Glucose X X* X
Liver Function Tests X X
Prothrombin time X X
Transferrin or Prealbumin** X X
Triglycerides X*** X
Complete Blood Count X X

Monitoring for Refeeding Syndrome

Below is important information to know for patients who are at risk of refeeding syndrome. Having awareness of what symptoms to watch for, knowing when symptoms occur, and what to do can allow you to optimize your patient’s nutritional status as safely as possible.

  • Symptoms of refeeding syndrome most often occur within 1-3 days after initiating feeding, but may occur up to 5 days following initiation of feeding.
  • Closely monitor your patient’s heart rate and fluid intake/output for changes that happen with initiation of feeding.
  • Hypophosphatemia is a classic first sign associated with refeeding syndrome.
  • Monitor electrolytes daily (K, PO4, Mg) for a minimum of 3 days. If your patient is at high risk of refeeding syndrome or shows signs of refeeding syndrome, monitor electrolytes for up to 1 week. Correct abnormalities concurrently with feeding and prior to advancing feeds.
  • Advance feeding as soon as is safely possible to avoid hypocaloric feeding for prolonged period (advancement of 200 -300 kcal every 1-3 days recommended)

Parenteral Complications

Macronutrient Complications

PN complications are often multifactorial. It is important to discuss these complications with your medical team to determine the most likely cause and establish an appropriate treatment plan. Below is a chart of possible complications associated with parenteral nutrition.

Causes and treatment for macronutrient-related problems associated with PN
Problem Possible Causes Treatment
EFA Deficiency
  • Inadequate provision of EFA
  • Prevention: 1-2% energy from linoleic, 0.5% energy from linoleic
  • Treatment: 250 mL 20% IVFE twice weekly
  • Dextrose overfeeding
  • Rapid administration of IVFE
  • Propofol administration
  • IVFE < 30% total kcal or < 1g/lipid/kg/day
  • Excessive protein
  • Dehydration
  • Reassess macronutrient requirements and provision
  • Additional fluid if indicated
  • Medical issues (diabetes, sepsis, catabolism, trauma, etc)
  • Insulin resistance
  • Refeeding
  • Glucocorticoids
  • Excess carbohydrates (CHO)
  • Correct blood glucose (BG) as per protocol
  • Adjust CHO intake

Dextrose Complications

Patients may experience side effects related to continuous dextrose administration.

Some patients who receive PN may have hyperglycemia-elevated blood glucose. This hyperglycemia may or may not be related to diabetes. In critical illness, levels of stress hormones are elevated, which can cause hyperglycemia.

It is very important to achieve adequate glycemic control in patients who are acutely or critically ill as prolonged hyperglycemia may cause higher infection rates or delay wound healing. Most institutions administer insulin to patients separately, although insulin could be added to the parenteral solution. Frequently, an insulin nomogram (i.e. Humulin R) is the preferred method to optimize glycemic control.

Another complication related to increased CHO intake (or if total energy intake is too high)  is increased ­CO2 production. Patients with compromised lung function may not be able to handle high CO2 production.

Occasionally with dextrose infusions we see lipogenesis (elevated triglyceride levels).

 Liver Complications

In patients who are receiving PN, we may see serum increases in various serum liver function tests. Increases in these values may indicate early signs of PN related liver disease.

If patients develop PN related liver disease there are several strategies to avoid its progression. Clinicians may:

  • cycle PN delivery over a shorter period daily (i.e. 12hrs)
  • decrease total energy intake to avoid overfeeding
  • consider the use of Omega-3 or mixed lipids (i.e.  SMOF)

Common blood tests include:

  • Bilirubin
  • AST (aspartate aminotransferase)
  • ALT (alanine transaminase)
  • GGT  (gamma-glutamyl transpeptidase)

Hepatobiliary Complications

Patients may develop hepatobiliary complications (i.e. related to liver disease) that may be associated with parenteral nutrition. Hepatobiliary complications such as steatosis, cholestasis, and gallbladder stasis share similar management strategies:

  • Rule out non-PN factors: hepatotoxic medications, herbal supplements, biliary obstruction, hepatitis, sepsis
  • Consider PN modifications:
    • Decrease dextrose
    • Decrease (< 1 g/kg/day)
    • Balance dextrose and IVFE
    • Cyclic PN infusion
    • Maximize enteral intake (oral diet or tube feeding) where appropriate
    • Prevent/treat bacterial overgrowth
  • Pharmacotherapy

Catheter or Blood Vessel Complications

Here is an overview of the potential catheter or blood vessel related complications of PN.

  • Blocked intravenous line: insufficient flushing, thrombosis, line is incorrectly positioned, precipitated lipid or medication.
  • Line infection: contamination of the line, prolonged use of the access device, contaminated parenteral nutrition solution, poor hand hygiene, not using sterile equipment, improper line care.
  • Phlebitis: leaving catheter in too long, using a catheter too large for the vein, irritation from medications, infusing a high concentration solution.
  • Thrombosis
  • Line displacement: inappropriate site selection, accidental pulling of the device.

Metabolic Complications

There are various metabolic complications that are possible when feeding patients parenteral nutrition. Please review each item in the list below to familiarize yourself with the complication. The “Troubleshooting” section of the Dietitians of Australia’s  Guide to Parenteral Nutrition (PDF)  will provide details on common interventions or solutions to these complications.

  • Hyperglycemia
  • Hypernatremia/ Hyponatremia
  • Hyperkalemia/ Hypokalemia
  • Hypercalcaemia/ Hypocalcaemia
  • Hyperphosphatemia/ Hypophosphatemia
  • Increased serum triglycerides
  • Elevated liver function tests
  • High BUN and creatinine

Long-Term PN Complications

PN-related bone disease is a long-term complication seen in some home PN patients. The etiology is unclear, however it may be related to inadequate or excess Vitamin D intake or increased urinary calcium loss. Many long term PN patients are also on steroids (i.e. for bowel disease). Ultimately these patients can develop osteomalacia or osteoporosis.


Poppy’s Education

Poppy is asking to speak to the dietitian to understand why she is not allowed to eat. She complains of being hungry. The dietitian will need to use easy to understand language to describe the indications for PN and how PN is administered. The dietitian should explain possible side effects and complications, but also be able to reassure Poppy with evidence that this is the best treatment plan.

  1. Think about the possible side effects and complications with PN.
  2. List 3 benefits of PN that you could share with Poppy.
  3. Create a plain-language explanation of PN to share with Poppy.

Pause and answer these questions using the information provided to you so far.

Implementation Summary

Implementing Poppy’s Nutrition Care Plan: Summary

Initiation of Parenteral Nutrition:  Start at 50% of requirements on day 1. If tolerated, plan to increase to 75% on day 3. If tolerated, plan to increase to 100% on day 4 or 5. Add in multivitamin and thiamine as per nutrition care plan.

Monitoring: electrolytes renal profile, calcium profile, LFTs, amylase, blood glucose, CBC, lactate, and TG. Specifically monitor K, PO4, Mg for risk of refeeding syndrome.

Clinical Documentation (“Ins and Outs”):

  • PN received
  • Urine output
  • Fluid balance (updated wt (with ongoing diuresis), re: nutrition care plan for fluid restriction)
  • Symptoms (patient report) and medical complications
PART 3: IMPLEMENT COMPLETE. Now that you’ve finished the section, pause to reflect on the implementation strategies discussed. When you’re ready, move on to Part 4: Evaluation.



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Preparation for Dietetic Practice Copyright © by Megan Omstead, RD, MPH is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.