Complications of Parenteral Nutrition Flashcards
What is the most common metabolic complication associated with PN?
Hyperglycemia
Cholestasis has been associated with ILE doses greater than __ gm/kg/day in adult patients receiving long term PN
1 gm/kg/day
ASPEN recommended phosphorus dose for PN formulation?
20-40 mmol/day
What is calcium supplementation in PN limited by?
Limited by calcium’s physical compatibility with phosphorus
How can excessive vitamin D be detrimental to the bone?
Excessive vitamin D can suppress parathyroid hormone and promote bone resorption
How does stress-associated hyperglycemia develop?
As a result of insulin resistance, increased gluconeogenesis, and suppressed insulin secretion
What is the ASPEN recommended target BG concentration in adult hospitalized patients?
140-180 mg/dL
What conditions has excessive carbohydrate administration been associated with?
Hyperglycemia, hepatic steatosis, and increased carbon dioxide production
In acutely ill patients, carbohydrate administration should not exceed a rate of:
4-5 mg/kg/min or 20-25 kcal/kg/day
When would the delivery of ~100 gm dextrose be warranted?
If the patient has a low BMI or poor glucose control
How often should capillary blood glucose concentrations be monitored in patients receiving short-acting subcutaneous insulin?
Every 6-8 hours
What is a common initial insulin regimen in PN?
0.05 to 0.1 units per gram of dextrose
0.15 to 0.2 units per gram of dextrose if patient is already hyperglycemic
What kind of insulin should be added to the PN formulation?
Regular insulin
What clinical outcomes is hyperglycemia associated with?
Increased risk of infection
Poor wound healing
Inability to gain weight
How can PN-associated hypoglycemia occur?
Excess insulin administration via the PN solution, IV infusion, or subcutaneous injection
What are treatment methods for PN-associated hypoglycemia?
Initiation of a 10% dextrose infusion, administration of an ampule of 50% dextrose, and/or stopping any source of insulin administration. Can also consider oral carbohydrate (glucose gel or chewable tablets) in mild hypoglycemia in patients who can tolerate it
What has been associated with rebound hypoglycemia?
Abrupt discontinuation of PN
How can the risk of rebound hypoglycemia be reduced?
1- to 2-hour taper down of the infusion, or half the infusion rate
What should be done if a PN solution must be discontinued quickly?
A dextrose-containing fluid should be infused for 1 to 2 hours following PN discontinuation to avoid a possible rebound hypoglycemia
ILE-free PN may result in what deficiency?
Essential fatty acid deficiency (EFAD)
What are clinical manifestations of EFAD?
Scaly dermatitis
Alopecia
Hepatomegaly
Thrombocytopenia
Fatty liver
Anemia
After what length of time receiving an ILE-free PN can EFAD occur?
Within 1-3 weeks in adults receiving ILE-free PN
Adult requirements for linoleic acid are met through exogenous sources or endogenously through the lipolysis of adipose tissue, but what can happen when hypertonic dextrose is infused?
Insulin is secreted and lipolysis is reduced, necessitating an exogenous source of fat provision
To prevent EFAD, what percent of daily energy requirements should be derived from linoleic acid and linolenic acid?
1-2% from linoleic acid
0.5% from linolenic acid
What is the infusion goal of 10% and 20% soy-based ILE administration to prevent EFAD?
500 ml of 10% soy-based ILE administered over 8-10 hours twice a week OR
250 ml of 20% soy-based ILE administered over 8-10 hours twice a week OR
500 ml of a 20% soy-based ILE given once a week
What needs to be considered (regarding preventing EFAD) when using an alternative oil-based ILE (such as those containing MCTs, olive oil, fish oil)?
A greater amount of ILE is required to meet essential fatty acid requirements because these non-soy based products contain lower quantities of linoleic and linolenic acid
How has linoleic acid (aka omega-6) been postulated to suppress the immune response?
By activating the arachidonic pathway
How is it suggested that certain long-chain fatty acids may impair immune function?
By interfering with phagocytosis and chemotaxis and may increase the patient’s risk of infection
What has been suggested as a strategy to reduce immunosuppression complications in critically ill patients receiving PN?
Withholding or limiting soy-based ILE for the first week of PN - recommendation based primarily on research from only 1 study
When can hypertriglyceridemia occur with PN?
With dextrose overfeeding or with rapid administration rates of ILE (>0.11 gm/kg/hour)
What complications may result from hyperlipidemia?
May impair immune response, alter pulmonary hemodynamics, increase risk of pancreatitis
What amount should ILE intake be restricted to?
<30% of total energy, or 1gm/kg/day
What are the ASPEN recommendations regarding serum triglyceride levels and the appropriate response?
Serum TG >400 mg/dL should be avoided when infusing ILE, and the ILE dose should be reduced or discontinued if this level of hypertriglyceridemia occurs
Why should the dose of ILE be reduced or discontinued in the mechanically ventilated patient receiving Propofol?
Because Propofol is supplied as a 10% ILE
Is ILE considered safe for use in pancreatitis without hypertriglyceridemia?
Yes
What condition is rare unless serum TG levels exceed 1000 mg/dL?
Pancreatitis due to ILE-induced hyperlipidemia