Exam # 3: Parental Nutrition Questions Flashcards
PPN vs TPN
1) Peripheral parenteral nutrition utilizes peripheral veins to administer nutrition, the maxmium osmolarity is 900 mOsm/L to avoid phlebitis, will not usually meet nutritional needs and is intended for short term usage (2-3) days. 2) Total peripheral nutrition or central parenteral nutrition utilizes a central vein ( the superior vena cava), provides total protein, calorie, and nutrient supplementation. The total osmolarity can exceed 1,000 mosm. intended for long term usage (7+ days).
Example of PPN
Clinimix
Criteria for the appropriate usage of PPN
1) you need peripheral vein access 2) be able to tolerate increased fluid volumes ( 2-3 L/day in a 60 kg adult) 3) require less than 2 weeks of PPN
Conditions warranting the usage of TPN
1) inadequate calorie and or protein intake to meet needs 2) anticipated inability to eat for more than 10 days 3) chronic illness and the inability to use the GI tract
Conditions that indicate TPN need
Overall intestinal failure ( severe malabsorption, short-bowel syndrome, obstruction, intractable diarrhea or vomiting, GI bleed, severe malnutrition) , bowel rest, severe malnutrition
Potential complications with TPN
infection, air embolism, catheter tear, catheter clot, phlebitis, loss of central vein access ( adults have 6-8 sites and children have 4-6 sites)
Why can TPN be tolerated with higher osmolarities?
the higher osmolarity load can be tolerated due to the high volume of blood returning to the heart
PICC
used for TPN short term - peripherally inserted central catheter (placed into the front of the elbow and threaded into the subclavian vein into the superior vena cava.
dextrose increments
concentrations of 2.5 - 70% with 5% incremental increases
D%W (D25W)
translates to 25% dextrose concentration
What is the minimal amount of dextrose used to spare protein?
1mg/kg/min
excess dextrose infusion can cause
lipid synthesis and fatty liver, elevations in liver function tests, hyperglycemia, an increase in the production in CO2
What is the most common malady associated with peripheral nutrition?
hyperglycemia; occurs when infusion rate exceeds that of the body’s ability to produce insulin
At what level of blood triglycerides should fat not be infused?
when fasting triglycerides are greater than 400 mg/dl; monitor triglycerides by measuring serum triglycerides pre-infusion and 6 hours post infusion
What are some possible additives to peripheral nutrition?
Minerals ( added last), histamine 2 antagonist, heparin, insulin
what is the purpose of adding histamine 2 antagonist?
to decrease gastric acid secretion
What is the purpose of adding heparin to PN?
to prevent clotting that might obstruct the flow of PN
What is the purpose of adding insulin to PN?
to help regulate serum glucose levels
What are some metrics evaluated while is a patient is on PN?
1) weight 2) fluid status 3) infection ( monitor WBC) and temperature
What is the most common liver dysfunction found in adults taking PN? Children?
Adult - steatosis ; children - cholestasis
What can cause liver dysfunction with PN?
excessive dextrose, lipid infusion, and/or calories.
What metric is seen with a dysfunctional liver?
elevated liver enzymes
How do we treat a dysfunctional liver associated with PN?
decrease dextrose intake, decrease IVFE intake, switch to cyclic infusion
Effects of prolonged PN
mucosal atrophy, enterocyte hypoplasia, decreased intestinal activity, very little appetite
How many days does it take for the gut to adjust to enteral intake?
about 5 days
Refeeding syndrome
initial PN infusion should aim to meet 75% to 100% of BEE, monitor for hypophosphatemia, hypokalemia, hypomagnesemia, fluid overload, congestive heart failure, and hyperglycemia, add electrolytes and minerals administered as needed.
Transitional feeding period
period during oral and or enteral nutrition is initiated and PN is discontinued, accomplished in a timed manner, it is necessary to avoid deterioration of nutritional status when PN is discontinued.
Example of Transition from TPN to Tube Feeding
1) Select appropriate tube feeding formula 2) start tube feeding at low rate ( 30-40cc/hr) 3) Increase 25-30 ml/hr every 8-24 hours tolerated 4) When patient meets 75% of nutrients via TF, PN can be discontinued
Oral facial hypersensitivity
neurological damage that is caused by a lack of oral stimulation especially when tube fed or using TPN ( manifests as overactive gag or cough reflex), touching the tongue can cause a gag reflex, touching the teeth or gums can use a strong bite reflex
Treatment of oral facial sensitivity
1) speech language pathologist 2) oral desensitization exercises 3) gradual introduction or different stimuli
Which approaches require consideration of osmolality?
Tube feeding and PPN
Which type of nutrients supplementation is inappropriate to use when a patient is exhibiting malabsorption issues?
Standard Enteral Formula
Which type of nutrition support can be administered at high rates/hour?
TPN
Generally speaking, providing excessive carbohydrates, protein, and fat is potentially a greater problem with what type of nutrition support?
TPN
