Monica - Week 8 - Exam 3 Flashcards
what are three reasons we give parenteral nutrition in acute care setting?
- administration of nutrients other than GI tract
- not able to tolerate enteral feedings
- delivers complete nutritional support
what are 4 considerations when it comes to parenteral nutrition?
- critical illness after 7 days of hospitalization and enteral not feasible
- protein-calorie malnutrition
- major GI surgery and not able to feed (GI resection)
- unable to meet energy requirements after 7 - 10 days by enteral route alone (helps supplement PO nutrient)
what are 8 other indications of parenteral nutrition?
- chronic severe diarrhea and vomiting
- complicated surgery or trauma
- intractable diarrhea (loss of F+E)
- GI tract abnormalities
- severe malabsorption
- GI obstruction
- severe anorexia nervosa
- short bowel syndrome (missing/removed; most nutrients absorbed here)
what is the osmolarity of PPN?
osmolarity NTE 900 mOsm/L
what is one indication for PPN?
supplement inadequate oral intake
how long can someone be on PPN?
temporarily; nutritional support for < 2 weeks
when is PPN administered?
administered around the clock or in cycles
how many calories does PPN offer?
provides < 2000kcal/day
what is the volume (size) of a PPN bag?
2000 - 3000 mL
what is the osmolarity of TPN?
ranges from 1500 - 2800 mOsm/L
what is one indication for TPN?
to correct nutritional deficits
who is a candidate for TPN?
a patient that has high protein/calorie requirements
how long can some be on TPN?
> 2 weeks
how many calories does TPN offer?
> 2000 kcal/day
how much dextrose might TPN contain?
may contain up to 50% dextrose
**may think about adding insulin??
what is the volume (size) of a TPN bag?
1 - 2 L bags; infusion volumes < PPN d/t higher tonicity
there is a risk for _______ when using both TPN and PPN.
phlebitis; 3-4 days –> start new IV to ensure patency and decrease risk of phlebitis
how is TPN given??
ONLY THROUGH A CENTRAL LINE; WE CAN’T GIVE THIS YET
what are 5 assessments/lab tests we need to be aware of when giving PN?
- height/weight, ideal body weight, % of weight loss
- electrolytes (Na+, K+, Mag+, glucose, Ca2+)
- protein level (6 - 8g/dL; protein deficit?)
- kidney function (BUN, Cr, GFR)
- liver enzymes
why are we assessing function of the kidneys and liver?
to see if liver and kidneys can handle the PN (metabolism and excretion); can’t give too much protein if kidney/liver problems
what is the normal range for pre-albumin?
17 - 40mg/dL
what does pre-albumin tell us?
- protein synthesis (mainly made by liver)
- assess malnutrition risk (can tell us RIGHT NOW if there is malnutrition)
what is the half life of pre-albumin?
2 days - that’s why it’s a good indicator of current state of malnutrition
T/F pre-albumin is more sensitive to changes in protein status
TRUE - d/t half life of 2 days
what is a lab test that monitors the efficacy of PN??
pre albumin
what pre-albumin level indicates severe nutritional deficiency?
< 10mg/dL
what pre-albumin level indicates severe protein depletion?
< 5mg/dL - other systems could be in danger - breakdown of muscle
what is the normal range for albumin?
3.5 - 5.0
what does albumin tell us?
it assesses nutritional status
what is the half-life of albumin?
20 - 24 days
what is the function of albumin?
maintains colloidal osmotic pressure –> prevents 3rd spacing
what do low levels of albumin indicate?
severe malnutrition, liver, and kidney disease
what do high levels of albumin indicate?
dehydration, severe vomiting or diarrhea
losing more fluid volume, so albumin is more concentrated
what are the 4 macronutrients in PN?
- water
- dextrose (CHO)
- lipids (fat)
- amino acids (protein)
what are the 3 micronutrients in PN?
- electrolytes
- vitamins
- trace elements
when are electrolyte levels drawn? why?
- all electrolytes are drawn daily
- assessed by pharmacy to adjust therapy
- assess for abnormal levels
what is the primary source of calories?
dextrose (carbohydrate souce) - 70 - 85%
when is dextrose increased?
gradually increased based on patients tolerance
what interventions should RN implement in relation to dextrose?
- evaluate glucose tolerance
- glucoscan orders
what are glucoscan orders for PN?
q6hrs initially and then qPM for qDay
**diabetics: increased frequency throughout therapy - already have insulin resistance issue
what are 3 reasons amino acids are added?
- synthesize proteins
- conserve lean body mass - promotes body mass
- promote wound healing - slows blood sugar rise
one gram of amino acid = _____ gram of protein
ONE
what is the percent of total calories for amino acid?
15 - 20%
T/F renal or hepatic disease may decrease protein need
TRUE
what are lipids?
- essential fatty acids
- dense source of calories
why are lipids added?
- help w cellular development
- formation of healthy cell membranes
what percentage of calories is lipids?
30% of calories
what is the primary source of lipids?
soybean oil; also safflower oil
T/F lipids is hung in conjunction with TPN with it’s own line and pump.
TRUE
why are electrolytes added? how are they calculated?
acid based balance; adjusted based on lab results
the liver converts ______ in the electrolyte solution into _______ via the _________.
acetate salts; bicarbonate; liver
***important to have a functioning liver
which vitamins are added?
both fat- and water-soluble vitamins
why are trace minerals added?
assist in transport of substances
what specific minerals can be added?
chromium, copper, manganese, zinc
what is special about iron?
iron not compatible; if needed. infuse separately on own pump and line
what are the four risks/complications?
- hyperglycemia
- rebound hypoglycemia
- refeeding syndrome
- fluid overload
what is hyperglycemia? how is it managed?
- impaired glucose tolerance
- insulin added or use sliding scale (educate pt)
- ↑ monitoring frequency
what should glucose levels be at initiation?
< 200 mg/dL
what is glucose target range?
110 - 150 mg/dL during therapy
how does rebound hypoglycemia occur? how can we prevent it?
- ↑ insulin secretion during therapy (hyperinsulinemia)
- PN withdrawn too rapidly
- wean PN off gradually
- reduce rate by 1/2 for 1 hr before d/c
what should you do if PN bag empties before next bag is ready?
hang D10W or D20W (based on dextrose concentration that the patient is receiving.
what should we assess for fluid overload?
- elevated BP, bounding pulses, distended neck veins, rales
- assess I + O and daily weights
what is refeeding syndrome?
overzealous caloric replacement
how does refeeding syndrome occur
insulin release triggers cellular uptake of K+, phosphate, Mg++
what is the hallmark sxs of refeeding syndrome?
profound hyposphatemia
what are the sxs of hyposphatemia?
cardiac dysrhythmias, respiratory arrest, and neurological distrubances
