TPN Flashcards
indications for TPN
GI tract dysfunction (short bowel, severe vomiting, diarrhea)
adjunctive tx for cancer (malnourished and not EN candidates)
pancreatitis (if EN exacerbates sx or disease)
critically ill (EN not available, intolerable) withold for up to 7 days
perioperative (pre-existing MN)
hyperemesis
eating disorders
is central or peripheral PN more common
central
central PN
dextrose =
amino acids (AA) =
electrolytes =
provides “complete” PN
5mOsm/g
10mOsm/g
1-2mOsm/mEq
peripheral PN is for patients who _______
do not have significant MN
have good peripheral vascular access
can tolerate large fluid volumes (2.5-3L/day)
need 5-14 days of PN support
3 IV access points for PN
subclavian
peripherally inserted central catheter
tunneled catheter
PN complications
costly, labor intensive, monitoring pneumothorax (partially collapsed lung), thrombisis, thrombophlebitis line sepsis inc bacterial translocation electrolyte abnormalities hyper/o glycemia hyperTG fluid overload osteoporosis/malacia hepatobiliary
refeeding syndrome
definition
treatment
caveat
rapid, severe depletion of K, Mg and phos in starved patients
limited electrolyte stores –> intracellular electrolyte shift
death can result
tx: supplementation of lytes PLUS thiamine 50-100mg/day
the more nutritionally depleted the SLOWER nutritional support should be initiated
in refeeding syndrome, which things make a patient more nutritionally depleted and therefore require slower nutritional support
chronic diseases (cancer, COPD, cirrhosis)
malabsorption
anorexia nervosa
previously morbidly obese and has lost weight
EtOH abuse
severely ill w/out nutritional support in last 7 days
PN components protein:
kcal/g ratio
_____g = 1 g nitrogen
commercially available concentrations
4kcal/1g protein
6.25g protein = 1g nitrogen
3-20%
Carbohydrates (CHO) kcal/g? commercially available concentrations pH range glycerol specifics
3.4kcal/1g CHO
2.5-70% (>10% require central admin bc they are hyperosmolar)
pH 3.5-6.5
glycerol provides 4.3kcal/g, available as 3% w AAs
Lipids (IVFE)
definition
oil suspension in an aqueous medium that has properties similar to chylomicrons
source of vitamin K (may interfere with warfarin)
Lipids
kgal/g?
allergy CI?
contains ______?
9kcal/g
cannot be used in soybean allergy
contains omega-6 PUFAs which promote production of pro-inflam cytokines
lipids monitoring and AE
infusion reactions (SOB, angina, palpitations, chills, rash, HA, N, fever) all rate related
hypertriglyceridemia >400 (inc risk w sepsis, pancreatitis, multi-organ failure, neonates)
hepatotoxicity
steps to initiating PN
- est vascular access (typically central)
- calc micronutrient req
- provide 25-30% on first day (CHO 150-200g initially)
- eval electrolyte needs and refeeding risk
- eval trace element and vitamin needs
- insulin?
- review compatibility
- ASPEN Guidance
“standard formula”
protein is 1-2g/kg/d
cant change AA, dextrose or lipids
rate is protein-based
individualized formula
use is standard is off by a lot lipid contribution is up to 30% protein 1-2g/kg/day dextrose = total - [protein-lipids] kcal est volume (2 in 1 vs 3 in 1)
what is 2 in 1
carbs and protein
use in ICU first week then add 100g lipids/week thereafter
whats 3 in 1
carbs
proteins
lipids
sodium daily requirement
1-2mEq/kg
potassium daily requirement
1-2mEq/kg
chloride daily requirement
as needed to balance acid base status
acetate daily requirement
prn to balance acid/base
Calcium daily requirement
10-15 mEq
Mg daily requirement
8-20 mEq
Phosphate
20-40
trace elements and their excretion
high-output ostomies or diarrhea –> add’nal Zinc
manganese and copper –> biliary tract
chromium, molybdenum, selenium–> renal
add phosphate to TPN ______
first!
everything but _____ must be mixed before admin
procalamine
vitamins are added when in regards to admin
immediately prior to admin
`Factors that affect calcium phosphate compatibility
AAs inc pH which dec solubility
dextrose concentration dec pH which inc solubility
if neonates have a fever what can happen with TPN admin
inc temp dec flow in IV line which can cause precipitation
monitoring of patients
fluids, weights qd glucose q1-6h elec daily-TIW LFT, visceral proteins, CBC, PT/PTT 1-2x/week protein turnover weekly triglycerides weekly
