TPN Flashcards
define malnutrition
deficiency/excess/imbalance of energy/proteins/other nutrients causing adverse effects on the body
what can malnutrition cause
impaired immunity decreased wound healing increased complications poor response to therapy (3x more likely to have complications) reduced growth/development death
what is acute malnutrition
develops rapidly in the presence of acute stress/injury
what is chronic malnutrition
develops in a number of disease states but requires long term monitoring and therapy
if a patient has Inadequate or unsafe oral intake but a Functional, accessible GI tract which feeding method would you use
enteral feeding tube
if a patient has Inadequate or unsafe oral intake but a non-functional, accessible GI tract which feeding method would you use
parenteral nutrition (IV)
what is parenteral nutrition
IV administration of nutritionally balanced, physiochemical, stable and sterile combination of water and nutrients
what makes up parenteral nutrition
wateramino acids glucose lipids vitamins trace elements electrolytes
maintenenace water requirements in PN
1500ml + 20ml/kg >20kg
causes of dehydration/increased fluid requirements with PN
fever, GI loss, blood loss and burns
causes of fluid overload/decreased fluid requirements with PN
blood transfusion, drugs, renal/cardiac failure
how much of your bw is made up of water
60%
nitrogen requirements in PN
0.2g/kg/day
when would more amino acids be required in PN
diseased/clinically stressed states
what are the amino acid requirements
20 in total, 8 cannot be synthesised and 5 conditionally essential
warning with TV amino acid administration
hypertonic - should not be administered alone
what affects energy requirements
age, activity, disease severity
what are the energy requirements
25-35 non-protein kcal/kg/day
why should glucose not be given alone
hyperglycaemia fatty infiltration of liver excessive co2 production and o2 consumption essential fatty acid deficiency
energy content of glucose
1g anhydrous glucose = 4kcal
energy content of lipids
10kcal/g of oil
lipid requirements
2.5g/kg/day
which acids contain essential fatty acids
linolenic and linoleic acids
what are the fat soluble vitamins
A, D, E, K1
what are water soluble vitamins
B1, B2, B6, B12, C, folic acid
why are vitamins important
play a key role in intermediary metabolism as co-factors and co-enzymes
in which diseases would you need altered vitamin requirements
□ Small bowel fistulae - decreased zinc □ Biliary fluid loss - decreased copper □ Burns - decreased zinc, copper and selenium □ Liver failure - copper and manganese clearance reduced □ Renal failure - aluminium, chromium, zinc and nickel clearance reduced
what are the 10 known trace elements required in PN
iron copperzinc fluorine manganese iodine cobalt selenium molybdenum chromium
which electrolytes are required in PN
sodiumpotassium calcium magnesium phosphate chloride acetate
what are the two reasons a patient may need TPN
- short term inpatient (NMB/obstruction or malnourished) - long term/home (non-functioning gut)
what are the two methods for TPN administration
peripheral administration (PICC) - 1st line central line
indications for a PICC line
short term supplemental feeding high sepsis risk no immediate central line access
feed requirements via PICC line
good line care and low tonicity feeds (<800mOsmol/L)
C/I for PICC lines
inaccessible peripheral veins high PN osmolality (high calorie/nitrogen content)
how do central lines work
put into subclavian vein or jugular vein - must be confirmed via x ray
indications for central lines
longer term feeding inaccessible peripheral feeding higher tonicity formulations (>2000mOsmol/L)
what are some pharmaceutical issues with TPN
physical stability, chemical stability and microbial stability
issues with physical stability with TPN bags
precipitation not seen in bags containing lipids - can cause embolism lipid destabilisation - coalescence occluding microvasculature - all PN fluids passed through filter before infusion
issues with chemical stability with TPN bags
vitamins undergo chemical degradation - all bags must be protected from light
issues with microbial stability with TPN bags
lots of nutrients - good for bacterial growth - use aseptic techniques
monitoring requirements with TPN
- ongoing requirements - complications - clinical symptoms: temp, bp, fluid, weight - lfts/electrolytes/bm/crp- calcium and albumin
complications with TPN
- line blockages (tip, blood/drug clot, line kinking) - line sepsis - thrombophlebitis - refeeding syndrome
what is refeeding syndrome
when infused nutrition exceeds tolerance of previously malnourished patient - can cause sudden insulin production
how to avoid refeeding syndrome
start feeding slowly - over 48 hours add thiamine if at risk
