Parenteral Nutrition in Practice Flashcards
what are the ways we can artifically feed patients?
PPN TPN nasogastric tube gastrostomy tube jejunostomy tube nasojejunal tube nasoduodenal tube
what is enternal nutrition? when is it used?
enteral nutrrition delivered into the gut by a tube is used where nutrition cannot be taken normally by mouth, but the gut is otherwise
working.
what are some examples of when enteral nutrition is needed?
–Strokes or other neurological conditions which impair swallowing
–After some types of operations on the face, neck, throat, gullet or stomach
–Blockages of the gullet or stomach
–After radiotherapy to the throat or gullet
what is PN?
nutrition solution for IV admin
what makes up PN?
–Carbohydrate: 60-70%
–Fat: 30-40%
–Protein: 1g protein/30-40kcal from non-protein
sources
–Electrolytes, minerals, vitamins, trace elements
who can get PN?
PN is a POM and therefore needs to be
prescribed by a Dr or an approved prescriber
what are the indications for PN for adults?
consider parenteral nutrition in people who are malnourished or at risk of malnutrition:
–a BMI of less than 18.5 kg/m2
–unintentional weight loss greater than 10% within the last 3–6 months
–a BMI of less than 20 kg/m2 and unintentional weight loss greater than 5% within the last 3–6 months.
–have eaten little or nothing for more than 5 days and/or are likely to eat little or nothing for the next 5 days or longer
–have a poor absorptive capacity, and/or have high nutrient losses
and/or have increased nutritional needs from causes such as catabolism.
what other reasons would PN be given?
–inadequate or unsafe oral and/or enteral nutritional intake
–a non-functional, inaccessible or perforated (leaking) gastrointestinal tract
what should people who are not severely injured, ill nor at risk of refeeding syndrome, the suggested nutritional prescription for total intake should provide?
•25–35 kcal/kg/day total energy (including that derived from protein)
•0.8–1.5 g protein (0.13–0.24 g nitrogen)/kg/day
•30–35 ml fluid/kg (with allowance for extra losses from drains and fistulae, for example, and extra input from other
sources – for example, intravenous drugs)
•adequate electrolytes, minerals, micronutrients (allowing
for any pre-existing deficits, excessive losses or increased demands) and fibre if appropriate
how should nutritional support be administered in seriously ill patients/ injured?
It should be started at no more than 50% of the estimated target
energy and protein needs.
•It should be built up to meet full needs over the first 24–48 hours according to metabolic and GI tolerances
how should people who have eaten little or nothing for more than 5 days have nutritional support introduced?
ntroduced at no more than 50% of
requirements for the first 2 days, before increasing feed rates to meet full needs if clinical and biochemical monitoring reveals no refeeding problems.
what are the indications you would used PN for paedratics?
–Prematurity –Gastrointestinal tract anomalies –Low birth weight infants –Major surgery –Inflammatory bowel disease –Respiratory disorders –Sepsis –Burns –Major trauma –Mucositis and malabsorption
how do hospital patients energy requirements differe in paeds?
–Reduced physical activity
–Energy losses from ostomies, malabsorption,
diarrhoea, infection
what is the energy requirement for paeds?
–Pre-term: 110-120kcal/kg/day
–0-1yrs: 90-100kcal/kg/day
what are the fluid requirements for paed patients?
Holliday–Segar formula
•100 ml/kg/day for the first 10 kg of weight,
•50 ml/kg/day for the next 10 kg
•20 ml/kg/day for the weight over 20 kg
what are the fluid requirements for males and females in a 24 hour period?
24-hour period, males
rarely need more than 2500 ml and females
rarely need more than 2000 ml of fluids.
how can PNs be administered?
by peripheral or central intravenous catheters. The solution needs to be
adjusted according to route of administration.
what is the max glucose conc and the osmolarity of a peripheral PN ?
maximum glucose concentration is 10 %, maximum osmolality is
1210 mosmol/kg.
what is the glucose concentration of a central pn?
theoretically can give very high glucose concentrations although we try to stay
below ~ 25% a fast flowing blood supply can
quickly dilute any solution infused, making it less
harmful to the surrounding tissue
how should a PN be initiated?
introduced progressively and closely monitored, usually starting at no more than 50% of estimated needs for the first 24–48 hours.
when should PN be stopped?
when the
patient is established on adequate oral and/or enteral
support.
how do you physically monitor for PN?
•Body weight, length/height and head circumference should be measured to assess growth and plotted on approved growth charts.
how do you ensure accurate measurement for physical monitoring?
For accurate weight measurement the
patient should be completely undressed.
•The same scales should also be used each
time for accurate measures
what metabolic complications can occur with PN?
•Short term complications can include re-
feeding syndrome, hyperglycaemia,
hypoglycaemia, hypertriglyceridemia and
mineral and electrolyte imbalances
how can you attempt to prevent metabolic complications?
Close monitoring during the first week of PN
helps to detect metabolic complications and
allow early correction
what is re-feeding syndrome? how should this be managed?
Reduction in basal metabolic rate during times of semi-
starvation
•Rapid change in metabolic status when feeding re-introduced
– can create life-threatening complications
•Generally re-introduce calories slowly, e.g. 50% day 1, 75%
day 2, 100% day 3 of PN
–May require slower titration
–Daily bloods essential in these patients
what affects the patients risk of re-feeding?
One or more of the following:
•BMI less than 16 kg/m2
•unintentional weight loss greater than 15%
within the last 3–6 months
•little or no nutritional intake for more than 10
days
•low levels of potassium, phosphate or
magnesium prior to feeding
or
Patient’s with two or more of the following:
•BMI less than 18.5 kg/m2
•unintentional weight loss greater than 10%
within the last 3–6 months
•little or no nutritional intake for more than 5
days
•a history of alcohol abuse or drugs including
insulin, chemotherapy, antacids or diuretics.
what nutrition is recommended for patients at risk of re-feeding?
starting nutrition support at a maximum of 10 kcal/kg/day, increasing levels slowly to meet or exceed full needs by 4–7 days
•using only 5 kcal/kg/day in extreme cases
•restoring circulatory volume and monitoring fluid balance and
overall clinical status closely
•providing immediately before and during the first 10 days of
feeding:
what supplements should be provided for patients at risk of refeeding?
–potassium, –Phosphate, –magnesium - oral thiamine 200-300mg daily vit b co strong 1 or 2 tablets 3x a day - multivitamin
why do you monitor a patients lipids?
Levels of lipids and triglycerides are needed to
determine the patient’s oxidative capacity for
lipid metabolism.
why do you monitor patients trace elements and vit def?
s can occur in patients receiving long-term PN and routine monitoring is not required unless the
patient has been parenterally fed for longer than one month.
•Once patients are on established mixed parenteral and enteral feeding, monitoring of micronutrients becomes less of an issue.
why do you monitor patients hepatic dysfunction?
It is essential that liver function parameters
are monitored during PN to allow early
detection of liver adverse events.
•Cholestasis is a recognized complication and
nutrition regimens can be adjusted to slow
and hopefully reverse progression
what potential complications is there of PN?
•Infection –Catheter related sepsis –Systemic infection •Metabolic –Glucose intolerance –Electrolyte disturbances –Acidosis –Cholestasis •Administration –Line access –Compatibility information
whats a general rule of compatibility with PN?
As a general rule, don’t mix PN and lipid with any
medicines
•Many constituents already contained in PN and
stability is assessed based on some actual and
theoretical data
what is perfereed, enteral or PN?
in general, enteral nutrition is preferred to parenteral nutrition as it is: •more physiological, •simpler, •cheaper •less complicated
