malnutrition Flashcards
when is oral feeding not advised
cognitive impairment
Dysphasia
Types of oral feeeing
By mouth
Normal food, softened food, thickened foods, puréed, fluids etc
What is first line enteral feeding
nasogastric tube
Complications of NG tubes
Tube misplacement Obstruction Electrolyte imbalance Hyperglycaemia Aspiration pneumonia! Larynx ulceration, pharyngeal pain Vomiting and diarrhoea Line infections Refeeding syndrome
How is parenteral nutrition done
Via central venous catheter
Difference between feeding or parenteral and enteral
Enteral made for patients needs
Parenteral from scratch bag
Indications for parenteral feeding
Where oral enteral unsafe
Or GI inaccessible or cannot function
How to testif enteral feed misplaced
pH shouldn’t be over 5.5
If over, immediate imaging to find it
What is refeeding syndrome
starvation for long time
if reintroduced to nutrients, surge in insulin
Encourages cells to take up potassium magnesium and phosphate which are already low in serum (and get lower) causing electrolyte imbalances
A causes arrhythmias, respiratory arrest, multi organ failure
definition of malnutrition
state resulting from lack of uptake/intake of nutrition leading to diminished physical and mental function and impaired clinical outcome from disease
rate of malnourishment upon admission to hospital
1 in 3 are manourished
what % of patients have lost weight at discharge
70%
factors that lead to malnutrition in hospitals
co-morbidities e.g. dementia inflexible mealtimes quality of food dysphagia, stomatitis, anaemia, poor dentition, ill fitting dentures inactivity low mood/depression polypharmacy excess nutritional losses repeated NBM status metabolic response to disease/injury
loss of what % of bodyweight preoperatively leads to 10x greater postop mortality?
> =20%
what increases with malnutrition?
mortality septic and post surgical complications length of hospital stay pressure sores readmissions dependency
what decreases with malnutrition?
wound healing
response to treatment
rehabilitation
QoL
CT advantages in formal nutrition assessment
provide info about body composition
-> however involves exposing patient to radiation
Why is BMI not used to assess malnutrition?
not representative of difference between fat and fat free mass
skin fold thicknesses used for malnutrition assessment
- triceps skinfold thickness
- mid upper arm circumference use similarly to determine lean body mass (positive association)
anthropometric analysis multifrequency bioelectrical impedance analysis used in which patients?
renal and haematology patients
what type of fat can CT scans distinguish between?
visceral and subcutaneous fat
-> highly accurate for evaluating levels of fat and fat free mass
problems with CT for nutritional assessment
expensive, expose individuals to small amounts of radiation
-> use for body comp restricted to research normally
-> being used more frequently in specialities where CTs are already part of the clinical treatment pathway
why are micronutrient and trace elements tests not undertaken easily?
time consuming
expensive
results skewed as a result of the acute inflammatory response
best way of obtaining dietary intake information
dietary history
what is used to estimate energy requirement
predictive equations estimating resting MBR
-> generally no more accurate than 70%
requirements to be malnourised
- BMI < 18.5
- unintentional weight loss >10% past 3-6/`1
- BMI <20 + unintentional weight loss > 5% past 3-6/12
people at risk of malnutrition
eaten little/nothing > 5 days and likely to have the same for the next 5
- poor absorptive capacity/high nutrient losses/increased nutritional needs
Feeding options when oral nutrition isn’t safe
enteral feeding (GI tract functional + accessible) parenteral feeding (GI tract not functional/accessible)
why is enteral nutritional superior to parentral?
it uses the gut
-> if parenteral used, aim to return to enteral then oral feeding as soon as/where clinically possible
what is recommended from longer term enteral tube feeding (>3 months)
gastrostomy/jejunostomy
what are the complications associated with enteral feeding?
- misplaced NGTs cause death
- mechanical (misplacement, blockage, buried bumper)
- metabolic (hyperglycaemia), deranged electrolytes)
- aspiration, nasopharyngeal pain, laryngeal ulceration, vomiting, diarrhoea
indication for parenteral nutrition
- inadequate or unsafe oral and/or enteral nutritional intake
OR - non-functioning, inaccessible or perforated GI tract
access points for CVCs?
tip at superior vena cava and right atrium-> different CVCs for short ad long term use
complications associated with parenteral nutrition?
mechanical (pneumothorax, haemothorax, cardiac arrhythmias, thrombosis, catheter occlusion, extravasion)
metabolic (deranged electrolytes, hyperglycaemia, abnormal liver, enzymes, oedema, hypertriglyceridemia)
catheter-related infection
low levels of what plasma proteins predicts poor prognosis?
albumin
how does the acute phase response affect albumin production?
inflammatory stimulus -> activation of monocytes and macrophages -> release of cytokines
cytokines act on the liver to stimulate production of some proteins whilst downregulating production of others like albumin
is albumin a valid marker of malnutrition in the acute hospital setting?
no
- though decreased in repsonse to inflammation, not marker of nutrition status nor indication for nutrition intervention in the acute setting
- best evidence - hypoalbuminaemia in obese trauma patients
- dietitian focused on the etiology/impact of the inflammatory state on nutrition status
how does introduction of carbohydrate affect the response to starvation? refeeding
stimulates insulin production -> Na/K ATPase (Mg cofactor)
drives K into cells and Na out of cells
carbohydrate and insulin drives PO4 into cells
- increased cellular uptake of glucose, K, Mg and phosphate
- thiamine is coenzyme for carb digestion -> deficiency occur in refeeding of vit B depleted patient
what can low concentrations of electrolytes from giving a starving person carbs cause?
- less Na and fluid excretion = expansion extracellular fluid compartment –> this leads to refeeding oedema
consequences of RFS?
- arrhythmia
- CHF -> cardiac arrest + sudden death
- tachycardia
- respiratory depression
- encephalopathy, coma, seizures, rhabdomyolysis
- Wernickes encephalopathy
what are the the criteria for defining at risk of refeeding syndrome
very little or no food intake for > 5 days
stages of RFS management
- start with 10/20kcal/kg
CHO 40-50% energy and micronutrients - correct + monitor electrolytes daily
- Administer thiamine from the onset of feeding
- Monitor fluid shifts + minimise risk of fluid/Na overload
whole process of nutrition in hospital
screening
assessment
diagnosis
plan - implement, monitor, evaluate
example of when NGT is contraindicated?
gastric outlet obstruction
go straight to ND/NJT
composition of paraenteral nutrition feeds
ready made scratch bags
what is short bowel syndrome
surgical resection or congenital defect/loss of absorption in bowel
characterised by inability to maintain energy, fluid, electrolyte or micronutrient balances when on a normal diet
