Nutrition in practice Flashcards
Define malnutrition
State of nutrition in which deficiency or excess of energy/ protein/ other nutrients causes measurable adverse effects on tissue
What is the cost of malnutrition to NHS England?
£19.6 billion
Name 4 generic causes of malnutrition
- Low intake due to inadequate availability or quality of food
- Reduced intake of food when food is available
- Increased nutritional requirments
- Lack of recognition and treatment
What can cause reduced intake of food
- Dysphagia
- Prolonged periods of nil by mouth
- Side effects of treatment
- Pain
- Psychological
- Social
- Poor dentition
- Reflux
What can cause increased nutritional requirments (3)
- Infections
- Involuntary movements
- Wound healing
What happens to respiratory and cardiac function during malnutrition
They both decrease
Does risk of pressure sores increase or decrease during malnutrition
Increase
Does risk of infection and ability to wound heal increase or decrease during malnutrition
Infection= increase
Wound heal=decrease
What are the 5 steps of MUST
1) BMI
2) Weight loss
3) Acute disease effect
4) Add scores from 1-3
5) Action plan
How much can weight change due to fluid fluctuation
Increase by 10-20%
What is meant by MUAC
Mid upper arm circumference
BMI=
Weight (kg)/ Height (m2)
Name some ways height can be measured in difficult situations (eg bedbound patients)
Knee height
Demi span
Ulna length
What is BMI likely to be if MUAC <23.5<20
<20
What is BMI likely to be if MUAC is >32
> 30
How much weight do the following ascites add
a) Tense ascites
b) Moderate ascites
c) Minimal ascites
a) 14 kg
b) 6 kg
c) 2.2 KG
How much weight do the following classifications of peripheral oedema add
a) Severe
b) Moderate
c) Mild
a) 10kg
b) 5 kg
c) 1 kg
Where is fat mass (skin folds) most commonly measured? What does it estimate?
Use the triceps site
Estimates total adiposity
How do you calculate fat free mass
Arm muscle circumference- mid upper arm circumference- (0.314 x triceps site)
What does handgrip dyanomometry measure
Muscle strength and endurance
What is the most abundant protein in the plasma
Albumin
What is normal range of albumin
35-50g/l
Function of albumin
Maintaining oncotic pressure
Name some causes of hypoalbuminaemia
- Inadequate protein intake
- Inflammation and sepsis
How does sepsis lead to hypoalbuminaemia
Capillary wall becomes porous and albumin drifts out
Why isn’t low albumin always detected in patients with malnutrition
Because in some patients who are starving, there is no inflammatory response so no reduction in vascular permeability
Define refeeding syndrome
Condition characterised by severe fluid and electrolyte shifts and related metabolic implications in malnourished patients undergoing refeeding
How do intracellular stores of K+, PO4- and Mg2 change during starvation
They deplete
During refeeding, what substrate is used for energy
Switches from fatty acids to carbohydrates
Why does switch from fatty acid metabolism to carbohydrate metabolism cause refeeding syndrome
Raised insulin secretion
Insulin stimulates potassium, phosphate and magnesium to return to cells
Intracellular stores replenished at expensive of plasma concentration
Describe what biochemistry tests would show in a refeeding syndrome patient
- Hypokalaemia
- Hypomagesaemia
- Hypophosphataemia
- Thiamine deficiency
- Salt and water retention
Describe the clinical consequences hypophosphataemia
Seizures Weakness Osteomalacia Impaired resp muscle function Cardiac failure Rhabdomolysis
Define rhabdomolysis
Results from muscle injury
Describe the clinical consequences of hypomagnesaemia
Tetancy, paraesthesia, seizures, ataxia
Arrhythmias
Anorexia
Abdo pain
Describe the clinical consequences of hypokalaemia
Paralysis Paraesthesia Rhabdomyolysis Resp depression Arrythmias Constipation
Which patients are at moderate risk of refeeding syndrome
Those with very little food intake for >5 days
Which patients are at high risk for refeeding syndrome
BMI<16
Unintentional weight loss >15% for >10 days
Low levels of K, PO, Mg
OR ANY OF THE 2
Patients BMI<18.5
Unintentional weight loss >10% for last 6 weeks
History of alcohol/ drug use
What is meant by enteral route?
Oral Nasogastric Orogastric Nasojejunal Gastrostomy Jejunostomy
What is meant by parenteral route
Peripheral or central (eg not via gastric)
When you enteral tube nutrition be advised
Insufficient oral intake/ oral intake not possible
But gut is functioning
What are the indications for parenteral nutrition
GIT unable to digest/ absorb or GIT cannot be assessed
Name the disadvantages of parenteral nutrition (6)
- Risk associated with placement
- Risk of catheter related sepsis
- Disordered liver function
- Gut atrophy
- Physological implications
- Cost
