What are the fixed and variable influences on dietary demand?
Fixed (basal metabolic rate):
- Membrane pumps, transport and signalling
- Mechanical work at a cellular and tissue level
- Substrate turnover
- Physical Activity
- Maintaining body temp
- Processing dietary intake
How do we calculate basal metabolic rate?
We can use direct calorimetry
Or more commonly use equations adjusted for illness, age, acqtivity etc.
A state where an imbalance of energy, protein & other nutrients causes measurable adverse effects on body form, function and clinical outcome.
What are the major signs of malnutrition?
Severe under-nutrition causes marasmus and kwashiorkor.
Over nutrition leads to obesity
Define marasmus and kwashiorkor
significantly lower than expcted weiht
Salt and fluid retention brought on by under nutrition leading to oedema & Ascites
How do we calculate BMI?
Weight in K
Divided by Height squared in metres
So for me roughly 75/1.8squared = 23
Define overweight in terms of BMI?
Overweight = BMI>25
Obese = BMI > 30
What are some conditions obesity predisposes you to?
Breast and bowel cancer
Hypertension, CVD disease, Diabetes, Fatty liver, NASH, Cirrhosis etc.
Define underweight in terms of BMI?
Underweight = BMI <20
Physical impairment tends to occur <18 and conseqeunces get severe <16
What are the clinical consequences of undernutrition?
- Impaired immune response
- Reduced muscle strength
- Impaired wound healing
- Impaired recovery from illness/surgery
- Impaired psycho-social function
- Poor clinical outcomes
What can cause under nutrition and how do we classify them?
- E.g. Anorexia or Flu
- Teeth problems
- Head injury
- Cancer of head/neck
- Loss of functioning gut mass below minimum required for digestion/absorption
- E.g. Short bowel syndrome
- Very Rare
How do we screen for patients at risk of undernutrition?
With the Malnutrition Universal Screening Tool! (MUST)
It can be carried out by anyone, no training required
What are the questions of MUST?
- <20 = 1 point
- <18.5 = 2 points
Unplanned in last 3-6 months
- 5-10% of body mass = 1 point
- >10% = 2 points
Have you eaten in last 5 days? (also if the patient is acutely ill and is likely to have no nutrional intake for more than 5 days)
- No = 2 points
Total score is from 0-6
How do we respond to a MUST Score?
0 - Review in the future, i.e. monitoring. This is done for patients and people in care homes + other risk groups
1 - Supplements, dietary advice and close monitoring
2 or more - Dietary advice, supplements, refer to a dietician
What are the high risk groups for malnutrition?
- The ill
- Socially isolated
- Old age
- Socially vulnerable groups
How do we treat malnutrition?
Call a state registered dietician
What types of feeding are available for the undernourised in hospital?
Fine Bore NG tube
Percutaneous Endoscopic Gastrostomy (PEG) tube
- I.e. a tube passes into stomach through abdominal wall
- For people with intestinal failuer
- Oral nutritional supplements