Nutrition in Health and Disease Flashcards
Describe how to screen for undernutrition.
Malnutrition universal screening tool;
- Picks up patients at risk of malnutrition.
- Validated in the community and hospital.
- Can be carried out by people without special training.
Step 1; - Height - Weight - BMI: <20 = score 1, <18 = score 2 Step 2; - Have you lost weight unintentionally in the last 3-6 months? Yes – 5% = score 1, yes – 10% = score 2 Step 3; - Have you eaten in the last 5 days? No = score 2 Results; - Score 2 – risk of undernutrition - Score 1 – supplements and watch - Score 0 – monitor
Describe the fixed and variable components of demand.
Fixed components;
- Membrane function: pumps, transport, signalling
- Mechanical work: cellular level, tissue level
- Substrate turnover
Variable components;
- Cost of processing the dietary intake
- Cost of physical activity
- Cost of maintaining body temperature
- Cost of growth
Describe basal metabolic rate.
- Can be measured by direct calorimetry
Usually calculated;
- Depends on lean body mass
- Schofield, Harris Benedict or Hernry (currently used) equations
- Various adjustments for activity and illness
- Easy to overestimate requirements
- Many systems contribute to metabolic demands and supply falls to gut and associated organs
Describe nutritional failure.
- Failure to meet the nutritional requirements of the individual.
- Development of deficiencies –> weight loss
- Or excess –> obesity
Define malnutrition.
A state of nutrition in which a deficiency or excess (imbalance) of energy, protein and other nutrients, causes measurable adverse effects on tissue/body form (body size, shape, composition), body function and clinical outcome.
Define overnutrition.
Overnutrition leads to obesity, which leads to longer term problems. They are often hidden and only become apparent over time.
BMI >25 = overweight, >30 = obese.
Define undernutrition.
Undernutrition leads to weight loss and impaired function. It is strongly associated with illness.
BMI <20 = underweight, <18 = physical impairment, <16 = increasingly severe consequences.
5% loss of body mass (unintentionally) can occur quickly, 10% loss becomes associated with increasing morbidity.
Describe the aetiology and complications of obesity.
Environment, exercise, genes –> obesity.
Obesity –> metabolic syndromes e.g. hypertension, cardiovascular disease, type II diabetes mellitus, fatty liver, NASH, cirrhosis.
Obesity –> cancer e.g. breast, bowel.
Describe the clinical consequences of malnutrition.
- Impaired immune response.
- Reduced muscle strength.
- Impaired wound healing.
- Impaired psycho-social function.
- Impaired recovery from illness and surgery.
- Poorer clinical outcomes.
Describe the 'difficult’ method of working out a patient’s nutritional requirements. Energy requirements (Schofield, 1985).
- Age
- Weight
- Sex
- Disease: increase of requirements, decrease of intake
- Activity
Nitrogen requirements (Elia, 1990);
- Based on body mass
- Allowance for stress factors
- Appropriate form for patients
Other requirements;
- Fluids
- Vitamins
- Minerals
- Trace elements
Describe the ‘easy’ method of working out a patient’s nutritional requirements.
Refer them to a state-registered dietician.
Describe the aetiology of undernutrition.
Appetite failure: anorexia nervosa, disease-related
- Access failure: teeth, stroke, cancer of head and neck, head injury
- Intestinal failure: reduction in the functioning gut mass below the minimal amount necessary for adequate digestion and absorption of nutrients.
Describe the management of access failure in malnutrition.
- Help with eating.
- Fine bore nasogastric tube.
- PEG tube.
Describe percutaneous endoscopic gastrostomy and its risks.
- Patient sedated
- Endoscopy carried out
- Needle and guidewire in stomach
- Tube pulled back down and out of skin
- Can be placed radiologically as well
- Safe but carries definite risks
- Can last 18 months without replacement
- Can be used at home
- Difficult ethical issues
How do you calculate BMI?
BMI = weight (kg)/height (m2)
