10. Nutritional Flashcards
Define nutritional assessment
The evaluation of an individual’s nutritional status + nutrient requirements
Why is nutritional assessment so important?
Acute + chronic malnutrition prevalent
Over and under-nutrition increasing
As indicated by national diet + nutrition survey 2008-2012;
Sugars: 11% limit (4-18 years higher)
Sat fat: 11% limit (19-64 years 12.6%)
Salt: 6g/day (>65 years 7.2g/day)
Fruit + veg: 5 portions/day (19+ years eating less, particulary girls 11-18 years)
Oily fish: average intake well below rec 1 portion/week in all age groups
Vit D: low vit D status in 23% adults + 22% children over whole year
- increases to 40% in both groups in winter
Iron: 46% girls + 23% women low iron intakes
How does the northern Irish diet compare to the rest of the UK?
Consume more unhealthy foods;
- milk/cream, carcass meat, butter, fresh potatoes (+78%)
Less healthy foods;
- margarine (-60%), fresh fish, fruit juice, other fresh produce
People living in London consumed nearly twice as much fresh fruit + veg as people living in N Ireland
How is nutritional status assessed?
History
Examination
Lab tests
What factors are identified in a general medical history that affect or indicate nutritional status?
Obesity Hyperlipidemia/CVD Hypertension Diabetes Alcoholism Failure-to-thrive Eating disorder Weight loss/gain Lactose intolerance GI disorders
What medications + vitamin/mineral supplements affect nutritional status?
Pharmaceutical agents
Over the counter medications
Vitamin + mineral intake
Herbal remedies
What social history + diet information (non medical) can be useful in a general history for assessing nutritional status?
Lifestyle assessment: employment + exercise
Alcohol history
Following special diet
How is a persons functional status assessed?
By Activities of Daily Living (ADLs);
- bathing
- dressing
- toileting
- transferring
- continence
- feeding
How is a persons diet history determined?
- 24 hour recall
- food frequency
- usual intake
- food record
Describe the 24 hour recall method for determining diet history
Documents pts intake of all food + beverage during previous 24 hr period
Ideal for;
- pts with diabetes: ability to assess timing of meals, snacks, insulin injections
Limitations;
- many pts do not rmb what they ate + cannot accurately estimate quantities consumed
Describe the Food Frequency method for determining diet history
Estimate the frequency + quantity of foods eaten during a weekly/monthly period;
- how often do you consume X during a typical week?
- how often do you eat out during a typical week?
Ideal method to evaluate intake of;
- fat
- sodium
- sugar
- dairy
- fruit/veg intake
Ideal for;
- pts with CVD, hypertension, osteoporosis
- pts questioning requirement of vitamin supp
- elderly pts who avoid food groups
Limitations;
- many pts do not remember what they ate + cannot accurately estimate quantities consumed
Describe the Usual Intake Method of determining diet history
Documents a pts usual intake, including breakfast, lunch, dinner + snacks
Ideal for;
- elderly pts (assess no meals eaten/skipped)
- infants/children/adolescents whose diets are not varied
Limitations;
- many pts not consistent with eating habits + state there is no usual pattern
List what a physical exam can reveal about a pts nutritional status
Head/neck: temporal wasting Triceps: skin fold measurements Hands: interosseus muscle wasting Mouth: condition of teeth, gums, tongue Abdomen: ascites, site of jejunostomy tube Skin: xanthomas, rash, edema
What is commonly examined in a laboratory evaluation of nutritional status?
Anaemia: Fe, folate, vitamin B12
Micronutrients
General malnutrition: serum proteins
Discuss the lab evaluation of serum proteins in assessing nutritional status
Albumin: 18-20 day half life
- slow fall in malnut/slow rise with repletion
- 50-60% blood plasma proteins
- ref range: 3.5-6.5 g/dL
Transferrin: 8-9 day half life
- influenced by status of iron stores
- TIBC measures capacity to bind iron with tf
- TIBC ref range: 250-370ug/dL
Prealbumin: 2-3 day half life
- decreases early in malnut/increases quick with repletion
- ref range: 19-38mg/dL
Changes in serum proteins indicate; Normal/increased levels; - increased synthesis - decreased losses - dehydration - well nourished
Decreased levels;
- decreased synthesis
- increased losses
- dilutional effect
- malnutrition
Define malnutrition
An unintentional weight loss of greater than 10% of body weight associated with serum albumin <3.5g/dL
What types of pts are at risk of malnutrition?
50% of hospitalised surgical pts experience malnutrition
What is MUST + how is it used in nutritional assessment?
MUST = Malnutrition Universal Screening Tool
5 step screening tool to identify adults who are;
- malnourished
- at risk of malnutrition (undernutrition)
- obese
Includes management guidelines - can be used to develop care plan
Used in hospitals, community + other care settings
Step 1: height + weight = BMI score
Step 2: note % unplanned weight loss + score
Step 3: Establish acute disease effect + score
Step 4: Add scores from previous steps to obtain overall risk of malnutrition
Step 5: Use management guidelines/local policy to develop care plan
What is malnutrition associated with (regardless of aetiology)?
Sub-optimal surgical outcome Increased rate of infection Longer hospital stay Impaired wound healing Frequent hospital re-admission for elderly More frequent post-op complications Increased risk of death
What are the 2 main types of malnutrition?
Marasmus: protein-energy malnutrition
Kwashiorkor: protein malnutrition
Describe marasmus
Protein-energy malnutrition;
- severe tissue wasting
- excessive loss of lean body mass + fat stores
- dehydration
- weight loss
S+Ss;
- normal hair
- old man appearance
- thin limbs with little muscle or fat
- very underweight body
Describe kwashiorkor
Protein malnutrition;
- retarded growth
- changes in skin + hair pigmentation
- edema
- low serum albumin
S+Ss;
- swelling of legs (edema)
- sparse hair
- moon face with little interest in surroundings
- flaky appearance of skin
- swollen abdomen
- thin muscles but fat present
Describe the main mechanisms of malnutrition
Impaired dietary intake
Malabsorption;
- coeliac disease
- Crohn’s disease
- short bowel syndrome (trauma/surgery, etc)
What are the routes for nutritional support?
Oral supplements Tube feeding; - nasogastric (NG) - naso-jejunal (NJ) - gastrostomy - jejunostomy Parenteral (IV)
Which is better: enteral (GI tract) or parenteral (IV) nutrition? Why?
Better to use gut if possible
Animal studies nourished by TPN without enteral feedings;
Atrophy of small bowel mucosa;
- decreased mucosal mass
- decreased enzyme activity
Decreased intestinal adaptive changes after small bowel resection
Bacterial translocation from GI tract to circulatory system can lead to sepsis
When is TPN possibly indicated?
Malabsorption
Massive bowel resection may result in short bowl syndrome (ischemia, trauma, malignancy)
GI tract obstruction
Impaired GI motility (ileus, pseudo-obstruction)
Abdominal trauma, injury or infection
Inflammatory bowel disease (Crohn’s, ulcerative colitis)
Severe pancreatitis
How is TPN administered?
TPN solutions are hypertonic
Infused via central venous catheter
Describe the Food Record Method for determining diet history
Written record by pt of everything they ate/drank over a 2-4 day period;
Ideal for;
- pts with difficulty losing weight
- pts who are eating out of control + gaining weight
- brittle diabetics
- emotional eaters
Limitations;
- many pts not motivated to write down everything (although those who do lose weight)
- difficult for physicians to take the time to review + comment (especially if not trained)
What characteristics can be measured in a physical exam to assist with nutritional assessment?
Cachexia (weakness/wasting due to illness)
Obesity
Height/weight + BMI
Location of body fat - abdominal or gluteal region
Describe the use of BMI in assessing pt nutritional status
Body mass index defined as weight (kg)/height (m2)
- replaces the Metropolitan Life height/weight tables
- correlates significantly with body fat, morbidity + mortality
Limitations;
- may be an overestimate of body fat in a very fit individual
Underweight: <18.5 Normal weight: 19-24.9 Overweight: 25-29.9 Class I obesity: 30-34.9 Class II obesity: 35-39.9 Class III obesity: >=40
