The Nutrition Care Process Flashcards
The nutrition care process
Nutrition assessment/reassessment
- ABCDE model
- interpret with evidence based standards
- record all social/environmental info and acknowledge correct reference ranges
Nutrition diagnosis
- identify and label problem
- determine cause and contributing factors
- cluster signs/ symptoms/ defining characteristics and document
Nutrition intervention
- plan nutrition intervention and plan of action
- formulate goals
- Document
Nutrition monitoring and evaluation
- monitor progress
- measure outcome indicators
- evaluate outcomes
- document
ABCDE model
Anthropometry - weight, height, weight history, body composition Biochemistry - blood tests Clinical - nutrition impact symptoms Dietary - diet history, quantitative/ qualitative analysis Exercise - type, duration
Why we measure body size and composition
Detect deficiencies and excesses that may be related to health or disease
Eg. Length and weight in infants- assessing growth patterns, is feeding adequate? Screen for conditions which impact on growth and development
Eg. Measurement of body fat levels- nutritional diagnosis with appropriate interventions
Eg. Monitoring weight and body fat levels in athletes- pre season training, competition targets
5 level model of compartmentalisation
Whole body Tissue Organ Cellular Molecular Atomic
Whole body
- Weight-
- Height- good report development. Quick, easy, non invasive, reference data
- BMI- WHO healthy weight ranges, classify as underweight, healthy weight, obese. Relies on assumption excess weight = excess fat.
- Childhood growth charts- monitors growth and development
- Circumferences- waist:hip obesity, head circumference for child growth.
Limitations of height and weight
Patient cannot stand or sit- visual estimate, use circumference, need to use surrogate measures such as ulna length and knee height
Curvature of spine- underestimated height and overestimated BMI
Altered hydration status- eg, oedema. Hydration status leads to over/underestimation
No info on body tissue composition- won’t diagnose muscle washing or XS adiposity- consider body comp measurement
Don’t distinguish excess fat and muscle bulk, or what type of tissue makes up body weight
Malnutrition- which sites are depleted, muscle, fat or both?
Changing weight- what tissue is gained or lost
Atomic
Total body potassium counter- can calculate body cell mass from total body K. Only one in Vic
In Vivo neutron activation analysis
Molecular
Fat free mass - skeleton muscle- strength - skeleton - cell, tissue and organ structure and function Metabolically active tissue
Fat mass
- adipose tissue, energy store
- visceral fat
Can be measured via dexa
Dual energy X- ray absorptiometry (DXA)
X-ray: attenuation of 2 beams of different energy
Different body tissues attenuate the beams differently
- distinguish soft tissue from bone mineral content (BMC)
- divide the soft tissue into lean tissue mass (LTM) and fat mass
- fat free mass = BMC + LTM
- fat mass- % fat
- can also provide bone mineral density and fracture risk, regional body composition
- Less accessibility for body composition- no Medicare rebate available
Quick, non invasive, not dependent on height and weight
requires trained operator, exposure to ionising radiation, not suitable for subjects who cannot lie still, strict protocol required- glycogen depleted and hydrated.
Precision: 1-2% for BMC, 1-3% FFN, 2-4% fat mass.
Accuracy: 1-3% difference bw scanner models
Bioelectrical impedance analysis (BIA)
Weak electric current passed through body which encounters resistance: fatty tissues- watery tissues (FFM)
Resistance and reactance measurements are used to calculate FFM or TBW using prediction equations
Quick, easy, inexpensive after purchase, non invasive, no radiation, small inter observer variability
Inaccurate if hydration altered, serum Na temp and posture may influence. Influenced by recent caffeine, alcohol and strenuous exercise
Precision: high
Accuracy: approx 3-5% for body fat; approx 2-8% for FFM
Densiometry
If we can measure density of the body we can calculate % body fat
From weight + % fat we can calculate fat mass and FFM
Underwater weighing
Need specialised equipment, not portable, subject cooperation, tolerable for some illnesses?
BOD POD
Air displacement plethsymography
Same principles as underwater weighting - density- % fat
Closed air chamber rather than water chamber.
Pea pod for young ones
Specialised equipment, not portable, subject cooperation, more tolerable than UWW
Other methods of weighing
Many limited availability more involved in research
Isotope dilution-
CT scanning- can examine quality of body tissue
MRI scanning- intramuscular fat
Ultrasound
When assessing il patients (acute/ chronic disease) interpret data with caution: assumptions based on data in health may not hold true in disease
Height measurement
<2 years Recumbent length Specialised equipment Correct positioning essential Monitoring growth- small changes to be detected, important to be confident change is real not an error. Height cannot decrease. Plotted against charts
> 2 years: standing height
Stadiometer or wall mounted
Correct positioning important
How does height change across the day? (Shrink a bit at night)
Surrogate measures of height: knee height, arm span, ulna length (prediction eqn)
Decide which surrogate measure to use: can subject spread arms out? If not, ulna length is only suitable measure
Weight measurement
Poorly calibrated equipment main source of error- poor preparation of client such as shoes, phone in pocket
Consider hydration status: oedema, full bladder, dehydration
Visual estimate if bed bound
