Biochemical (Laboratory Assessment of Nutritional Status)

Question 1

What is the advantage of biochemical tests? Disadvantage?

Answer 1

Advantage: Objective and quantitative; Disadvantage: No specific lab test that can diagnose malnutrition need to look at multiple test in addition to other components of the nutrition assessment process

Question 2

What are the purposes of Laboratory tests?

Answer 2

1) Diagnose a disease 2) Evaluate treatment plans 3) Monitor effectiveness of medications

Question 3

What are the routine medical tests?

Answer 3

CUCS: Clinical Chemistry Panels, Urinalysis, Complete blood count, Stool Testing

Question 4

Clinical Chemistry Panels

Answer 4

Blood work

Question 5

Urinalysis

Answer 5

Metabolic and kidney disorders, infection

Question 6

Complete blood count

Answer 6

count of the cells of the blood and description of RBCs

Question 7

Stool test

Answer 7

presence of blood, pathogens, and gut flora

Question 8

Reference Ranges

Answer 8

Constructed from a large number of test values (20 ->1000), reflect values found in approx 95% of population; 2.5% will fall above, 2.5% will fall below; 1/20 will have values outside of reference ranges.

Question 9

Critical Difference

Answer 9

The change in a lab value that is significant enough to give evidence that their is a problem. It is also important to understand trends

Question 10

What are the two routes that lead to malnutrition?

Answer 10

Starvation or stress/disease/injury

Question 11

Malnutrition: Starvation

Answer 11

1) Low food resources 2) Chronic starvation by choice 3) Anorexia nervosa

Question 12

Chronic-Disease-Related Malnutrition

Answer 12

1) Liver Failure 2) Kidney Failure, Cancer

Question 13

Acute Disease or Injury related malnutrition

Answer 13

Major infection, Burns, trauma, traumatic brain injury

Question 14

How does acute inflammation effect body composition?

Answer 14

Lean body mass is used to synthesize cytokines, positive acute-phase proteins, lactic acid, and white blood cells. Protein synthesis of other body parts is halted.

Question 15

How do cytokines effect systemic processes?

Answer 15

Cytokines increase the breakdown of muscle protein, alter the synthesis of albumin and pre-albumin by the liver, and overall stimulate and inhibit bodily functions.

Question 16

Negative Acute phase respondents

Answer 16

Decrease in response to acute phase proteins: albumin; pre-albumin (transthyretin); retinol binding protein; transferrin

Question 17

Positive Acute phase respondents

Answer 17

increase in response to acute-phase:

CRP. Increase often proportional to severity of tissue damage.

Question 18

When do APP levels fluctuate?

Answer 18

in response to tissue injury; trauma, burns, acute infections, M.I etc.

Question 19

What is the best marker for the inflammatory process?

Answer 19

CRP C-reactive protein: when levels decrease, patient is entering a stage of anabolism; nutrition becomes more and more important here.

Question 20

What is the disadvantage of CRP testing?

Answer 20

It is expensive, you need multiple measurements.

Question 21

Vital signs of inflammation:

Answer 21

Increased Temperature, heart rate, respiratory rate, blood pressure

Question 22

Laboratory signs of inflammation

Answer 22

Elevated WBC, CRP, glucose, depleted albumin.

Question 23

Anthropometric signs of inflammatory process.

Answer 23

Unintended weight-loss, loss of muscle mass, protein-energy metabolism

Question 24

What protein assessment is used most commonly?

Answer 24

Nitrogen balance. Tells us the presence and severity of a catabolic state. Others include creatine and albumin tests.

Question 25

Creatine levels

Answer 25

Fairly constant; proportional to muscle mass.

Question 26

What is the major by-product of protein metabolism?

Answer 26

Urea; excretion 12-20 g/day

Question 27

What are some of the limitations to the nitrogen balance test?

Answer 27

1) Hard to collect a valid specimen 2) Accuracy of assessing protein intake 3) Positive balance does not mean catabolism has decreased

Question 28

What is the most abundant protein in plasma?

Answer 28

Albumin 60%; half life 18-21 days

Question 29

What is the major function of albumin?

Answer 29

Maintain colloidal osmotic pressure (keeping fluid within’ circulation)

Question 30

What factors influence the levels of albumin in the plasma?

Answer 30

1) Increases with dehydration; decreases with over-hydration 2)Influenced by acute stress and inflammatory response (inversely related) 3) Influenced by underlying conditions.

Question 31

Albumin in the elderly

Answer 31

1) depressed levels common 2) low levels not accountable by (diet and weight) are attributed to chronic inflammatory response. 3) Need to treat the underlying causes of albumin levels

Question 32

What is the critical difference value for albumin?

Answer 32

8%