Nutrition SDL #3: Metabolic Stress & Starvation Flashcards
What are the risks of malnutrition in sick patients?
Slow recovery or worsened states
What are the 4 populations at risk for malnutrition upon admission?
- Elderly
- Chronically ill
- Poor
- Children
What are iatrogenic causes of malnutrition?
Malnutrition caused by medical staff (restrictive diets or fasting before procedures)
What should be done upon all admissions to the hospital?
ASSESS NUTRITIONAL STATUS
Stress causes the increased secretion of what 5 molecules?
- Cytokines (TNF, ILs)
- Catecholamines
- Glucocorticoids
- Glucagon
- Insulin
What are the 2 types of cytokines?
- Tumore Necrosis Factor (TNF)
2. Interleukin (IL-1)
What are the 7 effects of cytokines?
- Increased NO
- Fever
- Proteolysis
- Decreased albumin
- Increased fibroblasts
- Iron sequestration
- Zinc liver uptake
What 3 micronutrients are required in larger amounts in sick patients?
- Vitamin A
- Zinc
- Copper
What are the 2 phases of the stress response to trauma?
- Ebb
2. Flow
How long does the Ebb phase last?
1-2 days post-injury
How long does the Flow phase last?
Many days post-injury
What happens during the Ebb phase?
Initial response to cytokines and stress hormones
What happens during the Flow phase?
Energy production is boosted and fuel is transferred from adipose tissue and muscles to liver and injury site 1. Proteolysis 2. Gluconeogenesis 3. FA beta oxidation Catecholamine secretion decreases
What effect do the stress mediators have on insulin? What effect does this have on target tissues?
Cause insulin resistance to prevent glucose from being converted to glycogen, this impairs glucose transport to tissues so most of the glucose goes to the brain
Describe the stressed protein metabolism. 2 steps
- Cytokines cause proteolysis of muscle and visceral organs
2. AAs go to liver to produce glucose and acute phase proteins
How is urine affected by stressed?
Increase nitrogen/urea in urine (but still a (-) NB)
Describe the stressed carb metabolism. 2 parts
- Glycogen stores depleted faster
2. Protein gluconeogenesis
Describe the stressed lipid metabolism.
TAGs in adipose cells are broken down for FA beta oxidation in liver
How does stress affect ketogenesis?
It inhibits it in the fasted state
Why are plasma lipids higher during the stress response? 2 reasons
- Lipolysis
2. Insulin resistance
What are 4 (and optional 2) questions to ask a patient to assess nutritional status?
- Any food you can’t or don’t eat?
- GI problems?
- Take supplements?
PEDS: - Growth rate?
- Formula or breast milk?
What to check during physical examination for malnutrition? 2 things
- Hair plucking
2. Muscle wasting in temporal area, thighs, deltoids, interosseous muscles (fingers)
Describe the starvation carb metabolism. 3 steps
- Glycogen stores depleted slower (12 hrs or less)
- Protein gluconeogenesis
- Ketogenesis
What is the effect of excess ketogenesis? What is the minimum daily carb intake to prevent this?
Ketoacidosis
> 100 g carbs/day/adult
What is the major fuel source during starvation?
Fats
What is the major fuel source during stress?
All of them!!!