Nutritional support in trauma Flashcards
1
Q
Trauma
A
An injury or wound to living tissue caused by an extrinsic agent
2
Q
Mortality from trauma phase 1
A
- Shock
- Develops within 2-6hrs after injury; Lasts 24-48hrs
- Cytokines, catecholamines and cortisol secreted
- Primary aims = stop bleeding, prevent infection
- Peripheral vasoconstriction preserves vital organs
3
Q
Mortality from trauma phase 2
A
- Catabolic state
- Develops approx. 2 days after injury
- Catecholamines, glucagon, ACTH converted into cortisol
- Primary aims: avoid sepsis, provide adequate nutrition
- Increased lipolysis, Increased glycolysis, Increased neg nitrogen balance, Increased metabolic rate, Increased oxygen consumption
4
Q
Mortality from trauma phase 3
A
- Anabolic state
- Occurs approx. 3-8days after uncomplicated surgery
- Coincides with beginning of diuresis
Aims: - Adequate nutrition supply is critical in this phase
- Refeeding syndrome risk
- May last a few weeks or a few months
- Obesity paradox
5
Q
Inflammatory response at trauma site
A
- Bacteria and pathogens enter wound
2 .Platelets release clotting factors - Mast cells secrete factors that mediate vasodilation to increase blood delivery
- Neutrophils and macrophages phagocytose pathogens
- Macrophages secrete cytokines to attract immune cells and proliferate the inflammatory response
- Inflammatory response continues until wound is healed
6
Q
The five cardinal signs of inflammation
A
- Heat
- Redness
- Swelling
- Pain
- Loss of function
7
Q
Endocrine effects of cytokines
A
- Cytokine mediated secretion of catabolic hormones e.g. IL-1 and TNF-alpha - Catabolic hormones increase energy release
- Cytokine mediated inhibition of anabolic hormones - Anabolic hormones build up molecules the body needs
8
Q
Metabolic response to trauma phase 1
A
- Supply of glucose and oxygen is interrupted
- Glycogenolysis: 24hrs max; Glycogen glucose
9
Q
Metabolic response to trauma phase 2
A
- Gluconeogenesis
- Skeletal and secreted protein breakdown; 1kg muscle = 200g protein = 120g glucose
- Amino acids converted to glucose and lactate production
- Nitrogen loss:
10
Q
Metabolic response to trauma phase 3
A
- Lipolysis and Ketogenesis
- Free Fatty Acid = acetyl CoA = acetoacetate and hydroxybutyrate
- Ketone bodies converted back to Acetyl CoA to make energy
- Gradual change to ketone metabolism by CNS which spares protein stores and muscles
11
Q
Changes in protein after trauma
A
- Amount of new protein synthesised reduces and profile of proteins synthesised changes
- Increased inflammatory modulators and scavengers
- Decreased albumin
- Skeletal muscle proteolysis increases
- Increased free amino acids, plasma (ammonia)
- More nitrogen loss
12
Q
Lactate production in Hypoxia
A
- Decreased aerobic metabolism; increased anaerobic metabolism
- Pyruvate reduced to lactate
- Anaerobic metabolism can only continue until lactate becomes toxic, H+ inhibits enzymes
13
Q
Lactate: prognostic marker in trauma
A
- Failure of blood lactate to return to normal following trauma resuscitation carries a poor prognosis
- Blood lactate (mmol/L):
- <1, mortality: 18%
- 2-4, mortality: 74%
- > or equal to 5: 100%
14
Q
Primary malnutrition
A
- Protein-calorie undernutrition (starvation)
- Dietary deficiency of specific nutrients e.g. trace elements, water soluble/fat soluble vitamins
15
Q
Secondary malnutrition
A
- Nutrients present in adequate amounts, but appetite is suppressed
- Nutrients present in adequate amounts, but absorption and utilisation are inadequate
- Increased demand for specific nutrients to meet physiological needs
