Chapter 164 Metabolic Consequences of Trauma Flashcards
What is the “ebb and flow” phenomenon following trauma?
After a traumatic event - initially there is a decrease in metabolism secondary to hypovolemia and hypoperfusion. As treatment ensues and restoration of volume status takes place, the “flow” state occurs and hypermetabolism and inflammatory changes are seen.
What stimulates the sympathetic nervous syndrome to be activated in trauma?
Loss of blood or fluids (hypovolemia) - stimulate baroreceptors in the carotid bodies and aortic arch
Pain - causes catecholamine release via stimulation of the hypothalamus
What neuroendocrine activation is seen after the initial sympathetic activation?
Release of ACTH and growth hormone and ADH. The Renin-angiotensin-aldosterone system is also activated
What counterregulatory hormones cause hyperglycemia in trauma patients?
Glucagon, cortisol, growth hormone, catecholamines
What does epinephrine cause to occur, causing increased glucose?
Proteolysis, glycogenolysis and inhibition of insulin-mediated glucose uptake by muscle
What does cortisol cause to occur, causing increased glucose?
Gluconeogenesis, inhibits insulin activity and exacerbates the effects of glucagon and epinephrine
What is the most common acid-base disorder seen in trauma patients?
Metabolic acidosis
What characteristics define metabolic acidosis?
Low bicarbonate
Low CO2
pH <7.35
What molecules/substances in the blood cause metabolic acidosis?
Hydrogen ions, lactate, uremic acid, ketoacies, phosphates and other unmeasured anions
What is the “triad of death” entail?
Acidosis, hypothermia and coagulation disturbances
Why is it thought that hypothermia occurs with trauma?
A result of loss of vasomotor tone and subsequent vasodilation. Also, central thermoregulation may be altered and affect the body’s ability to respond to decreased temperatures.
What is cold diuresis?
Persistent hypothermia–>peripheral vasoconstriction–>sense of increased blood volume
Also, decrease in response to ADH
All result in worsened hypovolemia–>azotemia and renal dysfunction
How does hypothermia affect coagulation systems?
Platelet function is decreased via decreased production of thromboxane B2 and platelet adhesion molecules.
Lowered temperatures also affect enzymatic activity and fibrinolysis.
True or False: enteral feeding should be initiated in trauma patients as soon as possible
True
What is the “two-hit theory”?
A theory to explain why some patients have worse inflammatory responses than others with trauma. T
In this theory, the initial inflammatory response seen after trauma predisposes to a severe inflammatory response. Those with a second inflammatory trigger, such as surgical repair of the initial injury, SIRS and possible MODS can occur.
