svensson- shock and edema Flashcards
(57 cards)
Shock
a life threatening condition of circulatory failure that results in inadequate oxygenation of body tissue
What are the four types of shock
-distributive shock
-hypovolemic shock
-cardiogenic shock
-obstructive shock
Distributive shock
occurs as a result of vasodilation, the blood vessels are unable to maintain normal pressure (not profusing properly)
What are signs that are indicative of circulatory shock, (something that is apart of all the shock pathways)?
-arterial hypotension (increased blood pressure)
-tachycardia (increased heart rate)
-and signs of tissue hypoperfusion are present
What are signs of tissue hypoperfusion
-altered mental state
-mottle, clammy skin
-oliguria
-elevated blood lactate
Following circulatory shock in distributive shock, what happens that leads to distributive circulatory shock?
-normal or high cardiac output or SvO2
what are the main causes of distributive shock?
-sepsis (#1)
-anaphylaxis
-neurogenic
what are symptoms of distributive shock?
-hypovolemia and hypotension
-result if vasodilation and release of inflammatory mediators
Sepsis
- a life threatening organ dysfunction caused by a dysregulated host response to infection
septic shock
-a subset of sepsis in which underlying circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than sepsis alone
-a mortality rate of 25-50%
-ranks fist among causes of death in hospital ICUs
-accounts for an estimated 200,000 deaths in the US annually
What is the primary cause of septic shock?
-infection by endotoxin-producing gram-negative bacillus accounts for 70% of septic shock cases
Endotoxin
-gram negative bacteria have an outer membrane that is composed of endotoxin
-endotoxin is comprised of O-antigen, core oligosaccharide, and lipid-A
how does endotoxin cause infection?
the endotoxin triggers a cascade of chemokines which trigger effects
Does the amount of endotoxin affect the infection?
Yes, the quantity of endotoxin directly impacts the effects seen
What does a low quantity of endotoxin do
causes local inflammation
What does a moderate quantity of endotoxin do
causes systemic effects
What does a high quantity of endotoxin do
causes septic shock
What role does adrenomedullin play in septic shock?
-ADM in the intravascular compartment enhances endothelial barrier function when it binds to a receptor by causing contraction and closing the gaps it can also induce endothelial NO release which indirectly causes vascular smooth muscle cell relaxation
-if ADM passes into the interstitial compartment by passing through the endothelial barrier it can bind to vascular smooth muscle cells and trigger relaxation
What role does dipeptidy dipeptidase 3 play in septic shock?
-impaired tissue perfusion (dead endothelial cells) changes cellular necrosis which releases cytosolic DPP3 into the circulation
-cDPP3 rapidly breaks down circulating peptides (angiotensin metabolites)
-the break down angiotensin metabolites induces a blunted response which causes further deterioration of tissue perfusion through reduced VSMC contraction, sympathetic tone, vasopressin release, and catecholamine release
What are the mechanisms of anaphylaxis?
-immunologic (IgG)
-immunologic other
-non-immunologic
What are causes of hypovolemic shock
-hemorrhage
-severe burns
-severe vomiting, diarrhea
hypovolemic shock
the loss of plasma or blood volume
What happens after circulatory shock that leads to hypovolemic shock?
-low estimated cardiac output or SvO2
-low central venous pressure
what are symptoms of hypovolemic shock?
-internal or external fluid loss leading to organ failure
