Sepsis Flashcards
What is sepsis?
The response of the body to infection specifically where the infection is located within the blood stream
Why is sepsis so serious?
It can affect anyone at any age and can occur suddenly and unexpectedly become fatal rapidly
What are the signs and symptoms of sepsis?
Ones that are commonly seen in patients so it’s important to recognise what is happening quickly and ensure patients start treatment quickly.
For example:
-fever or low temperature
-feeling dizzy or faint
-confusion or disorientation
-changes in skin
-nausea & vomiting
-severe breathlessness
-decreased urine output
How does the NICE guidelines (2016) view sepsis?
-a clinical syndrome caused by the body’s immune and coagulation systems being switched on by an infection
-sepsis with shock is a life threatening condition that is characterised by low blood pressure despite adequate fluid replacement and organ dysfunction or failure
How does the body respond to infection?
-inflammation to inactivate and destroy the invading organism
-immune system to support the inflammatory response
What happens to the inflammatory response in sepsis?
-infection triggers the start of sepsis
-the invading organism releases toxins which are sensed by the capillary wall and cells respond by releasing cytokines
-cytokines trigger the different reactions we see
Explain what happens in the innate immune system response for sepsis.
-B and T cells either recognise bacteria and produce antibodies, or if first exposure then lymphocytes need to develop a response
-tissue mediators act locally on the cell wall of the capillary causing the vessel to dilate and the gaps between capillaries widen
-IL-1 and TNF -a are involved in the development of inflammation locally triggering the white blood cell response and activating neutrophils, causing pyrexia, tachycardia and lactic acidosis
How are white blood cells activated in the innate immune system during sepsis?
-activated neutrophils kill the bacteria through phagocytosis but also injure the cell wall in the blood vessel
-other white blood cells e.g monocytes which can kill the bacteria through phagocytosis will start to respond
-the C-reactive protein measurement seen on blood results is a measure of how many white cells are responding to the infection caused
-activated neutrophils release yet more tissue mediators that cause the blood vessel to dilate and the cell wall of the blood vessel becomes permeable
-leaky capillaries will allow small molecules e.g water out into the tissue, this will cause the blood circulating volume to fall, when this occurs the kidneys will respond by retaining fluid and urine output will fall.
How is the coagulation system affected?
-ability to clot blood changes (factors in blood that need to be activated prior to clotting)
-part of bacteria’s cell wall will trigger the blood vessel cell wall to release tissue factor (trigger for clotting process to start)
-platelets or thrombocytes start to clump together to respond to the perceived injury and fibrin is formed to develop the clot, resulting in micro clots which can develop into thrombi which then starts to block the blood vessel
What is the inflammatory response to sepsis?
-vasodilation- allows more blood to the area and takes waste away
-increased capillary permeability- allows proteins e.g antibodies to move out of the blood vessel into the surrounding tissue
-phagocyte emigration
-tissue repair
