(ID)- Sepsis Flashcards
What is sepsis?
Life-threatening organ dysfunction due to dysregulated host response to infection
Why is there systemic inflammation in sepsis?
Macrophages, lymphocytes and mast cells recognise pathogens releasing cytokines e.g. IL-6 and TNF
Immune activation causes systemic inflammation and release of NO (vasodilation)
What causes oedema in sepsis?
Cytokines cause endothelial lining to become more permeable
Fluid leaks out of the blood into the extracellular space
Why is extracellular oedema dangerous in sepsis?
Oedema creates a gap between the blood and tissue
Causes hypoperfusion of tissue
What causes disseminated intravascular coagulopathy in sepsis?
Activation of coagulation system leads to fibrin deposition causing thrombi formation
Thrombi formation consumes platelets and clotting factors leading to thrombocytopenia and haemorrhage
What can indicate disseminated intravascular coagulation?
Low platelets
Low fibrinogen
Raised d-dimer
Prolonged Prothrombin and Partial thromboplastin time (reduced circulating coagulation factors there increased time)
Schistocytes (excess fibrin strands haemolyse passing RBCs)
Why is there metabolic acidosis in sepsis?
Tissues have inadequate oxygen supply
Anaerobic respiration
Lactic acid is a waste product, causing serum lactate rise
What is septic shock?
Subset of sepsis with profound circulatory, cellular and metabolic abnormalities associated with greater risk of mortality than sepsis alone
What happens in septic shock?
Arterial blood pressure drops despite adequate fluid resuscitation causing organ hypoperfusion
How is septic shock diagnosed?
- Low MAP (below 65mmHg) despite fluid resuscitation requiring vasopressors
- Raised serum lactate (above 2mmol/L)
How is septic shock treated?
Aggressive IV fluids to improve blood pressure and tissue perfusion
NorAd
How do vasopressors increase MAP?
Vasoconstricts blood vessels
Increases vascular resistance and therefore MAP
Improving tissue perfusion
What criteria is used to assess severity of organ dysfunction in sepsis?
Sepsis-related Organ Failure Assessment (SOFA)
What are the risk factors for sepsis?
- Extremes of age
- Chronic conditions (COPD and diabetes)
- Chemotherapy, immunosuppressants or steroids
- Surgery
- Pregnancy and childbirth
- Indwelling medical devices
What do obs do patients with sepsis have?
- Raised temperature
- Tachycardia
- Tachypnoea
- Low oxygen saturation
- Hypotensive
- Reduced consciousness
