1/23/17 Intravascular infections Granger TEST #1 Flashcards
What is a bacteremia?
-Presence of bacteria in blood stream
What can bacteria in the blood lead to?
-Septic shock
shock = no blood pressure
What is metastatic infection?
-Bacteria in corners of the body (all locations/sites in the body)
What are two methods/ways of a bacteremia?
- Transient
- Continuous
What makes a bacteremia transient?
-The clearance exceeds entry
What makes a bacteremia continuous?
-Seeding exceeds clearance capacity
What does continuous bacteremia lead to?
-Endovascular infections
Where do you find transient bacteremias?
- Skin
- lungs
- joint
- bone
- abdomen
In a continuous bacteremia with septicemia what is a characteristic of the bacteria?
-They have high virulence
What type of infections can be caused by avirulent organisms?
-Endovascular infections
What is an example of endovascular infections?
- Infective endocarditis
- infected thrombus
- mycotic aneurysm
- infections of intravascular devices
When taking a blood culture how should the blood be removed?
-aseptically
What is the sensitivity of blood culture tests dependent on?
-Volume of the blood
Whenever you culture the blood infective endocarditis is it positive or negative?
-Positive
What are the (epidemiology) predisposition for endocarditis?
- Congenital heart disease
- Rheumatic heart disease
- Intravenous drug abuse (IVDA)
- Hospitalization
- Dental, urological, gastrointestinal
What is the pathogenesis of endocarditis?
- Turbulent blood flow
- Endothelial cell activation
- Fibrin and platelet deposition
- Silent or clinical bacteremia seed sterile vegetations
- Bacteria grow within fibrin vegetations
Do the valves of the heart receive nourishment? If so from where?
-Blood stream
What does the endocardium lack?
-Capillary circulations
Why is capillary circulation important?
-It is required for neutrophil access to the site of infection
Why is the infection of the valves of the heart dangerous?
-Because they don’t have capillary circulation allowing neutrophils to access the site of infection
If you have endocarditis without antibiotics what happens with the bacteria?
-They are imbedded within vegetations and are impossible to entirely eradicate
How do you diagnosis endocarditis?
-Look for the major and minor criteria?
-What are the major criteria for diagnosing endocarditis?
- Continuous bacteremia (found via blood culture)
- Target lesion on valve, supports, or endocardium (ECHO cardiography)
What are some minor criteria for diagnosing endocarditis?
- Fever
- Predisposing heart condition
- Injection druge user
- Embolic phenomena
- Immunological phenomena
If a patient comes to your clinic and you take a blood culture do find continuous bacteremia, has a fever, is an injection drug user, and has a positive ECHO cardiography (target lesion on valve, supports or endocardium) test what would you diagnose them with?
-Endocarditis
What causes Osler’s nodes?
-Embolic lesions
What causes conjunctival petechia?
-Embolic lesions
What causes the embolic lesions?
-Some of the vegetation breaking off of the valves in the heart caused from endocarditis
When you take a microbiologic culture from the bacteria causing endocarditis what bacteria do you see?
- Staphylococci
- Streptococci
- Enterococci
- Gram - bacilli
- Fungi
If you have non-virulent strep species do you see them in endocarditis cultures?
-Yes
What is the most common non-virulent strep species that you see in endocarditis cultures?
-Strep mutans
Who is at high risk for adverse outcome from IE?
- Prosthetic heart valves
- Previous infect endocarditis
- Congenital heart disease
- Cardiac transplanted hearts
What is a good way to prevent Infective endocarditis?
-Prophylactic antibiotics prior to procedures
How do you treat someone with endocarditis?
- Do Intravenous therapy
- Bactericidal regimen
When diagnosing endocarditis what is something that you have to give special attention to?
-Blood cultruing
