Intravascular Infections Flashcards
Bacteremia
presence bacteria in blood
1) Transient: clearance exceeds entry, from source of local tissue/organ infection
2) Continuous: seeding exceeds clearance > Endovascular infections
- Septicemia (sepsis syn): clearance mech over powered
Endovascular Infections
Infective endocarditis (IE) Infected thrombus (septic thrombophlebitis) Mycotic aneurysm (arterial wall infection) Infect of intravascular devices
Blood Cultures
blood removed aseptically dilution to broth sensitivity (volume) Specificity (false +) *timing imprt Sterile
Predisposition
congenital heart disease rheumatic heart disease dental, urological of GI conditions lead to bacteremia IV drug use Hospitialization
Pathogenesis
-all dead if no treatment
turbulent blood flow endothelial cell activation fibrin and platelet deposition silent or clinical bacteremia seed sterile vegetations bacteria grow within fibrin - staph aureus
perforation of non coronary cusp on mitral valve vegitation
Host Defenses
Endocardium doesnt need capillaries since blood flowing and receive nutrients there
no capillaries mean no neutrophils diapedesis or phage
innate and acquired imm mech are subverted
bacteria colonize and replicate in vegetations
Diagnosis IE Duke Criteria
- continuous bacteremia
- target lesion on valve, supports or endocardium
fever predisposition of heart condition injection drug user embolic phenomena imm phenomena
trans espophageal echocardiogram (TEE)
Symptoms from dysfunctional heart valve
Oslers nodes on hands
Eccymotic embolic janeway lesion on foot
roth spot in fundus of eye
conjunctival petechiae
Microbiology
Staphylococci (s aureus, coagulase -) Streptococci (viridian and gamma) Entercocci Gram - bacilli Fungi
Group A strep**
Clinical Correlation Complications
congestive heart failure stroke infarcts (spleen) glomerulonephritis mycotic aneurysms abscesses (local and distant, brain)
Prophylaxis?
changing with evidence based research
however incidences of IE after dental procedures is high so should prophylax esp if immunocompromised
High risk adverse outcome for IE if:
Pros heart valve
previous IE
congenital heart disease
cardiac Tx patient who develop vlavulopathy
Prevention
prophylactic antibiotics before procedures for high risk pts
IV or PO regimens at time of procedure
Treatment
intravenous
bactericidal regimen
length 2-8 wks (important factor)
Surgery
