Circulatory, RES, & Lymphatics Flashcards
bacteria in the blood
bacteremia
a broad term that includes bacterial toxins or fungi
septicemia
Most common sources of bacteremia
UTI, respiratory tract infection, infections of skin or soft tissues
Sepsis=
SIRS + suspicion or proof of an infectious cause
Sources of SIRS other than infection
pancreatitis, burns, trauma, PE, myocardial infarction, anaphylaxis and drug overdose
SIRS required two or more of the following
temperature elevated or decreased, increased HR, increased RR, significantly elevated or decreased WBCs OR 10% immature neutrophils
immature neutrophils
bands
sepsis assoc. w/ organ hypoperfusion
severe sepsis
indicators of organ hypoperfusion
reduction in urine output, mental status changes, systemic acidosis and/or hypoxemia
hypotension not responsive to fluid and pharmacologic treatment
refractory septic shock
sepsis+ hypotension (systolic pressure < 90 mm Hg)
septic shock
throwing clots in many different parts of the body
disseminated intravascular coagualation
death from septic shock is usually caused by
multi-organ failure
fatality rate of septic shock
40-60%
septic shock is classically induced by
gram - bacteria in the bloodstream-LPS
Gram + bacteremia causes septic shock via
peptidoglycan or exotoxins
release of vasoactive substance such as histamine can cause
arterial hypotension
TNF can affect cardiac muscle via
depression of cardiac muscle contractility-decreases organ perfusion
cell function is affected rather than organ destruction
cellular stasis
Tx septic shock-hypotension:
IV fluids (1-2L of normal saline over 1-2 h)
Tx septic shock-hypoxia:
ventilator therapy
Tx septic shock-DIC:
transfusion of fresh-frozen plasma and platelets to stop bleeding OR heparin to prevent thrombi formation
Tx septic shock-bacterial infection:
antibiotics
In septic shock patients what was the major determinant of outcome?
the interval between the onset of hypotension and the administration of antibiotics
What happens when you run out of clotting components during DIC
start to hemorrhage-need to give plasma/platelets
Early in DIC Tx
Heparin to prevent thrombi formation
Septic shock Tx for unknown bacterium
Vancomycin and gentamicin to cover both gram-positive, and gram-negative infections
Septic shock with generalized erythroderma
toxic shock syndrome-Staph. aureus, Strep. pyogenes
Septic shock with petechiae in skin
Neisseria meningitidis
Septick shock with petechial skin lesions in person who has been bitten by a tick in an endemic area
Rocky Mountain spotted fever
Septic shock with hemorrhagic skin lesions with history of consuming raw oysters
Vibrio vulnificus
Main method of diagnosing sepsis
blood cultures
% of infective endocarditis yielding + blood cultures
95%
When do you not do a blood culture for diagnosing sepsis
if the patient is already on antibiotic therapy
most common cause of septic shock
bacteria (gram +/ gram -)
Predisposing factors to pericarditis
pericardial effusion, immunosuppression, chronic diseases, cardiac surgery, chest trauma
common causes of pericarditis
streptococci, staphylococci, gram-negative rods, anaerobic bacteria, haemophilus influenzae, early complication of lyme disease (borrelia burgdorferi)
Tx of pericarditis
surgical drainage, systemic antibiotics
Dx: of pericarditis
very high fever, WBC count, and cardiac tamponade
may test pericardial fluid
fatality rate: pericarditis
untreated: fatal, treated: 40% mortality
Dx: mycobacterial pericarditis
bacilli observed in pericardial fluid or a biopsy of the site
acute infectious myocarditis should be suspected in patients with
dynamically evolving changes in ECG, echocardiography, and serum creatine kinase levels
infectious myocarditis most commonly associated with
non-bacterial pathogens (viruses-coxsackie B, trypanosoma cruzi protozoa, endomyocardial fibrosis-parasite)
bacterial causes of myocarditis
borrelia burgdorferi, orientia tsutsugamushi, rickettsia rickettsii, coxiella burnetii, mycoplasma pneumoniae, chlamydia pneumoniae, corynebacterium diphtheriae
high fever (103-104F), acutely ill, rapid damage to cardiac structures
acute bacterial endocarditis
acute bacterial endocarditis if untreated
progresses to death within weeks
mycotic aneurysm may result from
acute bacterial endocarditis
subacute bacterial endocarditis presentation
low-grade fever, night sweats, weight loss, vague constitutional complaints, indolent course (slow damage to the heart)
bacterial causes of acute bacterial endocarditis (ABE)
staph. aureus, beta-hemolytic streptococci, pneumococci
subacute bacterial endocarditis-bacterial causes
viridans streptococci, enterococci, coagulase-negative staph, HACEK group (normal oropharyngeal flora)
native valve endocarditis bacterial agents
staph. aureus, viridans streptococci, group D streptococci, enterococci, HACEK
injection drug users-endocarditis bacterial agents
staph. aureus, enterococci and streptococci
Prosthetic valve endocarditis early infections (within 2 months of implant) caused by
staphylococci, gram - organisms, fungi
Prosthetic valve endocarditis late infections caused by
mainly streptococci, but staphylococci also
transvenous pacemaker or implanted defribrillator-associated endocarditis causes
nosocomial, staph. aureus or coagulase- staph.
Most common causes of endocarditis
STAPH AUREUS!
clinical manifestations of endocarditis
fever, valve destruction, peripheral purpura, embolisms
nontender erythematous macules on palms or soles usually seen in ABE
Janeway lesions
painful, purplish nodules of the fingers, toes or feet usually seen in SBE
Osler nodes
dark, linear discolorations under the nails usually seen in SBE
Splinter hemorrhages
Embolisms in the heart and brain may result in
infarctions
predisposing factors to endocarditis
degenerative valve disease, prosthetic heart valves, IV drug abuse, and intracardiac devices
present in 50% of endocarditis cases
disease of the heart valves
how does disease of heart valves predispose to endocarditis
alters blood flow-disrupts endothelial surface-provides a focus for direct attachment and colonization of the bacterium
Common sources of bacteria causing endocarditis
transient bacteremia from dental, upper respiratory, urologic, and lower gastrointestinal diagnostic and surgical procedures
continuous bacteremia with endocarditis is caused by
continuous shedding of bacteria from vegetations
vegetation is composed of
platelets, fibrin, microcolonies of bacteria and inflammatory cells
Dx: of bacterial endocarditis
fever, positive blood cultures, peripheral emboli, visualization of vegetative growth on echocardiography
Tx of bacterial endocarditis
b/f blood culture results: vancomycin and gentamicin (covers staph, strep, enterococci) prolonged therapy (> 4 weeks), surgical vegetectomy and valve replacement in some cases
