Bacteremia/Sepsis Flashcards
what are endotoxins a part of? when the body responds to the bacteria, what happens?
cell wall of gram-negative bacteria; it causes a cascade of events that leads to illness
what are exotoxins?
proteins released into the surrounding area by the bacteria during cell growth
what do exotoxins do to your body? what do they lead to?
enzymatically inactivate or modify key cellular parts, leading to cell death or dysfunction
what does botulism exotoxin do?
decreases the release of NT from cholinergic neurons causing flaccid paralysis
what does tetanus exotoxin do?
decreases the release of NT from inhibitory transmitters causing spastic paralysis
what does cholera exotoxin do?
induces fluid secretions into the intestinal lumen causing diarrhea
what is one specific category of exotoxins?`
superantigens
what happens when bacteria is engulfed by APCs? (normal process)
after ingested, epitopes are put on the cell surface, CD4 cells recognize the epitope, expansion of the specific CD4 cell and immunity to newly introduced antigen
what happens with exotoxins and APCs? what does this cause excessive activation of?
they do not get ingested by APCs, it binds directly to it and cross links with CD4 cells (activates up to 20% of lymphocytes); excessive activation of lymphocytes and macrophages (uncontrolled synthesis and release of inflammatory cytokines)
definition of infection
presence of bacteria with LOCAL inflammatory response
definition of bacteremia
presence of viable bacteria in the blood
definition of sepsis…what is it clinically characterized by
evidence of infection plus life threatening organ dysfunction, clinically characterized by an acute change in 2 pts or greater in SOFA score
definition of septic shock
sepsis with fluid, unresponsive hypotension, serum lactate level greater than 2mmol/L and needing vasopressors to maintain mean arterial pressure of 65mm Hg or greater
three things that can cause cardiogenic shock
MI, valve damage, surgery
three things that can cause hypovolemic shock
loss of whole blood, loss of plasma, loss of extracellular fluid
two things that can cause obstructive shock
inability to fill heart (tamponade) and embolus
three things that can cause distributive shock?
neurogenic shock, presence of vasodilating substances in the blood (anaphylactic shock), presence of inflammatory mediators (septic shock)
mortality is higher for pts who progress to ________ ________
septic shock
which two age groups are more likely to get sepsis? are men or women more likely to get it?
neonatal period (birth to one month) and >65 yrs; men
predisposing host factors of sepsis (6)
extremes of age, immunosuppressive therapy, recent surgery, granulocytopenia, hyposplenism, diabetes
what is the SOFA used for?
sequential organ failure assessment- used to monitor for potential sepsis in ICU pt (constant, routine monitoring)
what are the seven variables for SOFA?
1). PaO2/FIO2 ratio
2). glascow coma scale score
3). mean arterial pressure
4). administration of vasopressors with type/dose/rate of infusion
5). serum creatinine or urine output
6). bilirubin
7). platelet count
score 0-24
what is qSOFA (quick SOFA) used for?
used in ED pts with known infection and to see if they are septic
what are the three assessment measures for qSOFA?
low BP (SBP <100), high RR (>22), and altered mentation (GCS <14)
what does bacteria do to procoagulation?
it increases procoagulation, so it alters the procoagulation/anticoagulation balance
cell damage leads to ________ _________ which leads to fluid leaking from the ______ to the ________ __________
vascular damage; vessels; interstitial space
what are the mechanism steps of sepsis starting from hypovolemia (5 steps)
hypovolemia, hypotension, hypoperfusion of organs (leads to signs and symptoms), organ failure, death
what are the initial signs and symptoms (sepsis)- 4
fever, vasodilation, warm flushed skin, +/- visible source of infection
what are the 3 main signs of organ involvement (septic shock)
neurologic, renal, cardiac
what are circulation, pulm, neuro, renal, GI, cardiac, and hematologic signs/symptoms of hypoperfusion
Circulation- hypotension Pulmonary- pulmonary edema- ARDS Neuro- altered mental status Renal- oliguria--- acute renal failure GI- infarcted bowel---GI bleeding Cardiac- angina (Hypoperfusion of muscle!) Hematologic- DIC
a patient presents with ______ and _________ suspect sepsis
fever and hypotension
look for what kind of source for sepsis?
bacterial
tx for sepsis
1) . IV fluid and vasoconstrictive agents- circulation support
2) . ongoing assessment of labs for progression of sepsis
3) . ABX- broad spectrum until culture results are back
what cells are impaired in hyperglycemia?
phagocytes
what does insulin prevent during sepsis? what level should blood sugar be kept between?
apoptotic cell death that is caused from hyperglycemia; 80-100
when are corticosteroids used in sepsis tx? what are guidelines for dosage?
those with vasopressor dependent septic shock; no greater than 300 mg/day for at least 5 days then tapered
what staph bacteria is a part of the normal flora? what does this cause?
S Aureus; skin infections
what does staphylococcal bacteremia invade? by invading this, what three things can it lead to?
bloodstream; endocarditis, osteomyelitis (60% of cases are caused by S aureus), other metastatic deep infections
tx of uncomplicated bacteremia
vancomycin 1 g q 12 hrs PLUS either impenem, meropenem, or piperacillin-tazobactam
90% of toxic shock syndrome cases occur in what population?
women of childbearing age
what two bacteria produces toxins for toxic shock syndrome?
staph aureus and strep pyogenes
what is the most common toxin of toxic shock syndrome?
toxin 1 (TSST-1), which is a superantigen produced by S aureus
how does a toxin cause toxic shock syndrome?
toxin is produced in a certain area (not a spread of bacteria like sepsis) and then the toxin is sent to the bloodstream, causing massive inflammatory rxn
presentation of TSS (7)
fever, macular rash (desquamation 1-2 weeks after onset), systemic hypotension, vomiting, diarrhea, myalgias, conjunctivitis
what are some non-menstrual conditions that can cause TSS (11)
diaphragm or contraceptive sponge use, IV drug use, osteomyelitis, pilonidal abscess, septic arthritis, cellulitis, burns, empyema, lung abscess, postpartum infection, postop wound infection
tx of TSS
supportive measures, ABX (staph- nafcillin or oxacillin, strep- PenG + clinda), cardiac/renal/pulm monitoring, surgery
what are the four types of shock?
cardiogenic, hypovolemic, obstructive, distributive
