Hunter: Sepsis and Septic Shock Flashcards
(blank) is rare, but can be serious
Fungemia (fungus in the blood)
How are bacteria and fungi normally cleared from the blood?
via the mononuclear phagocyte system (splenic macrophages and liver Kupffer cells)
Bacteremia or fungemia results when the numbers of microorganisms exceeds (blank)
the MPS clearance capacity
These two things are poorly cleared from the circulation by fixed macrophages of the MPS especially in the absence of opsonizing antibody
encapsulated bacteria and yeast
This type of bacteremia/fungemia occurs, lasting minutes to a few hours, and resolves; usually due to tissue trauma during medical procedures, can be due to manipulation of infected tissue, surgery in contaminated areas, or in early acute infections
transient bacteremia/fungemia
This type of bacteremia/fungemia occurs, clears, then recurs with the same organism, and develops with undrained closed-space abscesses (intra-abdominal, pelvic, perinephric, hepatic)
intermittent bacteremia/fungemia
Intermittent bacteremia can be seen in (blank) that fail to resolve, reflecting irregulat cycles of release into and clearance from the circulation of organisms infecting tissue
focal infections
**pneumonia, osteomyelitis
This form of bacteremia or fungemia is a cardinal feature of endocarditis and other types of endovascular infections (suppurative thrombophlebitis, infected aneurysms), reflecting constant shedding of organisms from endovascular foci into the circulation
continuous bacteremia/fungemia
What is the main example in which you would see continuous bacteremia or fungemia?
endocarditis
**continuous shedding of organisms from endovascular foci into the circulation
Continuous bacteremia also occurs early in these two cases
typhoid fever
brucellosis
Compare transient, intermittent, and continuous bacteremia on a scale
transient: bacteria level spikes and then it falls
intermittent: cycles of spikes and falls
continuous: always present or ever increasing
T/F: Bloodstream infections are usually caused by a massive amount of organisms in a given volume of blood
false; Bloodstream infections are frequently caused by relatively few organisms in a given volume of blood (<1- 10 colony forming units/mL of blood)
How should you draw blood if you expect a bloodstream infection?
draw 20-30mL of blood twice from two different sites and culture them in both aerobic and anaerobic conditions
**do not take blood from an indwelling IV or intra-arterial catheter unless you suspect a catheter-related infection
Bacteremia or Fungemia Can Occur Secondary to Spread from an (blank)
intravenous device
ex: biofilms on catheters or cannulas
**treat by removing the device, antibiotics won’t work
Most cases of clinically significant bacteremia or fungemia are the result of overflow from (blank)
an extravascular infection via hematogenous spread
In extravascular infection leading to bacteremia, microorganisms from a focus of infection often reach the capillary and venous circulation through (blank)
The process is dependent on the timing and interaction of multiple events and is thus much less predictable than intravascular infection
lymphatic vessels
The probability of bacteremia or fungemia is dependent on what two factors?
- source of infection
2. the microorganism
Most common sources of bacteremia?
UTI (E. Coli)
resp tract infections
infections of skin and soft tissues (ex: wound infection or cellulitis)
Any organism producing (blank) is likely to produce bacteremia at the same time
meningitis
The frequency with which any organism causes bacteremia is related to both (blank) and how often it produces infections
its likelihood to invade the bloodstream
T/F: Some bacteria and fungi are very difficult to isolate from blood cultures, so although the bacteria may be invading the bloodstream, it may be hard to find the bacteria in the blood
True
an inflammation of a vein wall frequently associated with thrombosis and bacteremia
suppurative (septic) thrombophlebitis
Why has the rate of superficial thrombophlebitis increased?
increasing use of IV catheters
What happens in septic thrombophlebitis?
there is formation of a thrombus resulting from trauma to the vessel, stasis of blood flow, or hypercoagulable state
the thrombus is then seeded with organisms and an infection is established
the infection can then spread to adjacent structures, leading to septic embolization
What is the difference between organisms that cause infection in superficial thrombophlebitis and deep thrombophlebitis?
superficial: usu nosocomial bacteria (S. aureus, S. epidermidis, gram-negative anaerobes)
deep infections: caused by organisms that reside on adjacent mucous membranes or commonly infected sites (Bacteroides, E. Coli, H. influenzae, S. pneumo)
This is suspected in pts with risk factors like surgery and indwelling venous cannulas; bacteremia is usually present; surgical exploration might be required; removal of IV catheter is necessary
suppurative (septic) thrombophlebitis
used to describe pathogens in the blood that are causing sepsis
septicemia
Some systemic responses to infection can be protective. But for non-protective responses, there is a progression of illness from (blank) to (blank)
systemic inflammatory response syndrome; multi-organ dysfunction syndrome
List the order of severity from systemic inflammatory response syndrome to multiple organ dysfunction syndrome
- systemic inflammatory response syndrome
- sepsis
- severe sepsis
- septic shock
- multiple organ dysfunction syndrome
What are the SIRS criteria (systemic inflammatory response syndrome)
Pt must have at least 2 of the following:
- temp > 38C or 36C
- HR > 90bpm
- resp rate >20
- white blood cells > 12,000 or <4,000
Sepsis in conjunction with at least one sign of organ failure or hypoperfusion, such as lactic acidosis (lactate >4 mmol/L), oliguria (urine output ≤ 0.5 mL/kg for 1 hour), abrupt change in mental status, mottled skin or delayed capillary refill, thrombocytopenia (platelets ≤ 100,000 cells/mL) or disseminated intravascular coagulation, or acute lung injury/acute respiratory distress syndrome
severe sepsis
Severe sepsis with hypotension (or requirement of vasoactive agents, (e.g., norepinephrine) despite adequate fluid resuscitation in the form of a 20-40-ml/kg bolus
septic shock
Dysfunction of two or more organ systems such that homeostasis cannot be maintained without intervention
multiorgan dysfunction syndrome
Approximately two-thirds of the cases of severe sepsis occur in patients with significant underlying illness. Sepsis-related incidence and mortality rates increase with (blank) and preexisting (blank)
age; comorbidity
Why is the incidence of cases of severe sepsis on the rise?
aging population
increasing longevity of patients w chronic diseases
high frequency in AIDS pts
widespread use of immunosuppressive drugs, indwelling catheters and mechanical devices