B3.005 - Causes of Sepsis Flashcards
How do bacteria get into the blood stream?
Brushing your teeth Trauma Other infections Indwelling devices IV Drug use
Diagnosis of sepsis
2 of 4:
- Tachypnea
- Tachycardia
- Hyperpyrexia
- Leukocytosis
What is sepsis
overwhelming blood stream immune response to infection
What is an infection highway
blood stream
What is stage 1 sepsis
Have at least 2 of the following and confirmed infection
- Body temp above 101 or below 96.8
- Heart rate over 90
- RR over 20
Stage 2 sepsis
Severe sepsis
Everything in sepsis plus one sign of organ failure
What are signs of organ failure
- significantly decreased urine output
- Changes in mental status
- Decreased platelets
- Difficulty breathing
- Abnormal heart function
- Abdominal pain
what is stage 3 sepsis
Septic shock
Must have previous signs plus very low blood pressure that does not respond to fluid replacement
Patients hospitalized for septicemia or sepsis were how much more likely to die
8 times more likely to die during hospitalization
Risk factors of sepsis
Older adults Chronic medical condition Immunocompromised Children less than 1 year Invasive devices
Bacteria forming colonies/biofilms on biomaterials are recalcitrant to what
antibiotic therapy
What causes 76% of all orthopedic infections
staph sp. #1 staph aureus #2 staph epidermidis
what is standard treatment of orthopedic infections
removal of implant, temporary insertion of antibiotic impregnated spacer and replacement of implant
what are the top pathogens that can lead to sepsis infections
Staph aureus
CONS
E. Coli
Strep sp.
What are the features of staph
Gram positive cocci Non motile, non spore forming Catalase + Oxidase - Facultative anaerobes Major component of normal flora (skin, nares)
What are clinical syndromes that can be caused by staph
Toxic shock syndrome Endocarditis Necrotizing pneumonia Sepsis Cellulitis Necrotizing fasciitis Pustolosis/Folliculitis Brain abcess Furuncle or carbuncle Impetigo Surgical wound Epidural abcess Device ass. infections
Key virulence factors of staph
Cytolysins
Multiple bi component leukocidins
Phenol soluble modulins
Enterotoxins
What are adherance factors of staph
Protein A
Fibronectin-binding proteins
Collagen binding proteins
What is the pathophys of septic shock
- Innate immune system recognizes microbes
- Immune factors activate endothelial cells and additional leukocytes
- immune system over responds including secondary mediators
- systemic endothelial damage, vasodilation and capillary leakage
- multiple organ failure
- death
what are microbial triggers of an immune response
gram negative bacteria - LPS
Gram positive bacteria - LTA, peptidoglycan, superantigens
General bacteria - flagellin
Viral nucleic acids
PAMP recognition by
Toll like receptors
What are super antigens
exotoxins that cross link TCR to class II MHC
Instead of activating 1 in 10,000 T cells as many as 1 in 5 T cells becomes stimulates
Leads to massive IFN gamma and IL-2 production
Acts on vascular endothelium to cause capillary leakage
What are superantigens produced by
staph aureus and sterp pyogenes
Best known for causing Toxic shock syndrome
Some Sa toxins
Treatment of sepsis
manage infection, identify infecting organism, antibiotics, catheter replacement, surgery
