Infection and Immunity Flashcards
What percentage of nosocromial infections are surgical site infections?
14-16%
What is the surgery with the highest rate of cases of SSI?
Intra-abdominal
What are patient related factors for risk factors for SSI?
- Extremes of age
- poor nutritional status
- ASA status >2
- DM
- Smoking
- Obesity
- co-existing infections
- colonization
- immunocompromise
- longer reop hospital stay
What are some microbial factors for risk of developing SSI?
- Enzyme production
- polysaccharuide capsule
- ability to bind to fibronectin
- biofilm and slime formation (implants)
What are some wound related factors for development of SSI?
- Devitilized tissue
- dead space
- hematoma
- contaminated surgery
- presence of foreign material
What is the most common cause of SSI?
S. aureus, including MRSA is most common
What is the normal presentation of an SSI? Timeframe? Gold standard dx?
- Presentation w/in 30 days post op
- local inflammation
- poor wound healing
- sx of systemic infection
- gold standard dx: aseptically obtained wound culture
What are some coniderations in anesthetic managmeent to prevent SSI?
- Manage pain
- acute pain can suppresses NK cell activity
- prevent hypothermia
- exacerbates stress response
- minimize catecholamine surges
- this can increase blood glucose, which increases risk of infection
SSI prevention in general?
- appropriate admin of prophylactic antibiotics
- usually within 1 hour prior to incision (2 hours for vancomycin and fluoroquinolones)
- redose in prolonged surgery >4hr
- most commom is first generation cephalosporin
- broad specturm, low side effects, high tolerability
- small bowel also need gram-negative coverage
- large bowel and femail need anaerobic coverage
- NO SMOKING FOR 4-8 WEEKS
- No alcohol 1 month
- optimize daibetics
- optimize nutritional status in cachexia or obesity
- postpone sx until active infection gone (if possible)
- optimize oxygenation with titration Fio2
- prevent hypothermia
- adequate analgesia
- hypocapnia should be avoided due to vasoconstrction
- optimize glucose control
- hyperglycemia inhibits leukocyte function
What are common antibiotics used for general srugery?
what surgery needs gram-negative coverage?
what needs anaerobic coverage?
- Most common abx is first-generation cephalosporin
- broad spectrum, low side effects, high tolerability
- small bowel needs gram-negative
- large bowel and female genital tract needs anearobic
What is recommendation for smoking prior to surgery?
stop 4-8 weeks beforehand
smoking increases respriatory and wound infection
What is recommendation for ETOH abstinence?
one month
What are CDC’s “Top 5 Recommendation” to prevent central line infections?
- handwashing prior to insertion or maintenance
- using full barrier precautions (hat, mask, sterile gown, sterile area covering) during insertion
- cleaning skin iwth chlorhexidine
- avoiding the femoral and peripheral arms whne possible
- IJ and SCL with lower risk; consider pneumo risk in SCL
- RoutinE daily inspection of catheters with removal ASAP
- Routine practice of hand sanitizer and scrubbing ports with alchol before every use of CVL
- Best “treatment” is prevention
What is risk of bacterial contamination in platelets? PRBC?
1: 5000 for platelet (think stored at room temp)
1: 50,000 for PRBC
What is the risk for viral transmission from blood transfusion?
Very low, HIV and hep C transmission 1:2 million
Why is there immunosuppression when receiving blood transfusion?
NK cell inhibition (even in autologous blood. it’s the storage process that kill NK cells)
irradiation decreases this risk
What decreases risk of bacterial contamination of blood product?
irradiation of blood
What is septic shock?
defined by hypotension not reversed with IV fluids
What is SIRS?What can a sirs response lead to?
Systemic Inflammatory Response Syndrome
- reaciton of body’s inflmmatory response in the absences of infection. Can be stimulated by
- trauma
- burns
- pancreatitis
- other
- SIRS can lead to
- systemic vasodilation
- altered capillary permeability
- MSOF
- Need volume resuscitation and pressors on board prior to sx!
What is distributive shock?
- high output cardiac failure with hypotension
- bounding pulses
- wide pulse pressure
can treat c norepi
Which gram bacteria is notorious for patients getting very sick, very fast?
gram negative
If pt has narrow PP, tachycardic, hypotensive with gram negative sepsis, what can be a first drug of choice?
Epinephrine
What is source control in OR for sepsis?
4 D’s
- Drainage
- intra abdominal abcess
- thoracic empyema
- septic arthritis
- pyelonephritis, cholangitis
- debridement
- necrotizing soft tissue
- pancreatic necrosectomy
- mediastinitis
- Device removal
- infected intravascular device
- urinary catheter
- infected IUCD
- Definitive contorl
- bowerl reseciton
- chole
finding underlying cause of infection requires urgent sx
ex- abscesses, infective endocarditis, power perforation or infarction, infected prosthetic device, endometritis, necrotizing fasciitis
Diagnosis of sepsis?
Dx via culture- all source
blood, urine, sputum minimum
narrow abx coverage ASAP