Infectious Disease Flashcards
What does antibiotic misuse mean?
Prescribed without indication (colnoization, fever, bacteriuria)
Too broad/too narrow
Wrong dose
Wrong duration
What does abx misuse contribute to? (2)
Resistance adverse events (c difficile)
What is the most common exposure in patients with CDI ?
abx
c difficile infection
What is the antimicrobial stewardship program (ASP)? 4
- improve abx prescribing practises
- limit emergence of abx rsistance
- enable more cost effective usage
- decrease CDI
What procedures require abx prophylaxis? to prevent catastrophic
- prosthesis (vascular surgery, orthopaedic)
- intra abdominal surgery + most urologic procedures
- spinal surgery
- invasive ophthalmic sx
When should you decide what abx you order?
“As soon as possible” before OR
How do you kno what abx to order, what specific issue to identify?
Allergies,
especially to G+ve (penicillins)
Whose responsibility is it to prescribe abx prophylaxis?
The surgeon’s
How do you dose ancef abx?
1g IV less than 60kg
2g IV more than 60kg
Which abx cannot be giving within 1 hour of incision?
Vanco (needs drip, and cannot be bolused)
Cipro
For a patient already on abx, do you give the prophylactic dose anyway?
Yes, it can be considered *** as 1 dose pre-op is not problematic
When do you redose cefazoline?
- 3-4 hours after first dose given, or last dose given
- When there is excessive blood loss (>1/3rd blood volume)
When do you discontinue prophy abx?
Within 24 hours
What is the cross reactivity between penicillins and cefazolin?
No more than 10%
What allergies to penicillin preclude its use?
- Anaphylaxis, resp disterss,
- urticaria (hives, not just rash)
- Steven Johnson’s syndrome
- Abx renal or liver dysfunction
What percent of clindaymycin resistance exists, from staph auerus, at TOH?
25 %
What cefazolin timing decreases SSI rate the most ?
Within 15 minutes of surgical incision
What % abx are inappropriately prescribed at TOH?
10 to 60% of the time
Klebsiella pneumonia skin and urine
-
What is hospital acquired pneumonia?
> 72 hr = HAP, not CAP
-resp flora, more likely to be colonized by s aureus, g-ves
Management of HAP (early)?
- Early (less than 5days) and no abx in prior 90 days
- - ceftriaxone or levofloxacine
Management of HAP (late)?
Late (> 5 days), abx in prior 90 days, im-suppresive disease or tx
-anti-pseudomonal coverage (ceftazidime, or piptazo +/or vanco)
Bacteruria?
- unless symptomatic rarely important
- do NOT tx urine without evidence of infection
- do NOT culture urine based on appearance or odour alone
When is a U/A sensitive for ruling out a UTI?
BOTH WBC and nitries negative
What are the only bacteria that creates nitrites?
“PUNCH-K”
proteus, ureoplasma, nocardia, cryptococcus, Hpylori, klebsiella
Pleural effusion grows CoNS, susceptible to vanco only, do you add vanco?
- No. CoNS (coag negative staph) is not typically a resp pathogen, therefore not tx indicated
- common contaminant
DDx for abnormal looking wound, ex post op THR ? (3)
- dehiscence without infection
- cellulitis (superficial infection)
- abscess (superficial or deep)
How do you assess possible abscess?
Ultrasound
SSI account for what pecent of HAI ?
second most common
Pathogenesis of SSI?
1-outside in (introduce organisms via skin at time of sgx)
or
2- from inside out (intra-abdo sx)
Therapy of SSI?
Cover skin organism
- cefazolin (staph or strep) or cloxacillin (staph)
- clinda if allergies - NB rates of clinda (25% MSSA)
- Vanco if MRSA
Cdiff tx?
- PO flagyl 500 q8h
- PO vanco 125mg q6h (not IV !)
- if ileus, consider PR vanco and or IV flagyl
- reassess all PPI use
what are the encapsulated organisms?
Strep pneumoniae
H Influenza
N Meningitidis
-need humoral immunity (B cels)
Degree of immunosuppression in an HIV pt depends on what?Degree of infectivity?
Immunosuppression - CD4 count
Infectivity - viral load
True or False, early (non-transplant related) post op infections same as in non-SOT (solid organ transplant) patients?
True
Asplenia can be anatomic or functional, which organisms do you worry about?
Encapsulated organisms, and parasites (malaria, babesiosis)
What is is OPSI?
Overwhelming post-splenectomy infection –> sepsis/death
Elective splenectomy, when do you vaccinate?
ideally 10 wks, but minimum 2 weeks before OR
EMERGENT splenectomy, when do you vaccinate?
2 weeks POST OR, or at discharge
TOH SPelenectomy guidelines suggest Rx of what else?
-amox-clav 875 mg PO BID x 7 days
or, -moxifloxacin 400mg PO Daily x7D (if pen allergy)
-Take if fever, unwell etc.
-medicalert bracelet
Which surgical resident level is most at risk of a needle stick injury?
PGY1
But your risk accumulates by the end of your training
Infection risk with Hep B from needlestick (in a patient WITH the disease)?
0% if vx responder
Infection risk with Hep C from needlestick (in a patient WITH the disease)?
- Risk is 1.8% from needlestick or cut
- unknown (but low) from splash to eye, nose or mouth
Infection risk with HIV from needlestick (in a patient WITH the disease)?
- 3% from needlestick or cut
0. 1% from splash to eye, nose, mouth, non-intact skin
Post-exposure follow-up, if patient is positive?
- PEP x 4 weeks
- Followup x 6 months
- Discontinue if negative, no follow-up
