Flashcards in 4 Infectious Disease Deck (48):
Cipro, Levo, Moxi: how to think about them:
All are good against G negs, and get better with G positives. Starting fro Cipro (good UTI) to Levo, to Moxi (good PNA).
Abx for CAP PNA?
Why Moxi not good?
inpt: Cef + azithro
Moxi: works, but try not to use b/c breed resistance to quinolones in UTIs
Vanc + Zosyn
add ampicilin for what criteria? (6)
Cef + Vanc.
+ ampicillin in young/old, + acyclovir if suspect herpes
UTI abx for:
1. ambulatory UTI
2. ambulatory pyelo
3. inpt pyelo
4. sick as shit
1. cipro, amox, or nitrofurantoin
4. vanc+ zosyn
which UTI abx to use in pregnancy
nitrofurantoin (macrobid) is only one
Cellulitis abx (3 main choices)
1. cephazolin (keflex). -- Outpt, for possible strep
These if you think MRSA:
Pt with suspected meningitis. Who needs CT scan first?
Focal neuro deficit
Lesion over puncture site
Pt with HIV and suspected meningitis. You get LP, which shows 97% lymphs, 250 WBCs, high protein, low gluc, high opening pressure. No bact seen on Gram stain.
What tests to order?
1. RPR for syphilis
2. cryptococcal Ag
3. AFB smear and culture
HIV ppx at what CD4 count, what med, and what backup meds?
1. PCP. <200. Bactrim, Dapsone, Atovaquone
2. Toxo. <100. Bactrim, Primaquine
3. MAC. <50. Azithro
IRIS--immune reconstitution inflamm syndrome
what is this
Starting HAART during severe infection can lead to poor outcome. Eg, in HIV pt with meningitis, HAART can cause immune response to increase ICP and cause herniation and death.
Your post-op pt develops PNA at post-op day 3. Allergic to penicillin with anaphylaxis. What can you give him?
HAP. So normally Vanc and Zosyn, but pen allergic.
MRSA: Vanc or Linezolid
Pseudomonas: Penem. Cipro covers pseudomonas but not enough strep. Ceftriaxone or Cefepime possible if allergy was just rash.
Person comes to ED with possible HIV exposure (needle stick, rape, condom failures). Do what
PEP. 2+1 retroviral for 4 weeks. Get viral load PCR
Pt with possible acute HIV. What test to get?
Get PCR for viral load.
NOT ELISA b/c it takes 6 weeks after infxn to create Ab.
HIV pt with PCP PNA. What tx, and when to add steroids?
Bactrim. Add prednisone if PaO2<70
TB: primary vs reactivation lesions: where in lungs?
primary: usu in middle and lower lobes
reactivation: apices, where O2 is highest
who's in which category
(> or equal)
>5mm: very sick.
HIV, TB close contacts, immunocompromised
>10mm: normal ppl with risk factors.
prison, military, healthcare, homeless
>15mm: no risk factors
soccer mom in Wyoming
Asx TB screening. What to do if?
1. PPD +, CXR -
2. PPD+, CXR +
1. No active infection. Latent. PPx INH for 9mo, + VitB6
2. Don't know if latent or active. Do AFB.
1) AFB+: active TB, do RIPE. actively infectious!!
2) AFB-: latent TB. PPx INH for 9mo, + VitB6
Sick pt in ED, you suspect active TB. How to approach, and what tests?
1. CXR looking for apical lesions.
2. Sputum AFB smears and cultures. CXR + or -, can't r/o active TB, so get these even negative CXR. 3 AM AFB smears, or 3 smears q8h.
3. If +culture, then active TB. RIPE.
If -culture, then Latent TB but sxs NOT caused by TB. Do PPx INH x9mo, and look for something else, maybe malignancy.
When is TB sputum culture positive a false positive?
False positive with MAC. Can occur with pt with suspected acute TB with CXR- but Cx+.
TB drug side effects
Isoniazid--neuropathy (give B6)
ALL have Hepatotox.
SIRS, sepsis, and severe sepsis criteria:
Temp <36, >38
RR >20 or pCO2<32
WBC <4, >12, or >10% bands
severe sepsis: SIRS+source, + organ dxsfunction:
-Vessels: SBP<90 or 40 less than nl
-Tissue: lactate >4
-Renal: elevated BUN, Cr
-Liver: LFTs, coags
Confusion, new onset
Urea >7 (or BUN>19)
BP: SBP <90 or DBP =60
2. outpt with close f/u, or admit
3-5: admit, with possible ICU
pt with suspected meningitis: You give empiric abx before CT and LP. How much time you have to get LP?
2-hr window to collect CSF
Fungal skin infections: how to approach?
1. 3 presentations to know
2. how to dx
1. patchy alopecia, patchy skin discoloration, itchy burning feet
2. dx with KOH prep and cx, but usu not necessary.
3. Hair or nail involvement? if so, systemic antifungals--over several months.
Otherwise, topical. Terbinafine for several weeks.
erysipeloid vs typical cellulitis
erysipeloid: with ascending lymphangitis, caused by strep
Typical: staph: expanding erythema
Ostemyelitis risk factors and bugs
Vanc+Zosyn immediately only if toxic, then abx based on sens:
-1 time bone bx for cx and sens. Do this quickly so broad spec abx doesn't spoil the bx.
-tx for 4-6 weeks.
-CRP, ESR, and MRI qweek.
Pt in ED with suspected gas gangrene on skin. What things to do next?
Suspicion based on creptius. Get XR to look for air (spec, not sens)
-Call surgery for emergency debridement. Start PCN and Clinda. Consider hyperbaric O2
CAP, HCAP, HAP, VAP definitions
HCAP: recently hospitalized within 90 days, reside in nursing home or long-term care facility, or received parenteral antimicrobial tx, chemo, or wound care within 30 days.
HAP: 48h+ after admission.
VAP: 48h+ after intubation
CAP PNA bugs to know with risk factors:
-atypical and smoker
-after viral URI
-strep pneumo, always MCC
-staph (add Vanc if Cef+Azithro not working in CAP)
-anaerobes, GNR, staph, strep pneumo
Sick pt in ED, HIV with suspected PCP PNA. Do what
BAL with silver stain, to r/o a rapidly fatal PCP (can progress to ARDS)
Atypical PNA with mycoplasma: what to know
assoc with IgM cold agglutinin dz
-complicated UTI criteria (5)
-how is tx different?
-tx requires 7 days abx vs 3d for uncomplicated
Pyelo inpatient treatment:
Admit, give empiric abx (ceftriaxone). If better by 48h, d/c with 14d outpt abx (cipro).
If not improving (fever resolving) after 48h, possible abscess. Do U/S or CT, then drain.
Males with UTI sxs, low back pain, and fever, but no CVA tenderness. No testicular tenderness. consider what?
Do rectal exam
Syphilis: 3 stages: sxs, dx, tx
1. painless chancre, possible inguinal LAD.
-Darkfield microscopy (serology useful only >4weeks)
-IM Pen G
2. rash palms/soles
-RPR or VDRL screen, FTA-Abs confirm
-IM Pen G
3. CNS, neuro sxs--tabes dorsalis, argyle robertson pupils
-CSF RPR (blood RPR is negative!)
-IV Pen 7-14d
Syphilis pt, allergic to penicillin, do what.
What if pregnant and pen allergic?
If preg, desensitize to penicillin. No doxy.
Genital ulcers: which 4 ulcers to know
2. H ducreyi (chancroid)
4. molluscum contagiosum
Genital ulcer: single painful ulcer, erythematous base, with inguinal LAD.
Gram stain and cx. Tx with Gram neg coverage--Doxy or Azithro
Pt with herpes lesions, resistent to acyclovir. What else to use?
Valcyclovir will also be resistent. Ganciclovir is only for CMV
malignant otitis externa
-what are the sxs/findings?
-immunocompromised pt, eg DM
-granulation tissue in ear, fever
-pain with chewing--invasion of base of skull (osteo)
-Tx with oral Cipro
severe anterior vs post epistaxis. What tx
anterior: ablation after bleeding has stopped. Can do packing while bleeding.
post: packing, abx for 72h for TSS ppx. Look for HTN, CHF.
Centor criteria, modified
Age <15. Age >44 is -1
2-3: rapid strep/strep cx
1. Blood Cx+ (bacteremia)
2. Echo+ (endocardial evidence)
3. new valve regurg
1. risk factor (valve dz, IVDA, prosth valves, hx endocarditis)
2. fever >38
3. vascular signs: septic emboli, pulmonary, janeway lesions
4. immune signs: glomerulonephritis, osler nodes, roth spots, RF
Definite: 2 major, 1 major + 3 minor, or 5 minor
Possible: 1 major+1 minor, 3 minor
-all native valves
-prosth valve <60 days
Think "vanc + gent" as starting point
-<60: Vanc + Gent + Cefepime
-60-365: Vanc + Gent
-365+: Vanc + Gent + Ceftriaxone
Subacute: wait for cx and sens
Endocarditis, when to do surgery (5)
1. vegetation >15mm
2. >10mm with embolization (stroke, MI, ALI). Usu MI and stroke are contraindications to surgery, but not now
4. valve destruction or CHF