uworld dec 3 Flashcards
What are most common bugs in cellulitis?
Grp A strep and S. Aurea, also can have C. Perfringens
What is usual cause of cellulitis?
IV catheters, incision, bites/wounds. Also can happen w/ venous stasis, lymphedema, DB ulcer
What is erysipelas?
Cellulitis confined to dermis & lymphatics. Usuall due to GAS.
What bug causes tetanus and how tx?
Clostridium tetani, G+ anaerobic tetani, tx with
What is osteomyelitis usually due to ?
S. aureus if catheter septicemia, coag - staph if prosthetic joint, salmonella in sickle cell
What are risks for osteomyelitis?
open fx, DM, IV drug use, sepsis
How use ESR & CRP w/ osteomyelitis
Used to trend tx effectiveness w/ cellulitis and other infxns
Best imaging study for osteomyelitis?
MRI is best for dx & assesing extent of disease
How tx osteomyelitis?
requires long term IV ABX with ABX used based cx. may require surgical debridement if significant bone involvement.
How easily r/o septic arthritis?
If painless ROM, then septic arthritis highly unlikely.
How get acute septic arthritis?
most often w/ hematogenous spread, can occur w/ contiguous spread as well from abscess etc.
Most common bugs of septic arthritis?
s. aureus most common, also strep. If young think N. gonorrhea,
Signs of septic arthritis of joint aspirate?
WBC>50k, mostly segs, no crystals
How tx septic arthritis?
tx immediately w/ empiric ABX, vanc or other staph ABX, consider surgical drainage
How does stg 1 of lyme disease px?
eryhtema migrans-> tx w/ dox
What causes hypertrophic cardiomyopathy?
usually px in younger pts, due to assym septal hypertrophy causing outflow obstrxn
What causes concentric hypertrophy of the heart?
constant pressure overload such as in AS or uncontrolled HTN, (eccentric hypertrophy does not cause CHF)
Best way to dx rotator cuff tear?
MRI of shoulder
What is case control study?
takes groups of disease patients and group of healthy pts, looks back @ freq of particular risk fx in the 2 groups. Looks at outcomes first, then risk fx
What is retrospective cohort study?
reviews records, looks @ positive risk fx and negative risk fx and determines who gets sick. (e.g. those who smoke vs those who didnt in cancer pts)
What is a cross-sectional study?
Looks at exposure and outcome at the same time, cannot establish causation. determines rate of illness in 2 groups.
What causes intraparenchymal hemmorrhage?
uncontrolled htn most commonly, leads to lacunar strokes in BG, putamen, thalamus, cerebellum. Rarely get lobar hemorrhages due to htn
How do putaminal strokes px?
get hemiplegia, hemisensory loss
first step in evaluation of solitary pulm nodule?
based on probability of having malignancy, if low risk- do serial CT scans, if interm risk & >1cm, do FDG-PET and surgical excision if positive, if <1cm do CT to further asses