Articles Flashcards
Power-Pulsed Lavage article
- Significantly reduces the amount of bacteria
- if it does not hurt go ahead and use it.
Patzakis article
-Foot divided into three sections for puncture wounds
-Highest to lowest for development of osteomyelitis:
Zone 1> Zone 2> Zone 3
Nail puncture through a rubber soled shoe
- Unsuccessful treatment group more likely to have received antibiotics in the community
- Unsuccessful treatment group waited longer to go to ED
- Gram + bacteria (cover staph)
- Gram - bacteria (cover pseudo)
Plantar puncture wounds in Children
Time of presentation: Day of injury: -prophylactic tetanus -cleansing of puncture -x-ray or sonography
24-36 hours after injury
- hospitalize for parenteral antibiotics
- perform surgery
1 week after injury
- retained foreign body must be removed
- osteomyelitis
Later symptoms
-deeper infections present
Hawthorn fragment in a child’s foot
-MRI may not be the best mode of visualization, use an ultrasound
Definition of SIRS
SIRS= more than one of the following:
- temp extremes
- high HR
- High Resp
- High WBC
Definition of sepsis
SIRS+infection
Severe sepsis
Sepsis+ organ dysfunction, hypoperfusion abnormality, or sepsis induced hypotension
Septic shock
- a subset of severe sepsis
- sepsis induced hypotension
MODS
-a continuum where the organ fail to maintain homeostasis
Types of fevers (5)
- infection: most common cause
- cytokine-mediated fevers
- central fevers:harm to the thermoregulatory regions of brain
- fever of unknown origin
- drug fever
Postoperative fevers (5)
- Day 1: Systemic Inflammatory response syndrome
- Day 2-3: respiratory causes
- Day 3-5: Urinary tract infection
- Day 4-7: wound infection, DVT and acute gout
Day 5-8: drug fever
Surgical management of diabetic foot infections
- broad spectrum antibiotics should be prescribed
- need a stepwise approach when it comes to these patients
Performing serum inflammatory markers for the diagnosis and follow up of patients with osteo
Inflammatory markers are: CRP, ESR, White blood cells, Procalcitonin.
- They will decline after initiation of antibiotic treatment
- ESR is the best marker used to monitor the response to therapy in patients with osteo. ESR declines in soft tissue infections not osteo
- Using inflammatory markers, particularly ESR with observation will go a long way
Acute Phase reactants predict risk of amputations in diabetic foot infections
- post treatment CRP level is a strong predictor of treatment failure and amputation risk in patients with diabetic foot ulcers
Value of WBC with differential in acute diabetic foot infection
- diagnosis of infection is made primarily on the basis of clinical signs
- a normal WBC and white cell differential should not deter the physician from taking appropriate action.
Angiograms: what do they visualize (3)
- distribution of disease
- length and severity of diseased segments
- demonstrate inflow and outflow vessels
Types of angiograms
- Computed tomography angiogram (CTA)
- Magnetic Resonance Angiogram (MRA)
- Digital subtraction Arteriography (DSA)
Computed Tomography Angiogram
- IV iodine rich contrast injected.
- CT scanning used
A rapid exam but not good for renal disease and becomes shadowed due to calcification.
Magnetic resonance angiogram
Does not require IV contrast (but if it does will use Gadolinium)
-This is a more expensive exam than the rest however gives you a very clear picture
Digital Subtraction arteriography
Gold standard
- Will give a superior resolution with lower doses of contrast in real time.
- However will have much higher exposure to radiation
CO2
- used as a negative contrast agent in DSA by displacing the blood.
- a great alternative for patients with renal failure or contrast allergy
Echocardiograms
-2 types and what are they used for
TTE and TEE
- TTE is a noninvasive procedure , however it may be blocked by body tissues, or scarring
- TEE is much less common and much more invasive. Usually only occurs when good visualization can not be obtained with TTE
Tech 99
-binds directly to calcium hydroxyapatite to form soluble salts via osteoblasts
- High sensitivity for low specificity:
- –osteomyelitis
- –recent surgery
- –arthritis
- –bone tumors
- –fracture
- – ischemic necrosis of bone
Gallium-67-
-identifies acute inflammation and infection
through:
—direct bacterial uptake
—phagocytosis of bacterial cells by phagocytes
—direct leukocyte labelling
Sensitive but not specific for acute osteo will also pick up:
- -infection
- -fractures
- inflammation
- -trauma
- -neoplasms
- -gout
Indium-111
- WBC are isolated from patient’s blood and labelled with Indium-111 and reinjected into patient
- Highly sensitive and specific for acute soft tissue and osseous infections
Ceretec Scan
Tc-99 labelled WBC
- High sensitivity for acute soft tissue and osseous infections
- Higher specificity for acute osteomyelitis than in In-111
- easier and less radiation than Indium-111, which allows more radioactive material to be used and increased anatomical contrast
SPECT/CT
- single photon emisssion CT
- Detects radio-labelled markers and creates an image
- Shows level of biological activity as well
What will acute osteomyelitis show on:
- Tc-99m Scan
- Ga-67 scan
- Indium scan
- Ceretec scan
- Tc 99:
- –Phase 1: +
- –Phase II:++
- –Phase III:+++
- Ga-67 scan: positive focal uptake
- Indium Scan: Positive
- Ceretec scan: Positive
What will Inactive Chronic osteo show on:
- Tc-99m Scan
- Ga-67 scan
- Indium scan
- Ceretec scan
- Tc-99m Scan
- –Phase I: +/-
- –Phase II: +
- –Phase III: +++
- Ga-67: negative
- Indium: Negative
- Ceretec scan: Negative
What will acute cellulitis show on:
- Tc-99m Scan
- Ga-67 scan
- Indium scan
- Ceretec scan
Tc-99m Scan:
- –Phase I:+++
- –Phase II: ++
- –Phase III: +
- Ga-67: Positive diffuse uptake
- Indium: Positibe
Ceretec Scan: Negative
Charcot joint:
- Tc-99m Scan
- Ga-67 scan
- Indium scan
- Ceretec scan
Tc-99m Scan:
- –Phase I: +/-
- –Phase II: +/-
- –Phase III: +++
- –Phase IV: ++/+++
- Ga-67: Negative
- Indium scan: Negative
- Ceretec scan: Negative
Positive Ceretec signifies?
acute osteomyelitis
Positive Indium indicates?
either acute osteomyelitis or acute cellulitis
Positive Ga-67 scan signifies?
- Positive focal uptake signifies: acute osteomyelitis
- Positive diffuse uptake signifies: acute cellulitis
Identifying the incidence and risk factors for reamputation among patients who underwent foot amputation article:
-Risks associated with reamputation
- Higher level amputations
- Longer hospitalization
- Insulin-dependent diabetes
- Gangrene on admission
Acute Kidney Injury definition
- abrupt and usually reversible decline in the GFR or decreased urine output within 7 days
- increase in creatinine of .3mg/dL within 48 hours
- 50 percent increase in creatinine within 7 days
- decrease in urine volume to <3mL/kg over six hours
Will result in an elevation of BUN, creatinine
AKI diagnosis: How to make it
- UA w/ microscopy
- BMP
- Serum and urine protein electrophoresis
- renal ultrasound
AKI treatment (4) things
- determine the cause
- remove any active insults
- minimize new injury
- identify the complications
Probing to bone in infected pedal ulcers article conclusion
-in hospitalized diabetic patients with limb-threatening infection, palpable bone at the ulcer base by Probe to bone test was significantly associated with underlying osteo.
Probe to bone test in a diaetic foot osteo in a clinical setting
- in a clinical setting the PTB test is better used to exclude osteo
- in a hospital setting the PTB test is more helpful in diagnosing osteo
Efficacy of MRI in diagnosing diabetic foot osteo in the presence of ischemia
- preoperative MRI effective in diagnosis of neuropathic ulcers
- Preoperative MRI less effective in diagnosis of ischemic ulcers
Statistical reliability of bone biopsy for the diagnosis of diabetic foot osteomyelitis article
- results suggest limited reliability of the histopathologic analysis of bone
- histopathologic bone biopsy should not be sonsidered the “standard” of diabetic foot osteo
Does this patient with diabetes have osteo of the lower extremity article
- osteo of the foot causes significant morbidity in patients with diabetes
- using the criteria of an ulcer that measures more than 2cm, positive PTB, an ESR greater than 70mm/h, an abnormal x-ray and MRI, along with a detailed history can help improve diagnostic accuracy and improve patient outcomes
Primary non surgical management of osteo of the foot in diabetics article
-urgent surgery is indicated in some patients, however non-surgical management of those without limb-threatening infection is associated with a high rate of apparent remission
Outcome of diabetic foot osteo treated non-surgically
- Bone culture based antibiotic therapy is an independent factor predictive of remission in diabetic patients with osteo of the foot
- there is also a possible negative effect of nonbone-based antibiotic therapy for osteo of the diabetic foot
Rate of residual osteo after partial amp in diabetic patients
- after debridement and irrigation it is recommended to routinely obtain bone margin cultures
- residual osteo has a statistical significant association with poor outcomes
Reasons for prophylactic use of antibiotics
- Following wounds
- For surgery
- For prophylaxis against bacterial endocarditis in patient with compromised heart valve
- Dental patients
Antibiotics used for prophylaxis (8)
- cefazolin
- cefuroxime
- Ceftriaxone
- Vancomycin
- Clindamycin
- Ciprofloxacin
- Levofloxacin
- Teicoplanin
Cefazolin
- use in Lower extremity
- Half life
- coverage
- Doseage
- most frequently used for lower extremity
- longest half-life of any 1st generation cephalosporin
- spectrum: anti-staphylococcal and gram negative
Dosing: 1-2g IV or IM before surgery
Cefuroxime
- what type of surgery is it used
- comparison to ancef
- usually used in cardiothoracic surgery
- may have better anti-staph than Cefazolin
Ceftriaxone
- half life
- spectrum
- longest half life of any cephalosporin
- relative lack of anti-staph activity
Vancomycin
- when is it used
- dosing
- used in penicillin or cephalosporin allergic patients or high MRSA expected areas
- 1g IV 12hours…. slow infusion over 1 hour
Clindamycin
Use?
Dose:
- useful in implant surgery
- great substitute for vancomcin in beta-lactam allergic patients
- dosing 600-900 mg IV
Ciprofloxacin
use:
activity:
very versatile but not used as likely in prophylaxis for lower extremity surgery
-mediocre anti-staphylococcal activity
Levofloxacin
coverage:
half life:
Oral vs. IV
- better staph and strep coverage than Cipro
- longer half life
- oral dosing achievable levels are similar as parenteral
Joint aspiration:
Uses
—-diagnosis vs therapy
Diagnostic:
-used in the evaluation for septic joint
-also used in the confirmation of gouty arthritis
Therapeutic
-injection with steroids for inflammatory condition
-drain effusion to relieve pressure
Aspiration of the ankle:
-approaches
Medial approach:
- more common
- leg kept at 90 degrees, insert needle between TA and medial malleolus.
Lateral approach: less common
-between lateral to EDL
Aspiration of the MTPJ
steps:
- distract the toe with gentle plantarflexion
- insert needle perpendicularly and into joint space medially
- avoid extensors
Synovial fluid analysis
WBC count to keep in mind
<2000WBC/mm3 is noninflammatory
> 2000 WBC/mm3 is inflammatory or septic
Synovial fluid analysis table
LOOK AT STEVEN’s tables
Late hematogenous infection of the 1 MTPJ
- It is more common for late hematogenous infections to come from knee and hip replacements.
- This case occured in 1st MTPJ due to misdiagnosis and the administration of steroids
Acute hematogenous osteo
-Labs to receive
CBC
ESR and CRP
Blood cultures
Acute Hematogenous osteo
Unique infecting organisms in:
- newborns
- children
Newborns: Group B strep
Children: H. influenzae
Acute hematogenous osteo treatment options (3)
- Incision and drainage
- cultures
- antibiotics that are tailored toward the infection
Pathogens isolated from deep soft tissue and bone in patients with diabetic foot infections
-main finding
Most of the time bone and soft tissue cultures differed
Minimum Inhibitory Concentration
-definition
Is the lowest concentration of a chemical which prevents visible growth of a bacterium overnight
Minimum Inhibitory Concentration
-Clinical use
used to confirm resistance and to determine in vitro activity of new antimicrobials
Minimum Inhibitory concentration
-Interpretation
-antimicrobials with the smallest MIC are the most effective
Minimum Inhibitory concentrations
-Breakpoint
- chosen concentration of an antibiotic which defines whether a species of bacteria is susceptible or resistant
- If the MIC is smaller than the susceptibility breakpoint then the bacteria is considered to be susceptible to the antibiotic
The role of polymethylmethacrylate antibiotic loaded cement-article
- Three big antibiotics are:
- tobramycin
- gentamycin
- vancomycin
-PMMA provides local delivery of high concentrations that do not depend on vascular support or have systemic toxicity complications
Infection control issues
- active surveillance cultures: definition
- Decolonization: definition
Active surveillance cultures:
- universal or targeted microbiological screening cultures for patients admitted to a hospital
- used to try and help control infections
Decolonization:
-a process used in infection control that destroys a resistant organism before it can cause infection and spread by using topical antibiotics and antiseptics
C. difficile
Diagnosis
Treatment:
Diagnosis:
-C. difficile infection requires demonstration of C.dif toxins or detection of toxigenic C.dif organisms
-Findings of pseudomembranous colitis are highly suggestive of C.diff
Treatment:
-discontinuation of inciting antibiotic
- Vanc: 125 mg QID PO
- Metronidazole: 500mg QID PO
Hospital acquired MRSA
-Buzzwords:
Treatment:
- Older patients
- In a care facility
- With chronic wounds
- Multiple recent antibiotic exposure
-treated: Vanco, Zyvox and Cubicin
Community acquired MRSA
-Buzzwords:
Treatment
- Younger patients
- Contain genes: USA300, PVL, SCC mec IV, and cycolytic peptides
Treatment:
- TMP/SMX (bactrim)
- Minocycline and doxycycline
How to differentiate between community and hospital aquired MRSA
Clindamycin induced susceptibility
