Exam 2: Septic Arthritis/ Physitis Flashcards
What 3 types of septic arthritis are seen in foals?
S, E, P
Which type of septic arthritis seen in foals usually only effects 1 site?
P-type
Which type(s) of septic arthritis seen in foals usually effects multiple sites?
S and E
What is the most common etiology of septic arthritis?
Bacterial
What is the greatest risk factor for septic arthritis/physitis in foals?
Failure of passive transfer
Why do you NEVER debride in cases of P-Type septic arthritis in foals?
Debridement damages the physis and causes premature closure!
What do you expect the cell count to be of synovial fluid analysis
in a foal with S or E-Type septic arthritis?
greater than 50,000
What do you expect the neutrophil percentage to be of synovial fluid analysis
in a foal with S or E-Type septic arthritis?
greater than 90% neutrophils
What abnormalties do you see on bloodwork in
cases of S or E-Type septic arthritis?
Increased fibrinogen ± leukocytosis
In cases of S or E-Type septic arthritis,
Fibrinogen is usually ______mg/dL with bone involvement
>900 mg/dL
What is the prognosis for septic arthritis in foals?
77% survival in foals
What are the iatrogenic risk factors for septic arthritis in adults?
Iatrogenic: synovial sx, fracture repair, arthrocentesis
This pathogen is seen as the causative agent in a third of the iatrogenic cases
of septic arthritis in adults, especially in arthrocentesis
Staphylococcus spp.
What is the gold standard for diagnosis of septic arthritis?
Microbiology
At what age is S-type septic arthritis seen in foals?
Less than 1 week old
What solutions should (and shouldn’t) be used for lavage in a case of septic arthritis?
USE: Balanced electrolyte solution (LRS, Normosol) +/- DMSO
Do NOT add chlorhexidine, povidone iodine- cytotoxic and unhelpful
Do NOT give 5% dextrose solution- will be feeding the bacteria!
What organism is most commonly isolated in a case of septic arthritis?
Staphylococcus spp.
T/F: In a case of septic arthritis in adults and foals,
it is important to check the umbilicus as a source of infection
FALSE
Only check umbilicus in foals
When is it acceptable to stop antibiotic treatment for septic arthritis?
Minimum 30 days and 2 weeks beyond resolution of clinical signs (whichever is longer)
T/F: Arthrotomy is contraindicated in the treatment of septic arthritis in cattle.
False
What is the mainstay of treatment for septic arthritis?
LAVAGE- Early and often; large volumes (5-10 liters)
What type of septic arthritis in foals typically presents with swelling, but usually without effusion?
P-Type
What are the three types of septic arthritis in foals?
S, E, P (Synovial, Epiphysis, Physis)
With what type of septic arthritis in foals might you be able to see subchondral lysis on radiographs?
E-Type
This is the most distal nerve block performed in the horse:
Palmar digital nerve block
Horses undergoing arthrodesis of this joint have an 80% prognosis for return to work:
Hindlimb pastern arthrodesis
This is the primary collagen found in tendons:
Type 1
Which type of septic arthritis seen in foals usually only effects 1 site while the others effect multiple sites?
P-type
Which type(s) of septic arthritis seen in foals usually effects multiple sites?
S and E-Types
What is the most common etiology of septic arthritis?
Bacterial
What is the greatest risk factor for septic arthritis/physitis in foals?
Failure of passive transfer
Why do you NEVER debride in cases of P-Type septic arthritis in foals?
Debridement damages the physis and causes premature closure!
What do you expect the cell count to be of synovial fluid analysis in a foal with S or E-Type septic arthritis?
Greater than 50,000
What do you expect the neutrophil percentage to be of synovial fluid analysis in a foal with S or E-Type septic arthritis?
Greater than 90% neutrophils
What abnormalities do you see on bloodwork in cases of S or E-Type septic arthritis?
Increased fibrinogen ± leukocytosis
In cases of S or E-Type septic arthritis, Fibrinogen is usually ______mg/dL with bone involvement
>900 mg/dL
What is the prognosis for septic arthritis in foals?
77% survival in foals
What are the iatrogenic risk factors for septic arthritis in adults?
Iatrogenic: synovial sx, fracture repair, arthrocentesis
This pathogen is seen as the causative agent in a third of the iatrogenic cases of septic arthritis in adults, especially in arthrocentesis
Staphylococcus spp.
In order to determine failure of passive transfer in a foal, you look at IgG levels. What is the normal level in a foal?
IgG greater than 800
What sites are most common for S-Type septic arthritis in foals?
Stifle, Tibiotarsal
What sites are most common for E-Type septic arthritis in foals?
Distal femur, talus, tibia, radius
What sites are most common for P-Type septic arthritis in foals?
Distal physis of MC3/MT3, radius, tibia
Acute, severe, very painful lameness in a foal less than 1 week old with effusion present is most characteristic of this type of septic arthritis.
S-Type
Mild, intermittent lameness in a foal a couple weeks old is seen. Suddenly, the lameness is exacerbated and effusion is seen. The foal had a history of diarrhea and its IgG levels at birth were low. What is your most likely diagnosis?
E-Type Septic Arthritis
A 2 month old foal is normal and healthy. All of a sudden, he becomes lame. You have localized the problem to the distal MT3. There are no signs of joint effusion, but on radiographs, soft tissue swelling is seen along with lysis around the physeal plate. What is your most likely diagnosis?
P-Type Septic Arthritis
How do you confirm your diagnosis of P-Type Septic Arthritis?
Aspirate the physis and submit for culture
If you cannot get a physis aspirate, what can you do to confirm your diagnosis of P-Type?
Bone biopsy
When running diagnostics for suspected septic arthritis, culture _______ treating with antibiotics
Culture before treating with antibiotics
Can you still culture if antibiotics have been given?
YES, but make sure to put the sample in the appropriate culture broth
Why do you tap AWAY from the wound in cases of septic arthritis?
To avoid bringing bacteria into the joint in case the joint isn’t actually involved.
Distend joint to determine joint involvement!
What are the 4 main goals of treatment of septic arthritis?
Eradicate infection
Eliminate inflammation
Minimize matrix loss
Minimize cartilage damage
After sample has been acquired, what type of antibiotics are given to treat septic arthritis?
Broad-spectrum (PEN/GEN) AND local antibiotics
Needle, or through-and-through lavage, uses ________ gauge needles, which are placed in all compartments
14 – 16G
Needle, or through-and-through lavage requires sedation and local anesthesia. What drugs are used in the joint to accomplish this?
2% Mepivicaine or Carbocaine
Why is Amikacin (Aminoglycoside) used as a first line defense locally in the treatment of septic arthritis even though bacteria are only intermittently susceptible to it?
Putting Amikacin directly into the joint allows for a HIGH MIC
_______mg of Amikacin provides _______ hours concentration,
which is greater than the MIC for most common pathogens
500 mg of Amikacin provides 72 hours concentration,
which is greater than the MIC for most common pathogens
This type of tourniquet is used to accomplish regional limb perfusion and is left on for 30 minutes
Esmarch tourniquet
This agent is used topically to help keep inflammation down during regional limb perfusion
SURPASS®
In cattle, this agent is used via regional limb perfusion in the treatment of septic arthritis
Florfenicol
In cattle, Florfenicol is used via regional limb perfusion because it is effective against these 2 bacterias responsible for causing septic arthritis
F. necrophorum, A. pyogenes
What is the general rule of thumb for dosage of antibiotics via regional limb perfusion?
1/3 of the systemic dose
A 25-27G ______ catheter is used to deliver antibiotics via regional limb perfusion
Butterfly catheter
This joint replacement fluid is the best adjunct therapy for treatment of septic arthritis because it is chondroprotective and not immunosuppressive while it replaces synovial fluid.
HA- Hyaluronic Acid
What medication is contraindicated in the treatment of septic arthritis?
STEROIDS (immunosuppressive!)
What agent is instilled into the joint after arthrocentesis in order to prevent
septic arthritis?
Ceftiofur
Describe the pathogenesis of septic arthritis
Synovitis–>Fibrin deposition–> Cellular infiltrates (inflammatory mediators)–>
decreased HA synthesis + loss of PG–> Joint effusion
Creates a cycle of cartilagenous matrix destruction
What do you see on radiographs of E-Type Septic Arthritis?
Subchondral lysis
In a suspected case of septic arthritis, C&S was inconclusive. What do you do next
if you still think it is, in fact, SA?
submit for FUNGAL culture
and repeat culture if the initial sample is negative
This is an important complication of septic arthritis and can
be the rate-limiting step
Contralateral limb laminitis
Which antibiotic can be given CRI to treat septic arthritis?
Beta-lactam abx
For regional limb perfusion:
qs to _______ mL for DISTAL limb
and
qs to _______ mL if ABOVE carpus/tarsus
qs to 30 mL for DISTAL limb
and
qs to 60 mL if ABOVE carpus/tarsus
What analgesic agents are used to treat patients with septic arthritis due to it
being excruciatingly painful
NSAIDS (Monitor for toxicity)
OPIATES
LIDOCAINE/KETAMINE (CRI)
OPIATES and DETOMIDINE (Via Epidural Catheter for hindlimb SA)
OMEPRAZOLE AND SUCRALFATE (GI Protectants to prevent ulcers)
