Bites, Sitngs And Infestations Flashcards
Approach to general bites and infectious wounds
1) ensure neuro vasculature status
- **make sure to look for bone and joint involvement
2) ensure tetanus vaccination status is up to date
- give toxoid = patient last vaccine was 10 yrs for clean wound; 5 yrs for dirty wound
- ***give immunoglobulin if patient has never had 3 full doses of the tetanus vaccine
3) treat prevent infection
- rabies = vaccine and immunoglobulin if no vaccine history; vaccine only if prior whole series vaccine was given.
- antibiotic most prescribed = clavulonic acid orally
- if bonejoint involvement = IV antibiotics always
4) wound care with irrigation with tap water or sterile water
5) closure or no closure
- **usually wound is left OPEN to heal by secondary intent
- **Absolute exception = facial wounds that would cause deformities (ALWAYS CLOSE)
- ** NEVER close wounds of hands and feet
- dont close cat or human bites usually
**closure criteria = uninflected, <24 hrs old and not on hand/foot and not immunocompromised
Human bites
10-34 yr group is most common
- breast = assume sexual assault
- arm bites > 2.5cm diameter = assume child abuse via an adult
2 broad categories
1) Clenched fist injuries (CFI)
- occurs in fights and mostly at MCP joints of 3rd/4th fingers
2) occlusive bites (more common)
- caused by children usually
Common bacteria in human bites
Staph/strep are most common
Also
- bactericides
- corynebacterium
- *only seen in human bites = elkinella corrodens**
- causes blood culture (-) endocarditis
- MUST treat this with amoxicillin-clavulonic acid
Cat bites
More likely in women and typically in upper extremity and hands/fingers
- 80% own the pet
- *most common deep infection bite (80%)**
- cellulitis, tenosynovits (requires surgery) osteomyelitis and joint injuries with abscesses (requires drainage)
- *Unique Bacteria = pasteurella multocida and bartonella henselae**
- 31% mortality due to sepsis
- tender lymphadenopathy
- headache, malaise and fever
always get x-rays to determine deep tissue involvement
Cat scratch fever
Caused by bartonella henselae
- bacteria found under cat nails and fences
Symptoms
- regional lymphadenopathy and fever and systemic symptoms
Treatment
- antibiotics
- DONT incision and drainage to lymph nodes
(Causes fistulous tracks that dont heal ever)
Dog bites
4.5 million dog bites per year, way more common in younger males
Adults = arm/hand Children = face and head and neck
Dog bites are more likely to kill due to injury and trauma damage
Infection rate = 30%
- is always polymicrobial (pasturella, staph,strep, neisseria, moraxella, bactericides, fusobacterium)
- Unique dog pathogen = capnocytophaga canimorsus*
- high risk for gangrene and sepsis
- usually only seen in cultures with immunocompromised people
- mortality = 30% (endocarditis, meningitis and sepsis)
always get xrays
What labs to check for infection.?
CBC, ESR, CRP
What is the #1 cause of surgery in human fight bites?
Tenosynovits
- shows necrosis and inflammation with extreme pain at tendons
Snakebites
Pretty rare with 45000 a year in US
- 97% = lower extremities
Most common venomous snake in US = pit viper
No data for morbidity but usually only kills in very young and elderly patients
- worst states = NC/AR/TX/GA
Most toxic snakes
- vipers (rattlers and copperheads, moccasin, pit viper)
- elapids (coral snakes, cobras and black mambas)
- red on black = venom lack!
- red on yellow = kills a fellow! (Venomous)
Effects of viper poison
Cell injuries, rhabdomyolysis, tender lymphadenopathy, sepsis, hemorrhagic bullae and compartment syndrome are common
Toxin does direct cellular injury
Systemic symptoms are prominent
- can also develop IgE mediated anaphylaxis
- also high risk of superinfection with gram (-) organisms
** if vipers gave venom in their bite, the site of the bite will be oozing. If not = may have been a “dry bite”
Treatment of venomous snake bites
Give Antivenin ASAP!
- indications = progression of local injury, coagulopathy, systemic effects
- side effects = anaphylactic reactions and serum sickness as well as pyretic effects
- *NEVER use tourniquets As well as incisions and suction of the bite
- increases neuro vascular injuries and contamination with oral flora for superinfection
Effects of elapid poisoning
Neurotoxic and irreversibly binds to ACh receptors
- casues ptosis, double vision, dysphagia, aphasia, descending paralysis and muscle weakness
- ultimately = respiratory failure And death
Treatment = antivenin
Gilamonsters
No deaths ever recorded
Grinds venom into the tissues and causes
- local pain, swelling and weakness
- hypotension and MIs are possible
Brown recluse bites
live in woodpiles and cellars. Are quartersized and brown
Are initially painless
- then erupt not a “volcano” lesion and leads to ischemic necrosis. Also hemolysis thrombocytopenia and renal failure within days if left untreated
- **kills even fast in children and elderly
Treatment
- hyperbaric oxygen chamber and surgical debridement
- acetaminophen/NSAIDs and opiods
- NEVER use ice! (Increases ischemia)
- can use dapsone unless G6PD patient (will cause hemolysis)
Black window bites
Red hourglass shaped and found in woodpiles and homes
Toxin = a-latrotoxin
- disables neuronal membranes by perimently opening ion channels and depletes ACh
Symptoms:
- immediate pain
- “target lesion”
- nausea/vomiting
- abdominal cramps that mimics appendicitis/peritonitis**
- cardiac arrhythmias (kills)
Treatment
- CAN use pain meds and ice
- can also give benzos and antivenin as well
- calcium gluconate is helpful also
