puncture wounds and bites
TRANSCRIPT
Puncture Wounds and Bites
Dr. Mohammed Niyaz PG ResidentDepartment of Emergency MedicineASTER MIMS-K
wounds whose depth exceeds the diameter of the visible surface injury
Involve plantar surface of foot
Cause : High-pressure injection equipmentAnimal bitesInvolving exposure to body fluids
PATHOPHYSIOLOGYshear forces between the penetrating object and tissue
Inoculation of organisms into deeper tissues
Closure of wound favors infection
Infection rate from plantar puncture wound- 6 to 11 %
• penetrate the joint capsule and produce septic arthritis,• penetration of cartilage, periosteum, and bone can lead to osteomyelitis
Gram positive organisms- Staphylococcus aureus, streptococcus
Pseudomonas aeruginosa isolated from plantar puncture wound
Risk Factors for puncture wound complications
Size and location of the wound
Condition of surrounding skin
Presence of foreign matter or devitalized tissue.
Proximity to underlying structures.
Distal function of tendons and nerves
Integrity of distal perfusion
CLINICAL FEATURES
DIAGNOSISINDICATIONS FOR IMAGING
Plain radiographs will detect >90% of radiopaque foreign bodies >1.0 mm in diameter
Organic substances, such as wood, thorns, other plant matter, have radiodensities close to that of soft tissue and cannot reliably be detected
USG can identify soft tissue foreign bodies, but the ability to detect small objects is limited
CT or MRI : patients with deep-space infection, persistent pain after a puncture wound, or treatment failure
TREATMENTAggressive wound debridement and irrigation (no
evidence of reduction in rate or severity of post puncture wound infections.)
Uncomplicated clean punctures <6 hrs : superficial wound cleansing and tetanus prophylaxis
Low-pressure (e.g., approximately 0.5 psi) irrigation of wounds : surface cleansing and allow visualization of the entrance site.
Prophylactic antibiotics in High risk cases : impaired host defenses, forefoot injuries and patients
sustaining punctures through athletic shoes
first-generation oral cephalosporin, antistaphylococcal penicillin, or macrolide.
COMPLICATIONSPain >48 hours post injury should undergo an evaluation
for retained foreign body or infection
CELLULULITIS•streptococcal and staphylococcal skin flora,•7- to 10-day course of a first-generation cephalosporin, antistaphylococcal penicillin, trimethoprim-sulfamethoxazole, or clindamycin
ABSCESS •Standard incision and drainage. •A short course of antibiotics is indicated if there is surrounding cellulitis.
DEEP SOFT TISSUE INFECTION •Parenteral antibiotics and surgical exploration with drainage of pus, excision of necrotic tissue, and irrigation of infected areas
OSTEOMYELITIS•Diagnosis : triple-phase radionuclide bone scan•will demonstrate osteomyelitis within 72 hours of the onset of symptoms.•Antibiotic administration after cultures
SKIN TATTOOING
Needle stick injurymajor concerns are the risk of infection with the hepatitis
viruses and the human immunodeficiency virus (HIV).Negligible for hepatitis A, 6% for hepatitis B, 2% for
hepatitis C, and 0.3% for HIVPostexposure prophylaxis is available for hepatitis B and
HIV
High-pressure injection injuries
Caused by industrial equipment designed to force grease, paint, or other liquids through a small-diameter nozzle at high pressures.
Extreme pressure can lacerate skin and fracture bones
Type, amount, and viscosity of material injected will determine the degree of tissue inflammatory response
Can produce vascular injuries, ischemic necrosis, and gangrene
Assessment of neurovascular integrity and tendon function Aggressive pain management using IV opioids Prophylactic antibiotic coverage against skin floraTetanus prophylaxis as indicated
Digital nerve blocks should be avoided, as they may further increase pressure in finger compartments
Risk of subsequent amputation is reduced if wide surgical debridement is performed within 6 hours of the injury
Epinephrine autoinjectorPatients present with pain due to the needle stick paresthesias, and
epinephrine-induced vasospasm to the injected area. In the extreme, the entire digit can be blanched and cold.spontaneous resolution, over 6 to 13 hours
subcutaneous phentolamine injection into the affected area reverses digital ischemia
A mixture of 0.5 mL of standard phentolamine solution (5 milligrams/mL concentration) and 0.5 mL of 1% lidocaine solution will produce a 1 mL total volume containing 2.5 milligrams of phentolamine that can be subcutaneously injected directly through the site of autoinjector puncture.
MAMMALIAN BITES
GENERAL PRINCIPLES : Prevention or treatment of local bacterial infection, and prevention, recognition, and management of subsequent systemic illness.
Aggressive irrigation and debridement of devitalized tissue
Determine the extent of underlying tissue damage, with special attention to the potential for penetration into joint spaces and tendon sheaths.
Indications for Primary Closure of Mammalian Bite Wounds
MICROBIOLOGY AND THERAPY OF INFECTIONSFROM CAT AND DOG BITESBacterial proliferation in tissue can lead to serious
cellulitis, tenosynovitis, and septic arthritis
5% of untreated dog bites will become infected80% of cat bites will become infected
Infection after a cat bite is often due to Pasteurella multocida, particularly if the infection has a rapid onset
Bite Wounds at High Risk of Infection
5- to 7-day course of an appropriate antimicrobialAmoxicillin-clavulanate is the medication most commonly recommendedpenicillin V or ampicillin should be adequate for Pasteurella multocida infections
Common Bites and First-Line Treatment
SYSTEMIC BACTERIAL INFECTIONSAFTER DOG AND CAT BITESCapnocytophaga canimorsus produces a rare but fulminant
bacteremic illness after a dog bite.
Fatal multi-organ failure in splenectomized patients or alcoholic or with other immunosuppressive disorders.
Diagnosis is confirmed with positive blood cultures.
Broad-spectrum therapy with penicillin and other agents is indicated in concert with aggressive resuscitation
Cat-scratch diseaseclinical syndrome of regional lymphadenopathy, caused by
Bartonella henselae 7 to 12 days after a cat bite or scratch. painful, matted masses of lymph nodes. low-grade fever, malaise,
fatigue, headache, nausea, and anorexia.
CNS (encephalopathy with headache, seizures, confusion, or AMS )Musculoskeletal (synovitis with joint pain and swelling)Lungs (pneumonitis with dyspnea and cough)Abdomen (granulomatous hepatitis or splenitis producing abdominal
pain)Eyes (retinitis with vision loss), and often with a prolonged fever.
ManagementDiagnosis- epidemiologic, clinical, histologic, and/or serologic criteria
Resolve in 2 to 5 months, and therapy is primarily pain relief and reassurance.
Large, painful, fluctuant nodes can be aspirated for symptomatic relief.
Patients with severe painful lymphadenopathy, a 5-day course of azithromycin may speed resolution of adenopathy
Immunodeficiencies- 7 to 10-day course of trimethoprim-sulfamethoxazole, ciprofloxacin, or rifampin.
Human bites More serious than bites from domestic animals due to the
nature of the event, location of the bite, and potential bacteria inoculated into the wound.
staphylococcal and streptococcal species, gram-negative rod Eikenella corrodens
Amoxicillin-clavulanate is recommended for treatment and prophylaxis
Herpes simplex virus infection
herpetic whitlow is a painful coalescence of vesicles, typically on the distal phalanx
Vesicles usually resolve in 3 to 4 weeks.
Treatment with oral acyclovir for 7 to 10 days or topical acyclovir ointment for 7 to 14 days may shorten the duration of the symptoms
RODENTS, LIVESTOCK, EXOTIC AND WILD ANIMALS
Rat-bite fever consists of two similar febrile illnesses - either Streptobacillus moniliformis (more common in North America) or Spirillum minus/minor (more common in Asia).
Incubation period 3 to 7 days.
Rigors and fever that progresses to migratory polyarthralgia and a maculopapular petechial or purpuric rash.
Infection can spread to the heart, brain, arteries, liver, kidneys, and lungs. Mortality rate -10% to 15%.
Treatment is penicillin, or for penicillin-allergic patients, doxycycline or tetracycline.
Livestock and large game animals can inflict serious tissue injury with their powerful jaws and grinding teeth.
systemic illnesses, such as brucellosis, leptospirosis, or tularemia.
Aggressive wound care, imaging to detect fracture, and prophylactic broad-spectrum antibiotics are recommended.
Antibiotic therapy guided by blood culture results.
Freshwater fish bites can harbor Aeromonas, streptococci, and staphylococci
Treatment includes a fluoroquinolone or trimethoprimsulfamethoxazole.
Saltwater fish bites require coverage for Vibrio, usuallywith a fluoroquinolone.
SYSTEMIC INFECTIONS: SPIROCHETES,RABIES, AND OTHER VIRUSESDisseminated spirochetal and viral illnesses that can result
from mammalian bites include syphilis, rabies, hepatitis, herpes B virus, or HIV.
In South Asia, monkeys are presumed to be at high risk for carriage and transmission of rabies.
North American reservoirs of animal rabies exist in bats, skunks, raccoons, and foxes
.Herpes B virus, also called Cercopithecine herpesvirus 1, can
be transmitted by bites from monkeys and other nonhuman primates.
In humans, infection with herpes B causes myelitis and hemorrhagic encephalitis with a case fatality rate of 70%.
Immediate and thorough wound cleaning after a bite reduces the chance of infection, and acyclovir or valacyclovir given immediately after injury can prevent or ameliorate this illness.