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.