Morning Report: 4/8/2014

Welcome back to Morning Report! Today’s edition is presented by Dr. Alsup!

 

Mammal bites

 

Cat bites

  • Deep puncture wounds, difficult to irrigate
  • 10-40% rate of infections
  • Staph, step and pasteurella multocida
  • P. multocida, a highly virulent, facultatively anaerobic, gram-negative rod found in the oral cavity or nasopharynx of 70 to 90% of healthy cats.
  • Abx required—dicloxacilin, cephalexin,.  Augmentin- recommended
  • Clindamycin-resistant pasteurella is out there

 

Dog bites

  • 4.5 million dog bites occur per year, affecting nearly 1.5% of the population, but only 20% (885,000) of victims seek medical attention. 1% of all ed visits
  • crush injury often with avulsions
  • Dog bites in patients who delay care by as little as 6 hours have an increased risk of becoming infected
  • Aerobes
    • Staphylococcus aureus, alpha-hemolytic and beta-hemolytic streptococci, Klebsiella, Bacillus subtilis, Pseudomonas, Enterobacteriaceae, Capnocytophaga canimorsus
  • Anaerobic organisms
    • Bacteroides, Fusobacterium, Peptostreptococcus, Porphyromonas, and Prevotella
  • C. canimorsus is a fastidious gram-negative rod that can cause overwhelming sepsis. It is part of the normal oral flora of both dogs and cats. More than 100 cases reports
    • Usually begins within 3 days of exposure (range 1-10 days).
    • fever, chills, myalgias, and vomiting
    • clinical picture on presentation is often that of sepsis, with hypotension, renal insufficiency, and disseminated intravascular coagulation (DIC).
    • Purpura, particularly on the face, and petechiae are frequent findings and may progress to symmetrical peripheral gangrene.
    • Cutaneous gangrene at the site of the bite strongly suggests C. canimorsus.
    • The mortality rate is 30%, with 70% of deaths occurring in immunocompromised patients.
  • Rosen’s: “it may be logical to limit the use of abx to high risk wounds, such as hand injuries, deep puncture wounds, or wounds in older and immunocompromised pts”

 

Human bites

Hand bites (fight bites)

  • Streptococcus and Staphylococcus species are common, but Eikenella corrodens and Bacteroides species are also typical pathogens. Because Eikenella is often resistant to clindamycin, first-generation cephalosporins, and erythromycin, patients with early infection are treated with amoxicillin with clavulanate.

 

Specifically ask about comorbidities with risk of poor wound healing (i.e. diabetes, peripheral vascular disease); use of immunosuppressive medications or steroids; history of splenectomy; chronic alcoholism, particularly with malnutrition; and parenteral recreational drug use.

SPECIES SUTURING PROPHYLACTIC ANTIBIOTICS
Dog All (except hands) High-risk wounds only* (all hand wounds)
Cat Face only All
Human Face (as needed) Hand, especially CFI

High-risk wounds: hand wounds, deep structure involvement (tendon, joint, bone), delayed presentation (>12 hours), contaminated wounds with foreign bodies or devitalized tissue, deep puncture wounds, high-risk patients.

 

FACTOR HIGH RISK LOW RISK
Species
Cat
Human
Primate
Pig, camel
Dog (excluding hand)
Rodent
Location of wound
Hand
Over joint or superficial tendon (CFI)
Through-and-through oral
Below the knee
Face
Scalp
Mucosa
Wound type
Puncture
Extensive tissue damage
Contaminated or devitalized tissue
Old (delayed presentation) or sutured
Large
Superficial
Clean
Recent
High-risk patients
Immunosuppressed, HIV positive
Transplant patient, steroid dependent
Diabetes, cancer chemotherapy
Prosthetic valve patients
Peripheral vascular disease
Elderly, alcoholic, cirrhosis
Social and compliance problems
 

CFI: closed-fist injury; HIV: human immunodeficiency virus.

 

CONCLUSIONS
Prophylactic antibiotics are recommended for dog bites of the hand and for high-risk patients. They are not indicated for routine dog bite wounds.
Patients at high risk should receive prophylactic antibiotics for C. canimorsus after a dog bite.
Cat bites and scratches have a high rate of infection, and prophylactic antibiotics are recommended for cat bites of the hand and for cat bites in high-risk patients.
Prophylactic antibiotics are recommended for human bites of the hand as well as for high-risk patients. They are also recommended for high-risk wounds, including deep punctures and contaminated wounds.
Ordinary human bite wounds, such as those exchanged among children (superficial, partial thickness, minimal tissue trauma), do not represent a high risk for infection or complication and do not require prophylaxis.
Wounds at high risk for infection should generally not be sutured.
All bites are considered tetanus-prone wounds.

 

Reference:

Rosen’s: Chapter 61

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.
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Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital

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