Australian Doctor 8th March issue | Page 30

30 HOW TO TREAT : MAMMALIAN BITE INJURIES

30 HOW TO TREAT : MAMMALIAN BITE INJURIES

8 MARCH 2024 ausdoc . com . au
Nicor / CC BY-SA 3.0 / bit . ly / 3YVOGIa
Tanner Ford , TRF Photography / CC BY 2.0 / bit . ly / 3PmrVdC
Figure 1 . Three-day-old dog bite . Figure 2 . Dog bite .
Brett Spangler / CC BY-SA 2.0 / bit . ly / 3Pinsbw
Figure 3 . Dog bite .
Figure 4 . Cat bite where traces of four fangs are visible . transmission ( although extremely uncommon ), including hepatitis B , C and HIV . Box 2 lists the high-risk bite injuries that require antimicrobial prophylaxis .
Patient history
Assessment of a bite injury includes a full medical history including factors that influence the risk of wound infection and wound healing . This includes comorbidities , immunosuppressive drugs or conditions ( including asplenia ), peripheral vascular disease and smoking ( this predisposes to poor healing and increases the risk of infection ), diabetes , alcohol consumption and age ( very young and older patients are at increased risk of infection ). Take a vaccination history , particularly focusing on tetanus vaccination ( and hepatitis B vaccination if it is a human bite injury ). When the injury is a human bite wound , also consider domestic violence and assault as part of the assessment .
Physical examination
When assessing bite injuries , it is important to consider the type of wound and the anatomical locations ( and thus the potential underlying structures that may be involved ). There are three broad types of bite injuries : puncture wounds , lacerations and tissue avulsion injuries . Dog bite wounds are more commonly lacerations and avulsions , whereas cat bites are more commonly puncture wounds . Bites that breach a joint capsule can cause tendonitis or septic arthritis and those that penetrate bone can cause osteomyelitis . Assess the size and depth of the bite wound and the involvement of any joint , tendon , bone or neurovascular structures . Undertake specific examination for individual tendon damage as penetrating wounds can cause tendonitis or rupture . 5 Consider X-ray imaging when there are any signs of crush or puncture wounds .
Reasons for surgical / specialist intervention
Some bite wounds can be managed in primary care or ED . However , a significant proportion will
Box 1 . Assessment of a patient with a bite injury
• Emergency management : — Prioritise emergency management of life- or limb-threatening injuries , including haemorrhage or neurovascular compromise .
• History of the bite : — Include the species of animal responsible , mechanism and severity of injury , the geographic location of the injury
( and associated infective risks ), and any delays to assessment and treatment .
• Patient history : — Include age , immune suppression , pregnancy , vaccination status and other risks for impairment of wound healing and increased risk of infection , such as smoking , alcohol excess and vascular disease .
• Physical examination : — The severity and location of the wound and the involved structures , any evidence of current infection — and whether washout , debridement and other surgical interventions are required .
• Investigations : — Order X-rays if a crush wound or any other risk of fracture and a wound swab for culture ( only if there is evidence of current infection ).
• Management :
— This includes wound care ( irrigation and wound debridement ), surgical referral and management ( including consideration of cosmetic outcome ), antimicrobial prophylaxis for infective risk , vaccination indications and addressing anxiety and psychological consequences .
need surgical referral ( see box 3 ) for procedures including debridement and reconstruction . In addition , any wound that has developed signs of infection may need debridement and antibiotic treatment for longer than a prophylactic course and directed against likely causative organisms ( consider discussion with an infectious diseases physician ).
Infection risk
The risk of infection following a bite injury relates to the species of the biter , patient characteristics that might predispose to infection ( and