Transcript Wound Management - PEM Database Online

Wound Management
• October 11, 2001
•
Gavin Greenfield and Bob Johnston
Objectives
• Wound Healing
• Wound Evaluation – History, Physical
examination
• Wound Preparation
• Wound Closure
• Specific Wounds
– face, scalp, eyebrow, eyelid, ear, lips,
intraoral, puncture, fingertip and nail, foreign
bodies, bites
Wound Healing
• “the primary goal of wound care is not the
technical repair of the wound; it is
providing optimal conditions for the natural
reparative processes of the wound to
proceed”
– Richard L. Lammers (Roberts and Hedges)
Skin Anatomy
• Epidermis
– keratinized squamous epithelium
– avascular
• Dermis
– dense, fibro-elastic tissue
– highly vascular
– cells of dermis mainly fibroblasts responsible for
elaboration of collagen, elastin, ground substance
• Subcutaneous layer (superficial fascia)
– connects dermis to underlying tissue
– contains variable amounts of adipose tissue
Case 1
• 1st year medical student comes in with
laceration to hand. You evaluate the
wound and feel it is appropriate for primary
closure. He asks you how the wound will
go about healing itself? What do you tell
him to appease his curious mind?
Wound Healing
• Stages
– hemostasis
– inflammation
– epithelialization
– fibroplasia
– contraction
– scar maturation
Wound Healing
• Inflammation
– serves to remove bacteria, foreign debris, and
devitalized tissue – a biologic debridement
– if this stage is prolonged (from infection,
foreign material, etc.) will get persistent
inflammation and result in poor wound healing
Wound Healing
• Epithelialization
– in sutured wounds, surface of wound
develops epithelial covering impermeable to
water in 24-48 hours
– eschar and surface debris impair this process
by inhibiting the migration of the epithelial
cells
Wound Healing
• Fibroplasia
– by fourth day fibroblasts begin synthesizing
collagen, initiating scar formation
– characterized clinically by pebbled red tissue
in wound base
Wound Healing
• Contraction
– movement of skin edges toward center of
defect, primarily in direction of underlying
muscle
– everting skin edges at time of repair accounts
for the subsequent wound contraction
Wound Healing
• Scar Maturation
– amount of scar tissue influenced by physical
forces acting across wound
– strength of wound increases rapidly from day
5-17, more slowly for additional 14 days, and
further collagen remodeling / maturation for 2
years
– strength of scar tissue never quite reaches
that of unwounded skin
Case 2
• Pt presents with two wounds – one is
sharp, linear laceration on L hand from a
clean knife. While riding her bike to
hospital she falls on a pristine, flat, clean
road and lands on dorsum of hand
producing a jagged irregular laceration.
• Which of the two has higher chance of
infection? Why?
Case 3
• Alcoholic, diabetic street person presents
with laceration to R forearm. He thinks he
did it about 24 hours ago but can’t
remember mechanism. On examination
small amount of soil type debris in wound.
• How will you manage this case?
Wound Evaluation – History
American College of Emergency Physicians: Clinical policy for the initial approach to patients
presenting with penetrating extremity trauma. Ann Emerg Med Vol 33 No. 5 May 1999
• identify all extrinsic and intrinsic factors that
jeopardize healing and promote infection
– mechanism of injury
– time of injury
– environment in which wound occurred
• potential contaminants, foreign bodies
– species of animal if bite
– pt’s medical problems / immune status
• tetanus immunization status
• handedness / vocation
Wound Evaluation - History
• Risk Factors for wound infection (Singer et al. Risk
factors for infection in patients with traumatic lacerations. Academic Emergency Medicine. July 1,
2001; 8(7): 716-20)
– older age
– diabetes
– laceration width
– presence of foreign body
Wound Evaluation – History
(mechanism of injury)
• Type of force causing wound
• Acute traumatic wounds caused by one or
combination of 3 forces
– shear
– compressive
– tensile
Wound Evaluation – History
(mechanism of injury)
• Shear Forces
– produced by sharp objects that cut through
the skin
– amount of energy required to cut skin with
sharp object is low therefore little energy
directed to surrounding tissue with minimal
cell damage
– results in lower risk of infection and problems
with wound healing because remaining tissue
is not devitalized
Wound Evaluation – History
(mechanism of injury)
• Compressive and Tensile Forces
– compressive forces produced when blunt object
impacts the skin at right angles (wounds tend to be
stellate or complex with ragged/shredded edges)
– tensile forces produced when a blunt object impacts
skin at oblique angles (wounds tend to be triangular
or produce a flap)
– compared to shear forces much more energy
deposited with high amounts applied to area around
wound
– results in devitalization of surrounding tissue with
higher incidence of wound infection
Wound Evaluation – History
(mechanism of injury)
• Shear vs. Compressive / Tensile Forces
– Infection
• with compressive / tensile forces the critical
number of bacteria needed to produce infection is
much lower (~100,000 organisms per gram of
tissue)
• with shear forces the number of bacteria needed to
produce infection is much higher ~ 10,000,000
organisms per gram of tissue
Wound Evaluation – History (time
of injury)
• “golden period” refers to time after injury that
wound can be safely closed without increased
risk of infection
– delay in wound cleaning is most important variable
– contrary to popular belief not a fixed number of hours
– “there is little change in wound infection rates in most
areas of the body for up to 19 hours after a variety of
traumatic injuries, and infection rates of simple
wounds involving the head are essentially unaffected
by the interval between injury and repair”
• Berk et al. Evaluation of the “golden period” for wound
repair: 204 cases from a third world emergency department.
Ann Emerg Med 17:496, 1988
Wound Evaluation – History (time
of injury)
• accelerated growth phase of bacteria
starts at 3 hours post wound
Timing of Closure
• primary, delayed primary, secondary
– decision to close a laceration is multifactorial
– base decision on wound history, physical
examination, host factors
• Revisit Case 3
Wound Evaluation – Physical
Examination
• Examine for:
– amount of tissue destruction
– degree of contamination
– damage to underlying structures
• Wounds may be classified into 6 categories
–
–
–
–
–
–
lacerations
abrasions
crush wounds
avulsion wounds
puncture wounds
combination wounds
Wound Evaluation – Physical
Examination
• Lacerations
– if caused by shear force little tissue damage
at wound edge and margins are sharp and
wound appears “tidy”
– if caused by compressive or tensile forces,
more force is required to produce the
laceration and therefore more tissue trauma;
often appear jagged, contused
Wound Evaluation – Physical
Examination
• Abrasions
– results from forces applied in opposite
directions (e.g. skin grinding against road
surface)
Wound Evaluation – Physical
Examination
• Crush Wounds
– caused by impact of an object against tissue,
especially over a bony surface, which
compresses the tissue
– at higher risk for subsequent compartment
syndrome
Wound Evaluation – Physical
Examination
• Avulsions
– wounds in which a portion of tissue is
completely separated from its base and is
either lost or left with a narrow base of
attachment
Wound Evaluation – Physical
Examination
• Puncture Wounds
– wounds with a small opening and whose
depth cannot be visualized
• Combination Wounds
Wound Evaluation – Physical
Examination
• Amount of tissue destruction / devitalized
tissue
Wound Evaluation – Physical
Examination
• Degree of Contamination
– bacteria and foreign material
– primary determinants of wound infection are
the amount of bacteria and dead tissue
remaining in wound
– the presence of undetected reactive foreign
bodies in sutured wounds almost guarantees
infection
Wound Evaluation – Physical
Examination
• Underlying Structures
– nerves, vessels, tendons, bones, joints
Wound Evaluation – Physical
Examination
• Wound Location
– has considerable importance in the risk of
infection
– high endogenous bacterial counts in hairy
scalp, forehead, axilla, groin, foreskin of
penis, vagina, mouth, nails
– wounds in areas of high vascularity more
easily resist infection (scalp, face)’
Delayed Primary Closure
• wound preparation (debridement,
cleansing, etc.), dress with saline soaked
fine mesh gauze, follow up in 72-96 hours
for debridement, repeat cleansing and
closure if no evidence of infection
Skin Preparation
• prevents transfer of bacteria into wound
from instruments, suture needles, gloved
fingers
• use whatever (no research suggest one
better than another)
• important to distinguish between skin
preparation and wound cleansing
Wound Cleansing (not skin
preparation)
• Soaking
– of little value and may actually increase
bacterial counts (Lammers, Fourre, Callaham et al. Effect of poviodine-iodine and
saline soaking on bacterial counts in acute, traumatic contaminated wounds. Ann Emerg Med 19: 709,
1990)
Wound Cleansing (not skin
preparation)
• Mechanical Scrubbing
– gentle scrubbing may be useful in wounds
older than 3-4 hours (a glycoprotein matrix
enters wound and may protect it from further
attempts to lower bacterial counts with
irrigation)
• Debridement of devitalized tissue
paramount to reducing risk of infection
• Scalpel excision of wound margins can be
used in grossly contaminated wounds
Wound Cleansing (not skin
preparation)
• Irrigation
– Equipment?
• 35 cc syringe with 18 G needle produces about 7-8 psi
– Solution?
• NS or 1% poviodine-iodine solution (ie. diluted Betadine) (Dire and Walsh: A comparison
of wound irrigation solutions used in the emergency department. Ann Emerg Med 1990; 19:704-708)
– infection rate in poviodine arm was lower than saline arm but not statistically
significant (4.3% vs 6.9%)
• Hydrogen peroxide kills fibroblasts and occludes microvasculature,
chlorhexadine toxic to tissue defenses, detergents contained in scrub
solutions cause tissue damage in wounds
– How much? (all expert opinion – no clinical trials)
• minimum of 100-300 cc with continued irrigation until all visible particles
removed
• 50-100 cc per cm of wound length
• if irrigation alone is ineffective in removing contaminants from a wound, the
wound should be lightly scrubbed
Prophylactic Antibiotics - Topical
• Ointments
– reduce formation of crust which could inhibit
epithelialization
– prevent dressing from adhering to wound
– routine use encourages pt inspection of
wound
– one randomized, double blind clinical trial
demonstrated reduced infection rate
• Dire et al. Prospective evaluation of topical antibiotics for preventing
infections in uncomplicated soft-tissue wounds repaired in the ED. Acad
Emerg Med 2:4, 1995
Prophylactic Antibiotics - Systemic
• no role for routine antibiotic use for most
wounds (Cumming et al. Antibiotics to prevent infection of simple wounds: A
meta-analysis of randomized studies. Am J Emerg Med 13:396, 1995)
• specific wounds: contaminated with debris,
feces, saliva; punctures, bites, extensive
tissue destruction, wounds in avascular
areas, oral lacerations, wounds involving
joint spaces, tendons, or bones; presence
of impaired host defenses
Wound Closure - Sutures
• Classification: nonabsorbable vs
absorbable
• Size (according to diameter): 6-0 face, 50,4-0 trunk and extremities, 3-0 scalp, sole
of foot
Wound Closure – Sutures Nonabsorbable
• Natural or Synthetic / Monofilament or Multifilament
– natural incite tissue reactivity (therefore increase risk of infection,
synthetic less so)
– monofilament have less pliability and knot security than
multifilament but multifilament increase risk of wound infection
• Natural multifilament - silk
– easiest to handle but poses greatest risk of infection because of
tissue reactivity (it is both a natural suture and multifilament)
• Synthetic monofilament – nylon (Ethilon), polypropylene
(Prolene), polybutester (Novafil)
• Synthetic multifilament – nylon, polyester (Mersilene)
Wound Closure – Sutures Absorbable
• Natural (collagen) or Synthetic (polymers)
• Natural – plain gut and chromic gut
– plain gut loses tensile strength the quickest (half life
5-7 days); produces marked tissue reactivity;
generally used only for oral mucosal closures
(because heal so quickly)
– chromic gut absorbed less rapidly than plain gut but
faster than synthetics (half life 10-14 days); less
tissue reactivity than plain gut because of chromic
coating; useful in situations where suture removal
may be difficult
Wound Closure – Sutures Absorbable
• Synthetic Multifilament – polyglycolic acid
(Dexon), polyglactin 910 (Vicryl)
– most commonly used in emerg for sq layers
• Synthetic Monofilament - polyglyconate (Maxon),
polydioxanone (PDS II)
• Remember – presence of any suture material in
a wound increases risk of infection;
subcutaneous sutures have highest risk
Wound Closure - Staples
• lower tissue reactivity than even the least
reactive suture material
• get less accurate closure with higher
chance of malapposition of wound edges
and development of scar
• generally reserved for sites where scar is
less of an issue (hairy scalp)
–
Kanegaye et al. Comparison of skin stapling devices and standard sutures for pediatric scalp
laceration: A randomized study of cost and time benefits. J Pediatr 130:808, 1997
Wound Closure - Tapes
• useful for flat, dry, nonmobile surfaces where
wounds fit together with no tension –ie
superficial, straight laceration under little tension
• more resistant to infection than sutured wounds
• adherence of tapes improved with use of
benzoin to skin surface
• recommend not getting wet but…
• should stay in place as long as equivalent suture
and will spontaneously detach as underlying
epithelium exfoliates
Wound Closure – Tissue Adhesives
(2-octylcyanoacrylate)
• closes wounds by forming an adhesive layer on top of
intact epithelium, which holds edges together
• cause inflammatory reaction within wounds
• Useful
– edges less than 5 mm apart, clean, sharp edges, clean
nonmobile areas, laceration less than 5 cm in length
• Not useful
– wounds near eye, on mucous membranes or mucosal surfaces,
wet wounds or those exposed to body fluids, or in areas with
dense hair, wounds under significant tension
Wound Closure – Tissue Adhesives
(2-octylcyanoacrylate)
• Literature
– in selected lacerations produces cosmetic
appearance that is comparable with standard suture
closure
• Singer et al. Prospective, randomized, controlled trial of tissue adhesive (2octylcyanoacrylate) vs. standard wound closure techniques for laceration repair. Acad
Emerg Med 1998; 5:94-99
• Quinn et al. A randomized trial comparing octylcyanoacrylate tissue adhesive and
sutures in the management of laceration. JAMA 1997;277:1527-1530
• Quinn et al. Tissue adhesive versus suture wound repair at 1 year: Randomized clinical
trial correlating early, 3 month, and 1 year cosmetic outcome. Ann Emerg Med
1998;32:645-649
• Maw et al. A prospective comparison of octylcyanoacrylate tissue adhesive and suture
for the closure of head and neck incisions. J Otolaryngol 1997;26:26-30
– may be useful for wounds under higher skin tension
• Saxena Octylcyanoacrylate tissue adhesive in the repair of pediatric extremity
lacerations. Am Surg 1999 May;65(5):470-2
• in above study they looked at 32 children with high skin tension lacerations (hand, feet,
over joints). Following closure splints were applied to restrict movement
Wound Closure – Tissue Adhesives
(2-octylcyanoacrylate)
• Application
– hold wound edges together with tissue
forceps (???), lightly wipe applicator tip over
area starting at least 5 mm from edge of
wound in direction of long axis of wound
(some authors support perpendicular
application), 3-4 thin layers, hold wound
edges together for 60 s post application
– avoid ointments and dressings
Wound Closure – Tissue Adhesives
(2-octylcyanoacrylate)
• Tips
– avoid latex gloves – use vinyl gloves
– avoid plastic instruments (ie. tissue forceps)
– if enters wound needs to be wet sponged
immediately
– use antibiotic ointment for removal of
hardened Dermabond in wound
Specific Wounds – Face
• high vascularity therefore low incidence of
infection
• debride minimally to preserve normal
facial contours
• be more aggressive with layered closure
Specific Wounds - Forehead
• unrepaired muscle layers more likely to
produce scars
• be liberal with deeper sutures in wounds
under tension
• reapproximate skin tension lines and
hairline precisely
Case 7
• 8 month old boy presents with 2 days
progressive lethargy with weakness L side
of body. 1 month ago was bitten on scalp
by dog. What has happened and how?
Specific Wounds - Scalp
• 5 layers
• can bleed +++
• shaving increases risk of infection; clip hair or
use ointment to mat it down
• check for disruption of galea and repair if
present (either single or layered closure)
• subaponeurotic (subgaleal) loose connective
tissue contains emissary veins that
communicate with intra-cranial venous sinuses
– subgaleal hematomas can become infected and
infection can be transmitted intra-cranially via
emissary veins
Specific Wounds - Eyebrow
• minimal if any debridement; if needed
angle scalpel parallel to direction of hair
shafts to minimize damage to hair follicles
and resulting alopecia
• never shave eyebrows
• use edges to serve as landmarks for
reapproximation
Specific Wounds - Eyelids
• Layers (out to in): skin, subcutaneous
tissue, muscle (orbicularis oculi and
levator palpebrae in upper eyelid),
supporting tissue (forward continuation of
sub-galeal aponeurotic layer of scalp),
tarsal plate (dense fibroelastic plate),
conjunctiva
• with any eyelid laceration ensure no
penetrating globe injury
Specific Wounds - Eyelids
• When to repair
– superficial; use 6-0 or 7-0 nonabsorbable synthetic,
small bites
• When to refer
– lacerations involving inner surface of lid
– lacerations involving lid margins (imperfect closure
results in ectropion or entropion)
– lacerations involving lacrimal duct (clue is laceration
of lower lid medial to punctum)
– lacerations associated with ptosis (levator injury)
– lacerations extending into tarsal plate
Specific Wounds - Ears
• Anatomy
– auricle (pinna) – modified horn shaped structure
composed of elastic cartilage covered by skin –
converges onto the external auditory meatus (canal)
– earlobe
• with blunt forces ensure no ruptured TM
• examine closely for subchondral hematoma
– absolutely have to avoid persistent hematoma
– need perfect hemostasis to prevent formation of
hematoma
– if present consider plastics or ENT referral
Specific Wounds - Ears
• gaping through and through lacerations
require 3 layer closure
– 1st – one or two sutures will approximate
cartilage edges, include anterior and posterior
perichondrium in suture
– 2nd – approximate posterior skin
– 3rd – anterior surface of ear using landmarks
joined point to point
• all repaired ears should be enclosed with
compression dressing
Specific Wounds - Nose
• Anatomy
– separated into two halves by the septum (cartilaginous structure)
– tip formed by two C-shaped alar cartilages covered directly by
skin
• Exposed cartilage increases risk of infection and
therefore needs to be covered
• Nasal trauma can result in septal hematoma
– can lead to permanent thickening of the septum with subsequent
airway obstruction
– pressure from a septal hematoma may cause necrosis and
subsequent erosion / rupture of septum
– aspirate with 18G needle or horizontal incision at base; nasal
packing following drainage will prevent reaccumulation
Specific Wounds - Lips
• Anatomy
– skin, vermilion border, vermilion, oral mucosa
– obicularis oris
• Always inspect intraoral and mucosal lip wounds
for foreign bodies – esp. teeth and teeth
fragments
• Lacerations through vermilion border
– use traction to the lips place first stitch at vermilion
border – need perfect alignment
– then repair obicularis oris
– then repair skin and remainder of lip
Specific Wounds - Lips
• Through and through lacerations
– 3 layer closure – 1st – mucosal layer with
rapidly absorbable suture – 2nd – orbicularis
oris – 3rd – skin
Specific Wounds – Intraoral
Armstrong. Lacerations of the Mouth. Emergency Medicine Clinics of North America Vol
18, No 3 August 2000
• Irrigation as per normal
• lacerations of buccal mucosa and gingiva heal
without repair of wound edges not widely
separated
• Small (<2cm) intraoral lacerations need not be
repaired
• Close bigger lacerations and lacerations with
flaps that fall between chewing surfaces with
absorbable sutures (plain gut, chromic gut or
synthetic absorbables)
Specific Wounds – Finger tip and
nail injuries
• Anatomy
– eponychium, lunula, nail root, nail,
hyponychium, germinal matrix, nail bed
(matrix)
– finger tip injuries are defined as occurring
distal to the insertion of the flexor and
extensor tendons at the level of the lunula
– classified as Zone I, II, III
Specific Wounds – Finger tip and
nail injuries
• Tip injuries with skin and pulp tissue loss only
(no exposed bone)
– if less than 1 square cm can treat conservatively with
serial dressing changes alone (wound heals by
secondary intention)
– if severed skin tip available can use as full thickness
graft; amputated tissue is debrided, de-fatted, then
sutured in place
– if greater than 1 square cm can consider using split or
full thickness graft from distant site vs conservative
management
Specific Wounds – Finger tip and
nail injuries
• Tip injuries with exposed bone
– if bony protuberance < 0.5 cm and soft tissue defect
less than 1 square cm trim back bone with rongeuer
and consider leaving wound open to heal by
secondary intention with serial dressing changes
– if wound dorsal obliquely angulated can treat with
bone shortening followed by primary closure of wound
using adjacent volar tissue
– amputations in a transverse or volar obliquely
angulated often require referral for sophisticated flaps
Specific Wounds – Finger tip and
nail injuries
• Nail Growth
– germinal matrix produces bulk of nail plate
– sterile matrix produces a layer of cells that is
added to the under surface of the growing nail
– if nail bed injury results in scarring of sterile
matrix will get a poorly adherent nail with
ridging – cosmetically not appealing
– takes 4 months for a new nail to reach
hyponychium
Specific Wounds – Finger tip and
nail injuries
• Injuries to nail and surrounding structures
– nail bed injured when force directed to dorsum of nail crushing
nail bed against underlying tuft of distal phalanx
• Subungual hematoma
– tradition deems that if occupies more than 50% of nail bed area,
remove nail and repair associated nail bed laceration
– Two prospective studies found simple trephination produced
good results (Seaberg et al. Treatment of subungual hematomas with nail trephination: A prospective study: Am J
Emerg Med 9:209, 1991.
Meek et al. Subungual hematomas: is simple trephining enough? J Accid Emerg Med 15:269, 1998)
– Roberts and Hedges suggest that if nail adherent do not
routinely remove nail to search for bed laceration
– remove nail and fix bed lacerations if nail partly avulsed or loose,
or if there are deep lacerations that involve the nailbed
– replace avulsed nail after bed repair and suture in place
Case 4
• 16 year old healthy male playing tennis
steps on a nail that punctures bottom of
shoe and punctures sole of foot.
• How will you approach and manage this
pt?
Specific Wounds – Puncture
Wounds
Reference: Up To Date 2000
• usually due to nails
• deeper the penetration, higher the
incidence of infection
• wounds in area of MTP joints penetrate
deeper because this is weight bearing
area
• increased risk of infection with wounds to
forefoot or shoe wearing at time of
puncture
Specific Wounds – Puncture
Wounds
• Microbiology
– partly dependent on environmental location
– Staph aureus, beta-hemolytic streptococci
(GAS), gram negatives
– pseudomonas common with wounds through
shoes
Specific Wounds – Puncture
Wounds
• Evaluation
– routine wound evaluation as previously
discussed
– have low threshold for x-rays, especially re
presence of foreign body
Specific Wounds – Puncture
Wounds
• Initial Management
– no prospective trials in literature
– Tetanus
– foreign body removal
– surface scrubbing
– questionable role for irrigation
– probably no role for coring, probing
– rest, foot elevation
Specific Wounds – Puncture
Wounds
• Antibiotics
– no prospective, randomized trials
– consider wound and host factors
Case 5
• Pt working in lumbar yard and walks by
piece of wound – catches leg on it and
ends up puncturing lower leg with piece of
wood. He feels “something is in there”.
• Manage
Soft Tissue Foreign Bodies
• foreign bodies promote infection, prolong
inflammatory phase of healing and result in poor
wound healing
• infections resulting from foreign bodies are
typically resistant to antibiotics
• every wound has a potential foreign body
• listen to pt’s if they think “something in there”
• all wounds require deliberate and careful
exploration
Soft Tissue Foreign Bodies
• Radio-opaque
– metal, aluminum, bone, teeth, glass, certain plastics,
gravel, sand
– obtain x-rays with underpenetrated “soft-tissue
technique”
• Radio-lucent
– organic material like wood, thorns, cactus spines,
some fish bones, most plastics
– sometimes indirect evidence of presence (radiolucent
filling defect when object is less dense than
surrounding tissue)
Soft Tissue Foreign Bodies
• if wound caused by radio-opaque material
and no foreign body found on exploration
or plain films – end search; otherwise:
• CT
• Ultrasound
• MRI
Soft Tissue Foreign Bodies
• Not all need to be removed
• Indications for foreign body removal
– Potential for inflammation or infection
– Toxicity
– Functional and cosmetic problems
– Potential for later injury
Case 6
• 25 year old female piano player presents
with 8 cm curvilinear laceration to dorsum
of dominant hand from a dog bite.
Specific Wounds - Bites
• Epidemiology
– 60-90% dog bites, cats 1-15%, rodents 1-7%,
other species less than 2%
• Dog Bites
– jaws can exert +++force but teeth not sharp
– results in relatively superficial crush injuries
– face and scalp most common site in children
– incidence of infection 5-10%
– infection rate on face 1-5%
Specific Wounds - Bites
• Cat Bites
– typical bite is a puncture wound
– possess long, slender, pointed teeth
– overall infection rate about 14% (80%
according to 2001 Sanford Guide); 28-80% in
NEJM article
Specific Wounds - Bites
• Microbiology of dog and cat bites (Talan et al. Bacteriologic
Analysis of Infected Dog and Cat Bites. NEJM January 14, 1999)
–
–
–
–
almost always polymicrobial
aerobes, anaerobes
Pasteurella canis most common isolate in dog bites
Pasteurella multocida most common isolate in cat
bites
– authors suggest that if antibiotics prescribed a beta
lactam antibiotic combined with a beta lactamase
inhibitor would be appropriate choice for prophylaxis
Specific Wounds - Bites
• Dog Bite Management (Cummings. Antibiotics to prevent
infection in patients with dog bite wounds: a meta-analysis of randomized trials. Ann
Emerg Med 1994;23)
– face, scalp, trunk – solid support for primary
closure
– ?distal extremities – look at wound and
patient factors; can probably primarily suture
all dog bite wounds
– prophylactic antibiotics only in high risk
wounds (hands, wound / patient factors)
Specific Wounds – Bites
• Cat Bite Management
– puncture wounds should be left open
– primary closure on face and scalp only
– consider delayed primary closure in other
locations
– consider prophylactic antibiotics in all cases
Specific Wounds – Human Bites
• Epidemiology
– 60-75% hands and upper extremities
• Microbiology
– polymicrobial
– mixed gram positive, gram negative, aerobic,
anaerobic
– eikenella corrodens
– Hepatitis B
• Complications of human bites most commonly
occur in hand wounds
Specific Wounds – Human Bites
• Management
– routine wound evaluation and care
– non-hand wounds can be closed primarily
– hand wounds need to be left open to heal by
secondary intention or delayed primary
closure
– routine prophylactic antibiotics in hand
wounds only
Objectives
• Wound Healing
• Wound Evaluation – History, Physical
examination
• Wound Preparation
• Wound Closure
• Specific Wounds
– face, scalp, eyebrow, eyelid, ear, lips,
intraoral, puncture, fingertip and nail, foreign
bodies, bites
Take Home Points
• Evaluate wound and patient factors when
determining closure, risk of infection, antibiotics,
etc.; infection is enemy
• Lacerations caused by compressive/tensile
forces result in more complications than
lacerations caused by knife cut (shear forces)
• “golden period” is not fixed and dependent on
many variables
• V-Y plasty for fingertip amputations
• re bites: routine antibiotics for all cat bites and
dog and human bites to hand