SURGERY
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and fibroblasts. In addition, it’s hydrophilic,
which means it promotes moist healing.
Nitrofurazone has broad-spectrum antimicrobial
activity but little efficacy against Pseudomonas
species. It’s hydrophilic but delays epithelialisation and is a known carcinogen.
Gentamicin sulfate is an appropriate choice
when a wound is suspected to be infected with
gram-negative bacteria. It also promotes epithelialisation.
Patients that undergo autolytic debridement tend
to be more comfortable at the wound site because
it’s not as painful as surgical or mechanical débridement, Dr. Miller says. However, the disadvantage is
significant sometimes—this is a slow process. It may
take a couple of days before it becomes noticeably
effective.
New avenues of healing
While the old standbys are still around—and will be
most likely for some time other approaches have
been gaining attention recently. Here are a few:
Biosurgical debridement—AKA medical maggots!
These creepy crawlers may make your skin crawl,
but they may turn out to be very beneficial in wound
management, Dr. Miller says. At the moment they’re
being studied more in human medicine than veterinary.
Wound-healing enhancers: These two woundhealing enhancers you’d expect to find in your kitchen rather than your wound-care arsenal.
• Honey. Some claim that honey enhances
wound debridement, reduces edema (it’s hypertonic to the wound, so it draws fluid out of surrounding tissues) and inflammation, promotes
granulation and epithelialisation, and has some
antibacterial activity. Dr. Miller is reserving judgment. “There is no current data that this is doing
better than other wound management strategies,” she says. “It sounds great, but is it actually working? I’m not sure.” If you do use honey
for treating wounds topically, Dr. Miller recommends unpasteurised medicinal grade honey.
• Granulated sugar. Like honey, sugar’s benefits
seem to arise from its hypertonic character.
It’s purported to reduce oedema, have some
antibacterial properties, accelerate sloughing
of any devitalized tissue and promote granulation of the wound. The main challenge? Experts
recommend using a 1-cm-thick layer over the
wound to be effective. Talk about messy!
Circling the drain? Another goal for wound-healing therapy is to provide adequate drainage. What’s
new here is … ready for it? Vacuum-assisted drainage! This technique uses open-cell sterile polyure-
thane foam that can be trimmed to the wound size.
This is then sealed to the wound with an adhesive drape
to which a vacuum is attached. The vacuum-generated
pressure draws the wound fluid into a reservoir.
Applying sub-atmospheric pressure (negative 125 mm
Hg to be exact) is thought to increase blood flow to the
wound tissues, increase the speed with which granulation tissue forms and reduce micro-organism numbers
(although this effect has not been reproduced). A significant benefit is that this method of wound treatment
allows for bandage changes every two days or so, depending on how exudative the wound is.
Bandages: So what’s new in bandages?
interactive dressings.
Two words:
These primary (closest to the wound) layers are semiocclusive and non-adherent. They’re hydrophilic, helping create the desired moist healing environment, but
can cause maceration of normal skin, so they should
be applied only to the wound bed. Some can modulate
cell activity and growth factor release. They are highly
absorbent, which allows a longer time between bandage changes—and that’s a beautiful thing.
There are two getting attention right now:
• Calcium alginate. Made from seaweed, calcium
alginate comes in ropes and sheets for different
wound types. It stimulates granulation and epithelialisation. Fair warning: When it’s doing its job,
over time it turns into a viscous, jelly-like substance
against the wound and secondary bandage layer,
so it needs to be rinsed off. It can be used during inflammatory and repair phases of healing. Depending on how exudative the wound is, bandage
changes should occur every one to five days.
• Polyurethane foam. This material is
even more absorbent than calcium alginate, is comfortabl