1. food and drink
2. food
3. condiments and dressings

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How to Debride
a Wound
Objectives
At the end of this article,
the clinician should be able to:
1) Identify the important attributes and indications for
wound debridement.
2) Describe at least three
different types of wound
debridement.
It’s important to
understand these
five basic methods.
3) Understand the indications and basic techniques underlying each of the abovementioned types of wound
debridement.
Welcome to Podiatry Management’s CME Instructional program. Our journal has been approved as a sponsor of Continuing Medical Education by the Council on Podiatric Medical Education.
You may enroll: 1) on a per issue basis (at $17.50 per topic) or 2) per year, for the special introductory rate of $109 (you
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An answer sheet and full set of instructions are provided on pages 210-212.—Editor
By Joshua Johnson, D.P.M., Brent P.
Nixon, D.P.M., M.B.A., David G. Armstrong, D.P.M., M.Sc.
T
he diabetic foot is constantly
at risk of daily breakdown,
sometimes preventable and
sometimes not. When it breaks
down and ulcerates, the foot may
develop an acute wound, and acute
wounds heal through the normal
healing process. The main concern
with diabetic foot wounds is that
most of the time they behave not
as acute wounds, but rather as
chronic ones. These types of
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wounds pose the ultimate challenge for the physician treating the
lower extremity. The problem arises
because a chronic wound does not
follow the usual healing phases. To
properly treat this type of wound,
the physician needs to correctly debride and off-load the wound. In
terms of importance, debriding the
wound may be as critical or even
more critical in healing the wound,
than off-loading (1). There are five
main methods to debride a chronic
wound: 1. Debridement with
scalpel and tissue forceps, nippers,
or scissors, 2. Biosurgical (maggot)
therapy, 3. Newer methods, such as
ultrasonic surgical debridement, 4.
Mechanical Debridement (by removing dry gauze from a wound)
and 5. Autolytic debridement (from
macerating tissue until it is able to
be removed). Again this is dressingrelated. These five methods of
wound debridement are not stand
alone methods but are often used
in combination to correctly treat
the wound. The purpose of this
paper is to provide a practical basis
for performing the first three of the
above-mentioned methods.
Continued on page 122
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Debride...
Surgical Debridement
Surgically debriding the wound
with the use of the scalpel and tissue forceps or nail nippers may be
the most efficient method of treatment to achieve a complete removal of nonhealing tissue(2). One
drawback of this method is that it
can cause excessive pain and
bleeding (in the sensate or coaguopathic patient, respectively) and
needs to be performed carefully.
For larger wounds, the tissue may
be handled with sterile tissue forceps and scalpel or for smaller
wounds with a tissue nipper or
scissors(1). The skin may be incised
(Figure 1-Figure 5) or the nipper
may be introduced to the fullest
extent of the undermining between the epidermis and dermis
(Figure 6-Figure 9). When debriding the skin, all nonviable, non-
bleeding tissue should be removed.
All callus, necrotic tissue, and eschar prohibit healing of the
wound. If the border between the
viable and nonviable tissue is
clearly demarcated, then skin
should be excised along the border. If the border is not clearly defined, then one should start in the
center of the wound and remove
concentric circles of the skin until
viable tissue is reached. Tissue
should be removed circumferentially about the wound until the
periphery of the wound exhibits a
firm connection between epidermis and dermis (1). Upon reaching
the edge of the wound, normal
bleeding should occur. When
there are clotted venules at the
skin edge, further dissection
should be carried out until normal
bleeding is encountered (4) . Any
non-viable tissue should be removed centrally from the wound,
as required, through sharp excision or curretage. Digital pressure
may then be applied to the wound
to achieve hemostasis. The wound
may then be probed to assess the
involvement of underlying tissue
and for the presence of occult infection. The wound will then be
dressed with a standard wound
dressing and properly off-loaded.
The hallmark of an appropriately
off-loaded wound is the noticeable
lack of undermining at the
wound’s edge at follow up. Offloading will help to decrease the
unwanted tissue at further visits
for surgical debridement.
The key disadvantage of aggressive surgical debridement is that it
requires a modicum of experience
on the part of the clinician and a
modicum of healing potential (ie.
arterial outflow) on the part of the
patient. These two issues are somewhat less important when chronic
Figure 1—Callus buildup around the wound before scalpel
debridement
Figure 2—Callus buildup around the wound before scalpel
debridement
Figure 3—Excision of callus buildup with scalpel and tissue
forceps
Figure 4—The wound after removal of initial callus tissue
with scalpel
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PODIATRY MANAGEMENT • NOVEMBER/DECEMBER 2003
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wounds are instead treated with
maggot debridement therapy and
ultrasonic surgical debridement(5).
Biosurgical (Maggot) Therapy
Maggot therapy has been used
for centuries and was well understood by the military physicians
who found that battle wounds infested by maggots had healed
quickly without infection(6). Maggot therapy was first introduced
in the United States in the 1930s
by Bier(6,7), and became quite popular until the invention of the antibiotic and aggressive surgical debridement(6). Maggot therapy reintroduced itself in the U.S. in the
late 1980s, and the use of medicinal larvae or maggot debridement
therapy has steadily increased in
usage in the past 10 years, particularly in many progressive, high-
volume wound care centers in Europe and Asia. One factor in this
increase is over the past decade
inpatient care of wounds has declined, and outpatient wound
management has increased(7). Our
center uses this modality frequently in care of patients who
are not candidates for aggressive
frequent surgical debridement, as
described above.
Maggot therapy has been used
for many years and is securing a
place in wound care(2,5,6,7,8,9). The object is to apply the maggots to the
wound and keep them from escaping from the wound, while allowing them to breathe and grow. The
maggot therapy application process
is consistent throughout the literature.
First, the wound needs to be
surgically debrided as much as is
appropriate and have any eschar
removed. As famished as they
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may be, the maggots do
not eat through the eschar formation as quickly
and efficiently as other necrotic tissue.
Second, a cage-like dressing has
to be made around the wound. This
is performed by preparing the periwound area with a skin adhesive.
This allows the peri-wound barrier
to firmly attach to the skin and not
leak.
Third, the peri-wound barrier is
constructed. This peri-wound barrier is either made of hydrocolloid
dressing or waterproof tape. This
dressing can be formed by cutting
strips and applying them to the periphery of the wound connecting at
the corners.
Fourth, a nylon or Dacron chiffon dressing is constructed to accept and contain the larvae on the
tissue. The chiffon can be laid on
Continued on page 124
Figure 5—The wound after complete removal of callus
leaving a good granular base
Figure 6—Insertion of nail nippers into callus surrounding
wound
Figure 7—Continuation of wound debridement with tissue
nippers
Figure 8—Continuation of wound debridement with tissue
nippers
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NOVEMBER/DECEMBER 2003 • PODIATRY MANAGEMENT
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Debride...
two pieces of moist gauze and
set on the Mayo stand close to
wound for easy application.
Fifth, the larvae are now applied
to the dressing (Figure 10-Figure
12). Depending on the size and
depth of the wound, anywhere
from 50-1,000 maggots, 24-48
hours old, are applied to the
wound(5). The chiffon/4x4 dressing
with maggots is transferred to the
wound and adhesive foam tape is
used to secure the dressing to the
hydrocolloid dressing.
Sixth, an air permeable dressing
is applied to the wound, usually
done by a gauze layer dressing allowing air into the wound, not
causing a necrotic liquification that
is harmful to the maggots. The
gauze layer absorbs the exudate
produced by the maggots.
If the wound is located on a
weight-bearing surface then care
must be taken to off-load the area
so the maggots are not disturbed.
It has been suggested that 10 maggots/cm2 of necrotic tissue be applied(9). It is easier to leave smaller
maggots on for 2-3 days, but it has
been reported that larger maggots
changed every 24 hours debride
the wound more efficiently and
faster(9).
When the dressing is changed,
the maggots are flushed from the
wound or picked out of the
wound using tissue forceps. The
larvae are significantly larger, up
to four times the size of when
they were applied, about 1 cm in
length (10). If the necrotic and fibrotic tissue has been adequately
removed from the wound, then a
standard wound dressing may be
applied. If the wound base is not
completely granular, then another application of maggot therapy
can be applied. The goal behind
maggot therapy is to rid the
wound of unwanted tissue and
stimulate the formation of granulation tissue. Maggot therapy is
an effective method to debride
the wound (Figure 13–Figure 17).
Ultrasonic Surgical Debridement
Ultrasonic wound debridement
technology has been used for many
years in neurosurgery and general
surgery in Europe and Asia. In the
United States, it has only been used
in the treatment of diabetic foot
wound. Research suggests that ultrasound is the gentlest option for
cleaning injured skin, as well as decreasing the blood loss or pain associated with the treatment(11).
The principles behind ultrasonic debridement are the concepts of thermal, cavitation, and
“direct” effects. “Thermal” refers
Continued on page 125
Figure 9—Complete debridement of wound with tissue
nippers
Figure 10—Maggots in the jar before application
Figure 11—Removal of maggots from the jar with a
tongue depressor
Figure 12—Maggots being spread on chiffon dressing before application to the wound
124
PODIATRY MANAGEMENT • NOVEMBER/DECEMBER
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to the heat generated by the ultrasound bath that can be easily
controlled and dissipated in the
water to prevent tissue damage.
This application is used when the
wound is completely immersed in
the water bath, but it is not used
in foot debridement. “Cavitation” refers to the shearing action
of stable microtubes in alternating high and low pressure waves
that are generated by the ultrasonic transducers. The “direct” effect refers to any result after the
ultrasonication that cannot be
described by the first two effects(12).
Ultrasonic debridement for foot
wounds is performed as if a surgical
instrument were being directly applied to the wound along with constant purging. The extremity is not
immersed in an ultrasonic water
bath but is put under a stream of
pressure delivered from the machine. One of the systems used in
ultrasonic debridement is the Sonoca Soring system. The system has
the portable ultrasonic unit and the
sonotrode (Figure 18). The three
different modes on the machine are
1. superficial mode bubbling, that
has no tissue contact, 2. superficial
mode touching, that has full skin
contact, and 3. immersion mode.
The superficial mode bubbling is
used on soft coatings; the superficial mode touching is used on
necrotic tissue; and the immersion
mode is used for deep wounds and
wound pockets. The sonotrode can
be in the form of a spatula, hoof, or
ball.
In one study, the treatment
was applied three times per week
for a duration of thirty seconds
per square centimeter of wound at
the maximum available output of
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25kHz. The sonotrobe
was set to superficial
mode touching and 5 ml of
Ringer’s solution was applied
per minute for continued purging(13). It is recommended that for
smaller wounds the application
should be applied from 30-60
secs/cm2, and for bigger wounds
the time should be limited. Different wounds have been treated
with all three types of the
sonotrobe, all three modes, and
times ranging from seconds to 30
minutes. When applying the treatment the patient should be situated so that the water does not pool
but flows off the patient. It has
been recommended that when
first applying the application, the
power should be set at 60% and
then moved to 100%(14). The process can be painful and some topical antibiotics may be needed.
Continued on page 126
Figure 13—The wound before application of the maggot
therapy
Figure 14—After application of maggots
Figure 15—Continued healing of the wound
Figure 16—Continued healing of wound after maggot
therapy
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Also, the probe should constantly be moved around the
wound and concentrated in the
center tissue, to avoid pain at the
edge of the wound. Moving the
probe too slowly does not allow
enough heat exposure and moving the probe too quickly prevents
sufficient exposure to bacteria. Ultrasonic surgical debridement does
effectively reduce bacterial count
and remove particulate matter (12)
(Figure 19-Figure 21).
Summary
The diabetic chronic wound is
difficult to treat, but proper treatment is essential. The wound
needs to be properly off-loaded
and debrided for healing to take
place. There are three effective
methods for debridement: surgical
debridement, biosurgical (maggot
wound management in the U.S.
therapy), and ultrasonic debrideDebriding the wound is essential
ment, all three have a part in
for the wound to heal, and so
wound healing. The application
learning how to effectively deof these three methods has been
bride a wound is critical for the
discussed. As stated earlier these
methods can and will be used in
Continued on page 127
combination
throughout the
length of the
wound
treatment. Surgical
debridement has
been around for
many years and
will continue to
be used. Maggot
therapy is making a strong
comeback
in
wound management. Ultrasonic
debridement is
newer and is
slowly working Figure 17—Continued healing of wound after maggot
i t s w a y i n t o therapy
Figure 18—Soring Sonoca ultrasound machine
Figure 19—Application of ultrasonic debridement to the
wound
Figure 20—Continued application of ultrasonic debridement
Figure 21—Continued application of ultrasonic debridement
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PODIATRY MANAGEMENT • NOVEMBER/DECEMBER 2003
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E X A M I N A T I O N
podiatric surgeon. Understanding these three methods
and their application will contribute greatly to wound
management. ■
See instructions and answer sheet
on pages 210-212.
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References
1. Armstrong, DG, Lavery, LA, Vazquez, JR, Nixon, BP, Boulton, AJM: How and why to surgically debride neuropathic foot
wounds. J Am Podiatr Med Assoc 92:402-404, 2002
2. Steed, DL, Donohoe, D, Webster, MW, Lindsley, L: Effect
of extensive debridement and treatment on the healing of diabetic foot ulcers. J Am Coll Surg 183:61-64, 1996
3. Attinger, CE, Bulan, E, Blume, P: Surgical debridement: the
key to successful wound healing and reconstruction. Clinic in
Podiatric Medicine and Surgery 17:599-630, 2000
4. Rayman, A, Stansfield, G, Woollard, T, Mackie, A, Rayman,
G: Use of larvae in the treatment of diabetic necrotic foot. The
Diabetic Foot 1:7-13, 1998
5. Mumcuoglu KY, Ingber A, Gilead L, Stessman J, Friedmann
R, Schulman H, Bichucher H, Ioffe-Uspensky I, Miller, Galun R,
Raz I: Maggot therapy for the treatment of diabetic foot ulcers.
Diabetes Care 21:2030-2031, 1998
6. Bonn, D: Maggot therapy: an alternative for wound infection. The Lancet 356:1174, 2000
7. Sherman RA, Sherman J, Gilead L, Lipo M, Mumcuoglu
KY: Maggot debridement therapy in outpatients. Arch Phys Med
Rehabil 82:1226-1229, 2001
8. Mumcuoglu KY, Ingber A, Gilead L, Stessman J, Friedmann
R, Schulman H, Bichucher H, Ioffe-Uspensky I, Miller J, Galun,
Raz I: Maggot therapy for the treatment of intractable wounds.
Int J Dermatol 38:623-627, 1999
9. Mumcuoglu, KY: Clinical applications for maggots in
wound care. Am J Clin Dermatol 2:219-227, 2001
10. Armstrong, DG, Mossel, J, Short, B, Nixon, B, Knowles,
EA: Maggot debridement therapy:a primer. J Am Podiatr Med
Assoc 92:398-401, 2002
11. Souhrada, L: New methods sounds out bacteria in skin
wounds. Hospitals 62:80, 1988
12. Nichter, LS, Williams, J: Ultrasonic wound debridement.
The Journal of Hand Surgery 13A:142-146, 1988
13. Cshulze, CH, Hulskamp, T, Schikorski, M, Thies, E: Effective, gentle low-pain wound debridement with low frequency ultrasound applied using mobile equipment. Section for general,
accident and visceral surgery phlebology.1
14. Schulze, CH, Oesser, S, Seifert, J: Investigations into the
antibacterial effect of low-frequency ultrasound applied by using
the spherical soring Sonoca probe-tip (sonotrode) Endotoxin laboratory for surgical research: in vitro project report 03/2001 Edition 08/20/02:1-5, 2002
(Left to right): Joshua Johnson is a second year surgical resident at the Southern Arizona VA Medical Center. Brent
Nixon is the Chief of Podiatry in the Department of Surgery
at the Southern Arizona VA Medical Center. David Armstrong is the Director of Research in the Department of Surgery at the Southern Arizona VA Medical Center
www.podiatrym.com
1) What is a complication of surgical debridement in wound management?
A) Excessive bleeding and pain
B) Good granular wound base
C) Eschar formation
D) Excessive fibrotic tissue
2) A good time to use maggot therapy in
wound management is when
A) Patients are not good candidates for aggressive surgical debridement
B) As a last resort
C) Before using surgical debridement
D) There is a disvascular wound
3) Application of maggot therapy is first done
A) Before surgical debridement
B) By debriding necrotic tissue and eschar
formation
C) By applying Coban above the wound
D) By making a peri-wound barrier
4) After having applied one round of maggot
therapy, when is it appropriate to apply another
round of maggot therapy?
A) When the wound is completely granular
B) When the wound is bleeding and very
painful
C) When the wound does not have a complete granular base
D) When the wound edges are macerated
5) Maggots in the wound will help to stimulate
which of the following?
A) Fibrotic tissue
B) Eschar formation
C) Ligament tissue
D) Granulation tissue
6) Which of the following is a mode setting on
the ultrasound machine?
A) Superficial mode bubbling
B) Superficial mode touching
C) Immersion mode
D) All of the above
Continued on page 128
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7) In smaller wounds what is the
recommended time to apply the
ultrasound therapy?
A) 30-60secs/cm2
B) 20-70secs/cm2
C) 1 minute only
D) 3 minutes/cm2
8) Which of the following is an
effective method of wound debridement?
A) Surgical debridement
B) Biosurgical/maggot
therapy
C) Ultrasound therapy
D) All of the above
9) Why are chronic wounds
more difficult to heal than acute
wounds?
A) Chronic wounds don’t
follow the normal healing
pattern
B) Acute wounds don’t bleed
as much
C) Chronic wounds bleed
more
D) Acute wounds have more
fibrotic tissue present
10) What are the 2 key factors in
treating a wound?
A) Debridement and
dressing
B) Off-loading and dressing
C) Debridement and offloading
D) None of the above
11) Of the debridement methods available, which is the most
efficient?
A) Biosurgical/maggot
therapy
B) Surgical debridement
C) Ultrasound therapy
D) Autolytic debridement
128
(cont’d)
12) What is the method of applying maggots to the wound?
A) Directly applying them to
the wound
B) Applying them after applying the chiffon dressing
C) Applying them before surgical debridement
D) Applying them through a
hole in the peri-wound
barrier
13) What determines the number of maggots used on the
wound?
A) Amount of fibrotic tissue
present
B) How long the wound has
been present
C) Size and depth of the
wound
D) Where the wound is located on the foot
14) What detrimental effect in
the wound can cause the maggots to die off?
A) Necrotic liquification
B) Fibrotic tissue
C) Bleeding
D) Exposed bone
15) When would the setting of
superficial mode bubbling be
used in ultrasound therapy?
A) On soft coatings
B) Necrotic tissue
C) Deep wounds
D) Wound pockets
16) When applying ultrasound
therapy to the wound, the most
pain can be felt in the
A) Center
B) Edges
C) Center and edges
D) It is not painful
PODIATRY MANAGEMENT • NOVEMBER/DECEMBER 2003
17) If the probe is moved too
quickly over the wound, what
can be the possible outcome?
A) Too little exposure to
bacteria
B) Increase in bacteria count
C) Increase in fibrotic tissue
D) Not enough heat exposure
18) Why did maggot therapy fall
out of favor in the US years ago?
A) Invention of the antibiotic
and aggressive surgical debridement
B) Ultrasound therapy was introduced
C) It did not work
D) It is too expensive
19) When the wound is properly
off-loaded what will be noticed
at the next visit?
A) Fibrotic tissue
B) Increase in wound size
C) Lack of undermining at
the wound’s edge
D) Hyperkeratotic tissue
around the wound edge’s
20) In surgical debridement, if
the border of the wound is not
clearly defined debridement
should begin
A) In the center
B) At the wound edges
C) Where the wound looks
the worst
D) Where the wound looks
the best
SEE INSTRUCTIONS
AND ANSWER SHEET
ON PAGES 210-212
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