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A superabsorbent layer which holds
the wound exudate away from
the skin
A film which ensures a high
moisture-vapour-transmission rate
(MVTR), which allows for one-way
transpiration of the collected exudate
vapour, making a canister redundant.
The dressing forms part of a pack
that can be prescribed when required.
The pack contains a single-use pump
—which lasts for seven days — and
two individually packed dressings with
fixation strips (allowing the wound to be
inspected if necessary).
The pump is operated by a single
orange button and uses normal lithium
AA batteries. At the end of a treatment
button is pushed again, the therapy
will pause and will automatically
restart after an hour if the button is not
pressed again before this time. A range
of dressing sizes are available, but the
dressing should be big enough to cover
both the wound and allow the port to
be situated on healthy periwound skin.
It is essential to ensure that the port
is not placed on the open wound as
this may lead to fluid transfer via the
dressing into the tubing that connects
the dressing to the device. This can
affect treatment, as it could cause a
blockage which would lead to reduced
or no pressure being delivered.
It has been demonstrated that the
action of PICO dressings alone, or in
combination with a foam or gauze filler,
is virtually identical to the mechanism
of action of conventional, more
cumbersome NPWT devices (Borgquist
et al, 2010).
The patient/carer does need to
be able to manage the device, which
involves understanding how to
silence the alarms, troubleshoot, and
disconnect and reconnect the device
cycle, the batteries can be recycled,
while the pump should be disposed
of as non-clinical waste.The PICO
system incorporates three lights so that
clinicians and patients know that the
system is working:
A green light which flashes
constantly to indicate it is
working properly
Two amber alarm lights which flash if
there is an issue (one indicates an air
leak; a second shows that the battery
charge is low).
The batteries may be replaced within
the seven-day life of the pump.
The pressure is nominally set at
-80mmHg and a single push of the
orange button starts the therapy. If the
Table 1:
NPWT: indications, contraindications and precautions
Indications
Acute, sub-acute, traumatic and dehisced wounds
Chronic wounds, diabetic foot ulcers, leg ulcers or pressure ulcers, skin grafts/flaps, closed surgical incisions
Partial-thickness burns
Contraindications
Wounds with any necrotic tissue and/or eschar, or greater than 50% soft slough in the wound bed
Previously confirmed, untreated osteomyelitis (bone infection)
Malignancy in wound (with exception of palliative care to enhance quality of life)
Exposed arteries, veins, organs or nerves, or anastomotic sites (surgically connected structures, such as
blood vessels, tendons, etc)
Emergency airway aspiration
Pleural, mediastinal or chest tubing drainage
Surgical suction
Non-enteric and unexplored fistulae
Anastomotic sites
Precautions
Patients with previous history of non-concordance with treatment modalities; those receiving anticoagulant
therapy or platelet aggregation inhibitors; any patient with active bleeding
Untreated malnutrition
Wound infection must be treated concomitantly with appropriate antibiotics or antimicrobial agents
Care must be taken at all times to ensure that the NPWT pump and tubing does not lie in a position which
could cause damage to the patient; trail across the floor where it could become contaminated or cause
a trip hazard; present a risk of strangulation or a torniquet effect; or become twisted or trapped so that
negative pressure is prevented
See manufacturer’s instructions for a full list of precautions
Table 2:
Pros and cons of different NPWT fillers
Positive qualities
Negative qualities Wound types
Foam
›
Stimulates rapid granulation tissue
formation, wound contraction
›
Removal of high volumes of exudate
Can be difficult to
apply to wounds
with an irregular
shape/contours
›
Compartment
syndrome
›
Acute wounds with
large tissue loss
›
Postoperative
open abdomens
and sternotomy
wounds
Gauze
›
Easy and fast to apply to uneven, large,
deep wounds
›
Reduced pain and trauma reported
on removal
›
Slower initial stimulation of granulation tissue
›
Reduced post therapy contraction may
reduce scarring
Not as efficient as
foam at facilitating
exudate removal
›
Cosmetic surgery
›
Skin flap
preparation/
stabilisation
›
Skin grafts and use
over joints
›
Application tips
Tips to ensure successful NPWT
application include:
Wound size and volume: wounds
greater than 0.5cm in depth are
likely to require a foam or gauze
sub-filler and wounds treated
with larger dressing sizes should
generally be no more than 2cm
in depth — the filler will need to
be changed two or three times
per week
Amount and type of exudate:
when used on moderately
exuding wounds, the size of
the wound should be no bigger
than 25% of the dressing pad
The wound should fit
comfortably within the area of
the pad, allowing the port to be
situated over healthy skin
Showering is permissible: the
pump should be disconnected
and kept in a safe location
outside of the shower, and the
dressing tubing should hang
downwards to prevent any
water getting in.
NPWT IN THE COMMUNITY
12
JCN supplement
2015,Vol 29, No 5