Download Using negative pressure therapy in wound healing

Keywords: Tissue viability/Negative
pressure wound therapy/Chronic wounds
Nursing Practice
Innovation
Tissue viability
●This
article has been double-blind
peer reviewed
Complex wounds may benefit from negative pressure therapy. Consideration
must be given to appropriate patient selection and dressing application
Using negative pressure
therapy in wound healing
In this article...
T
ypes of wound for which negative pressure wound
therapy is suitable
C
onsiderations for patient selection
U
sing negative pressure wound therapy in the community
Author Heidi Guy is tissue viability clinical
nurse specialist and honorary lecturer, East
and North Herts Hospital Trust and
University of Hertfordshire; Lorraine
Grothier is clinical nurse specialist tissue
viability, Central Essex Community
Services, Maldon.
Abstract Guy H, Grothier L (2012) Using
negative pressure therapy in wound
healing. Nursing Times; 108; 36, 16-20.
Negative pressure wound therapy, also
referred to as topical negative pressure
therapy, is a useful treatment for a variety
of acute and chronic wounds and, unlike
many other wound treatments and
dressings, has a relatively good evidence
base to demonstrate its effectiveness. This
article considers its application in both
primary and acute care.
W
ound healing does not
always follow a simple
path; some acute wounds
fail to heal and some
become chronic. Negative pressure wound
therapy (NPWT) can be used to aid healing
in acute, chronic, closed incisional, closed
skin graft and open abdomen wounds.
Unlike many other wound treatments
and dressings, it has a relatively good evidence base to demonstrate its effectiveness, but manufacturers list some contraindications and situations requiring
caution (Box 1).
Negative pressure (suction) is applied to
the wound bed through a foam or gauze
contact medium using an electrically, battery or mechanically powered pump; this
involves achieving an airtight, vacuum,
seal. The benefits of NPWT include:
enhanced healing and granulation tissue
formation (Othman, 2012; Schintler, 2012);
management of highly exuding wounds
(Schintler, 2012; Mouës et al, 2011); reduced
dressing changes compared with more conventional dressings (Wu and Armstrong,
2008); reduced nurse time (Dowsett et al,
2012); reduced costs (Othman, 2012); and
improved quality of life (Othman, 2012).
The treatment is thought to assist
healing by providing a moist environment
and removing interstitial fluid and exudate (Schintler, 2012; Mouës et al, 2011); and
enhancing granulation tissue formation
(Schintler, 2012), angiogenesis (Mouës et
al, 2011) and tissue perfusion (Schintler,
2012; Mouës et al, 2011). Others have
reported fluctuations in blood flow
(Borgquist et al, 2011; Malmsjö et al, 2009a),
which may be useful in patients with compromised vascularity.
Until recently, funding for NPWT was
restricted to the acute sector, but it is
increasingly available in the community
due to the introduction of competing
devices, the availability of consumable
dressings on prescription, and the drive to
prevent hospital admissions and facilitate
early discharge. However, access in community setting is variable (Othman, 2012).
5 key
points
1
Negative
pressure wound
therapy has been
found to aid
healing in many
complex wounds
The therapy
can be used in
both acute and
community
settings
Practitioners
using NPWT
must be trained to
use the specific
device
Patient
selection must
involve assessing a
range of factors in
addition to the
wound requiring
treatment
NPWT must be
applied
carefully to avoid
damaging the
wound bed or
causing pressure
damage to the
surrounding skin
2
3
4
5
Dressings
A range of studies evaluating gauze-based
and foam-based NPWT have considered the
difference in tissue formation (Malmsjö et
al, 2012; Fraccalvieri et al, 2011a) and deformation (Malmsjö et al, 2012), healing rates
(Dorafshar et al, 2012); pain at dressing
change (Dorafshar et al, 2012; Fraccalvieri et
al, 2011b), contraction (Anesäteret al, 2011;
16 Nursing Times 04.09.12 / Vol 108 No 36 / www.nursingtimes.net
Promoting wound healing
using a gauze-based dressing
Nursing Practice
Innovation
Malmsjö et al, 2009b), scar tissue depth
(Fraccalvieri et al, 2011a), and effect on
microvascularity (Malmsjö et al, 2009a).
Little difference has been demonstrated
between the two, although patient-reported
pain on dressing change has been consistently significantly lower with gauze (Dorafshar et al, 2012; Fraccalvieri et al, 2011b). The
use of gauze also requires fewer dressing
changes and, without the need to sculpt the
foam, less nursing time at dressing change
(Dorafshar et al, 2012).
Patient selection
Patients whose wounds are suitable for
NPWT need to be assessed for their ability
to live with the device. The following factors should be considered:
» Level of mobility and risk of tripping –
drain tubes can create a trip hazard for
those with reduced mobility, who may
also find the larger pumps too
cumbersome;
» Level of cognitive ability and risk of
pulling the dressing or tubes off;
» Mental health status and ability and
willingness to adhere to the treatment
regimen – which involves wearing the
pump at all times and having two or
three dressing changes a week, and to
care for the pump;
» Position of wound or wounds and the
ability to obtain and maintain a seal;
» Pain at dressing changes – some
patients may need nitrous oxide for
pain relief, or if this is ineffective or
unavailable (for example in community
settings) it may be necessary to
discontinue NPWT.
Dressing application
The application of NPWT dressings is not
difficult but it requires an understanding
of how the therapy works and training
in the use of the specific device. Staff
undertaking dressing changes should
have the appropriate knowledge and
training – poor dressing technique can
lead to wound complications or breaches
in the seal.
The wound is filled with gauze or foam,
depending on the device used, then a drain
is applied to facilitate the application of
negative pressure and remove wound exudate. Drains are either inserted into the
wound filler or on top, again depending on
the device. Any areas of undermining,
tracks or sinuses must be fully explored
and filled to ensure negative pressure is
achieved at these deepest areas. Practitioners applying NPWT must ensure that:
» Healthy skin is not damaged by contact
with foam, gauze or drains;
BOX 1.
CONTRAINDICATIONS
AND CAUTIONS
Contraindications
● Wounds involving untreated
osteomyelitis
● Wounds exposing blood vessels or
organs or with an unexplored fistula
● Wounds including open joint capsules
● Skin malignancy and excised skin
malignancy – except for palliative care
● Wounds with necrotic tissue
Cautions
● Wounds with visible fistula
● Wounds with exposed bone or tendon
● Clotting disorder (risk of bleeding)
● Compromised micro-vascular blood
flow to wound
Source: European Wound Management
Association (2007)
» Exposed tissues such as tendon or bone
are not damaged;
» Dressing materials are not left to
embed into granulation tissue;
» Drains do not cause pressure damage;
» Patients and staff are familiar with the
functionality of the pump;
» Foam/gauze does not come into contact
with intact skin;
» Intact skin is lined with film dressing if
foam needs to extend onto it, for
example with small wounds or when
bridging more than one wound;
» When more than one piece of foam or
gauze are used no gaps are left between
the pieces;
» An airtight seal is created using film
dressing (Chariker et al, 1989) – this
may require adhesive gel provided by
the manufacturer or stoma paste to
help facilitate a seal in awkward areas
of the body (Fig 1);
» For drains secured on top of the
dressing, if the drain port is larger than
the wound, it must not extend beyond
the dressing margin onto skin, to
prevent pressure damage.
The use of a low-adherent liner dressing
became standard practice when using
foam because it prevented the foam
adhering to the wound bed. However,
Jones et al (2005) demonstrated that liner
dressings can reduce the level of pressure
delivered to the wound bed. They are
unnecessary unless bowel, tendon or bone
is being protected or dressing adherence
causes painful dressing changes. Care
must be taken to ensure that all liner is
18 Nursing Times 04.09.12 / Vol 108 No 36 / www.nursingtimes.net
removed at dressing change, as there has
been a reported case of liner dressing
growing into the wound and scar tissue
(Tan et al, 2009). Cutting gauze or foam
should be carried out away from the
wound as this can leave fragments in the
wound, which can become embedded in
healing granulation tissue.
Carving foam is a skilled procedure as it
involves creating a shape that fits into the
wound contours. If more than one piece of
foam is used it is important to document
how many so they can be counted out at
dressing change. The wound bed should be
thoroughly examined for flecks of foam or
threads of gauze at dressing change so that
these can be removed.
It is also necessary to secure drains at
the exit point of the dressing to help obtain
a seal and to prevent skin damage due to
pressure at the exit point.
NPWT in community settings
The introduction of NPWT in community
settings means patients with chronic and
complex wounds can be treated at home,
and also facilitates early discharge. The
pathway in Fig 2 is an example of a community provider that purchased 18 NPWT
devices and uses an online ordering system
for the provision of dressings (Knight,
2010). Nine devices are held in locations
throughout the organisation across the
integrated care team (ICT) bases. These
teams include community nurses, community assessment team and community
matrons as well as other therapy and
liaison nurses based within the local acute
hospital. Nine devices are stored in the
tissue viability centre for the initiation of
therapy as required in the community.
The pathway was designed to ensure
that patients with NPWT initiated in hospital can be discharged home and receive
equitable care. However, it is extremely
important that any potential risks or
hazards are identified for patients
Fig 1. Stoma paste around wound edge
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Innovation
FIG 2. COMMUNITY NPWT PATHWAY
Referral from ward to ICT team via liaison/discharge team
Discharge team/liaison inform patient that the device will be changed in
the community
Discharge team/liaison send referral to local ICT and copy to tissue viability
team
ICT arrange date and time for changeover of hospital rental device at
patient’s home within three days of discharge
ICT takes out device with appropriate dressings. Wound and risk
assessment completed; any risk or potential risk documented and
appropriate action taken. Patient/carer given written information and
contact numbers
Hospital device cleaned and returned immediately after changeover
Each time a device is used details are entered on a NPWT spreadsheet on a
shared drive to track and monitor the device
ICT contacts tissue viability for joint visit and to agree the care plan.
Timescales for review documented in the care plan depending on patient
needs. Decision to stop therapy agreed with tissue viability team, ICT or
responsible medical practitioner where appropriate
Owned device and accessories cleaned and returned to ICT base. The ICT
team is responsible for maintaining devices and ensuring accessories/leads
are returned
receiving therapy at home including clinical suitability for NPWT (European
Wound Management Association, 2007).
The risk of accidents and misuse can be
reduced by ensuring the following points
are considered:
» Community staff delivering NPWT are
trained by the tissue viability team in
partnership with the appropriate
manufacturer;
» Staff are familiar with local guidance
and have been assessed by the tissue
viability team as competent to carry out
a wound assessment;
» Staff are aware of local infection
prevention guidelines, wear protective
gloves and aprons when changing the
dressing or canister, and clean the
equipment appropriately;
» Patients receive an information leaflet
and contact details for reporting faults
or clinical issues;
» Equipment is maintained and
serviced according to manufacturers’
guidance;
» The device can be plugged in to an
electricity supply where necessary,
without the use of extension leads to
avoid causing a trip hazard;
» Patients are advised to be careful if they
have animals or small children as
unpredictable behaviour may lead to
accidents.
Conclusion
NPWT is a useful and effective wound
treatment that can be applied in both
the community and hospital setting. Collaborative working between acute and primary care can ensure a seamless care
pathway for patients who will benefit from
this therapy. However, there are risks associated with NPWT, not all of which have
been fully explored in this article, that need
to be considered before using it. The range
of devices available today means NPWT can
be accessible to patients in any setting. NT
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