52
WOUND CARE TODAY
2014,Vol 1, No 1
FOCUS ON WOUND INFECTION
›
be the only sign of infection that is
displayed (Patel, 2008).
There are also signs and
symptoms of wound infection that
may be attributed to a cause, other
than wound infection (
Table 3
).
COMMON INVESTIGATIONS
FOR WOUND INFECTION
Wound swabbing is the most
frequently and easily used method of
confirming the causative organism
of wound infection, and can assist
in accurately identifying possible
antibiotic sensitivities. However,
if used indiscriminately, it can be
costly. The accuracy of a wound swab
result has also been questioned, as
it may only detect surface bacteria
that has colonised the wound and
not deep-seated bacteria within
the wound bed (WUWHS, 2008). A
technique that has been suggested
to assist in a more robust collection
of wound swabbing is the Levine
technique:
›
The wound is cleaned first to
remove surface bacteria
›
A swab is rotated over the
wound bed with sufficient
pressure to express fluid
from below the surface of
the wound (WUWHS, 2008)
›
Accurate and relevant
information should
be provided on the
microbiology form, including
wound type, site and any
antibiotic therapy that the
patient is receiving. This
assists the microbiologist
in determining the most
likely pathogen causing the
infection (Bowler et al, 2001).
Blood tests that may reveal
an elevated white cell count and
elevated serum reactive protein
Did you know:
that wound infection is
usually identified by clinical
observation, as subtle
changes to the inflammatory
response can be observed
over time by constant and
repeated observation.
Table 1:
Risk factors associated with wound infection
(adapted from Wounds UK, 2009)
Risk factor
Examples and rationale for risk factor
Comorbidities that may
reduce oxygen perfusion
(cardiovascular or
respiratory disorders)
›
May reduce wound oxygen tension resulting in an environment that
promotes bacterial growth (Sibbald et al, 2007)
Metabolic disorders such
as diabetes that may impair
the immune response
›
Reduces neutrophil activity which can interfere with the ingestion of
bacteria, increasing the risk of infection (Slaughter, 1993)
Malnutrition
›
Inadequate nutrition and poor nutritional status can lead to a poor
immune response (Dealey, 2005)
Medication
›
Some medications, such as corticosteroids, cytotoxic therapy and
immunosupressants, may interfere with the immune response
and reduce neutrophil activity
Age
›
Changes that come with age may affect the immune response and ability
of a wound to heal (Wilson, 2006)
Psychological factors
›
These may lead to an unhealthy lifestyle, such as smoking, poor diet,
poor personal hygiene
Wound characteristics, such
as size, location and tissue
type present
›
Chronic wounds are more at risk of infection due to the longer exposure
of multiple organisms
›
Wounds around the anal area are more at risk of contamination
›
Necrotic and sloughy tissue provide a medium for bacterial growth
(Sibbald et al, 2007)
Type of wound
›
For example, a surgical wound that arises from long and/or
contaminated surgery
Several clinicians have
sought to validate which signs
and symptoms of wound
infection are most accurate,
in an attempt to develop
assessment criteria or tools to
provide a consistent approach
to identifying wound infection
(Cutting and Harding, 1994;
Wilson et al, 1986; Gardner et
al, 2001; EWMA, 2005). There
are signs and symptoms of
infection that are common to
all wound types, as well as ones that
are specific to chronic wounds (
Table
2
). In patients who display two or
more, clinicians should suspect that
wound infection is present (Sibbald
et al, 2007).
A patient with spreading
systemic infection may show signs
and symptoms such as spreading
erythema, lymphangitis, crepitus,
wound breakdown/dehiscence,
malaise and pyrexia. These patients
require immediate specialist referral
and fast intervention and treatment
to avoid potentially serious
complications, such as loss of limb
or death.
Certain signs and symptoms may
be difficult to identify in particular
circumstances. For example, odour
is a subjective measurement and
may not be accurately detected by
the clinician (Gardner et al, 2001).
Pain may also be difficult to assess
in patients with neuropathy or
altered sensation, such as those
with diabetes (
Figure 2
). This should
be considered within the holistic
assessment. Patients that have
an altered immune response, or
patients with diabetes mellitus,
may also not display obvious signs
of infection. For these patients,
clinicians should maintain extra
vigilance, as delayed healing may
Figure 2.
Diabetic neuropathy is a risk factor for
wound infection.
