Page 21 - Medicine and Surgery

P1: JYS
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Chapter 1: Perioperative care 17

during pyrexial episodes) and any pus or wound dis- throbbing, ‘slow’ pain, which is conveyed by the larger
charge sent for microscopy and culture. Patients with non-myelinated C fibres. Nociceptive pain is usually
pyrexia and no obvious localising signs or symptoms acute,tendstoresolveastissuehealsandrespondswellto
may require imaging such as ultrasound, CT scanning opioid analgesia (see below). Injury or abnormal func-
or isotope bone scanning to identify the source of infec- tion within the nervous system causes neuropathic pain.
tion. Itisfeltasanareaofburningorashootingpain.Itmaybe
triggered by non-painful stimuli such as light touch, so-
Management
calledallodynia.Examplesofcausesincludepostherpetic
Prophylaxisagainstinfectionincludesmeticuloussur-

neuralgia, peripheral neuropathy, e.g. due to diabetes,
gicaltechniqueandtheuseofprophylacticantibiotics.
and phantom limb pain. Neuropathic pain is often diffi-
Severely contaminated wounds may be closed by de-
culttotreat,partlybecauseofitschronicbutepisodicna-
layed primary suture. Contaminated cavities, such as
ture and it is less responsive to opiates. Most of the time,
theabdomen,requiretheplacementofsurgicaldrains.
pain has both nociceptive and neuropathic components.
Where possible the underlying cause of the infection

should be treated, e.g. removal of infected material,
Benefits of treating pain
closure of anastomotic leaks.
The principal reason for treating pain is to relieve suf-
Superficial surgical site infections may respond to an-

fering. It improves patients’ ability to sleep and their
tibiotics (penicillin and flucloxacillin, depending on
overall emotional health. However, good pain control
local policy). Deeper surgical site infections may re-
can also have other benefits: postoperatively it can im-
quire the removal of one or more skin sutures to al-
prove respiratory function, increase the ability to cough
low drainage of infected material. Abscesses generally
and clear secretions, improve mobility and hence reduce
require drainage either by surgery or radiologically
the risk of complications such as pneumonia and deep
guided aspiration alongside the use of appropriate an-
vein thromboses. This allows a faster recovery.
tibiotics.
Assessing pain
Pain control To diagnose and then treat pain first requires asking the
patients about their pain. Often, if pain is treated aggres-
Many medical and surgical patients experience pain.
sively and early, it is easier to control than when the pa-
Surgery causes tissue damage leading to the release of
tient becomes distressed and exhausted. Patients should
localchemicalmediatorsthatstimulatepainfibres.Inad-
be asked to score their pain on a scale from none to very
ditiondirectdamagetonervescancausepain.Ischaemia,
obstruction, infections, inflammation and joint disease severe (sometimes a 10-point scale is useful, where 0
represents no pain and 10 the worst imaginable pain). In
also cause pain. Cancer is an important cause of pain.
some cases where verbal communication is not possible
Pain may be induced by movement, which is sometimes
or difficult, a visual scale of 1–10 or pictures of faces rep-
unavoidable, e.g. the thorax and abdominal wall when
resenting degrees of pain is useful. They should be asked
breathing. In contrast, immobility can cause pain due to
what precipitates pain, such as movement or breathing,
pressure sores and joint stiffness. In addition, a patient’s
and whether the pain prevents or interrupts sleep. It is
perception of pain is altered by many factors, including
important to establish whether the pain is nociceptive,
the patient’s overall physical and emotional well-being,
neuropathic or both. Often there is more than one pain
cultural background, age, sex and ability to sleep ade-
and these may require separate treatment plans.
quately.Depressionandfearoftenworsentheperception
In a patient who is already taking analgesia, it is use-
of pain.
ful to assess their current use, the effect on pain and any
Types of pain side-effects.Thepatientshouldalsobeaskedabouthisor
Tissue damage causes a nociceptive pain, which can be her beliefs about drugs they have been given before. The
further divided into a sharp, stabbing pain, which is patients should be involved as far as possible in the man-
conveyed by the finely myelinated Aδ fibres, and a dull, agement of their pain. Adverse effects such as nausea