Anesthesia Student Survival Guide
Jesse Ehrenfeld, Richard Urman, and Scott Segal, editors
© 2010 Springer Science and Business Media
CASE STUDY
Chapter 26: Perioperative Acute and Chronic Pain Management
A 32 year-old woman seeks consultation with you in the pain management clinic. Six
months ago she sprained her left elbow and wrist in a fall while roller blading. After
recovering uneventfully with splinting of her wrist and wearing a sling for four
weeks, she has developed severe pain again. She describes it as burning and
constant. She describes tingling, “electric shock” sensations over the affected area. It
covers the dorsum of her hand, both sides of her forearm, and the posterior aspect of
the elbow and lower arm. She notes that she cannot type with her left hand and that
she cannot lift her backpack with her left arm. She finds showering painful and
keeps the arm out of the water; she avoids long-sleeved shirts because the fabric
rubbing against her skin is painful. On examination the limb is purplish and
mottled, edematous, and cool to the touch. There is less hair than on comparable
regions of her right arm. The nails of her left hand are thickened, discolored, and
longer than those on her right. Lightly stroking the dorsum of her hand with a
fingertip causes pain.
You perform the initial evaluation with your attending. You are asked to dictate the note
describing the patient’s pain presentation. Which of the four main types of pain will you
characterize hers as?
The four main categories of pain are nociceptive, inflammatory, neuropathic, and
dysfunctional. This patient’s acute injury has long passed, so her pain is probably not
nociceptive or inflammatory, and is likely neuropathic. The characteristics of the pain as
well (type, pain descriptors) are also consistent with this classification. It is important
not to characterize it as dysfunctional until other types have been excluded.
Which pain descriptors will you use to describe her symptoms?
The patient’s pain can be described in her own terms (burning), and the location,
intensity, and variation in the pain should be noted. For example, behavioral choices
she makes (showering, dressing) should be noted. You will also ask her about variation
during the day, effect of analgesics, document the duration of her symptoms and the
relationship to her injury. This patient has described allodynia, pain elicited by a
normally nonpainful stimulus, and dysesthesia and paresthesia, abnormal sensations
occurring spontaneously or in response to stimulation. You have verified allodynia on
your exam (stroking her hand) but have not demonstrated hyperalgesia, an exaggerated
perception of pain in response to a normally painful stimulus, because you wisely did
not attempt a painful stimulus.
Anesthesia Student Survival Guide
Jesse Ehrenfeld, Richard Urman, and Scott Segal, editors
© 2010 Springer Science and Business Media
What is your working diagnosis? How could you verify it?
The patient appears to have complex regional pain syndrome, type I, formerly known
as reflex sympathetic dystrophy. We base this diagnosis on the pattern of her pain and
its relationship to her injury: it followed local trauma without nerve damage (which
might have made it type II, formerly causalgia), she has cutanous evidence of
sympathetic excess and disuse atrophy, and she has allodynia. She thus meets the
International Association for the Study of Pain’s criteria for the diagnosis, which are
sensitive but not specific for the disorder. Although not considered definitive, a
strongly suggestive diagnostic test is a favorable response to sympathetic blockade of
the affected extremity. You could perform a localized chemical sympathectomy of the
limb by infusing phentolamine into the arm isolated by a tourniquet. More commonly,
you could block the stellate ganglion on the affected side (see below). If evidence of
sympathectomy is seen, for example by vasodilation and warming of the extremity, and
if some pain relief is observed, the diagnosis is strongly supported.
What treatment would you offer her?
A stellate ganglion block is performed by injecting local anesthetic adjacent to the
transverse process of C6, palpated medial to the carotid artery at the level of the cricoid
cartilage in the neck. Fluoroscopic guidance can improve the efficacy and possibly
safety of the block. The spinal and epidural spaces lie close to the correct needle
position, as do the carotid and vertebral arteries. If a stellate ganglion block is effective,
the block can be repeated several times over the next few weeks. In a fortunate
proportion of patients, the pain relief lasts far longer than the effect of the local
anesthetic, and may actually lengthen over time. Unfortunately, some patients do not
experience progressively longer relief or even relief extending longer than the block,
and other treatments will be needed. Multimodal therapy is recommended whether
blocks are successful or not. First, the patient needs psychological counseling that her
symptoms are not the result of direct tissue damage, and that she can and must begin to
use the extremity more as analgesia allows. Physical therapy taking advantage of less
painful periods is essential. Anxiety, depression, and sleep disorders should be
addressed by counseling and likely medication. Other medications that may be helpful
include those directed at neuropathic pain (such as antiepilepsy or antidepression
drugs), opioids, and NSAIDs. The condition can be difficult to treat, so if one therapy
fails, a different one should be tried, in order to facilitate rehabilitation efforts.