Page 265 Guide to Pain Management in Low-Resource Settings

Complex Regional Pain Syndrome 253

and opioids (controlled-release) can be prescribed. Th e particular setting and meets the standards of a com-
most important adjuvants for the treatment of neuro- munity or primary care level. Th e application of nerve
pathic pain are tricyclic antidepressants (amitriptyline) block techniques should be reserved for specialized pain
and anticonvulsive drugs (gabapentin). After taking into management centers (“referral hospital level”). Th e ad-
consideration their possible contraindications and their vantage of treatment in specialized pain management
anticholinergic eff ects, the physician should increase centers is, besides the reliability of making the diagnosis
the dose slowly. Furthermore, the dose should be high of CRPS and the use of sympathetic blocks, the greater
enough before its effi cacy is evaluated. Th e dose of ami- experience in dosing the physical and the occupational
triptyline should be initially 25 mg in the evening (alter- treatment—fi nally, it is perhaps the most essential issue
natively 10 mg). Th e dose can be increased every seven for the function recovery of the aff ected extremity.
days in 25-mg steps up to a maximal dose of 75 mg. Th e
starting dose of gabapentin is 3 × 100 mg, and the dose What are today’s insights about
should be increased in 300-mg steps every three days. the pathophysiology of CRPS?
A dose of at least 1800 mg/d should be achieved. Espe-
cially in cases of arthrogenic pain (particularly during Currently, there is no global pathophysiological concept
physical examination), oral glucocorticoids are indicat- that explains all the symptoms in CRPS. Th ere are sev-
ed (prednisolone in decreasing doses of 90/60/30/10/5 eral possible explanations. Next to hints for a genetic
mg for 14 days). predisposition, infl ammation seems to play an impor-
Invasive therapies: Th e sympathetic nervous tant role. In the context of a neurogenic infl ammation,
system can be blocked either by unilateral anesthetic C fi bers and some receptors may release neuropeptides,
blockades of the lower cervical sympathetic ganglion inducing clinical signs such as vasodilatation and ede-
(stellate ganglion) (10–15 mL bupivacaine 0,5%) or by ma. Additionally, experts are discussing the concept of a
blocks of the lumbar or thoracic sympathetic chain (5 disease of the central nervous system, in which changes
mL bupivacaine 0.5%). Intravenous regional anesthe- of the aff erent neurons, such as pathological connec-
sia blocks are seldom performed because of poor eff ect tions with the sympathetic nervous system, may cause
and painful procedures. Th e indication for a sympa- spontaneous and evoked pain. Th e pattern of symptom
thetic block is pain at rest despite immobilization and/ spread resembles that of diseases of the central nervous
or pronounced allodynia. Sympathetic blocks not only system. Th e central nervous dysregulation is assumed
reduce the pain, but can often also improve the motor to result in maladaptation, for example a change in the
and autonomic impairment. However, it is important to ambient temperature induces an inadequate reaction of
prove that the sympatholysis was technically successful skin blood fl ow and sudomotor function. Furthermore,
by noting a signifi cant skin temperature increase in the cortical reorganization processes seem to play an im-
supplying area. portant role, wherein the degree of the reorganization
Nonpharmacological options: As long as pain correlates positively with the spread of the mechanical
at rest prevails, therapy should be restricted to consis- hyperalgesia and the pain, which in turn is reversible us-
tent immobilization of the aff ected extremity in a po- ing the appropriate treatment.
sition higher than the heart, supported by a splint and
by lymphatic drainage. After a distinct decrease of the Pearls of wisdom
pain, physical and occupational therapy come to the
fore. Initially, the proximal joints of the aff ected and the • Th ree important aspects account for the diag-
contralateral extremity should be treated. Especially in nosis of CRPS: pain or functional impairment,
cases of sensory impairment and allodynia, desensitiza- which is disproportionate to the inciting event;
tion exercises are indicated. Th e main treatment prin- hints of sensory, vasomotor, sudomotor, or motor
ciple should start with stimulus adaptation, followed by impairment in the past; and current fi ndings of
exercises aiming at pain-free mobility and improvement sensory, vasomotor, sudomotor, or motor impair-
of fi ne motor skills, and ultimately movements against ment in the clinical examination
strong resistance. • Th e treatment must not induce pain. If a treat-
Th erapy for CRPS, with regard to the use of medi- ment procedure leads to escalation of pain, this
cal and nonmedical treatment, does not require any procedure must be given up. Th e following three