Page 310 Guide to Pain Management in Low-Resource Settings

298 Steven D. Waldman

follows: Th e aorta lies anterior and slightly to the left of • Do analyze the information obtained from diag-
the anterior margin of the vertebral body. Th e inferior nostic nerve blocks in the context of the patient’s
vena cava lies to the right, with the kidneys posterolat- history, physical, laboratory, neurophysiological,
eral to the great vessels. Th e pancreas lies anterior to and radiographic testing.
the celiac plexus. All of these structures lie within the • Don’t over-rely on information obtained from di-
retroperitoneal space. Selective blockade of the celiac agnostic nerve blocks.
plexus can provide the pain management specialist with • Do view discordant or contradictory informa-
useful information when trying to determine the cause tion obtained from diagnostic nerve blocks with
of chest wall, fl ank, and/or abdominal pain. By block- skepticism.
ing the intercostal nerves and celiac plexus on succes- • Don’t rely on information obtained from diagnos-
tic nerve block as the sole justifi cation to proceed
sive visits, the pain management specialist may be able
with invasive treatments.
to diff erentiate which nerves are subserving the patient’s
• Do consider the possibility of technical limita-
pain.
tions that reduce the ability to perform an accu-
Selective nerve root block rate diagnostic nerve block.
• Do consider the possibility of patient anatomical
Improvements in fl uoroscopy and needle technology
variations that may infl uence the results of diag-
have led to increased interest in selective nerve root notic nerve blocks.
block in the diagnosis of cervical and lumbar radicular • Do consider the presence of incidence pain when
pain. Although selective nerve block is technically de- analyzing the results of diagnostic nerve blocks.
manding and requires resources that may not be avail- • Don’t perform diagnostic nerve blocks in patients
able in many settings, the technique may help identify who are not currently having the pain you are
the reason behind the patient’s pain complaint. Th e use trying to diagnose.
of selective nerve root block as a diagnostic or prognos- • Do consider behavioral factors that may infl uence
tic maneuver must be approached with caution because, the results of diagnostic nerve blocks.
due to the proximity of the epidural, subdural, and sub- • Do consider that patients may premedicate them-
arachnoid spaces, it is very easy to inadvertently place selves prior to diagnostic nerve blocks.
local anesthetic into these spaces when intending to
block a single cervical or lumbar nerve root. Th is error
References
is not always readily apparent on fl uoroscopy, given the
small amounts of local anesthetic and contrast medium [1] Dawson DM. Carpal tunnel syndrome. In: Entrapment neuropathies,
used. 3rd ed. Philadelphia. Lippincott-Raven; 1990. P. 53.
[2] Griffi th HR, Johnson E. Th e use of curare in general anesthesia. Anes-
thesiology 1942;3:418–20.
[3] Pitkin G. Controllable spinal anesthesia. Am J Surgery 1928;5:537.
Pearls [4] Waldman SD. Greater and lesser occipital nerve block. In: Atlas of in-
terventional pain management, 2nd ed. Philadelphia: Saunders; 2004. p.
23.
• Th e use of nerve blocks as part of the evaluation [5] Waldman SD. Stellate ganglion block. In: Atlas of interventional pain
of the patient in pain represents a reasonable next management, 2nd ed. Philadelphia: Saunders; 2004. p. 104.
[6] Waldman SD. Cervical facet block. In: Atlas of interventional pain man-
step if a careful targeted history and physical ex- agement, 2nd ed. Philadelphia: Saunders; 2004. p. 125.
[7] Waldman SD Intercostal nerve block. In: Atlas of interventional pain
amination and available radiographic, neurophys- management, 2nd ed. Philadelphia: Saunders; 2004. p. 241
iological, and laboratory testing fail to provide a [8] Waldman SD. Celiac plexus block. In: In: Atlas of interventional pain
management, 2nd ed. Philadelphia: Saunders; 2004. p. 265.
clear diagnosis. [9] Winnie AP, Collins VJ. Th e pain clinic. I: Diff erential neural block-
• Th e overreliance on a prognostic nerve block as ade in pain syndromes of questionable etiology. Med Clin North Am
1968;52:123–9.
the sole justifi cation to perform an invasive or
neurodestructive procedure can lead to signifi -
cant patient morbidity and dissatisfaction.