Interventional Chronic Pain Treatment in Mature Theaters of Operation
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28. INTERVENTIONAL CHRONIC PAIN pain, nonradicular arm pain, groin pain, noncardiac spinal and myofascial pain); and anticonvulsants TREATMENT IN MATURE THEATERS chest pain, and neck pain. The most common diag- and tricyclic antidepressants (usually prescribed for OF OPERATION noses conferred on these patients were lumbosacral radicular and other forms of neuropathic pain). The radiculopathy, recurrence of postsurgical pain, large majority of patients received at least one inter- IMPACT OF NONBATTLE-RELATED INJURIES lumbar facetogenic pain, myofascial pain, neuro- ventional procedure. The most frequently employed AND TREATMENT pathic pain, and lumbar degenerative disc disease. nerve blocks were lumbar transforaminal epidural The most common noninterventional treatments steroid injections (ESIs), trigger point injections, Acute nonbattle injuries (NBIs) and chronic pain have been nonsteroidal antiinflammatory drugs cervical ESIs, lumbar facet blocks, various groin conditions that recur during war have been termed (NSAIDs; > 90%); physical therapy referral (for back blocks, and plantar fascia injections. Table 28-1 lists the “hidden epidemic” by the former surgeon pain, neck pain, and leg pain); muscle relaxants (for procedures for common nerve blocks conducted in general of the US Army, James Peake. Since statistics have been kept, the impact of NBIs on unit readiness TABLE 28-1 has increased. In World War I, NBI was the fourth leading cause of soldier attrition. In World War II PROCEDURES FOR COMMON NERVE BLOCKS CONDUCTED IN THEATER and the Korean conflict, NBIs were the third leading cause of morbidity. By the Vietnam War, NBIs had Injection Injectate Need for Comments become the leading cause of hospital admissions, Volume* (mL) Fluoroscopy? where they have remained ever since. However, increasing evidence demonstrates that in-theater Cervical ESI 2–4 Yes Use of local anesthetic controversial. Cervical TFESI may management of NBIs and recurrent chronic pain result in death or paraplegia and should not be done in austere environment. syndromes can improve return-to-duty rates. The current system of military treatment levels, Interlaminar lumbar ESI 3–5 Strongly Performing blind ESI associated with a high likelihood of advised injectate failing to reach targeted area. designed to facilitate the rapid evacuation of wounded soldiers based on their medical condi- Transforaminal lumbar 2–3 Yes Superior outcomes compared to interlaminar ESI. tion and needs, was developed in World War ESI II—predating the establishment of pain management Intraarticular facet blocks Cervical: 1 Yes Likelihood of relief higher in patients with acute as a medical specialty. No personnel are currently Lumbar: 1–2 inflammatory process. deployed specifically for pain management (acute or Trochanteric bursa 3–5 No Similar outcomes for fluoroscopically and landmark- chronic) at level-III combat support hospital (CSH) injection guided injections. facilities in either Iraq or Afghanistan. Instead, anes- Sacroiliac joint block 2–4 Yes < 25% chance of intraarticular spread in landmark-guided thesiologists and other pain specialists are deployed injections. in their primary specialties and are expected to Lateral epicondylar 0.5–1.5 No Mixed results for treatment. provide pain management services as needed in ad- injection dition to their regular full-time duties. This situation Subacromial bursa 4–10 Advised May use posterior or anterolateral approach; 50%–80% has resulted in a varying standard of pain manage- injection accuracy rate for blinded injections. ment care in theaters of operation. The modern CSH has key infrastructure such as radiology services (eg, Piriformis muscle 3–8 Yes May use nerve stimulator to locate sciatic nerve (adjacent injection to muscle) if fluoroscopy is not available. Injection of local fluoroscopy, radiography, computed tomography) anesthetic may cause sciatic nerve weakness. and full surgical, laboratory, and pharmacy support, which can facilitate chronic pain clinical services if Carpal tunnel injection 1–2 No Not superior to NSAID treatment after 2 months. properly staffed. Greater occipital nerve 2–4 No Difficult to clinically distinguish from referred cervical The most common presenting complaints of NBI injection pain. during Operation Iraqi Freedom have been radicular ESI: epidural steroid injection. NSAID: nonsteroidal antiinflammatory drug. TFESI: transforaminal epidural steroid injection. leg pain, axial low back pain (LBP), nonradicular leg *Volume of injectate consists of 1 to 2 mL of depot (long-acting) corticosteroid plus local anesthetic. 107 28 INTERVENTIONAL CHRONIC PAIN TREATMENT IN MATURE THEATERS OF OPERATION theater. Significantly, when treated in theater, 94.7% A mainstay interventional treatment for LBP Zygapophyseal Joint Pain. Lumbar zygapophyseal of soldiers returned to their units. Differences in is ESI. ESIs exert their beneficial effects through (facet) joint pain accounts for approximately 15% of return-to-duty rates support aggressive pain man- their antiinflammatory properties, inhibition of patients with chronic axial LBP. Typical presentation is agement in forward-deployed areas. the enzyme phospholipase A2, and suppression of a dull aching pain, usually bilateral, that radiates from ectopic discharges from injured neurons. Although the low back into the buttocks and thigh. Although TRIAGING PATIENTS FOR TREATMENT ESIs have been successfully used to treat axial back the history and physical examination can be sugges- As a result of limited pain management pain, ideal candidates for the procedure are those tive of facet joint pain, an analgesic response to fluo- resources, coupled with the risk involved with with pain of less than 6 months’ duration, leg pain roscopically guided low-volume diagnostic blocks, soldier transport, healthcare providers must triage greater than back pain, young age, intermittent of either the zygapophyseal joints themselves or the NBI pain patients based on the anticipated risk– pain, and absence of concomitant spinal stenosis. medial branches that innervate them, is the gold stan- benefit ratio. Soldiers with acute or recurrent The use of fluoroscopic guidance is highly recom- dard for diagnosis. The interventional treatment of overuse injuries (eg, tendonitis or bursitis) can mended for interlaminar ESIs and is required for facetogenic pain consists of either intraarticular injec- usually be handled at a level I facility such as a transforaminal ESIs. ESIs performed without the tions with corticosteroid, which may benefit a small battalion aid station. For soldiers who require more fluoroscope have a high technical failure rate, even percentage of patients with an acute inflammatory sophisticated interventions, the battalion or brigade when performed by experienced practitioners. component, or more frequently radiofrequency dener- surgeon must decide whether a medical evacuation Transforaminal ESIs, although technically more vation of the nerves that innervate the painful joints. to a CSH is warranted. This decision is based upon challenging than interlaminar ESIs, are generally Because of the lack of radiofrequency capability, com- several factors: the likelihood of quick resolution of associated with superior outcomes because medica- bination diagnostic/therapeutic intraarticular facet the pain issue, the soldier’s motivation to remain in tion is deposited directly over the affected nerve injections are recommended in theater. In patients theater, the soldier’s military occupational specialty, root (Figure 28-1). with radiological evidence of an acute inflammatory the probability of recurrence, the commander’s Patients suspected of radicular pain should process, intraarticular corticosteroids may afford up to desire to keep the soldier in theater, the treatment receive computed tomography (CT) scans of the 3 months of excellent pain relief (Figure 28-2). capabilities at the CSH, and the risk of medical appropriate spine evacuation. level. Whereas magnetic resonance Figure 28-1. Lateral fluoroscopic view demonstrat- Figure 28-2. Antero-posterior fluoroscopic view CHRONIC PAIN CONDITIONS ENCOUNTERED imagery (MRI) is the ing needle position for L4-5 transforaminal epidural demonstrating needle position for bilateral L3 and steroid injection. L4 facet joint (medial branch) nerve blocks. IN THE FIELD gold standard for imaging soft tissue Low Back Pain. LBP is the most common complaint and disc anatomy, CT likely to be encountered by the pain practitioner scans are sensitive deployed to the CSH. Its high incidence is probably at determining caused by a combination of factors encountered the presence of in theater: the heavy loads service members must disc pathology. carry, frequent transportation over rough terrain in Although ESIs are military vehicles with stiff suspensions, heavy indi- considered by many vidual body armor, sleep deprivation, and the high practitioners to be the degree of psychosocial stressors faced by soldiers best interventional deployed to combat zones. Among the various therapy for radicular causes of LBP, radiculopathy from nerve root ir- pain, controversy ritation may be the most commonly encountered exists regarding their condition. long-term efficacy. 108 INTERVENTIONAL CHRONIC PAIN TREATMENT IN MATURE THEATERS OF OPERATION 28 Sacroiliac Joint Pain. Sacroiliac (SI) joint pain is a 28 frequent source of axial LBP, accounting for roughly 15%to 20% of cases. Compared to other causes of back pain, SI joint pain is more likely to result from