ADVANCING
YOUR PRACTICE
Is
low back pain getting on your nerves?
By Yvonne
D’Arcy, CRNP, CNS, MS
Low back pain is a very
common patient complaint. The back is one of the most
integral structures of the body, providing support for
muscles and tendons while protecting the spinal cord.
Because it’s the foundation of the body's support,
it’s subject to wear and tear from overuse, incorrect
use, disease, the aging process, and obesity. Any of
these can cause deterioration of the vertebral bodies
and disks, resulting in low back pain.
A 2002 study reported that
26% of respondents experienced low back pain during
a 3-month period.1 Nonspecific low back pain
is the fifth most common reason for healthcare provider
visits in the United States.2 It isn’t
only causes pain and suffering for patients, but depletes
healthcare resources. Correspondingly, the costs of
time lost from work and disability reach into the millions
of dollars. Proper treatment of back pain can include
medication, exercise, or even surgery.
Patients at risk
The pain and disability of low back pain are the most
common reasons patients seek healthcare.3
The condition can be caused by a number of factors,
including arthritis, aging, normal wear and tear, degeneration,
arthritic bone spurs, structural damage, or a malignancy.4
Risk factors that predispose patients to low back pain
include the following:
- poor physical condition
without a regular exercise regimen
- age over 55 years
- lifting heavy loads
or engaging in daily hard physical labor
- obesity
- reduced spinal canal
dimensions (spinal stenosis)
- lower socioeconomic
status (less access to healthcare).4-6
Workers who sit at desks
for long periods of time or stand all day may find that
low back pain can be a life-altering condition. Quality
of life is heavily affected by chronic low back pain,
as pain may interfere with the ability to work, sleep,
and maintain relationships.
As the U.S. population
ages, the prevalence of low back pain resulting from
degenerative changes seen in these patients will increase.
There are 89 million baby boomers who are at risk for
degenerative disk disease (DDD).7 A high
prevalence of arthritis will contribute to a large number
of patients with low back pain from facet disease and
bone spurs.
The spine and common
spinal conditions
The spine consists of vertebral bodies and disks. The
vertebrae are divided into three major sections: cervical,
thoracic, and lumbar. There are seven cervical vertebrae,
identified as C1 through C7; 12 thoracic vertebrae,
identified as T1 through T12; and five lumbar vertebrae,
identified as L1 through L5.
Below the lumbar vertebrae
are the sacrum, consisting of five fused vertebrae,
and the coccyx with four fused vertebrae.8
The spine has normal curvatures at the cervical and
lumbar area. Proper posture maintains spinal alignment
and can decrease the possibility of low back pain. The
vertebral body has a central canal for the spinal cord
and transverse processes where the spinal nerve roots
are located.
Each vertebra has a vertebral
body that’s separated from the adjacent vertebra
by a soft, fluid-filled gelatinous disk.8
This disk acts as a cushion for mechanical stress and
gives the spine its flexibility. It also maintains support
and posture. Each disk is surrounded by a fibrous envelope,
known as the annulus, that consists of 12 concentric
layers of fibrous tissue. This tissue helps secure the
disk in place.
The aging process has an
acute effect on these disks. By age 20, the vascularity
of each disk decreases, and by age 30, the desiccation
of the disk can cause fissures in the vertebral body
endplates. This leads to DDD, which isn’t so much
a disease, but part of the aging process.7
As degenerative changes take place and each disk becomes
less supple, compression can cause the disk to rupture
through the annulus, resulting in a herniated disk.
This can be extremely painful since the nerve root can
be impinged leading to radiculopathy.6 Patients
with DDD develop vertebral osteophytes; this condition
is called spondylosis.7 The disk becomes
flatter, cracks develop, and the vertebra develop roughened
edges where osteophytes (bone spur type formations)
form. It can also affect the facets of the spine and
develop into facet disease.
Two other spinal conditions
can cause low back pain. Spondylolysis is a defect in
the vertebral arch caused by mechanical stress. This
injury is found in children who participate in gymnastics
and other sports, such as wrestling or football, where
hyperextension of the spinal body is possible.7
The damage in the posterior part of the vertebra causes
the vertebral body to become malpositioned, generally
in the lumbar spine. Because of the malpositioning,
the patient will present with constant low back pain—there
may also be motor or sensory loss at L4-5 and S1. Spondylolisthesis
is a subluxation of the lumbar vertebrae where one vertebra
overrides the lower vertebra. It can present with severe
pain and radicular symptoms, bowel or bladder dysfunction,
and weakness in the lower extremities.
Older patients with osteoporosis
may experience vertebral compression fractures. These
compression fractures are extremely painful as the nerve
root of the vertebral body is compressed. Osteoporosis
causes the vertebral bone to become porous and prone
to fracture. Older patients also experience desiccation
of the vertebral disks, which destroys the cushioning
function.
It’s estimated that
95% of the population will have DDD by age 50.7 Patients
with DDD present with deep midline low back pain that
can radiate to buttocks or thighs. There may be motor
weakness, sensory changes, absent or diminished reflexes,
and, in more severe cases, bowel or bladder dysfunction.8
Patients with spinal stenosis and herniated disks account
for 3% to 4% of low back pain patients; cancer, 0.7%;
and compression fractures, 4%.2
Diagnosing low
back pain
The American College of Physicians and the American
Pain Society have developed a joint guideline for diagnosing
and treating low back pain.2 The first guideline
recommendation requires a complete focused history and
physical exam. A focused history and physical exam can
indicate the frequency of symptoms, location and duration
of the pain, history of the pain, and prior treatment.
Information about any concurrent infection or neurologic
symptoms such as numbness or muscle weakness should
also be investigated.
The physical exam should
include the straight leg raise to determine if a disk
is herniated. Since most herniated disks occur in the
lumbar spine, this diagnostic tool, along with a neurologic
exam that includes great toe and foot dorsiflexion,
plantar dorsiflexion, and ankle reflexes, can identify
the area of pain. Practitioners should look for the
patient to experience pain when the leg is at a 30 to
70 degree increase, as that range affects the nerve
roots.2
This information can be
used to categorize patients in one of the following
groups: nonspecific low back pain, back pain potentially
associated with radiculopathy or spinal stenosis, or
back pain potentially associated with another spinal
cause.2 Practitioners should also assess
for psychosocial risk factors (for example, depression,
lack of coping skills, anxiety disorder, and substance
abuse disorder) that could predict the risk for chronic
disabling back pain. This assessment is more predictive
of the outcome of treatment than the physical exam or
the pain severity or duration.
The second recommendation
states that clinicians should try to avoid imaging or
other diagnostic tests in patients with nonspecific
low back pain.2 Rationale for this recommendation
includes the exposure of patients to unnecessary radiation
in the lumbar and lower abdominal area of the body.
The use of plain radiography and advanced imaging with
computerized tomography (CT) or magnetic resonance imaging
(MRI) have not been associated with improved patient
outcomes. For the majority of patients with nonspecific
back pain, the use of imaging creates increased exposure
to radiation, increased cost of treatment, and does
not positively affect treatment outcome.
The third recommendation
indicates instances where imaging should be used.2
Patients who have severe or progressive neurologic deficits
or those in which serious underlying conditions are
suspected should have diagnostic imaging and testing.
Conditions that merit immediate imaging include cancer
with suspected cord compression, vertebral infection,
and cauda equina syndrome. MRI is preferred over CT
because it allows better visualization of the spinal
structures. MRI can detect annular tears and disk fragments,
and is helpful in identifying cancer and infection.
The fourth recommendation
states that those who present with persistent low back
pain and signs and symptoms of radiculopathy or suspected
spinal stenosis should be evaluated using an MRI, the
preferred imaging study, or CT only if the patient is
a candidate for surgery or epidural steroid injection.2
In addition to diagnosing
the physical injury, practitioners should be aware that
depression is common in patients with chronic pain,
and the rate of suicide in patients with chronic pain
is twice the rate of patients without pain.9
Practitioners should assess patients' moods at each
visit, and explain to them that depression is not uncommon
for those with chronic pain.
Pharmacologic treatment
options
Acute low back pain generally resolves within 6 to 12
weeks, regardless of treatment.10 The 15%
of patients with acute low back pain who don’t
improve within that time period are considered to have
chronic low back pain.3 Treatment approaches
differ, depending on the severity of back pain.
Medications are the first
line of pain management for most patients, but the challenge
is: Which medication and for how long? In a recent study,
80% of primary care patients who complained of low back
pain were prescribed at least one medication at the
initial office visit; more than one-third were prescribed
two or more.11
- Acetaminophen.
One of the most common medications patients use at
home and that’s recommended by clinicians is
acetaminophen. It has minimal risk when taken in dosages
lower than the recommended adult maximum dose of 4,000
mg/day. Doses of 4,000 mg/day can result in asymptomatic
elevations of liver function tests even in healthy
adults, but the risk profile to these increases has
not been clearly identified.11 Even though
acetaminophen is less effective than nonsteroidal
anti-inflammatory drugs (NSAIDs), it’s still
worth considering as a firstline option because of
its low cost and low risk profile.
- NSAIDs.
There are two different types of NSAIDs: NSAIDs that
affect both COX 1 and COX 2 prostaglandin production
and COX 2 medication that’s COX 2 selective
and doesn;t affect the COX 1 prostaglandins that protect
the stomach lining. The COX 2 medications are prescription-only,
but nonselective NSAIDs are available over the counter.
The risk-benefit profile
is a concern when using NSAIDs to treat low back pain.
Both types of NSAIDs can increase cardiovascular risks
and renovascular events. Nonselective NSAIDs have an
increased risk of ulceration and gastrointestinal (GI)
bleeding (using aspirin with NSAIDs can increase the
risk for GI bleeding).5 NSAIDs should be
prescribed at the lowest dose for the shortest period
of time.2
- Opioid analgesics.
The third recommendation for medication is an opioid
analgesic or tramadol. These medications should be
prescribed for patients who have failed to obtain
relief with acetaminophen or NSAIDs. Pain should be
severe or disabling before opioids are considered
for treatment.3 In the short term, they
may be efficacious, but long-term benefit is less
clear.12 The incidence of substance abuse
is high, with a finding of aberrant medication disorder
occurring in up to 24% of patients.12 In
a study of 800 patients treated in primary care practices
for chronic pain and prescribed opioids, the addiction
rate was about 4% for patients who had been exposed
to opioids or had a history of substance abuse.13
Another unfortunate occurrence
is the development of opioid-induced hyperalgesia. This
condition is an atypical hyperalgesic state where pain
severity is increased dramatically unrelated to the
original pain stimulus.14 The syndrome is
thought to be caused by long-term use of opioids that
create pain generation in the central nervous system
and no longer require nociceptive input to create pain.
- Other medications.
Other medications can be used alone or in conjunction
with primary pain management regimens. These include
antidepressants, antiseizure medications, muscle relaxants,
benzodiazepines, and steroids.
Nonpharmacologic
interventions
When patients don’t show improvement with standard
treatment, evidence-based nonpharmacologic therapies
should be added to the medication regimen. Acute low
back pain, which has been present for less than 4 weeks,
may benefit from spinal manipulation or superficial
heat. Exercise therapy, both supervised and at-home
regimens, hasn’t proved effective for acute low
back pain.2
Subacute low back pain,
which has persisted between 4 and 8 weeks,
may benefit from interdisciplinary rehabilitation that
includes a physician, NP, and nurses; physical therapy;
psychological, social, and vocational intervention;
or cognitive behavioral therapy. Chronic low back may
benefit from acupuncture; exercise prescribed by a physical
therapist, massage, or yoga; progressive relaxation
in which the patient relaxes various areas of the body,
from head to toe in sequence; spinal manipulation; and
interdisciplinary rehabilitation that uses many different
disciplines such as nursing, medical, physical therapy,
psychology, etc.2, 15-17
Surgical options for treating
vertebral fractures include vertebroplasty, which repairs
and strengthens the vertebra; and kyphoplasty, which
repairs the vertebra and corrects the curvature of the
spine. In a review of vertebroplasty and kyphoplasty,
85% of the patients who underwent vertebroplasty and
92% of patients who underwent kyphoplasty reported good
pain relief with the procedure.18
There’s conflicting
and insufficient evidence related to the use of epidural
or other injections for relieving low back pain.19
Prolotherapy, the injection of irritant solutions into
weakened back muscles, doesn’t have evidence to
support its use alone; however, when added to a comprehensive
regimen of rehabilitation, the injections were more
effective than control injections.20
Educating patients
Discuss medication options with patients carefully.
Many patients with chronic pain rely only on medication
to manage pain. It’s important to see medication
as a part of the treatment regimen rather than the only
option. All patients with chronic low back pain should
be encouraged to use a multimodal approach to managing
their condition.
In the acute phase, remaining
active, using heat, and medication, such as acetaminophen
and NSAIDs, will produce the best outcome. If the pain
persists, a rehabilitation program and relaxation can
provide benefit.
For chronic pain, the combination
of medication and complementary techniques provide the
best outcome. If pain is severe or disabling, opioids
may be an option. Yoga and exercise can help increase
flexibility in tense muscles. Using different types
of exercise therapy can be helpful, such as exercise
classes, swimming, or water therapies. Teaching patients
to use relaxation techniques can help them conquer feelings
of helplessness and decrease stress.
Encourage patients to stay
as active as possible, and help them choose pain management
that fits their lifestyle. For example, yoga and massage
may not be realistic options for all patients. Relaxation,
stress relief, and meditation can help build useful
coping skills.
References
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2. Chou R, et al. Diagnosis and treatment of low back
pain: a joint clinical practice guideline from the American
College of Physicians and the American Pain Society.
Ann Intern Med. 2007;147(7):478–491.
3. Von Korff M, Saunders K. The course of back pain
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Source: Nurse Practitioner.
May 2009.
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