Transcript Nontraumatic Low Back Pain - Calgary Emergency Medicine

Nontraumatic Low Back Pain
Sarah McPherson
Oct. 3, 2002
Why is it important?
• High disease prevalence
• most expensive cause of work-related
disability
• wide variations in medical care
Sickness days appear to be
increasing
Waddell, G. Ann Rheum Dis. 1993;52:317-19
Practice patterns in the USA
• US National
survey of 114 ER
physicians
• answered
questionnaire of
case vignettes
• results reflect that
practice pattern
does not follow
recommended
guidelines or the
medical literature
Elam KC, J Emerg
Med.1995;13(2):143-50
What causes low back pain?
• May originate from
many spinal
structures:
– ligaments
– facets
– periosteum
– muscles
– fascia
– blood vessels
– nerve roots
– anulus fibrosus
• ~ 85% no
pathoanatomical
diagnosis
Important questions to ask
• Is there a systemic disease that is the source for the
pain?
• Is there any indication that surgical evaluation is
required?
• How can I provide the best symptomatic relief?
• Can I help to prevent chronicity or recurrence?
What are the indications for further
imaging?
AHCPR guidelines for the ordering of radiographs:
Possible Fracture:
Possible tumor or infection:
major trauma
minor trauma age >50
chronic steroid use
osteoporosis
> 50yrs
< 20 yrs
history of cancer
constitutional symptoms
recent bacterial infection
iv drug use
immunosuppression
supine pain
nocturnal pain
Problems with the AHCPR guidelines
• There has been no prospective validation therefore
we do not know the sensitivity or specificity
• following the guidelines would increase utilization by
~ 200% Suarez-Almazor. JAMA .1997 277(22). 1782-86
• plain radiographs are not sensitive for the diseases
that require specific therapy
– 23% epidural abscess, 25% disc space infection, 68% bone
tumor, 90% vertebral osteomyelitis
Liang, M. Arch Intern Med. 1982, 142: 1108-12
• radiation dose of lumbar radiographs 40X > than CXR
Whalen, JP.Dis Mon. 1982;28:73
What about MRI?
• Advantages:
– highly sensitive for the detection of infection,
tumors, nerve root compression, spinal stenosis
• Disadvantages:
– imaging may not correlate with clinical disease
• 25% of asymptotic patients have disc herniation
• 50% healthy young adults will have bulging or
degenerative discs on MRI Jarvik, J.Radiology.1997;204(2):447-54
– cost effectiveness
So when should you order an MRI?
• No validated clinical guidelines
• Recommendations:
–
–
–
–
clinical suggestion of underlying infection
clinical suggestion of underlying cancer
persistent neurologic deficit
evidence of cauda equina syndrome
When is surgical evaluation required?
• Cauda equina syndrome (surgical emergency)
– bladder or bowel dysfunction (usually urinary retention)
– numbness to perineum and medial thighs (saddle
distribution)
– bilateral leg pain, weakness and numbness
• progressive or severe neurologic deficits
• persistent neuromotor deficit after 4-6 weeks
• persistent sciatica for 4-6 weeks (not low back pain
alone)
Deyo, RA. NEJM. 2001; 344(5): 363-70
Pharmaceutical treatment of LBP
AHCPR Guidelines:
– Recommended medications:
• Acetominophen
• NSAIDs
– “Optional” medications:
• muscle relaxants
• opioids for < 2 weeks
– Recommended against:
•
•
•
•
•
opioids > 2 weeks
phenylbutazone
oral steroids
colchicine
antidepressants
Evidence for NSAIDs
• NSAID vs Placebo
– 9 RCT (5 high quality, 4 low)
– heterogeneity between studies with respect to
dosing, mode of administration and type of NSAID
RESULTS:
– NSAIDs provide better pain control than placebo
– improved global improvement in patients treated
with NSAIDs
– decreased need for additional analgesia in NSAID
groups
van Tulder, MW. Spine 2000;25:2501-13
Evidence for NSAIDs
• NSAID vs Acetominophen
– 5 RCT (1 high quality, 4 low)
RESULTS:
– 2 low quality studies showed no difference
– 1 low quality and 1 high quality showed
superiority of NSAID for pain control
Bottom line: Conflicting evidence but NSAIDs
appear more effective than
acetominophen
van Tulder, MW. Spine 2000;25:2501-13
Evidence for NSAIDs
• NSAID + muscle relaxant
– 3 RCT (1 high quality, 2 low quality)
Results:
– all 3 studies showed combined therapy to be
better than NSAID alone but results not
statistically significant
van Tulder, MW. Spine.2000;25:2501-13
Evidence for NSAIDs
• Comparisons of different NSAID types
– 24 trials
– looked at ibuprofen, indomethacin, diclofenac,
ketorolac, tenoxicam, piroxicam, naproxen
RESULTS:
– equal efficacy
Evidence for NSAIDs
• NSAID vs COX-2
– RCT
– N = 104
– nimesulide vs ibuprofen
Results:
– no difference in pain or stiffness scores
– no difference in side effects
Pohjolainen, T. Spine 2000; 25(12):1579-85
What about muscle relaxants
• 14 RCT (8 high quality, 6 low quality)
• 8 high quality:
– 5 showed improvement in pain intensity, 3 no
difference
• many different muscle relaxants studied
(cylcobenzaprine, tizanidine, diazepam, baclofen, butabarital)
• all appear to have equal efficacy however
good studies with head to head comparisons
are lacking
van Tulder, MW. Spine. 1997;22(18): 2128-56
Cyclobenzaprine (Flexeril)
• 14 RCT’s reviewed in meta-analysis
• all studies but 2 treated for > 14 days
• dosing was 10mg tid
• Outcomes measured:
–
–
–
–
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local pain
muscle spasm
tenderness to palpation
range of motion
activities of daily living
Cyclobenzaprine - outcomes
• Moderate
improvement for all
outcome measures
• NNT = 3
Browning, R. Arch Intern Med.
2001; 161:1613-20
Cyclobenzaprine - Side effects
• 53% of
patients
experience at
least one side
effect
compared with
28% in the
placebo group
What if your patient prefers “natural”
remedies?
• The efficacy of willow bark extract
– RCT: high (240mg) and low dose(120 mg) willow
bark vs placebo
– N = 210
– outcomes measures VAS at 4 weeks, need of
break-through analgesia
– Results:
high dose > low dose > placebo
Chrubasik, S. Am J Med.2000;109:9-14
Medical Management - What should
you choose?
• Regular dosing of NSAID of your choice for 12 weeks
• addition of muscle relaxant (warn of side
effects), acetominophen or a narcotic may be
of benefit
• the optimal combo of meds and duration is
not known
To rest or not to rest?
• current guidelines advocate bed rest for a
maximum of 2 days for LBP and up to 2
weeks for sciatica
QUESTIONS:
– Is there any evidence to suggest that bed
rest may improve recovery?
– Is there any evidence that bed rest may be
harmful?
Bed rest has not been shown to be
effective treatment for LBP
Systematic review:
– 10 trial identified evaluating therapeutics of bed
rest
– length of bed rest varied from 2-7 days
– 8 trials showed no difference in pain scores or
activities of daily living
– despite differences in length of rest, no trials
showed a difference or efficacy of bed rest
Waddell, G. Br J Gen Prac. 1997;47:647-52
Could bed rest actually have negative
effects?
Bed rest vs Exercises vs ordinary activity?
– RCT to 3 groups (N= 67,52,67)
– outcome measures of duration & intensity of pain,
absence from work, ability to work, & Oswestry
back disability index
– groups evaluated at 3 and 12 weeks
– control group had less absenteeism, decrease pain
intensity scores and similar satisfaction to bed rest
group
Malmivaara, A. NEJM.1995;332(6):351-55
3 week outcomes
Outcomes at 12 weeks
Bed rest for Sciatica
• RCT 2 weeks bed rest vs normal activity
• N = 92 & 91
• outcome measures: global assessment of
function, pain scores, absenteeism, surgical
requirements
• evaluated at 3 and 12 weeks
Vrooman, PCAJ. NEJM.1999;340(6):418-23
Bed rest for sciatica
Results:
– 10 % lost to follow-up
– mean # days in bed 22hr vs 10 hrs
– no difference in outcome measures at 3 or 12
weeks
• Bed rest is definitely not more effective in
treating sciatica
• Is it harmful? - this study does not answer
that & no other studies were found in my
review
Physiotherapy and exercise programs
Systematic Review – 1991
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–
–
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16 studies identified
Only 4 high quality studies
Different types of therapy studied
Chronic and acute LBP
– 10 studies reported no difference between
treatment and nontreatment groups
– 6 studies reported positive results in the PT group
Koes, BW. BMJ. 1991;302:1572-6
What is the role of physiotherapy?
• Since 1991 5 more studies looking at PT for
acute LBP
Positive Studies
– 1 study identified
– Retrospective review of randomly selected patients
with acute LBP
– Looked at 3 groups (immediate PT, start at 2-7
days or Pt started at 8-179days)
– Delayed therapy group had increased absenteeism
and more physician visits
What is the role of physiotherapy?
• 4 negative studies
Cherkin et al , NEJM. 1998; 339(15) 1021-9:
– prospective RCT McKenzie PT vs chiro vs
educational booklet
– N = 323, LBP < 7 days
– PT and chiro group had less “bothersome”
symptoms at 4 weeks but not at 12 weeks
– no difference in Roland disability scores,
absenteeism or recurrences at 1 or 2 years
– PT and chiro costs similar, both +++ more
expensive than educational booklet
What is the role of physiotherapy?
Faas, A et al. Spine 1995;20(8):941-7:
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–
–
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prospective RCT
no treatment vs PT vs sham PT
N= 473, LBP < 3 weeks
Outcomes:
• higher absenteeism in PT group
• no difference in releif from symptoms
• no decreased duration of pain episodes
– follow-up at 1,2,4 and 12 months
What is the role of physiotherapy?
Dettori, JR et al. Spine. 1995;20(21):2303-12:
–
–
–
–
prospective RCT
flexion vs extension exercises vs no exercises
N = 152, LBP < 7 days
Outcomes:
•
•
•
•
no difference in pain scores
no difference in disability scores
no difference time to return to work
~60% recurrence rate at 6-12 months in all categories
– follow-up at 1,2& 4 weeks, and at 6-12 months
What is the role of Physiotherapy?
• Does not appear to decrease acute symptoms
• does not appear to decrease recurrence of
back pain
• despite the literature, physiotherapists are
convinced from experience that it works
What about spinal manipulation?
• Meta-analysis of 7 studies
• LBP 2-4 weeks
• improvement in pain at 2-3
week post onset of treatment
(50% vs 67%)
• difference gone within weeks to
months
• studies did not look at disability
scores or work absenteeism
Shekelle, PG.Ann Intern Med. 1992;117(7): 590-8
Is there a role for Acupuncture?
• Number of studies have been done looking at
the role in chronic LBP (> 3 months)
• no studies looking at acupuncture acutely
• appears to be beneficial in reduction of pain,
improved activity, and decreased analgesic
requirements
Ernst, E. Arch Intern Med. 1998;158:2235-41
Christer, C. Clin J pain. 2001;17(4): 296-305
Ghoname, E. JAMA. 1999;281(7): 818-23
Overview of non pharmaceutical
interventions
• Bed rest is not helpful and is probably
harmful
• Physiotherapy does not appear to reduce
symptomatology or prevent recurrence
• spinal manipulation may reduce short term
symptoms but loses its effect in the long term
• accupuncture appears to be helpful in chronic
LBP
Factors predicting chronicity
• ~ 10% of all LBP becomes chronic
• Risk factors include:
– psychosocial issues primarily
•
•
•
•
•
fear avoidance model
depression
poor coping skills
chronic daily stress
poor job satisfaction
– clinical
• large disc protrusion
Williams, R. Arch Phys Rehab Med. 1998;79:366-73
Burton, K. Spine. 1995;20(6): 722-8
Hasenbring, M. Spine. 1994: 19(24): 2759-65
Klenerman, L. Spine. 1995: 20(4): 478-84
Can we influence the path to
chronicity?
• Prospective study of high risk patients
– treatment of risk factor based cognitive behavioral
intervention vs electromyographic biofeedback
(relaxation techniques) vs no intervention
– improved pain reduction, decreased immobility in
daily life, decreased depression immediately post
intervention and at 6 months
– high risk patients with intervention had results
similar to low risk patients
Hasenbring, M. Spine. 1999;24(23):2525-35
Can we influence Chronicity
• Prospective RCT educational booklet vs
advice consistent with current guidelines
Can we influence chronicity
• Effects of the booklet
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–
–
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improvement in beliefs at 1 year
decreased fear avoidance beliefs
improved Roland disability scores
no difference in pain scores
Burton, K. Spine. 1999; 24(23): 2484-91
Can we influence patients returning
to normal work?
• The sooner the recommendation to return to
work is made, the more likely the patient will
comply
• the probability of return to work decreases as
length of time off work increases
• subjective pain ratings does not correlate
with a person’s ability to accomplish physical
activities
Hall, H. Spine. 1994; 19(18): 2033-37
Influencing return to work
• Prospective study looking at unrestricted
return to work recommendations vs return to
work with restricted duties
– enrolled patients through their PT rehabilitation
program
– part way thorough they enforced that all patients
be given unrestricted return to work instructions
regardless of pain ratings
– OUTCOMES:
• increased return to work in unrestricted group (84% vs
47%)
Hall, H. Spine . 1994;19(18): 2033-37
Overall recommendations
• Regular NSAID +/- muscle relaxant/Tylenol
• Spinal manipulation likely shortens course of
symptoms
• PT may be helpful
• education emphasizing benign course of
disease and encouragement to decrease fear
avoidance behaviors