| INTRODUCTION
There is an ever increasing body of CRPS research which covers
many apsects of this disease. The following is a list of CRPS
studies in 2002. Since new studies are always being done, this
file will be edited frequently.
Should you find a 2002 study that is not listed here, please
contact us.
STUDIES A-M
Berde CB,Lee BH, Scharff L, Sethna NF, McCarthy CF, Scott-Sutherland
J, Shea AM, Sullivan P, Meier P, Zurakowski D, Masek BJ.Physical
therapy and cognitive-behavioral treatment for complex regional
pain syndromes. J Pediatr 2002 Jul;141(1):135-40 Pain Treatment
Service and the Departments of Physical Therapy, Orthopaedic Surgery,
and Psychiatry, Children's Hospital, Boston, Massachusetts.
Complex regional pain syndromes (CRPS; type 1, reflex sympathetic
dystrophy, and type 2, causalgia) involve persistent pain, allodynia,
and vasomotor signs. We conducted a prospective, randomized, single-blind
trial of physical therapy (PT) and cognitive-behavioral treatment
for children and adolescents with CRPS. Children 8 to 17 years
of age (n = 28) were randomly assigned to either group A (PT once
per week for 6 weeks) or group B (PT 3 times per week for 6 weeks).
Both groups received 6 sessions of cognitive-behavioral treatment.
Assessments of pain and function were repeated at two follow-up
time periods. Outcomes were compared at the three time points
through the use of parametric or nonparametric analysis of variance
and post hoc tests. All five measures of pain and function improved
significantly in both groups after treatment, with sustained benefit
evident in the majority of patients at long-term follow-up. Recurrent
episodes were reported in 50% of patients, and 10 patients eventually
received sympathetic blockade. Most children with CRPS showed
reduced pain and improved function with a noninvasive rehabilitative
treatment approach. Long-term functional outcomes were also very
good.
PMID: 12091866
Bruehl S, Harden RN, Galer BS, Saltz S, Backonja M, Stanton-Hicks
M. Complex regional pain syndrome: are there distinct subtypes
and sequential stages of the syndrome?Pain 2002 Jan;95(1-2):119-24
Department of Anesthesiology, Vanderbilt University School of
Medicine, Vanderbilt University Medical Center, Suite 403-G MAB,
1211 Twenty-First Avenue South, 37232-1557, Nashville, TN, USA
This study tested for evidence supporting the clinical lore of
three sequential stages of complex regional pain syndrome (CRPS)
and examined the characteristics of possible CRPS subtypes. A
series of 113 patients meeting IASP criteria for CRPS underwent
standardized history and physical examinations to assess CRPS
signs and symptoms in four domains identified in previous research:
pain/sensory abnormalities, vasomotor dysfunction, edema/sudomotor
dysfunction, and motor/trophic changes. K-Means cluster analysis
was used to derive three relatively homogeneous CRPS patient subgroups
based on similarity of sign/symptom patterns in these domains.
The resulting CRPS subgroups did not differ significantly regarding
pain duration as might be expected in a sequential staging model.
However, the derived subgroups were statistically-distinct, and
suggested three possible CRPS subtypes: (1) a relatively limited
syndrome with vasomotor signs predominating, (2) a relatively
limited syndrome with neuropathic pain/sensory abnormalities predominating,
and (3) a florid CRPS syndrome similar to 'classic RSD' descriptions.
Subtype 3 showed the highest levels of motor/trophic signs and
possible disuse-related changes (osteopenia) on bone scan, despite
having directionally the briefest pain duration of the three groups.
EMG/NCV testing suggests that Subtype 2 may reflect CRPS-Type
2 (causalgia). Overall, these results are consistent with limited
previous work that argues against three sequential stages of CRPS.
However, several distinct CRPS subtypes are suggested, and these
could ultimately have utility in targeting treatment more effectively.
PMID: 11790474
Graham LE, McGuigan C, Kerr S, Taggart AJ. Complex regional
pain syndrome post mastectomyZ Orthop Ihre Grenzgeb 2001 Sep-Oct;139(5):452-7
Rheumatol Int 2002 Jan;21(4):165-6 Registrar in Rheumatology,
Musgrave Park Hospital, Belfast, Northern Ireland. lorradam@wlink.com.np
Complex regional pain syndrome includes the previously termed
condition reflex sympathetic dystrophy. It is a chronic pain disorder
diagnosed on the basis of symptoms and skin changes and is known
to have a psychological element. It is a rare complication after
surgery, especially mastectomy. We present two females who developed
this syndrome after undergoing mastectomy for chronic mastalgia.
These cases demonstrate that amputation of an organ for chronic
pain can result in reflex sympathetic dystrophy developing in
a nearby limb.
PMID: 11843174
STUDIES N-Z
Rho RH, Brewer RP, Lamer TJ, Wilson PR Complex regional pain
syndrome.Mayo Clin Proc 2002 Feb;77(2):174-80 Division of Pain
Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Complex regional pain syndrome (CRPS), formerly known as reflex
sympathetic dystrophy, is a regional, posttraumatic, neuropathic
pain problem that most often affects 1 or more limbs. Like most
medical conditions, early diagnosis and treatment increase the
likelihood of a successful outcome. Accordingly, patients with
clinical signs and symptoms of CRPS after an injury should be
referred immediately to a physician with expertise in evaluating
and treating this condition. Physical therapy is the cornerstone
and first-line treatment for CRPS. Mild cases respond to physical
therapy and physical modalities. Mild to moderate cases may require
adjuvant analgesics, such as anticonvulsants and/or antidepressants.
An opioid should be added to the treatment regimen if these medications
do not provide sufficient analgesia to allow the patient to participate
in physical therapy. Patients with moderate to severe pain and/or
sympathetic dysfunction require regional anesthetic blockade to
participate in physical therapy. A small percentage of patients
develop refractory, chronic pain and require long-term multidisciplinary
treatment, including physical therapy, psychological support,
and pain-relieving measures. Pain-relieving measures include medications,
sympathetic/somatic blockade, spinal cord stimulation, and spinal
analgesia.
PMID: 11838651
Weber M, Neundorfer B, Birklein F. Sudeck's atrophy: pathophysiology
and treatment of a complex pain syndromeDtsch Med Wochenschr 2002
Feb 22;127(8):384-9 Neurologische Klinik (Direktor: Prof. Dr.
B. Neundorfer), Friedrich-Alexander-Universitat Erlangen.
Sudeck's atrophy: pathophysiology and treatment of a complex
pain syndrome. SUMMARY: The "Morbus Sudeck" or Complex
Regional Pain Syndrome (CRPS) forms a typical triad of motor,
sensory and autonomic symptoms. It is clinically characterized
by spontaneous pain and hyperalgesia not limited to a single nerve
territory and disproportionate to the inciting event. An underlying
pathophysiology which could explain the whole symptomatology of
CRPS is still unknown. Therefore, nowadays therapy is still symptomatic.
However, recent research led to a better understanding of the
disease and to the beginning of a pathophysiologically orientated
therapy.
PMID: 11859448
Zuniga RE, Perera S, Abram SE. Intrathecal baclofen: a useful
agent in the treatment of well-established complex regional pain
syndrome.Reg Anesth Pain Med 2002 Jan-Feb;27(1):90-3 Department
of Anesthesiology and Critical Care Medicine, University of New
Mexico School of Medicine, Albuquerque, New Mexico 87131-5216,
USA.
BACKGROUND AND OBJECTIVES: We present 2 case reports that illustrate
that chronic intrathecal (IT) baclofen administration may be efficacious
in treating patients with long-standing complex regional pain
syndrome, type I (CRPS I) who have failed treatment with multiple
drugs and procedures.
CASE REPORTS: Both cases presented were women who developed CRPS
I following multiple lower extremity surgeries. One patient had
had symptoms for 5 years and had continued symptoms despite multiple
sympathetic blocks, sympathectomy, spinal cord stimulation, and
various medication trials. The other patient had had chronic lower
extremity pain for 30 years and symptoms of CRPS for about 5 years.
Her symptoms continued despite multiple sympathetic blocks, sympathectomy,
and many medications. Neither patient had motor dysfunction (dystonia,
tremors, spasticity) associated with their painful disorder. One
patient experienced good control of pain, allodynia, and autonomic
dysfunction with a combination of IT baclofen and clonidine after
failing treatment with IT morphine. Baclofen alone produced intolerable
side effects at the doses required to produce adequate analgesia.
The other patient experienced long-term control of pain, allodynia,
and autonomic symptoms with IT baclofen alone.
CONCLUSIONS: IT baclofen appears to be an option for patients
with intractable CRPS who have failed other modalities, including
IT morphine.
PMID:11790510
IASP (International Association
for the Study of Pain) Congress
San Diego, CA
August 15, 2002.
The following studies will be presented at this congress. Many
of these studies are being developed as new treatment options
for CRPS.
Studies are listed by abstract number.
Abstract ID: 1218-P134
IMPROVED TECHNIQUES FOR EXAMINATION AND TREATMENT OF COMPLEX REGIONAL
PAIN SYNDROME (CRPS) - A PILOT STUDY.
M. Imamura1, S.T. Imamura1, A.A. Fischer2, D.A. Cassius3, A.E.
Carvalho Jr1 1 Division of Physical Medicine, Foot Clinic, Dept.
Orthopaedics and Traumatology, University of So Paulo, São
Paulo, Brazil , 2 Mount Sinai School of Medicine, New York, NY
, 3 Moss Bay Center, Seattle, WA
Aim of Investigation: To evaluate improved techniques for examination
and treatment of CRPS of the lower limbs.
Methods: Fourteen adult patients with CRPS I (12) and II (2) of
the lower limbs, of various etiologies, for mean duration of 14.6
months were evaluated. Patients were tested for dermatomal hyperalgesia
by a skin scratch test, pinching and rolling the skin, and electric
skin conductance. Myotomal hyperalgesia was evaluated based on
the presence of muscle spasm, taut bands, trigger points (TrPs)
and tender spots (TSs). All patients received tricyclic antidepressants,
neuroleptics, non- steroidal anti-inflammatory drugs, analgesics
and a functional rehabilitation pro gram. Treatment was combined
with paraspinous blocks, pre injection blocks and needling and
infiltration of taut bands, TrPs and TSs, when a segmental sensitization
was diagnosed. Pain intensity was evaluated by visual analog scale
(VAS) before and after treatment.
Results: VAS values reduced (p=0.002) from 9.11.4 to 5.12.7 with
treatment. The dermatomal hyperalgesia present prior to treatment
was reduced towards normalization. Spasm and TrPs in the corresponding
myotome became less tender. A segmental distribution of sensitization
was noted at multiple (2-3) levels in 85.7% of the patients.
Conclusions: Improved examination techniques showed that pain
in CRPS is frequently manifested as a sensitization in a spinal
segmental distribution. By treating the spinal segmental sensitization,
CRPS patients had a significant reduction in their pain intensity.
Abstract ID: 1217-P133
COMPLEX REGIONAL PAIN SYNDROME PRESENTS IN IDENTICAL TWINS
L.L. Brown, M. Stanton-Hicks Pain Management Center, Cleveland
Clinic Foundation, Cleveland, OH
Aim of Investigation: To report the occurrence of complex regional
pain syndrome in a set of identical twin sisters. To review the
literature and to discuss the contribution of this case to the
growing body of evidence suggesting a genetic influence in the
development of complex regional pain syndrome.
Methods: Chart review was conducted for two identical twin sisters.
History of original injury, disease progression and response to
diagnostic and therapeutic procedures is reported.
Results: Identical twin sisters, aged 36, both sustained work
related injuries to their right ulnar nerves that progressed to
complex regional pain syndrome. Original evaluations, including
radiographs, electromyelograms, and nerve conduction studies were
normal. After a prolonged course of various failed therapeutic
modalities, Twin A had a peripheral nerve stimulator implanted.
Twin B is currently receiving a course of bier block treatments
awaiting approval for a peripheral nerve stimulator.
Conclusions: A linkage between neuropathic pain and a single autosomal
recessive gene has been demonstrated in mice.1 Further work has
suggested an HLA antigen association with complex regional pain
syndrome.2,3 This is the first case report of complex regional
pain syndrome existing in human identical twins. The development
of symptoms in the same limb further lends support to a potential
genetic component predisposing one to this chronic neuropathic
pain state.
Key Words: complex regional pain syndrome; reflex sympathetic
dystrophy; heredity; MHC-HLA References: 1. Devor M, Raber P.
Pain, 42,1990, 51-67. 2. Kemler MA. Neurology, 53, 1999, 1350-51.
3. Mailis A, Wade J. Clin Jrnl Pain, 10(3), 1994, 210-17.
Abstract ID: 1216-P132
CORRELATION BETWEEN CUTANEOUS TROPHIC CHANGES AND MYOCARDIAL INFARCTION
R. Casale1, T. Savarin2, S. Pieropan2, P. Mazzi2, B. Sommovigo3
1 Clin. Neurophysiology, "S.Maugeri" Found. Rehabil.
Institute, Montescano (PV), Italy , 2 Dept. Internal Med., Univ.
of Verona, Verona, Italy , 3 European School of MCR, Pavia, Italy
Introduction. Pain from myocardial infarction (MI) can be referred
to superficial and deep somatic structures and also generate skin-referred
trophic changes. Connective tissue massage is a physiotherapeutic
technique consisting in the recognition of specific areas of dorsal
cutaneous altered trophism, empirically related to the presence
of visceral pathologies, the lateral subscapular cutaneous area
(SSCA) being related to cardiac diseases. The aim of this preliminary
study was to determine whether MI positively correlates with trophic
alterations in SSCA.
Methods. 24 consecutive non-randomized pts (8M; 16M mean age 41)
referred to an Emergency Unit for chest pain were studied. Immediately
after the clinical stabilization, independent observers scored
the presence or absence of SSCR. Troponin (TP) levels (TP<0.1mg/ml
= normal, TP>3 mg/ml = myocardial necrosis) were recorded by
other independent observers. Results. 7 out of 24 patients had
a final diagnosis of a painful cardiac disease with increased
TP levels (6 MI, 1 myocarditis): 6 had SSCA trophic changes. 17
had a generic diagnosis of chest pain of non-cardiac origin: only
5 had positive SSCA changes. (Fisher's test: p = 0.023; Sensitivity
= 6/7 = 86%; Specificity = 12/17 = 71%; Positive predictive value
= 6/11 = 54%; Negative predictive value = 12/13 = 92%).
Conclusion. Trophic changes in SSCA positively and statistically
correlate with biohumoral indices of MI pointing out that acute
cardiac pain due to MI can acutely induce skin-referred trophic
changes. The absence of trophic changes also has a relevant predictive
value in detecting non-cardiac pain (92%).
Abstract ID: 1215-P131
PAIN-CORRELATED REORGANIZATIONAL PROCESSES OF THE SOMATOSENSORY
CORTEX IN PATIENTS WITH COMPLEX REGIONAL PAIN SYNDROME I (CRPS
I)
B. Pleger1, P. Schwenkreis1, F. Janssen1, O. Rommel1, P. Ragert1,
B. Vlker2, C. Maier2, M. Zenz2, M. Tegenthoff1
1 Neurology, Kliniken Bergmannsheil, Ruhr-University, Bochum,
Germany , 2 Anaesthesiology, Kliniken Bergmannsheil, Ruhr-University,
Bochum, Germany
Aim of Investigation: In the case of CRPS, the involvement of
the central nervous system in the development of pain stays unsolved.
The aim of this study was to determine, if there are pain-correlated
representational changes of the somatosensory cortex in CRPS.
Methods: We performed a SSEP mapping in 7 patients with CRPS I
of one upper limb with electrical stimulation of the median and
ulnar nerve to get an idea of the magnitude of hands representational
field.
Results: We found a significant smaller Euclidean distance between
the median and the ulnar nerve N20-dipole localizations of the
somatosensory cortex contralateral to the CRPS-affected limb.
The difference between the polar angels of the N20-dipole localizations
of both nerve representations mirrored a smaller representational
field of the CRPS-affected hand. The mean pain value was correlated
with the changes of the corresponding representational field of
the affected limb. Little actual pain was associated with small
changes of the representational field, while subjects with large
cortical reorganization complained high pain levels.
Conclusions: Cortical reorganization processes of hands` representational
field seem to be closely related to the amount of nociceptive
processing. Probably, pain-related thalamic hyperactivity leading
to a disturbed input in post-connected somatosensory pathways
might explain our findings of a smaller cortical representation
area of the CRPS-affected hand.
Abstract ID: 1214-P130
COMPLEX REGIONAL PAIN SYNDROME: FIRST DATA OF A PROSPECTIVE STUDY
EVALUATING THE EFFICACY OF REGIONALLY ADMINISTRED GUANETHIDINE
L. Demartini1, R. Bettaglio1, M. Allegri1, G. Bonetti1, A. Violini1,
A. Braschi2, A. Nava1 1 palliative care and pain therapy, Fondazione
Maugeri, Pavia, Italy , 2 anesthesia and intensive care institute,
Pavia's University, Pavia, Italy
Aim of investigation: We planned a study to evaluate the short
and long term efficacy of regional sympathetic blockade with guanethidine
in patients with CRPS with pain scales (Neuropathic Pain Scale
and Brief Pain Inventory).
Methods: Since January 2001 we enrolled 17 patients fulfilling
the IASP criteria for CRPS. All of them were studied with bone
scintigraph, telethermography and TcPO2 to evaluate vasomotor
changes, QST and von Frey needling for sensory changes; NPS and
BPI were applied. A great majority of patients had already received
other treatments prior to the study with no or poor effect. The
patients were treated with a course (six) of regional sympathetic
blockades according to the tecnique of Hannington-Kiff and then
they were revalued. When pain and impairment improved but still
persisted the patients underwent another course of blockades and
were then revalued.
Results: The NPS values, after treatment (first course), show
a significant reduction in all items, specially pain intensity
(from 7.23 to 3.17); deep pain intensity (from 7.64 to 3.83) improves
more than surface pain intensity (from 3.76 to 2.47). BPI values
show a reduction not only of pain intensity but also of functional
impairment in daily living (from 7.82 to 3.58) and sleep (from
5.86 to 1.88).
Conclusions: Pain has various mechanisms in CRPS. With this study
it seems that regional sympathetic blockade is not only effective
on pain but also (specially) on functional impairment. We saw
improvement of edema and joint movement before reduction of pain.
These data justify further evaluation.
Abstract ID: 1213-P129
COMPARATIVE EVALUATION OF THREE THERAPEUTIC MODALITIES FOR MANAGEMENT
OF CRPS TYPE I OF UPPER EXTREMITIES: INTRAVENOUS REGIONAL BLOCK
WITH BRETYLIUM, INTRAVENOUS REGIONAL BLOCK WITH GUANETHIDINE AND
INTERMITTENT STELLATE GANGLION BLOCKS WITH BUPIVACAINE
G.P. Dureja, T. Jayalakshmi, B. Ghai, S. Prakash, H.L. Kaul Pain
Clinic, All India Inst of Med Sciences, New Delhi, India
AIM OF INVESTIGATION: To evaluate three different therapeutic
modalities for management of CRPS Type I of upper extremities
in a randomized prospective clinical trial.
METHODS: Sixty-four consecutive patients with CRPS-I of upper
extremity were the subjects of this study. After a clinical evaluation
for diagnostic criterion of CRPS-I, a 3-Phase Bone Scan was done
to confirm the diagnosis. The patients were then randomly assigned
to receive either stellate ganglion blocks with 10 ml of 0.25%
Bupivacaine on alternate days for a maximum of 10 blocks (Group
A, n=23) or, IVRA with 1.5 mg/kg Bretylium and 10 mg lidocaine
(30 ml volume) repeated twice at 15 days interval (Group B, n=21)
or, IVRA with 0.3 mg/kg Guanethidine and 10 mg lidocaine (30 ml
volume) (Group C, n=20) repeated twice at 15 days interval. Various
objective parameters evaluated included digital plethysmography,
telethermometry, doppler flowmetry and scoring of Pain relief,
edema and range of motion on a 0-10 score. Minimum follow up duration
was 6 months and complete pain relief and functional improvement
was considered as successful outcome.
RESULTS: IVRA with Bretylium resulted in an earliest (mean 6.3
days) and maximum relief in pain (VAS <3), and functional parameters
in 20 out of 23 patients (P<0.01). Intermittent stellate ganglion
blocks provided relief in pain (VAS<5) and functional parameters
in 15/21 patients. IVR block with Guanethidine was least effective
and only 3 out of 20 patients had acceptable pain relief.
CONCLUSIONS: Intravenous regional block with Bretylium resulted
in a successful outcome in 86.8% patients with CRPS-I.
Abstract ID: 1212-P128
PSYCHONEUROPATHOLOGICAL FEATURES OF CUTANEOUS HYPERALGESIAS/ALLODYNIAS
IN CRPS I AND II.
R.J. Verdugo, L.A. Bell, M. Campero, F. Salvat, B. Tripplet, J.
Sonnad, J.L. Ochoa Oregon Nerve Center, OHSU, Portland, OR
Aim of Investigation: To discern patterns of hyperalgesias/allodynias
in CRPS I and II and to investigate their pathophysiological natures.
Methods: 132 patients with CRPS I and II underwent neurological
and neurophysiological evaluation following a standard clinical
protocol and conventional nerve conduction, electromyography,
somatosensory evoked potentials, transcranial magnetic stimulation,
quantitative somatosensory thermotest, infrared telethermography,
and placebo-controlled somatic and sympathetic nerve blocks.
Results: Two distinct semeiologic entities surfaced; classic neurological
vs. atypical, fulfilling the description of CRPS II and I respectively.
The CRPS II group (34.9%) exhibited sensory-motor patterns restricted
to the anatomical distribution of nerves and spinal roots and
had evidence of peripheral nerve pathology. The CRPS I group (65.1%)
departed from the laws of anatomy, physiology and pathology. They
had physiological normality of central and peripheral motor and
sensory pathways and abundant psychogenic signs.
Conclusions: These different clinical-physiological characteristics
of hyperalgesias/allodynias signal either psychogenic dysfunction
or structural pathology. These findings question the dictum that
tactile allodynia signals central neuronal sensitization. The
historical argument, when re-examined under evidence-based standards
yields contradiction and gratuitous extrapolation. The refractoriness
of a many neuropathic pain patients to hypothesis-driven, invasive,
or addictive therapy, betrays current misinterpretation of their
authentic neuropathogical and psychopathological origins, while
highlighting the iatrogenic connotation of the present paradigm.
Acknowledgement: Supported NIH grant NS 39761.
Abstract ID: 1211-P127
SKIN BLOOD FLOW CHANGES DURING KETAMINE/MIDAZOLAM ANESTHESIA FOR
INTRACTABLE CRPS-I
A. Ploppa1, R.T. Kiefer1, B. Noh1, P. Rohr2, J. Grothusen3, L.
Distler4, H.J. Dieterich1, K. Unertl1, R.J. Schwartzman3
1 Anesthesiology, Eberhard-Karls University, Tuebingen, Germany
, 2 Anesthesiology, Klinikum Saarbruecken, Saarbruecken, Germany
, 3 Neurology, MCP-Hahnemann University, Philadelphia, PA , 4
Pain Therapy, Caritasklinik St.Theresia, Saarbruecken, Germany
Aim of investigation: To detect and monitor changes in skin blood
flow during experimental high dose ketamine-midazolam anesthesia
for intractable cases of CRPS-I by Laser Doppler Flowmetry (LDF).
Methods: Patients suffering from therapy-refractory CRPS I (duration:
4 months-6 years) received ketamine-midazolam anesthesia over
5 days. Skin perfusion was determined by LDF (Perimed, PF 4100)
on D-II and radial forearm. In one patient with severe allodynia
at the upper arm this area and D-II were measured.
Results:Significantly decreased skin perfusion seems to occur
in late stages with manifest atrophic and dystrophic signs. Under
ketamine anesthesia, a significant increase in skin blood flow
was observed (clinical correlate: hyperemia, edema) in the first
72 hours. Areas of maximal allodynia showed the strongest increase
in blood perfusion (up to ten-fold, p<0.05). The highest increment
in skin blood flow was observed in patients with dystrophy and
atropy. During the following days, normalization of skin blood
flow and regaining vasomotor activity were observed (clinical
correlate: decrease of swelling, hyperemia, temperature changes).
Conclusions: LDF might be a valid and noninvasive method to monitor
skin perfusion changes and potentially success of therapeutic
procedures for CRPS I. Further evidence is needed to qualify and
quantify regained vasomotive activity as indicator of effective
CRPS-I therapy.
Abstract ID: 1210-P126
KETAMINE-MIDAZOLAM ANESTHESIA FOR INTRACTABLE COMPLEX REGIONAL
PAIN SYNDROME-I
R.T. Kiefer1, P. Rohr2, A. Ploppa1, H.J. Dieterich1, K.H. Altemeyer2,
J. Grothusen3, K. Unertl1, R.J. Schwartzman3
1 Anesthesiology, Eberhard-Karls University, Tuebingen, Germany
, 2 Anesthesiology, Klinikum Saarbruecken, Saarbruecken, Germany
, 3 Neurology, MCP-Hahnemann University, Philadelphia, PA
Aim of Investigation: Sufficient pain relief for Complex Regional
Pain Syndrome Type I (CRPS-I/RSD) remains challenging. Accumulating
evidence points to the involvement of sensitized central pain
projecting neurons by NMDA-receptor activation. This evidence
is the rationale for prolonged NMDA-blockade with ketamine in
intractable CRPS-I patients.
Methods: Six patients with steadily worsening CRPS-I, who failed
all standard medical and sympatholytic treatment, were anesthesized
in the ICU's of hospitals in Tuebingen and Saarbruecken, Germany.
Treatment was initiated by bolus injections of ketamine (0.5mg/kg)
and midazolam (2.5-5mg) until deep sedation (Ramsay Score 4-5)was
reached.Therapy was maintained with infusions of ketamine (3-7mg/kg/h)
and midazolam (0.15-0.3mg/kg/h) over five days. On the fifth day
infusions were slowly tapered. 3 patients did not require intubation
and 3 were pre-emptively intubated (1 for increased aspiration
risk, 2 due to respiratory infection).
Results: Six patients underwent treatment without significant
complications. All showed an excellent immediate response and
were pain free and without spontaneous or touch evoked allodynia
or hyperalgesia. One patient has remained completely pain free
for more than 2 years. Five of the six patients had return of
the pain of the original injury, but are relieved of the hyperalgesia,
mechanical and thermo-allodynia and swelling in the affected areas.
Conclusions: Prolonged ketamine-midazolam anesthesia shows promise
as an effective therapeutic option for severe and otherwise intractable
cases of CRPS-I.
UPDATE Sept. 2002:
For more information about these studies, please contact the doctors
listed in the abstracts or visit IASP at www.iasp-pain.org.
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