Continuous Peripheral Nerve Blocks at Home for Treatment of Recurrent Complex Regional Pain Syndrome I in Children

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Continuous Peripheral Nerve Blocks at Home for Treatment of Recurrent Complex Regional Pain Syndrome I in Children
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    PAIN AND REGIONAL ANESTHESIA   Anesthesiology 2005; 102:387–91 © 2005 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc.  Continuous Peripheral Nerve Blocks at Home for Treatment of Recurrent Complex Regional Pain Syndrome I in Children Christophe Dadure, M.D., *  Frederic Motais, M.D., *  Christine Ricard, M.D., *  Olivier Raux, M.D., *  Rachel Troncin, M.D., *  Xavier Capdevila, M.D., Ph.D. †  Background:  Recurrent complex regional pain syndrome I isnot rare in the pediatric population. The authors conducted thisstudy to evaluate the efficacy of continuous peripheral nerve blocks with elastomeric disposable pumps associated with ini-tial Bier blocks for the treatment of recurrent complex regional pain syndrome I in children.  Methods:  After parental informed consent, 13 children whodid not respond to conventional complex regional pain syn-drome treatment were included (mean age, 13 yr; range, 9– 16 yr). After general anesthesia, peripheral nerve block wasperformed using 0.5 ml/kg lidocaine, 1%, with epinephrine and 0.5% ropivacaine injected in the peripheral nerve block cathe-ter.Then,a20-minBierblockwasperformedusingatourniquet and 0.2 ml/kg lidocaine, 1%; 3 ml/kg hydroxyethyl starch 130/06; and 5 mg/kg buflomedil injected intravenously. A solu-tion of 0.1 ml · kg   1 · h   1 continuous ropivacaine, 0.2%, wasinfused through the catheter using an elastomeric pump for 96 h. Need for rescue analgesia, occurrence of side effects, and status of motor and sensory block were recorded at hours 1, 6,12, 24, 48, 72, and 96. Children and parents completed a satis-faction assessment. All of the children had follow-up visits after 2 months.  Results:  Postoperative analgesia was excellent. The median pain score was 0 for each period studied. Motor blockade wasminimal before 12 h (median, 1) and absent thereafter. Onechild needed rescue analgesia. All children were able to walk easily after the initial 24-h period (walking score, > 4). Children and parents were all satisfied. Children returned home under parental surveillance beginning in the 24th hour. Neither pe-ripheral nerve block nor Bier block caused side effects. After 2months, none of the children exhibited any clinical symptom of recurrent complex regional pain syndrome.  Conclusion:  Ambulatory continuous peripheral nerve block associated with an initial Bier block seems to be a significant and novel contribution to treat recurrent pediatric complexregional pain syndrome I. It allows complete pain relief, early mobilization, and rapid return home, representing a psycho-logical advantage for these children. COMPLEX regional pain syndrome (CRPS) type I   isdefined as a painful, disabling syndrome accompanied by edema and sudomotor and vasomotor dysfunction. Var-ious treatments in adults have been reported, but notechnique has shown superiority for treating or prevent-ing CRPS I. 1 The reported methods include physicaltherapy, behavioral measures, and use of antidepres-sants, anticonvulsants, or transcutaneous electrical nervestimulation. Other authors have proposed regional anes-thesia with intravenous local anesthetics, guanethidine,reserpine, bretylium, nonsteroidal antiinflammatory drugs, droperidol or calcium-regulating drugs, 1 or block-ade of sympathetic activity by epidural analgesia 2 or peripheral nerve blocks. 3–5 Complex regional pain syndrome type I has also beendescribed in a pediatric population. 6 The pathophysiol-ogy of CRPS I is not clear. A treatment using Bier block  with local anesthetics, 7 physical therapy, and cognitive–behavioral treatment should be recommended. Unfortu-nately, recurrent episodes have been reported in 50% of children. 8 The median time to recurrence was 2 months with physical therapy alone. 8 One of the key elements of CRPS I treatment is intense physiotherapy. Intense exer-cise therapy has been proposed for initial treatment of childhood CRPS I, 8 but this treatment is very painful.The use of ambulatory continuous peripheral nerveblocks (CPNBs) to alleviate pain, allow intense physio-therapy, and treat CRPS I has not been prospectively studied in children with this syndrome. Ambulatory elastomeric or electronic pumps havebeen often used at home for the postoperative periodafter orthopedic surgery in adults. 9–12 The use of such devices to restore optimal autonomy in children hasrecently been demonstrated in the postoperativeperiod. 13 The aim of the current study was to evaluate thefeasibility and efficacy of CPNB at home by means of disposable elastomeric pumps associated with an initialBier block in the treatment of recurrent CRPS I inchildren. Materials and Methods  After we received institutional review board approval(Montpellier, France) and consent of each patient or family, 13 consecutive children who had upper or lower  This article is accompanied by an Editorial View. Please see:Berde CB, Lebel A: Complex regional pain syndromes inchildren and adolescents. A  NESTHESIOLOGY   2005; 102:252–5.  * Assistant Professor, † Professor, Head of Department.Received from the Department of Anesthesia and Critical Care Medicine,Lapeyronie University Hospital, Montpellier, France. Submitted for publicationMarch 3, 2004. Accepted for publication October 7, 2004. Support was providedsolely from institutional and/or departmental sources. Address reprint requests to Dr. Dadure: Département d’ Anesthésie Réanima-tion A, Hôpital Lapeyronie, 371 Avenue du Doyen G. Giraud, 34295 Montpellier,France. Address electronic mail to: chdadure@yahoo.fr. Individual article reprintsmay be purchased through the Journal Web site, www.anesthesiology.org.  Anesthesiology, V 102, No 2, Feb 2005  387  limb CRPS I and who met the inclusion criteria wereincluded in the study. All had either failed to respond toa 6-month regimen of physical therapy, cognitive–behav-ioral treatment, oral drugs (10 mg/night nortriptyline,300 mg gabapentin three times a day), and transcutane-ous electrical nerve stimulation or had subsequently ex-perienced recurrence.The children were premedicated with 0.4 mg/kg mi-dazolam. Intraoperative general anesthesia was inducedin all children using 3–5 mg/kg propofol and 1   g/kgintravenous fentanyl.Mechanical ventilation was used after tracheal intuba-tion or insertion of a laryngeal mask airway. Anesthesia was maintained with 50% nitrous oxide in oxygen and a2% inspired fraction of sevoflurane.Peripheral nerve blocks were performed before theBier block procedure using a nerve stimulator for precisenerve location (Stimuplex ® ; Braun, Melsungen, Ger-many). The landmarks described by Singelyn  et al. 14  were used for popliteal blocks, and the landmarks de-scribed by Dalens  et al. 15  were used for axillary blocks. With a starting output of 1.5 mA (frequency, 1 Hz; time,50 ms), needles were advanced until they triggered therequired muscle contraction. The position was judgedadequate when muscle contractions were still elicited at0.5 mA. A 20-gauge multiperforated catheter (Plex-olong ® ; Pajunk, Geisingen, Germany) was inserted alongthe guide from 3 to 5 cm. Contrast medium (0.1 ml/kgIopamidol 200; Shering Pharmaceutical, Lys-Lez-Lannoy,France) was injected into the catheter, and an antero-posterior radiograph of the region was obtained within5 min. Children with unreliable catheter location wereexcluded. After catheter placement, 0.5 ml/kg of anequal-volume mixture of 0.5% ropivacaine and 1% lido-caine with 1:200,000 epinephrine was injected  via  thecatheter over a 5-min period.Then, a 20-min Bier block was performed. After exsan-guination of the limb extremity and inflation of thetourniquet, 0.2 ml/kg lidocaine, 1%; 5 mg/kg buflomedil;and 3 ml/kg hydroxyethyl starch 130/06 were injectedintravenously. Buflomedil is a peripheral vascular dilator and an anti-ischemic agent. This   1 and   2 adrenolyticdrug has a relaxant effect on vascular smooth muscleincreasing the arterial and venous blood flow with func-tional restoration of the microcirculation. Hydroxyethylstarch is used to expand the volume of lidocaine andbuflomedil after limb exsanguination. The tourniquet was deflated after 20 min without complication, andgeneral anesthesia was discontinued.In the postoperative period, a continuous infusion of 0.2% ropivacaine was administered at 0.1 ml · kg  1 · h   1 using disposable elastomeric pumps (Infusor LV; Baxter Laboratories, Maurepas, France). Disposable multirateinfusion pumps were used at a flow of 2, 3, 5 or 7 ml/h. A nonsteroidal antiinflammatory drug (40 mg/kg niflu-mic acid twice daily the first 48 h) was administeredintravenously over a 15-min period to all children. In thepostoperative period, sensory blockade was evaluatedusing cold sensation (ether on a ball of cotton wool)tested at hours 1, 6, 12, 24, 48, 72, and 96. At the sametime, motor blockade was evaluated for the selectedmuscles of each nerve territory using a Bromage scale. 16 Nurses evaluated postoperative pain in the surgical wardat hours 1, 6, 12, and 24 and at home at hours 48, 72, and96 with a visual analog scale ranging from 0 (no pain) to10 cm (most imaginable pain), as well as amounts of rescue analgesia. If pain control was considered insuffi-cient (visual analog scale score  3) in the postoperativeperiod, an intravenous injection of 0.2 mg/kg nalbu-phine in the first 24 h and a codeine–acetaminophentablet at home were administered as rescue analgesia. At24 h, a walking score was noted in all children rangingfrom 0 (rest in bed) to 5 (complete free walk). If there was no complication, the patient returned home under parental surveillance after 24 h. Intense exercises (elbow flexion and extension [1 patient], ankle movements [12patients] against resistance: plantar flexion, eversion,dorsal flexion, proprioceptive physiotherapy, and mas-sages) conducted by a physiotherapist were started 1 h after the continuous peripheral nerve block inductionand at 6, 12, and 24 h at the hospital and twice daily athome. At the end of the study period, satisfaction levelsof children and parents were recorded (unsatisfied, sat-isfied, or very satisfied). Adverse effects (pruritus, nau-sea, vomiting, dysesthesia, hematoma, urinary retention,local infection, or local anesthetic toxicity) were noted. All of the children had a follow-up visit after 2 months, at which time absence or severity of pain, walking disor-ders, and disabling symptoms were recorded.Statistical analysis was performed using SAS software version 8.02 (SAS Institute, Cary, NC). The quantitativeanthropometric scores were expressed as median(range), motor blockade was expressed as median(10th–90th percentiles), and pain scores were expressedas median (25th–75th percentiles and range). Repeated-measures analysis of variance was used for continuous variables. Comparisons between values at the times stud-ied were made using the Mann–Whitney U test for non-parametric data, and the chi-square test was used for categorical data. A significance threshold of   P     0.05 was retained. Results Thirteen patients, four boys and nine girls, were in-cluded in this study. The median age was 13 (9–16) yr and the median weight was 57 (26–95) kg. Informationon the clinical course of the children before we per-formed the continuous peripheral nerve blocks is shownin table 1. Twelve popliteal nerve blocks and one axillary nerve block were performed. No block failures were388  DADURE  ET AL.  Anesthesiology, V 102, No 2, Feb 2005  noted. Confirmation of correct location of all catheters was obtained with contrast medium radiographs.Postoperative analgesia was excellent. The medianpain score was 0 for each period studied. Pain duringphysiotherapy (visual analog scale values) is reported infigure 1. Rescue analgesia was necessary in only onepatient, whose pain scores were outside the 25th–75th percentile range. This child had previously been treated with oral morphine. This patient received two injectionsof intravenous nalbuphine during the first 24 h of thestudy.Observed motor blockade was minimal before 12 h (median value, 1) and absent thereafter (fig. 2). The 13children in the study were able to walk easily after a 24-h period (walking score,  4). All parents and children reported high satisfaction(both parents and child were satisfied in one case, and inthe other cases, both parents and children were very satisfied) with the pain management at rest and duringall periods of intense physiotherapy throughout thestudy.None of the children had associated hematoma or catheter infection. No dysesthesia, urinary retention, or any other sign of local anesthetic toxicity was noted. Noneurologic symptom was noted after withdrawal of thedisposable pumps by a nurse in the surgical ward at 96 h.There was no accidental removal of the catheter duringthe study. After 2 months, no child presented any clinical symp-tom of recurrent CRPS, and all of the patients were able  Table 1. Information on the Clinical Course of the Children before Treatment with Continuous Peripheral Nerve Blocks PatientNo. Age,yr VASScorebeforePNB Site of InjuryType ofInjuryDuration ofConservativeTreatment Treatment before BlockCognitiveBehavioralTreatmentPhysicalTherapy Disabling Syndrome 1 15 10 Left ankle Sprain 6 months Amitriptylineclonazepam,calcitoninYes Yes Alodynia,hyperesthesiaedema, vasomotordisorder2 11 10 Right ankle Trauma 6 months Amitriptylineparacetamol,tramadolYes Yes Alodynia,hyperesthesiaedema3 13 10 Left ankle Sprain 6 months Amitriptylineparacetamol,paroxetineYes Yes Alodynia,hyperesthesiaedema4 12 10 Wrist right Trauma 6 months Calcitonin,amitriptylineYes Yes Hyperesthesiaedema vasomotordisorder5 13 10 Right ankle Sprain 7 months Amitriptylineclonazepam,tramadol, calcitoninYes Yes Alodynia,hyperesthesiaedema6 12 8 Left ankle Sprain 6 months Clonazepam,amitriptylineYes Yes Hyperesthesiaedema7 9 9 Left ankle Trauma 7 months Clonazepam,amitriptyline,calcitoninYes Yes Alodynia,hyperesthesiaedema8 14 10 Right ankle Trauma 6 months Amitriptylineparacetamol,paroxetine, tramadolYes Yes Alodynia,hyperesthesiavasomotordisorder9 13 10 Right ankle Sprain 6 months Clonazepam,amitriptyline,calcitoninYes Yes Alodynia,hyperesthesiaedema10 16 10 Left ankle Sprain 8 months Clonazepam,amitriptyline,calcitonin, tramadolYes Yes Alodynia,hyperesthesiaedema, vasomotordisorder11 13 8 Left ankle Sprain 6 months Clonazepam,amitriptylineYes Yes Hyperesthesiaedema12 14 10 Right ankle Trauma 8 months Clonazepam,amitriptyline,calcitoninYes Yes Alodynia,hyperesthesiavasomotordisorder13 15 9 Right ankle Sprain 6 months Clonazepam,amitriptyline,calcitoninYes Yes Alodynia,hyperesthesiaedema PNB  peripheral nerve block; VAS  visual analog scale. 389 PERIPHERAL NERVE BLOCK AND CRPS I IN CHILDREN  Anesthesiology, V 102, No 2, Feb 2005  to resume normal activity. During the period of recruit-ment of these 13 patients, a total of 37 children werereferred to us for CRPS I. Discussion  This study shows that ambulatory CPNB associated with an initial Bier block is effective against intractableor recurrent CRPS I in children. This treatment providedcomplete short-term pain relief and allowed early in-tense mobilization and a rapid return home.The absence of a comparative control group with sa-line in the CPNB or without CPNB merits comment.Despite recent case reports, 7 many cases of recurrentCRPS I have been reported in the literature in childrentreated with serial Bier blocks. 17 In case of recurrentCRPS I, the poor success rate of isolated Bier blocks isalready established. 1,17 Furthermore, our ethics commit-tee ruled against a randomized comparative design inchildren in view of the pain levels anticipated duringintensive physiotherapy.In adults, few studies have shown short- and long-termbenefits of peripheral nerve blocks in the treatment of CRPS I. 2,3 Recently, several case reports have empha-sized the importance of continuous or repeated periph-eral nerve blocks 4,5,18 for control of acute pain andimprovement of CRPS I treatment. Because recurrentCRPS I remains a therapeutic challenge in pediatric pa-tients, 19  we evaluated the use of 4-day continuous pe-ripheral nerve blocks with disposable elastomericpumps. We chose ambulatory pumps because of their documented efficacy, simplicity, and safety for ambula-tory postoperative analgesia in adult outpatients. 9–12 These devices permit optimal pain relief and rapid res-toration of a child’s autonomy in the postoperative pe-riod. 13  Although repeated sympathetic blocks have beenshown to be effective against the pain associated with CRPS I in adults, especially in recurrent cases, 20 repeatedintravenous guanethidine injections do not improvelong-term results regarding the treatment or preventionof CRPS I. 1,17,21 Furthermore, intravenous guanethidinehas been associated with many adverse effects, includingnausea, vomiting, orthostatic hypotension, dizziness, di-arrhea, and weakness. 17  We used a buflomedil–lidocainemixture to reduce these adverse effects during the initialBier block and adjuvant 4-day continuous peripheral nerveblock, which provided complete pain relief at rest andduring exercise. The excellent control of pain achieved inthis manner facilitates the other two aspects of CRPS treat-ment: physiotherapy and psychotherapy. 5,7,22 Intense exercise therapy is necessary to treat child-hood CRPS effectively and to decrease the high inci-dence of recurrence reported in patients treated usingonly physical therapy and cognitive–behavioral treat-ment. 8,19 Continuous nerve blocks are recommendedprimarily to reduce pain and facilitate intensive physicaltherapy and functional rehabilitation, 5,22  which are es-sential goals of CRPS I treatment. 22,23 Because physio-therapy is very painful during CRPS I and CPNB is indi-cated during postoperative mobilization in children, 13  we used CPNB for physiotherapy in these children. Painrelief was complete in our patients, and intense physio-therapy was fully applied. Continuous epidural analgesiaallows the same level of pain management for physicaltherapy. Nevertheless, continuous peripheral nerveblock should be easier at home than is continuous epi-dural analgesia.Kotiniemi  et al. 24 emphasized the usefulness of post-operative pain control and play activities influenced by the hospital environment for behavioral modification inchildren. The authors recommended encouraging such play to help children cope with the challenging experi-ence of hospitalization. The use of disposable pumpspermitting rapid discharge of children would certainly  Fig. 1. Visual analog scale (VAS) values during physiotherapy. The  box  represents the 25th–75th percentiles; the  dark line  isthe median. The  extended bars  represent the 10th–90th percen-tiles, and the  dark circles  represent values outside this range.Fig. 2. Course of motor block values during the studied period. At each period, the  vertical lines  represent the 25th–75th per-centiles, and the  box  is the median value. 390  DADURE  ET AL.  Anesthesiology, V 102, No 2, Feb 2005  reduce the need for behavioral modification trainingdesigned to improve tolerance of extended hospitaliza-tion (fig. 3). Moreover, although cognitive behavioraltheory has documented efficacy against chronic pain, 25 the value of cognitive–behavioral psychotherapy has notbeen fully demonstrated in patients with CRPS I. 22 In conclusion, this study shows that 4-day CPNB asso-ciated with initial Bier block is effective against intracta-ble and recurrent CRPS I in children. A relevant decreasein short-term pain was observed in our population of children. This reduction in pain facilitated physiotherapy and cognitive–behavioral treatment for CRPS I. The useof disposable pumps permitted reduced hospital stay and continuation of this treatment at home. 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