E. Viel

Brachial plexus block with bupivacaine : effects of added alpha-adrenergic agonists : comparison between clonidine and epinephrine

The effects of clonidine and epinephrine, administered into the brachial plexus sheath, were evaluated in 60 patients who underwent surgery of the upper limb. All patients received 40 to 50 ml of 0.25% bupivacaine, injected into the brachial plexus sheath, using the supraclavicular technique. The patients were randomly allocated to two groups so that 30 patients received 150 μg clonidine hydrochloride (Group I), and 30 received 200 μg epinephrine (Group II). The quality and the duration of analgesia were assessed as well as, the possible side-effects. The block produced with the addition of clonidine was longer (994.2±34.2 vs 728.3±35.8 min) and superior to that with epinephrine (P<0.001). No major side-effects were recorded. We conclude that the injection of clonidine into the brachial plexus sheath is an attractive alternative to epinephrine to prolong the duration of analgesia following upper limb surgery under conduction anaesthesia.RésuméLes effets de l’addition d’agents agonistes alpha-adrénergiques à la bupivacaïne lors de blocs du plexus brachial ont été évalués chez soixante patients ayant une intervention chirurgicale sur le membre supérieur. L’ensemble des patients a reçu 40 à 50 ml de bupivacaïne à 0.25% pour réaliser un bloc du plexus brachial par voie sus-claviculaire. Les patients du groupe I (n=30) recevaient par la même voie 150 μg de clonidine, ceux du groupe II (n=30) 200 μg d’ adrénaline. La durée et la qualité de l’analgésie sont ensuite étudiées ainsi que les éventuels effets adverses. Une différence statistiquement significative a été retrouvée en ce qui concerne la durée d’analgésie qui était supérieure dans le groupe clonidine (994,2±34,2 min vs 728,3 ±35,8 min; P<0.001). Aucun effet adverse majeur n’est retrouvé. Les auteurs concluent à l’intérêt particulier de la clonidine pour prolonger la durée d’ analgésie après chirurgie du membre supérieur réalisée sous anesthésie régionale.

Neurolytic blockade of the obturator nerve for intractable spasticity of adductor thigh muscles.

Neurolytic blockade is one of the therapeutic possibilities to treat spasticity of various muscles. In patients with spasticity of the adductor thigh muscles, a percutaneous approach to the obturator nerve is often difficult. We describe a new approach to the obturator nerve and we examine its feasibility. The second objective was to assess the efficacy of obturator neurolysis for the management of adductor thigh muscle pain and spasticity associated with hemiplegia or paraplegia. Nerve blocks were performed via a combined approach using fluoroscopy and nerve stimulation to identify the obturator nerve. Neurolysis was performed by injection of 65% ethanol. We performed 27 blocks in 23 patients. Technical evaluation was achieved in terms of number of attempted needle insertions, time to accurate location of the nerve and success rate. The efficacy of the block was assessed using four scores: degree of alleviation of muscle spasm and triple flexion of the lower limb, improvement of gait and facilitation of hygienic care. Success rate of the technique was 100% with a time to accurate nerve location of 130 ± 35 s. Compared with scores measured immediately before the block, all studied parameters were significantly improved. Efficiency was significant on adductor muscle spasticity (p < 0.001 at 1 day and p < 0.01 at 60 and 120 months). Triple flexion was also significantly improved (p < 0.05 from 1 to 120 days), as well as gait (p < 0.02) and hygiene (p < 0.01) scores. No complications occurred. The combined approach of the obturator nerve represents a new technique which proved to be accurate, fast, simple, highly successful and reproducible. Obturator neurolysis was confirmed as an efficient and cost‐effective technique to reduce adductor muscle spasm and related pain and to improve gait and hygienic care in patients with neurological sequelae of stroke, head trauma or any lesion of the motor neurone.

Analgésie postopératoire par cathéter fémoral après fracture du col du fémur chez la personne âgée : étude prospective randomisée ☆

INTRODUCTION The usefulness of peripheral femoral nerve block for pain management after hip fracture has been established. This prospective and randomised study compared the analgesia effect of a continuous femoral nerve block (CF) versus two conventional analgesia procedures after hip fracture. PATIENTS AND METHODS Patients. (n=62) scheduled for surgery under spinal anaesthesia were prospectively included. After surgery, analgesia (48 hours) was randomised: group FC (femoral catheter, anterior paravascular approach, initial bolus followed by continuous infusion of ropivacaine 0.2%), group P (iv 2 g propacetamol/6 hours), group M (sc morphine, 0.05 mg/kg per 4 hour). Intravenous morphine titration was performed, followed by subcutaneous (sc) morphine every 4 hours according to the VAS score. The primary end-point was the morphine requirements. Secondary end-points were VAS score, side effects, and mortality. RESULTS Demographic data and surgical procedures were similar between groups. After morphine titration, the VAS pain score did not differ between groups. All patients in-group M received additional morphine. Morphine mean consumption was increased in CF group: 26 mg (5-42) versus P: 8 mg (3-12) (p=0.0001) or M: 19 mg (8-33) (p<0.006) while constipation was decreased in P group vs CF. Percentage of patients requiring no morphine was similar between P (n=6; 28%) and CF (n=6; 28%) and greater than M (n=0; 0%). Hospital discharge, cardiovascular or pulmonary complications and mortality after 6 months showed no statistical difference. CONCLUSION Continuous femoral nerve block provided limited pain relief after hip fracture did not reduced side effects and induced an expensive cost.

Article originalAnalgésie postopératoire par cathéter fémoral après fracture du col du fémur chez la personne âgée : étude prospective randomiséeAnalgesia after hip fracture repair in elderly patients: the effect of a continuous femoral nerve block: a prospective and randomised study☆

INTRODUCTION The usefulness of peripheral femoral nerve block for pain management after hip fracture has been established. This prospective and randomised study compared the analgesia effect of a continuous femoral nerve block (CF) versus two conventional analgesia procedures after hip fracture. PATIENTS AND METHODS Patients. (n=62) scheduled for surgery under spinal anaesthesia were prospectively included. After surgery, analgesia (48 hours) was randomised: group FC (femoral catheter, anterior paravascular approach, initial bolus followed by continuous infusion of ropivacaine 0.2%), group P (iv 2 g propacetamol/6 hours), group M (sc morphine, 0.05 mg/kg per 4 hour). Intravenous morphine titration was performed, followed by subcutaneous (sc) morphine every 4 hours according to the VAS score. The primary end-point was the morphine requirements. Secondary end-points were VAS score, side effects, and mortality. RESULTS Demographic data and surgical procedures were similar between groups. After morphine titration, the VAS pain score did not differ between groups. All patients in-group M received additional morphine. Morphine mean consumption was increased in CF group: 26 mg (5-42) versus P: 8 mg (3-12) (p=0.0001) or M: 19 mg (8-33) (p<0.006) while constipation was decreased in P group vs CF. Percentage of patients requiring no morphine was similar between P (n=6; 28%) and CF (n=6; 28%) and greater than M (n=0; 0%). Hospital discharge, cardiovascular or pulmonary complications and mortality after 6 months showed no statistical difference. CONCLUSION Continuous femoral nerve block provided limited pain relief after hip fracture did not reduced side effects and induced an expensive cost.

Is epidural anaesthesia using bupivacaine safe in patients with atrio‐ventricular conduction defects?

Bupivacaine is known to interact with the conductive system of the heart, also when used in epidural anaesthesia. Ten patients, undergoing bupivacaine epidural anasthesia for lower limb or pelvic surgery, who presented a history of cardiac conduction disturbances, were studied. The ECG was continuously monitored and a right ventricular bipolar electrode was used to monitor the following parameters: heart rate, QRS duration, QT, Atria‐His and His‐Ventricle intervals. No significant change was noticed, even in patients with a high grade conduction defect. The mean plasma level of bupivacaine was 0.33 ± 0.23 μg/ml. Based on this experience, it seems that lumbar epidural anaesthesia with bupivacaine can be safely used in patients with asymptomatic AV conduction abnormalities.

Clinical Application of Ropivacaine for the Lower Extremity

Ropivacaine is a new amide local anaesthetic, which is the first commercially available in its category as a pure S-(-) enantiomer. In most recent studies, ropivacaine exhibited a very close pharmacodynamic profile to equipotent doses of bupivacaine. Concentrations of 0.5%, 0.75% and 1% (5, 7.5 and 10 mg/mL, respectively) ropivacaine are used for intraoperative anaesthesia, while the concentration of 0.2% (2 mg/mL) is preferred for postoperative analgesia, either alone or in combination with opioids and/or clonidine. Ropivacaine is responsible for excellent postoperative analgesia following epidural and peripheral perineural injections, using single-shot injections and continuous infusions. Differential sensory/motor block is only apparent at low concentrations (0.2% and less). A significant amount of recent literature focuses on its use for peripheral blocks of the lower limbs, i.e. sciatic and femoral nerve blocks. The primary benefit of ropivacaine is its lower toxicity, mainly lower cardiotoxicity, following accidental intravascular injection. This higher therapeutic index leads to an improved safety profile as compared with potent local anaesthetics such as racemic bupivacaine. For that reason, ropivacaine is a good choice for both intraoperative and postoperative regional anaesthesia and analgesia.

Bénéfices-risques et modalités de surveillance des différentes techniques et méthodes d'analgésie postopératoire

This review aimed to determine the benefits-risks ratio of postoperative analgesia. The various agents usually used for intravenous postoperative analgesia (paracetamol, NSAIDs, opioids), and the techniques for postoperative analgesia (PCA, epidural, perinervous block) are analysed. The rules proposed for the monitoring of postoperative analgesia are considered.

Opioid and local anesthetic combination for brachial plexus block to provide postoperative analgesia.

To the Editor: We read with interest the article by Candido et al.1 and would like to thank them for having redesigned our previous study2 on the efficacy of buprenorphine to provide prolonged pain relief when added to local anesthetic for brachial plexus block. We agree with the authors on the need for using a shorter-acting local anesthetic than we did and also for having used a comparison with an “additive-free” control group. We would like to comment on the puzzling and conflicting results of the studies concerning opioids in peripheral nerve blocks and those administered intraarticularly. Many studies were published in the past decade showing conflicting results on the efficacy of various opioids (morphine, fentanyl, sufentanil, buprenorphine, butorphanol) in prolonging the duration of local anesthetics, especially in their ability to prolong analgesia. In our previous study, we obtained very wide ranges in the duration of analgesia, from 15 to 50 hours with buprenorphine. We think that discrepancies arise from 3 problems: (1) the use of long-acting local anesthetics in many studies; (2) the use of opioids that do not bind with the same affinity with all types and subtypes of opioid receptors; and (3) the heterogeneity of the studied populations. Indeed, most of the studies, which have been conducted in the postoperative setting, included roughly 2 types of patients: those suffering from acute pain (i.e., trauma), and those having surgery in a specific context of inflammatory disease (i.e., rheumatoid arthritis). Although the action of opioids on peripheral nerve was shown 22 years ago3, the evidence of their action on the immune response and on the inflammatory response4-6 is a more recent finding. Recently, peripherally selective -opioids, thus unable to cross the blood-brain barrier, have been shown to induce analgesic and also anti-inflammatory effects,7 purportedly by inhibiting peripheral release of proinflammatory peptides. Many observations, clinical as well as experimental, are consistent with the hypothesis that an inflammatory process seems to facilitate peripheral opioid mechanisms. In dental surgery, Likar et al.8 showed that 1 mg morphine combined with articaine and epinephrine produced prolonged pain relief in patients presenting with acute inflammatory tooth pain. The same treatment was not effective in elective dental surgery without inflammation. Binder et al.7 also showed that the anti-inflammatory response was sometimes delayed by 24 or 48 hours. This could be an explanation to the observed range of analgesic duration in the study of Candido et al. as well as in previous studies. In fact, the level of postoperative pain appears closely linked to the intensity of inflammation,9 and Pritchett10, in 1997, showed that the level of intra-articular substance P, which is a powerful inflammatory agent, may predict the level of postoperative pain relief. We therefore believe that further trials are necessary to assess the efficacy of buprenorphine or any other opioid, comparing “inflammatory” versus “noninflammatory” patients in the model of brachial plexus blocks.

Algodistrofia o síndrome doloroso regional complejo tipo I

Resumen La algodistrofia simpatica refleja se define como un sindrome doloroso articular y periarticular vinculado a trastornos vasomotores y desencadenado por diversas causas, que evoluciona en forma tipica desde una fase aguda hiperemica y dolorosa hasta una fase secundaria distrofica con rigidez y retracciones. La algodistrofia se observa con frecuencia en enfermedades neurologicas o del aparato locomotor. La fisiopatologia no es clara, pero la accion de los sistemas simpaticos de control central del dolor parece ser determinante. Solo el diagnostico clinico en fase precoz, confirmado por un aumento de captacion regional en la gammagrafia osea, permite aplicar un tratamiento combinando reeducacion funcional y medicamentos. El objetivo del tratamiento en fase inicial caliente es movilizar la zona afectada y prevenir la formacion de retracciones y adherencias, drenar el edema de los tejidos blandos, preservar la funcion y evitar la exclusion funcional del miembro afectado. A esto se anade la prescripcion de diversos medicamentos que han demostrado ser eficaces: corticoterapia transitoria, calcitonina en inyecciones subcutaneas o intramusculares, y difosfonatos. El efecto y la indicacion de los bloqueos simpaticos posganglionares (guanetidina, buflomedil) o ganglionares (bloqueo del ganglio estrellado o de la cadena simpatica lumbar) son motivo de controversia y no pueden constituir la via terapeutica unica o predominante. La algodistrofia es un sindrome doloroso que se observa en algunas enfermedades del aparato locomotor, en el que la prescripcion temprana de reeducacion y de medicamentos adecuados, asi como la excelencia en la coordinacion de las medidas terapeuticas, son indispensables para combatir con exito esta anomalia que, en caso de adoptarse medidas tardias y/o incoordinadas, suele avanzar de forma prolongada e invalidante.

Is Epidural Anaesthesia Using Bupivacaine Safe in Patients with Atrio-ventricular Conduction Defects?

Bupivacaine is known to interact with the conductive system of the heart, also when used in epidural anaesthesia. Ten patients, undergoing bupivacaine epidural anaesthesia for lower limb or pelvic surgery, who presented a history of cardiac conduction disturbances, were studied. The ECG was continuously monitored and a right ventricular bipolar electrode was used to monitor the following parameters: heart rate, QRS duration, QT, Atria-His and His-Ventricle intervals. No significant change was noticed, even in patients with a high grade conduction defect. The mean plasma level of bupivacaine was 0.33 +/- 0.23 micrograms/ml. Based on this experience, it seems that lumbar epidural anaesthesia with bupivacaine can be safely used in patients with asymptomatic AV conduction abnormalities.