Aditivos de anestésicos locales/Additives to local anesthetics

Efectos facilitadores de la dexmedetomidina perineural en el bloqueo neuroaxial y periférico: una revisión sistemática y meta-análisis.  Facilitatory effects of perineural dexmedetomidine on neuraxial and peripheral nerve block: a systematic review and meta-analysis. Abdallah FW, Brull R. Department of Anesthesia and Pain Management, St Michael's Hospital, and Women's College Hospital, University of Toronto, Toronto, Canada. Br J Anaesth. 2013 Jun;110(6):915-25. doi: 10.1093/bja/aet066. Epub 2013 Apr 15. Abstract Nerve blocks improve postoperative analgesia, but their benefits may be short-lived. This quantitative review examines whether perineuraldexmedetomidine as a local anaesthetic (LA) adjuvant for neuraxial and peripheral nerve blocks can prolong the duration of analgesia compared with LA alone. All randomized controlled trials (RCTs) comparing the effect of dexmedetomidine as an LA adjuvant to LA alone on neuraxial and peripheralnerve blocks were reviewed. Sensory block duration, motor block duration, block onset times, analgesic consumption, time to first analgesic request, and side-effects were analysed. RESULTS: were combined using random-effects modelling. A total of 516 patients were analysed from nine RCTs. Five trials investigateddexmedetomidine as part of spinal anaesthesia and four as part of a brachial plexus (BP) block. Sensory block duration was prolonged by 150 min [95% confidence interval (CI): 96, 205, P<0.00001] with intrathecal dexmedetomidine. Perineural dexmedetomidine used in BP block may prolong the mean duration of sensory block by 284 min (95% CI: 1, 566, P=0.05), but this difference did not reach statistical significance. Motor block duration and time to first analgesic request were prolonged for both intrathecal and BP block. Dexmedetomidine produced reversible bradycardia in 7% of BP block patients, but no effect on the incidence of hypotension. No patients experienced respiratory depression. Dexmedetomidine is a potential LA adjuvant that can exhibit a facilitatory effect when administered intrathecally as part of spinal anaesthesia or peripherally as part of a BP block. However, there are presently insufficient safety data to support perineural dexmedetomidine use in the clinical setting. KEYWORDS: acute pain; regional techniques, anaesthetic techniques; regional; brachial plexus, analgesic techniques; subarachnoid, analgesics; postoperative, sympathetic nervous system; dexmedetomidine   http://bja.oxfordjournals.org/content/early/2013/04/14/bja.aet066.full.pdf Aditivos de los anestésicos locales para bloqueos nerviosos periféricos  Additives to local anesthetics for peripheral nerve blockade. Brummett CM, Williams BA. University of Michigan Health System, Ann Arbor, Michigan, USA. Int Anesthesiol Clin. 2011 Fall;49(4):104-16. doi: 10.1097/AIA.0b013e31820e4a49. Abstract Many additives to local anesthetics to prolong the duration of analgesia for peripheral nerve blocks have been studied. In this review, the authors focus on the more commonly described additives, including epinephrine, clonidine, dexmedetomidine, buprenorphine, dexamethasone, tramadol, sodium bicarbonate, and midazolam. While the primary focus of this review is the effect of the additive on the duration of analgesia, neurotoxicity and other safety concerns are also discussed. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427651/pdf/nihms398160.pdf  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3427651/ Atentamente Anestesiología y Medicina del Dolor www.anestesia-dolor.org