Núcleo Coeruleus. Neurotransmisores, Funciones y Patología
|
Dr. Mauricio Valenzuela-Harrington, Dr. Vicente Negrete-Díaz, Dr. Antonio Rodríguez-Moreno.
Departamento de Fisiología, Anatomía y Biología Celular. Universidad Pablo de Olavide. Sevilla, España
Anestesia en México 2007;19;155-166
Resumen
El Nucleus Coeruleus es la principal fuente de noradrenalina en el sistema nervioso central. Este complejo nuclear debido a sus aferencias y eferencias está involucrado en diversas y variadas funciones. Además está involucrado en diversas enfermedades y alteraciones del sistema nervioso central cuando su funcionamiento no es correcto. En esta revisión se describen estas funciones del nucleus coeruleus así como la forma en que participa en enfermedades del sistema nervioso tales como Enfermedad de Alzheimer, Parkinson, Depresión y estrés y su papel en procesos de drogodependencia y síndrome de abstinencia.
Palabras claves: Locus Coeruleus, noradrenalina, neuromodulador, receptores a y b adrenérgicos.
|
| Dexmedetomidina como adyuvante intratecal para analgesia postoperatoria |
Dexmedetomidine as an intrathecal adjuvant for postoperative analgesia.
Gupta R, Bogra J, Verma R, Kohli M, Kushwaha JK, Kumar S.
Indian J Anaesth 2011;55:347-51
Background: Spinal anaesthesia is the most common approach which is used for lower limb surgery. Dexmedetomidine is the recent drug which acts on α2-adrenergic receptors in the dorsal horn of the spinal cord to produce analgesic effects. Aim: Efficacy and safety of intrathecal dexmedetomidine added to ropivacaine. Setting and Design: Randomised double blind trial. Methods: Sixty patients were randomly allocated to receive intrathecally either 3 ml of 0.75% isobaric ropivacaine + 0.5 ml normal saline (Group R) or 3 ml of 0.75% isobaric ropivacaine + 5 μg dexmedetomidine in 0.5 ml of normal saline (Group D). Results: The mean time of sensory regression to S2 was 468.3±36.78 minutes in group D and 239.33±16.8 minutes in group R. Duration of analgesia (time to requirement of first rescue analgesic) was significantly prolonged in group D (478.4±20.9 minutes) as compared to group R (241.67±21.67 minutes). The maximum visual analogue scale score for pain was less in group D (4.4±1.4) as compared to group R (6.8±2.2). Conclusion: The addition of dexmedetomidine to ropivacaine intrathecally produces a prolongation in the duration of the motor and sensory block.http://www.ijaweb.org/temp/IndianJAnaesth554347-4409631_121456.pdf
|
| Dexmedetomidina atenúa la respuesta simpatoadrenal a la intubación traqueal y reduce los requerimientos anestésicos perioperatorios |
Dexmedetomidine attenuates sympathoadrenal response to tracheal intubation and reduces perioperative anaesthetic requirement.
Keniya VM, Ladi S, Naphade R
Indian J Anaesth 2011;55:352-7
Background: Dexmedetomidine, an α-2 adrenoreceptor agonist, is gaining popularity for its sympatholytic, sedative, anaesthetic sparing and haemodynamic stabilising properties without significant respiratory depression. Methods: We assessed the efficacy of dexmedetomidine in attenuating sympathoadrenal response to tracheal intubation and analysed reduction in intraoperative anaesthetic requirement. Sixty patients scheduled for elective surgery of more than 3 hours were randomly selected. Control group received isoflurane-opioid and study group received isoflurane-opioid-dexmedetomidine anaesthesia. Dexmedetomidine infusion in a dose of 1 μg/kg was given over 10 min before the induction of anaesthesia and was continued in a dose of 0.2-0.7 μg/kg/Hr until skin closure. All patients were induced with thiopentone, fentanyl and vecuronium. Haemodynamic variables were continuously recorded. Results: The need for thiopentone and isoflurane was decreased by 30% and 32%, respectively, in the dexmedetomidine group as compared to the control group. After tracheal intubation, maximal average increase was 8% in systolic and 11% in diastolic blood pressure in dexmedetomidine group, as compared to 40% and 25%, respectively, in the control group. Similarly, average increase in heart rate was 7% and 21% in the dexmedetomidine and control groups, respectively. Fentanyl requirement during the operation was 100±10 μg in the control group and 60±10 μg in the dexmedetomidine group. Conclusion: Perioperative infusion of dexmedetomidine is effective in attenuating sympathoadrenal response to tracheal intubation. It has significant anaesthetic and opioid sparing effect
|
| Dexmedetomidina y clonidina en anestesia epidural: una evaluación comparativa. |
Dexmedetomidine and clonidine in epidural anaesthesia: A comparative evaluation.
Bajwa SJ, Bajwa SK, Kaur J, Singh G, Arora V, Gupta S, Kulshrestha A, Singh A, Parmar SS, Singh A, Goraya S.
Indian J Anaesth 2011;55:116-21
Efforts to find a better adjuvant in regional anaesthesia are underway since long. Aims and objectives are to compare the efficacy and clinical profile of two α-2 adrenergic agonists, dexmedetomidine and clonidine, in epidural anaesthesia with special emphasis on their sedative properties and an ability to provide smooth intra-operative and post-operative analgesia. A prospective randomized study was carried out which included 50 adult female patients between the ages of 44 and 65 years of (American Society of Anaesthesiologists) ASAI/II grade who underwent vaginal hysterectomies. The patients were randomly allocated into two groups; ropivacaine + dexmedetomidine (RD) and ropivacaine + clonidine (RC), comprising of 25 patients each. Group RD was administered 17 ml of 0.75% epidural ropivacaine and 1.5 μg/kg of dexmedetomidine, while group RC received admixture of 17 ml of 0.75% ropivacaine and 2 μg/kg of clonidine. Onset of analgesia, sensory and motor block levels, sedation, duration of analgesia and side effects were observed. The data obtained was subjected to statistical computation with analysis of variance and chi-square test using statistical package for social science (SPSS) version 10.0 for windows and value of P< 0.05 was considered significant and P< 0.0001 as highly significant. The demographic profile, initial and post-operative block characteristics and cardio-respiratory parameters were comparable and statistically non-significant in both the groups. However, sedation scores with dexmedetomidine were better than clonidine and turned out to be statistically significant (P< 0.05). The side effect profile was also comparable with a little higher incidence of nausea and dry mouth in both the groups which was again a non-significant entity (P> 0.05). Dexmedetomidine is a better neuraxial adjuvant compared to clonidine for providing early onset of sensory analgesia, adequate sedation and a prolonged post-operative analgesia.
http://www.ijaweb.org/temp/IndianJAnaesth552116-3326202_091422.pdf
|
| Efectos de la dexmedetomidina agregada a ropivacaína caudal en cirugía pediátrica de abdomen inferior. |
Effects of dexmedetomidine added to caudal ropivacaine in paediatric lower abdominal surgeries.
Anand VG, Kannan M, Thavamani A, Bridgit MJ.
Indian J Anaesth 2011;55:340-6
Purpose: The objectives of this study were to compare the effects of caudal dexmedetomidine combined with ropivacaine to provide postoperative analgesia in children and also to establish its safety in the paediatric population. Methods: In a randomised, prospective, parallel group, double-blinded study, 60 children were recruited and allocated into two groups: Group RD (n=30) received 0.25% ropivacaine 1 ml/kg with dexmedetomidine 2 μg/kg, making the volume to 0.5 ml and Group R (n=30) received 0.25% ropivacaine 1 ml/kg + 0.5 ml normal saline. Induction of anaesthesia was achieved with 50% N 2 O and 8% sevoflurane in oxygen in spontaneous ventilation. An appropriate-sized LMA was then inserted and a caudal block performed in all patients. Behaviour during emergence was rated with a 4-point scale, sedation with Ramsay's sedation scale, and pain assessed with face, legs, activity, cry, consolability (FLACC) pain score. Results: The duration of postoperative analgesia recorded a median of 5.5 hours in Group R compared with 14.5 hours in Group RD, with a P value of <0.001. Group R patients achieved a statistically significant higher FLACC score compared with Group RD patients. The difference between the means of mean sedation score, emergence behaviour score, mean emergence time was statistically highly significant (P<0.001). The peri-operative haemodynamics were stable among both the groups. Conclusion: Caudal dexmedetomidine (2 μg/kg) with 0.25% ropivacaine (1 ml/kg) for paediatric lower abdominal surgeries achieved significant postoperative pain relief that resulted in a better quality of sleep and a prolonged duration of arousable sedation and produced less incidence of emergence agitation following sevoflurane anaesthesiahttp://www.ijaweb.org/temp/IndianJAnaesth554340-4341177_120331.pdf
|
| Papel funcional de los receptores alfa-1 en la regulación del flujo sanguíneo cerebral. |
The functional role of the alpha-1 adrenergic receptors in cerebral blood flow regulation.
Purkayastha S, Raven PB.
Indian J Pharmacol [serial online] 2011 [cited 2011 Sep 15];43:502-6.
Cerebral vasculature is richly innervated by the α-1 adrenergic receptors similar to that of the peripheral vasculature. However, the functional role of the α-1adrenergic receptors in cerebral blood flow (CBF) regulation is yet to be established. The traditional thinking being that during normotension and normocapnia sympathetic neural activity does not play a significant role in CBF regulation. Reports in the past have stated that catecholamines do not penetrate the blood brain barrier (BBB) and therefore only influence cerebral vessels from outside the BBB and hence, have a limited role in CBF regulation. However, with the advent of dynamic measurement techniques, beat-to-beat CBF assessment can be done during dynamic changes in arterial blood pressure. Several studies in the recent years have reported a functional role of the α-1adrenergic receptors in CBF regulation. This review focuses on the recent developments on the role of the sympathetic nervous system, specifically that of the α-1 adrenergic receptors in CBF regulation.http://www.ijp-online.com/text.asp?2011/43/5/502/84950
|
|
No hay comentarios:
Publicar un comentario