RESUMEN
Attempts were made to place 8-cm 22G needles into the spinal canals of four preserved cadavers using the skin entry point most commonly associated with the lateral interscalene brachial plexus block or Winnie approach (that is, at the level of the cricoid cartilage). Eleven successful attempts were confirmed by computed tomography. Needle angles that were cephalad, transverse or slightly caudad were associated with entry into the spinal canal at depths of 5.0 cm or less from the skin. The only needle entry into the spinal canal with a needle angle of > 50 degrees to the transverse plane (< 40 degrees to the sagittal plane) entered the intervertebral foramen at a depth of 7.7 cm from the skin. We conclude that the use of markedly caudad angulations of needles no longer than 5.0 cm may minimise the chances of spinal canal entry and spinal cord damage.
Asunto(s)
Plexo Braquial , Bloqueo Nervioso/métodos , Canal Medular/anatomía & histología , Anciano , Anciano de 80 o más Años , Vértebras Cervicales/anatomía & histología , Vértebras Cervicales/diagnóstico por imagen , Femenino , Humanos , Masculino , Agujas , Bloqueo Nervioso/efectos adversos , Bloqueo Nervioso/instrumentación , Canal Medular/diagnóstico por imagen , Traumatismos de la Médula Espinal/prevención & control , Tomografía Computarizada por Rayos XRESUMEN
Imaging of the brachial plexus with MRI and standard two-dimensional (2D) ultrasound has been reported, and 2D ultrasound-guided regional anaesthetic block is an established technique. The aim of this study was to map the orientation of the brachial plexus in relation to the first rib, carotid and subclavian arteries, using three-dimensional (3D) ultrasound. A free-hand optically tracked 3D ultrasound system was used with a 12 MHz transducer. 10 healthy volunteers underwent 3D ultrasound of the neck. From the 3D ultrasound data sets, the outlines of the brachial plexus, subclavian artery and first rib were manually segmented. A surface was interpolated from the series of outlines to produce a spatially orientated 3D reconstruction of the brachial plexus. The brachial plexus could be mapped in all volunteers, although a variation in image resolution between individuals existed. Anatomical variations were demonstrated between the 10 volunteers; the most notable and clinically relevant was the alignment of the plexus divisions. 3D reconstructions illustrated the plexus, changing its orientation from a vertical alignment in the interscalene region to a more horizontal alignment in the supraclavicular fossa. Spatial mapping of the brachial plexus is possible with 3D ultrasound using the subclavian artery and first rib as landmarks. There is a deviation from the conventionally described anatomy and this may have implications for the administration of regional anaesthesia.
Asunto(s)
Plexo Braquial/diagnóstico por imagen , Adulto , Plexo Braquial/anatomía & histología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Costillas/anatomía & histología , Costillas/diagnóstico por imagen , Arteria Subclavia/anatomía & histología , Arteria Subclavia/diagnóstico por imagen , UltrasonografíaRESUMEN
OBJECTIVE: To examine the relationship between prolonged isoflurane sedation and reversible neurologic dysfunction in children requiring intensive care. DESIGN: Retrospective, case note review from January 1987 to August 1993. SETTING: Pediatric intensive care unit. PATIENTS: Twenty-nine children, aged 6 months to 10 yrs, requiring endotracheal intubation and mechanical ventilation for upper airway infection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fourteen patients with laryngotracheobronchitis (croup) and 15 patients with epiglottitis required endotracheal intubation and ventilation. These children were treated with different sedative and muscle relaxant drugs, including opiates, benzodiazepines and chloral hydrate. Twelve (41%) of 29 children were sedated with isoflurane (0.25% to 1.5%) for > 24 hrs. All patients subsequently developed reversible ataxia, agitation, hallucinations, and confusion lasting < or = 72 hrs postextubation. Neurologic dysfunction was not observed in 12 patients who did not receive isoflurane nor in five patients who received isoflurane for between 1 and 15 hrs. Neurologic signs resolved in all patients before hospital discharge, and all children had normal neurologic examinations 4 to 6 wks later as outpatients. CONCLUSIONS: A high occurrence rate of reversible neurologic dysfunction occurs when isoflurane is used as a sedative for > 24 hrs in pediatric patients.
Asunto(s)
Cuidados Críticos , Isoflurano/efectos adversos , Enfermedades del Sistema Nervioso/inducido químicamente , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Intubación Intratraqueal , Isoflurano/administración & dosificación , Masculino , Enfermedades del Sistema Nervioso/epidemiología , Respiración Artificial , Estudios Retrospectivos , Factores de Tiempo , Reino Unido/epidemiologíaRESUMEN
Continuous axillary nerve block was used to relieve pain after a chemical burn to the arm in a child on mechanical ventilation after liver transplantation. The analgesia was sufficient to replace parenteral analgesia and allow extubation.
Asunto(s)
Aprotinina/efectos adversos , Traumatismos del Brazo/etiología , Plexo Braquial , Quemaduras Químicas/etiología , Complicaciones Intraoperatorias , Bloqueo Nervioso/métodos , Dolor Postoperatorio/terapia , Axila , Bupivacaína , Femenino , Heroína , Humanos , Lactante , Trasplante de Hígado , Desconexión del VentiladorRESUMEN
A double-blind study was set up to investigate the effect of warming local anaesthetic solutions on the latency of onset of subclavian perivascular brachial plexus blocks. Twenty-four adult patients were randomly allocated into two equal groups. In group A the local anaesthetic was injected at room temperature, while in group B the local anaesthetic solution was prewarmed to 37 degrees C in a thermostatically controlled heating block. All blocks were performed using 0.5 ml/kg of a solution prepared by mixing equal volumes of 0.5% bupivacaine with adrenaline 1:200,000, and 1% prilocaine. The speed of onset of sensory blockade was significantly increased when the temperature of the local anaesthetic solution was increased to 37 degrees C. There were no adverse side effects in either group.