Pain on injection from propofol may be avoided by changing its formulation.

BACKGROUND: After using propofol for a decade, pain on injection had been considered routine by patients and medical personnel. When given propofol from a different manufacturer, patients did not complain. Two preparations of propofol were compared. METHODS: A comparative, double-blind, randomized study was conducted in 22 adult patients undergoing pain relief procedures; they received sedation by an intravenous injection of 1.7 mg/kg of propofol and then were treated with paravertebral injections. Pain on injection was assessed by verbal complaint, movement of the extremity, of the whole body and recollection of pain at induction, when discharged. Propofol from Baxter Laboratories, mixed with either 5 ml of 2% lidocaine or 5 ml of NaCl 0.9%, was compared with propofol Laboratorios Gray, which was similarly mixed. Injections were randomly administered four times, blindly, to each of 22 patients. Statistical analysis was conducted using the analysis of variance method. RESULTS: A total of 352 propofol injections were given. Each of the four propofol solutions was administered 88 times; of patients receiving Baxter propofol+saline, 74 (84%) had pain; when mixed with 2% lidocaine 45 (50.2%) complained. After propofol Gray with NaCl 0.9% was given, two patients (2.2%) experienced pain. Propofol Gray with 2% lidocaine produced no pain. None of the latter group remembered having pain, whereas, those given propofol Baxter 54 (61.3%) and 26 (29.5%) remembered experiencing pain at injection. Pain on injection was prevented and statistically reduced (<0.01) with the propofol from Laboratorios Gray. CONCLUSIONS: By changing the formulation (size of molecules and their dispersion) of propofol, pain on injection was avoided.

Défi cits neurológicos y aracnoiditis secundarios a anestesia neuroaxial: rol de parestesias, punciones durales, anestésicos locales y género. Protocolo para su tratamiento / Neurological defi cit and arachnoiditis secondary to neuroaxial anesthesia: role of paresthesia, dural puncture, local anesthetics and gender. Treatment protocol

Introducción: De las complicaciones de la anestesia neuroaxial, la aracnoiditis y el déficit neurológico representan uno de los problemas más serios a los que pueda enfrentarse el anestesiólogo, aun cuando la frecuencia real es desconocida las consecuencias funcionales para los pacientes y legales para el médico son devastadoras, debido principalmente al hecho que la mayor parte de los pacientes no son tratados con oportunidad y las probabilidades de un desenlace catastrófico aumentan. Material y método: Revisión de casos. Resultados: Se presenta una serie de casos en los que se analizan los factores que posiblemente influyeron en la presencia de las complicaciones, los tratamientos empleados y su eficacia para disminuir la incapacidad remanente y lograr su recuperación, así como el resultado de aplicarlo oportunamente. Discusión: Es necesario reconocer que una vez que estas complicaciones se presentan, el objetivo principal es iniciar un plan terapéutico que evite o disminuya las secuelas permanentes, para lo cual se requiere iniciar inmediatamente un tratamiento específico que permita la pronta recuperación de la función; sin embargo, en la actualidad, aún no hay un protocolo de tratamiento que haya demostrado ser eficaz en la disminución de las secuelas (AU)

Introduction: Among the complications of neuroaxial anesthesia, arachnoiditis and neurological deficit represent one of the most serious problems that anesthesiologists can face. Although the real frequency of this complication is unknown, the functional consequences for the patient and legal repercussions for the physician are devastating, mainly because most patients are not treated in a timely fashion, increasing the probability of a catastrophic outcome. Methods: Case review. Results: We reviewed a series of cases and analyzed the factors that possibly influenced the presence of complications, the treatments used and their effectiveness in reducing permanent disability and in achieving recovery, as well as the results of their timely application. Discussion: Once these complications appear, the primary objective is to initiate a therapeutic plan that avoids or reduces permanent sequels. To do this, specifi c treatment that allows functional recovery must be started immediately. However, currently there is no treatment protocol with demonstrated effectiveness in reducing sequels (AU)

Eficacia y tolerabilidad de esteroides epidurales vs. dosis bajas de esteroides mas metamizol mas D-propoxifeno administrados por vía paravertebral en pacientes con síndrome post-laminectomía / Efficacy and tolerability of epidural steroids vs low doses of steroids plus metamizol plus propoxyphene administered paravertebrally for postaminectomy syndrome patients

El reconocimiento de la acción antinociceptiva de los antiinflamatorios no esteroideos (AINEs) ha motivado su combinación con dosis moderadas de opiáceos con objeto de obtener una mayor analgesia, mientras que se reduce la necesidad de emplear dosis altas de esteroides. Un grupo de 142 pacientes adultos, que habían desarrollaron radiculopatía y lumbalgia después de la primera discectomia, en los que se demostró radiologicamente fibrosis y cicatriz periradicular, en el sitio de operación, se dividieron en dos subgrupos al azar. El grupo A (69 pacientes), fue tratado con inyecciones peridurales de 80 mg de metilprednisolona (MTP) en 3ml de bupivacaína 0.25% (BPV) después de obtener medidas controles de dolor, actividad física y la ingestión de medicamentos usando el Esquema del Progreso del Dolor, obteniendo un promedio control antes de iniciar el tratamiento. El grupo B (73 pacientes) fue tratado con inyecciones paravertebrales en los niveles L4-L5 y L5-S1, de 5 mg de metamizol (DPN), y 12.5 mg de propoxifeno (PPX) agregados a 10 mg de MTP y 1 ml de BPV 0.5%, bilateralmente en cuatro sesiones. Las mismas evaluaciones se llevaron a cabo cada 3 semanas después de cada tratamiento. Todos los pacientes mejoraron clínicamente, sin observarse diferencias significativas entre ambos grupos; Cuando se compararon los valores totales de mejoría clínica, se observaron los niveles controles significativos (p> 0.05) solo cuando se compararon con las mediciones de mejoría clínica, tomadas antes de iniciar el tratamiento en ambos grupos. Se presentaron efectos secundarios como incremento de peso, equimosis, edema fascies lunar y eritema facial en los pacientes del grupo A. La punción dural incidental (3) y cefalea por punción dural (2) se encontraron solo en el grupo A. Un paciente requirió ser tratado con un parche hematico epidural. Ocurrió parestesia en 1 paciente de cada grupo. No se encontraron diferencias significativas de mejoria entre grupos de pacientes con radiculopatia post-laminectomia lumbar, al ser tratados con MTP y BPV peridural y un grupo semejante que recibio la mitad de la dosis de MTP, mas BPV, DPN y PPX, en los espacios paravertebral L4-L5 y L5-S1. Los efectos secundarios y la morbilidad predominaron en el grupo tratado con inyecciones peridurales. Inyectando fuera del canal vertebral dosis reducidas de un opiáceo y de un antiinflamatorio, permitió usar solo la mitad de la dosis total de MTP. Ya que se obtiene una mejoría semejante, al evitar los efectos indeseables de los esteroides, así como las posibles complicaciones típicas de inyecciones epidurales, hacen de esta modalidad terapéutica una alternativa definitiva (AU)

As the clinical applications of the central antinociceptive action of the non-steroidal antiinflammatory agents have been recognized, their combination with mild doses of opiods has been explored in order to be able to reduce or eliminate the repetitious usage of steroids. A group of 152 adult patients with recurrent radiculopathy after the first laminectomy, at either L4-L5 or L5-S1 levels, in whom periradicular fibrosis and scarring had been shown at MRI exam, was separated at random into two subgroups. Subgroup A included 69 patients that were treated with four epidural injections of 80mg of methylprednisolone (MTP) in 3ml of 0.25% bupivacaine (BPV). Changes in pain level, physical activity and the type of medications used were followed using the Pain Progress Score that evaluates five parameters graded from 0 to 2, before initiating treatment and again before each of the three subsequent injections, given at three week intervals. Subgroup B included 73 patients treated by paravertebral injections of 40mg of MTP, 50mg of dipyrone (DPN), 12.5mg of propoxyphene (PPX) and 1ml of 0.5% BPV at the L4-L5 and L5-S1 spaces, bilateral. All patients improved clinically without observing statistically significant differences between the two groups; however, there was a significant difference (p< 0.05) when the post-treatment scores were compared to the control values, at every evaluation. There was however an important variant, as the patients in group A had more side effects (increased weight, edema, echymosis and moon fascies) and developed complications derived from the epidural injections (3 incidental dural punctures, two postdural puncture headaches, one of which required an epidural blood patch, as treatment). Similar clinical improvement was seen from either of the two treatment modalities studied; however, since most of the side effects and the morbidity typically observed after a series of epidural injections of steroids can be obviated by administering a reduced dose of steroids, an antiinflamatory agent and a low dose opiate in the paravertebral spaces adjacent to the previously operated level, this therapeutic alternative is recommended (AU)

Myelopathy with syringomyelia following thoracic epidural anaesthesia.

Under general anaesthesia and muscle relaxation, a thoracic epidural catheter was inserted at the T8-T9 level in a 7-year-old boy scheduled to have a Nissen fundoplication to provide postoperative analgesia. After 4 ml of lignocaine 1.5% was injected through the catheter, hypotension resulted. Fifty-five minutes later 5 ml of bupivacaine 0.25% produced the same effect. In the recovery room a similar injection resulted in lower blood pressure and temporary apnoea. Sensory and motor deficits were noted the next day and four days later magnetic resonance imaging demonstrated spinal cord syringomyelia extending from T5 to T10. Four years later, dysaesthesia from T6 to T10 weakness of the left lower extremity and bladder and bowel dysfunction persist. The risks of inserting thoracic epidural catheters in patients under general anaesthesia and muscle relaxation are discussed, emphasising the possibility of spinal cord injury with disastrous consequences.

Justificación de la denominación de nuestraespecialidad: algiología / Rationale for the name of our speciality: algiology

No disponible

Neurologic deficits and arachnoiditis following neuroaxial anesthesia.

Of late, regional anesthesia has enjoyed unprecedented popularity; this increase in cases has brought a higher frequency of instances of neurological deficit and arachnoiditis that may appear as transient nerve root irritation, cauda equina, and conus medullaris syndromes, and later as radiculitis, clumped nerve roots, fibrosis, scarring dural sac deformities, pachymeningitis, pseudomeningocele, and syringomyelia, etc., all associated with arachnoiditis. Arachnoiditis may be caused by infections, myelograms (mostly from oil-based dyes), blood in the intrathecal space, neuroirritant, neurotoxic and/or neurolytic substances, surgical interventions in the spine, intrathecal corticosteroids, and trauma. Regarding regional anesthesia in the neuroaxis, arachnoiditis has resulted from epidural abscesses, traumatic punctures (blood), local anesthetics, detergents, antiseptics or other substances unintentionally injected into the spinal canal. Direct trauma to nerve roots or the spinal cord may be manifested as paraesthesia that has not been considered an injurious event; however, it usually implies dural penetration, as there are no nerve roots in the epidural space posteriorly. Sudden severe headache while or shortly after an epidural block using the loss of resistance to air approach usually suggests pneumocephalus from an intradural injection of air. Burning severe pain in the lower back and lower extremities, dysesthesia and numbness not following the usual dermatome distribution, along with bladder, bowel and/or sexual dysfunction, are the most common symptoms of direct trauma to the spinal cord. Such patients should be subjected to a neurological examination followed by an MRI of the effected area. Further spinal procedures are best avoided and the prompt administration of IV corticosteroids and NSAIDs need to be considered in the hope of preventing the inflammatory response from evolving into the proliferative phase of arachnoiditis.

Leg edema from intrathecal opiate infusions.

Despite the increasing popularity of intrathecal infusions to treat patients with long-term non-cancer-related pain, this therapy is not without serious side-effects. Five out of 23 patients who had intrathecal infusions of opiates for longer than 24 months developed leg and feet edema. As predisposing factors, cardiovascular disease, deep venous thrombosis, peripheral vascular disease, and venous stasis of the lower extremities were considered. Every patient who developed pedal and leg edema after the implantation of an infusion pump was also found to have leg edema and venous stasis prior to the time when the pump was inserted. This complication was severe enough to limit their physical activity, and to produce lymphedema, ulcerations and hyperpigmentation of the skin. Reduction of the edema occurred when the dose of the opiate was decreased, and in two cases in which the infusion was discontinued, there was almost complete resolution of the syndrome. It appears that the pre-existence of pedal edema and of venous stasis is a relative contraindication to the long-term intrathecal infusion of opiates in patients with chronic non-cancer pain.

Evaluación de la neurotoxicidad de la indometacina administrada en forma crónica en el espacio intratecal de ratas / Assessment of the neurotoxicity of indometacine administered chronically in the intrathecal space in rats

Objetivos: Evaluar la posible neurotoxicidad de la indometacina por vía intratecal.Material y métodos: Un estudio prospectivo, doble ciego se llevó a cabo en 10 ratas adultas empleando una preparación diseñada a infundir continuamente 20 µg . m l- 1 de indometacina a través de un catéter en el espacio subaracnoideo usando una microbomba implantada, por 11 días. Otro grupo de 10 ratas recibió infusiones similares de solución salina al 0,9 por ciento, por el mismo periodo.Resultados: Todos los animales sobrevivieron el periodo de observación sin alteraciones neurológicas ni de comportamiento.A la autopsia, estudios macroscópicos y microscópicos no demostraron lesiones neurotóxicas definitivas. Dos ratas en cada grupo tuvieron en la médula espinal signos de inflamación crónica inespecífica. En un espécimen del grupo que recibió indometacina, se notó leve congestión vascular en la pia; estos hallazgos se adjudican a la presencia del catéter, que actuaría como cuerpo extraño.Conclusiones: Varios estudios realizados en preparaciones de la médula espinal han demostrado una función antálgica de un número de los AINEs a nivel del sistema de receptores NMDA y de prostaglandinas medulares. Los estudios aquí reportados demostraron la ausencia de neurotoxicidad específica producida por la infusión intratecal continua de indometacina durante once días (AU)

[Original contributions of Latin Americans to anesthesiology]. / Contribuciones originales de latinoamericanos a la anestesiología.

The original contributions of Latin American physicians to the science of anesthesiology are described. Many contributions have been unfairly ignored mainly because they were never published in English, but others have likewise been passed over even when published in the most prestigious journals in the field. Although many discoveries by Latin Americans have been made in the area of regional anesthesia, a considerable number of contributions have involved other aspects of anesthesia as well.

Modifications to the postanesthesia score for use in ambulatory surgery.

The Aldrete Score has withstood the changes in anesthesia and surgical care that have developed in the past three decades. Nevertheless, it is imperative that (1) a modification is made to incorporate the most effective monitor of the respiratory and hemodynamic functions, e.g., pulse oximetry; and (2) the five indices previously used be expanded by incorporating five more indices including dressing, pain, ambulation, fasting/feeding, and urine output to evaluate patients undergoing ambulatory surgery and anesthesia. A patient's recovery from anesthesia and surgery, using 10 indices graded 0, 1, or 2, would provide criteria for street fitness and discharge to home when the patient reaches a postanesthesia recovery score of 18 or higher.

Infections from extended epidural catheterization in ambulatory patients.

BACKGROUND AND OBJECTIVES: Patients with severe and noncancer pain were treated with prolonged epidural infusions of analgesics in their homes, and the incidence of infection was determined. METHODS: In 504 adult patients, 3,164 polyamide lumbar epidural catheters were infused with analgesics of low-dose bupivacaine and fentanyl intermittently from 2 to 80 days at their home. When patients developed fever, headache, back pain, and leukocytosis, the presence of infection was confirmed by either computed tomographic scan, epidurogram, or sonogram. RESULTS: Nine infections (0.27%) occurred. Of these, two were epidural abscesses, two were fascitis, and five were cellulitis. Staphylococcus epidermidis was cultured in every case. All of them were treated with 1.5 g intravenous cefuroxime sodium every 8 hours. None of the patients required surgical intervention. In a subgroup of patients treated with the first 1,462 infused catheters, seven infections developed (0.4%), whereas in the subsequent 1,702 cases that received prophylactic penicillin or erythromycin, in 6-day cycles, there were only two infections (0.11%). CONCLUSIONS: Temporary epidural infusions of analgesics up to 80 days are feasible in ambulatory patients with a low rate of infections. Preliminary observations appear to indicate that prophylactic antibiotics given intermittently further reduce the feasibility of infections. However, these observations may not apply to longer-lasting epidural infusions.

Skin to cervical epidural space distances as read from magnetic resonance imaging films: consideration of the "hump pad.".

STUDY OBJECTIVE: To measure the distances from the skin to the epidural space (DSES) of the lower cervical and upper thoracic intervertebral spaces. DESIGN: Retrospective review of films of the cervical spine as obtained by magnetic resonance imaging (MRI). SETTING: Health care facility that provides diagnosis and treatment of patients with chronic pain. MEASUREMENTS AND MAIN RESULTS: MRI sagittal films of 100 patients, who had diagnostic studies for chronic headaches and cervicobrachial radiculopathy, were reviewed. Measurements were made of DSES, the dural sac, and the spinal cord by centimeter ruler. Estimates were also made of the width of the epidural space by measuring the distance from the ligamentum flavum to the dural sac. The longest DSES were noted at C6-7 and C7-T1 levels, with a mean of 5.7 cm, but they decreased to a mean of 5.4 cm at the T1-2, and to 4. 7 cm at the T2-3 intervertebral spaces. One of the major factors in this variability was the presence of an accumulation of fatty tissue along the lower cervical and upper thoracic area, which the authors named the "hump pad." This accumulation appears to be thicker in obese patients, with a slight correlation coefficient with the patient's weight. The distances from ligamentum flavum to dural sac, representing the depth of the epidural space, averaged 0.3 cm, 0.4 cm, 0.5 cm, and 0.4 cm, respectively. CONCLUSIONS: In the cervical spine, DSES varies from space to space. In obese individuals, the fat pad may increase DSES at the lower cervical intervertebral spaces. The longest mean distances from the ligamentum flavum to the dural sac and to the spinal cord were found at the T1-2 and T2-3 levels, precisely where DSES is shorter. All things being equal, the upper thoracic intervertebral spaces appeared to provide a greater margin of safety for insertion of epidural catheters to treat cervicobrachial radiculopathies.

Infusiones epidurales en pacientes ambulatorios con dolor crónico

Desde 1985 hasta la actualidad, el uso del espacio epidural para la infusión de medicamentos, se ha desarrollado enormemente en diferentes campos de la medicina. En obstetricia no sólo ha permitido el alivio del dolor durante los diferentes períodos del parto, sino que también esto se lleva a cabo de tal manera que la paciente se mantiene ambulante. Su utilización en Cirugía ha permitido la expansión de dicho procedimiento en el área de la pediatría y en síndromes dolorosos agudo y crónicos oncológicos y no oncológicos, proveyendo analgesia efectiva durante los procesos agudos. Además de esta cualidad, les brinda mejor calidad de vida y una incorporación parcial o total a las actividades diarias de los pacientes con padecimientos crónicos. En la actualidad nuestra experiencia se basa en la utilización de infusiones epidurales de dosis bajas de anestésicos locales y opioides aplicados a diferentes niveles de la columna vertebral, en pacientes ambulatorios con dolor de origen no canceroso, luego que estos han sido tratados previamente con otros procedimientos sin encontrar mejoría. Es importante señalar, que los pacientes deben reunir ciertas condiciones para su elegibilidad, que van desde el diagnóstico y estudios radiológicos precisos, hasta evoluciones psicológicas. Una vez aceptado el paciente, es instruido y educado en todo lo relacionado con el tratamiento (procedimiento, contenido y control de las infusiones, complicaciones, etc) con la finalidad de satisfacer las necesidades del paciente y obtener su permiso legal. En tal forma hemos podido implantar catéteres de polietileno durante 162 días, comectados a bombas de infusión desechables y de bajo costo. Los resultados favorables obtenidos y el bajo costo de dicho procedimiento al compararlo con otros procesos más invasivos, complicados y quizás con bajo porcentaje de efectividad, ha permitido abrir nuestras mentes a otras posibles aplicaciones como litiasis renal, pancreatitis crónica intermitente, reemplazos de rodilla, etc. Igualmente es nuestro deseo que sea accesible a personas de limitados recursos económicos, brindándoles la satisfacción de vivir una vida libre de dolor físico y mental