Efecto del fentanilo intratecal en hiperlagesia secundaria posoperatoria de cirugía ligamento cruzado anterior de rodilla / Effect of Intrathecal fentanyl on secondary hyperalgesia, in patients undergoing anterior cruciate ligament repair

BACKGROUND AND OBJECTIVES: Fentanyl addition is a common practice when administering spinal anesthesia. Intrathecal fentanyl has been associated to increased postoperative pain and increase morphine consumption, but considered to be related to acute opioid tolerance. This prospective, randomized, blind study evaluates the effect of intrathecal fentanyl in the development of secondary hyperalgesia, measured with Von Frey filaments, in patients undergoing anterior cruciate ligament repair. METHODS: 46 patients having anterior cruciate ligament repair, received intrathecal hyperbaric bupivacaine 13.5 mg with fentanyl 20 mcg or no fentanyl addition. Light touch pain threshold was measured with von Frey filaments before anesthesia, at 6 and 24 hours post anesthesia in the non-operated thigh and in the forearm. Visual analogue pain scores and morphine consumption were also measured at the same time. RESULTS: Baseline thresholds to mechanical stimuli were similar in both groups. In the forearm, analysis showed a decreased threshold for the non-fentanyl group at 24 h p = 0.036. In the lower extremity, control and treatment group showed lower thresholds (secondary hyperalgesia) p = 0.002 but no difference between them p = 0.795. VAS score and morphine consumption did not differ among groups. CONCLUSIONS: Spinal fentanyl added to hyperbaric bupivacaine showed no evidence of an augmented state of hyperalgesia after ACL repair, neither by pain threshold modification nor clinical outcomes. On the contrary, at 24 h, fentanyl may have a protective effect at levels above the spinal block.

ANTECEDENTES Y OBJETIVOS: El uso de fentanilo es una práctica común en la administración de anestesia espinal. Su aplicación se ha asociado a un aumento del dolor post operatorio y a un aumento en el uso de morfina; por otro lado, se ha vinculado a una tolerancia aguda a opioides. El siguiente estudio prospectivo, randomizado y ciego, evalúa los efectos del fentanilo intratecal en la aparición de hiperalgesia secundaria, medida a través de filamentos Von Frey, en pacientes operados de ligamento cruzado anterior. METODOLOGÍA: Se incluyeron a 46 pacientes operados de ligamento cruzado anterior (LCA) con una dosis intratecal de bupivacaína hiperbárica de 13,5 mg; con y sin la adición de fentanilo de 20 mcg. Se midió el umbral del dolor mecánico, a través de filamentos Von Frey, antes de la anestesia, a las 6 y 24 horas postanestesia en el muslo no operado y en el antebrazo. Al mismo tiempo, se midió la puntuación del dolor en la escala verbal numérica (EVN) y el consumo de morfina. RESULTADOS: Los umbrales basales ante la estimulación mecánica resultaron similares en ambos grupos. En el antebrazo, el análisis mostró una disminución del umbral en el grupo de pacientes sin fentanilo, a las 24 h, p = 0,036 comparado con uso de fentanilo. En el muslo, el grupo control y tratamiento mostró umbrales más bajos (hiperalgesia secundaria) p = 0,002; no obstante, no se mostraron diferencias entre ellos. No se mostraron diferencias entre las puntuaciones de la EVN y el consumo de morfina en los dos grupos. CONCLUSIÓN: No hay evidencia que la adición de fentanilo espinal, a la dosis de bupivacaína hiperbárica, haya contribuido a un aumento en la hiperalgesia tras la reparación del LCA, medido por la modificación del umbral del dolor, ni en los resultados clínicos. Al contrario a las 24 h fentanilo puede tener un efecto protector de la hiperalgesia secundaria sobre el nivel del bloqueo espinal.

Influencia de la posición en la visualización con ultrasonido del nervio ciático en la fosa poplítea por médicos en formación / Patient positioning and ultrasound visualization of the sciatic nerve in the fossa by anesthesia residents

OBJECTIVE: Evaluate the effect of the patients' position in obtaining a good quality image of the sciatic nerve at the popliteal fossa by anesthesiology trainees. METHODS: First and 2nd year residents of our anesthesiology program scanned de right popliteal fossa of a unique subject. The subject laid in 3 different positions (supine, lateral and prone). Before the scanning, residents reviewed a video showing basic ultrasound probe management and images of the sciatic nerve at the popliteal fossa. Time elapsed upon receiving the ultrasound probe and obtaining a good quality image was measured (at least 70% counter definition and 3 clearly identified structures within the nerve). An evaluator (blinded to the subject position) determined during real time observation the quality of the image. Residents completed a questionnaire regarding the experience lived. RESULTS AND CONCLUSIONS: 26 residents completed the study. There were no statistical differences in the overall time needed by residents to obtain a good quality image in the 3 different positions. Although 96% felt that position influenced the ability to obtain good image. From this experience residents would prefer to do an US guided popliteal block on the prone position.

OBJETIVOS: Evaluar la influencia de la posición del paciente en la obtención de una imagen de calidad del nervio ciático a nivel poplíteo por médicos en formación del programa de anestesiología. METODOLOGÍA: Médicos en formación del programa de Anestesiología examinarán desde la cara posterior la fosa poplítea derecha de un único sujeto en tres posiciones diferentes. Previamente serán expuestos a un video del uso del ecógrafo y de imágenes del nervio ciático a nivel poplíteo. Se consignará el tiempo desde que reciben el transductor hasta obtener imagen del nervio ciático con al menos 70% de definición de contorno y más de 3 estructuras visibles en su interior. Un investigador en tiempo real, ciego a la posición del modelo, decidirá si la imagen cumple los criterios. Finalmente completan una encuesta sobre apreciación subjetiva de la experiencia. RESULTADOS Y CONCLUSIONES: Se evaluaron 26 residentes en total. No hubo deferencias en el tiempo que necesitaron para obtener una imagen de buena calidad del nervio ciático a nivel de la fosa poplítea en las distintas posiciones.

Perioperative lumbar plexus block and cardiac ischemia in patients with hip fracture: randomized clinical trial / Bloqueio perioperatório do plexo lombar e isquemia cardíaca em pacientes com fratura de quadril: ensaio clínico randomizado

Abstract Background Perioperative myocardial ischemia is common among patients undergoing hip fracture surgery. Our aim is to evaluate the efficacy of perioperative continuous lumbar plexus block in reducing the risk of cardiac ischemic events of elderly patients undergoing surgery for hip fractures, expressed as a reduction of ischemic events per subject. Methods Patients older than 60 years, ASA II-III, with risk factors for or known coronary artery disease were enrolled in this randomized controlled study. Patients were randomized to conventional analgesia using opioid intravenous patient-controlled analgesia or continuous lumbar plexus block analgesia, both started preoperatively and maintained until postoperative day three. Continuous electrocardiogram monitoring with ST segment analysis was recorded. Serial cardiac enzymes and pain scores were registered during the entire period. We measured the incidence of ischemic events per subject registered by a continuous ST-segment Holter monitoring. Results Thirty-one patients (intravenous patient-controlled analgesia 14, lumbar plexus 17) were enrolled. There were no major cardiac events during the observation period. The number of ischemic events recorded by subject during the observation period was 6 in the lumbar plexus group and 3 in the intravenous patient-controlled analgesia group. This difference was not statistically significant (p = 0.618). There were no statistically significant differences in the number of cases with increased perioperative troponin values (3 cases in the lumbar plexus group and 1 case in the intravenous patient-controlled analgesia group) or in terms of pain scores. Conclusions Using continuous perineural analgesia, compared with conventional systemic analgesia, does not modify the incidence of perioperative cardiac ischemic events of elderly patients with hip fracture.

Resumo Justificativa A isquemia miocárdica perioperatória é comum em pacientes submetidos à cirurgia de fratura de quadril. Nosso objetivo foi avaliar a eficácia do bloqueio perioperatório contínuo do plexo lombar na redução do risco de eventos cardíacos isquêmicos em pacientes idosos submetidos à cirurgia para fraturas de quadril, expresso como uma redução de eventos isquêmicos por indivíduo. Métodos Pacientes com mais de 60 anos de idade, ASA II-III com fatores de risco para ou com doença coronariana conhecida foram incluídos neste estudo controlado e randomizado. Os pacientes foram aleatorizados para analgesia convencional usando analgésicos opioides para administração de analgesia intravenosa controlada pelo paciente (Intravenous Patient-Controlled Analgesia - IVPCA) ou analgesia contínua com o bloqueio do Plexo Lombar (PL), ambas iniciadas no pré-operatório e mantidas até o terceiro dia de pós-operatório. Monitoração contínua de ECG com análise do segmento ST foi registrada. Enzimas cardíacas seriadas e escores de dor foram registrados durante todo o período. Medimos a incidência de eventos isquêmicos por indivíduo registrados com monitoração contínua do segmento ST via Holter. Resultados Trinta e um pacientes (IVPCA 14, PL 17) foram incluídos. Não houve eventos cardíacos sérios durante o período de observação. O número de eventos isquêmicos registrados por sujeito durante o período de observação foi de seis no grupo PL e três no grupo IVPCA. Essa diferença não foi estatisticamente significativa (p = 0,618). Não houve diferenças estatisticamente significativas no número de casos com aumento dos valores de troponina no perioperatório (três casos no grupo LP e um caso no grupo IVPCA) ou em termos de escores de dor. Conclusões O uso da analgesia perineural contínua comparado ao da analgesia sistêmica convencional não modifica a incidência de eventos isquêmicos cardíacos no período perioperatório de pacientes idosos com fratura de quadril.

La simulación puede mejorar la seguridad de los pacientes sometidos a procedimientos endoscópicos gastrointestinales bajo sedación / Simulation can improve patients’ security in gastrointestinal endoscopic procedures under sedation

background: Appropriate sedation is crucial for a successful gastrointestinal endoscopy procedure (GEP); however, this is associated with adverse events, therefore adequate capacitation in this subject is mandatory. Simulation is an excellent teaching tool but its use in the setting of sedation teaching for GEP has not bee explored. The aim of this study was to assess the impact of a simulation course on sedation for GEP procedures done by endoscopist. Methods: A checklist to assess the endoscopists’ sedation performance for GEP was developed. This checklist was used to assess the sedations’ quality before and after a high fidelity sedation simulation course for GEP. Differences before/after the intervention was calculated using the McNemar’s test. A p ≤ 0,05 was considered significant. Results: All participants were assessed 15 times pre and post intervention. After the simulation, there was a significant improvement in patients’ airway assessment, in the level of awareness about patients’ condition during the procedure and in the monitoring after the procedure. All participants considered simulation should be compulsory before obtaining a license to sedate patients. Conclusions: The implementation of a sedation course based on simulation cases directed to endoscopists improved patient safety and sedations’ quality during the procedure. Simulation should be considered as a valid teaching tool, which is an enormous challenge to the anaesthesiologists.

Introducción: Una adecuada sedación contribuye al éxito de un procedimiento endoscópico gastrointestinal (PEG); sin embargo, esto puede estar asociado a eventos adversos, siendo importante la capacitación al respecto. La simulación es una excelente herramienta docente, pero su uso en la enseñanza de sedación para PEG no ha sido explorada. El objetivo de este estudio fue evaluar el impacto de un curso de sedación para PEG dirigido a endoscopistas basado en simulación. Materiales y Métodos: Se diseño una lista de cotejo para evaluar la calidad de la sedación impartida por endoscopistas durante PEG. Con dicho instrumento se determinó la calidad de la sedación antes y después de un curso de simulación de alta fidelidad sobre sedación para PEG. La magnitud de las diferencias secundario a la intervención se calcularon utilizando el test de McNemar. Una p ≤ 0,05 se consideró significativa. Resultados: Todos los participantes fueron evaluados 15 veces antes y después de la intervención. Después de la intervención, mejoró significativamente la evaluación de vía aérea, el nivel de alerta por las condiciones del paciente durante el procedimiento y el seguimiento posterior. Todos los participantes consideraron que la simulación debería ser obligatoria antes de obtener privilegios clínicos. Conclusiones: La implementación de un curso de sedación basados en simulación dirigidos a endoscopistas mejora la calidad de esta y la seguridad del paciente durante el procedimiento. La simulación debe ser considerada como una estrategia de enseñanza válida en este contexto lo que plantea un gran desafío a todos los anestesiólogos.

Dexametasona para profilaxis de náuseas y vómitos postoperatorios: efecto sobre la glicemia en pacientes con diabetes mellitus tipo 2 y en no diabéticos sometidos a cirugía laparoscópica / Effects on blood glucose of prophylactic dexamethasone for postoperative nausea and vomiting in diabetics and non-diabetics

Background: Postoperative nausea and vomiting (PONV) prophylaxis with dexamethasone may produce significant hyperglycemia in the postoperative period. Aim: To evaluate if this effect is of greater severity in type 2 diabetics compared with non-diabetic patients. Material and Methods: Forty non-diabetic and thirty type 2 diabetic patients undergoing laparoscopic cholecystectomy were studied in a prospective and double-blind fashion manner. Patients were randomly distributed into 4 groups: Group I, non-diabetics control (n = 20), Group II, non-diabetics dexamethasone (n = 20), Group III, type 2 diabetics control (n = 15), and Group I V, type 2 diabetics dexamethasone (n = 15). Immediately after induction, patients in groups I and III received isotonic saline and patients in the dexamethasone groups received 8 mg iv of the steroid. Capillary blood glucose concentrations were measured at baseline and every 2 hours during the first 12 hours since the start of surgery. A linear mixed effect model, adjusted for baseline capillary glucose concentration, age and duration of surgery was used to analyze the data. Results: No effect of the presence of diabetes mellitus was observed in the evolution of glucose concentrations. There was a difference in capillary glucose concentrations between patients who received dexamethasone and placebo that started 2 hours post-intervention, reaching a mean maximum difference of 34 mg/dl (adjusted model, p < 0.001) at 10 hours post-intervention. Conclusions: In this study, Type 2 diabetic patients did not show a higher susceptibility than non-diabetics to develop postoperative hyperglycemia after the use of prophylactic dexamethasone for PONV.