Héctor J Lacassie

Dexamethasone for postoperative nausea and vomiting prophylaxis: effect on glycaemia in obese patients with impaired glucose tolerance.

Background and objective Dexamethasone given to prevent postoperative nausea and vomiting may produce significant hyperglycaemia in the perioperative period. The effect of dexamethasone on patients with impaired glucose tolerance is unknown. Methods Thirty obese patients with impaired glucose tolerance undergoing laparoscopic Roux-en-Y gastric bypass surgery were studied in a double-blind fashion. Patients were randomly distributed into two groups: the dexamethasone group (n = 15) received dexamethasone 8 mg intravenously after induction of anaesthesia; the control group (n = 15) received isotonic saline. Fingerprick capillary blood glucose concentrations were measured at baseline and every 2 h during the first 12 h after the start of surgery. Results In both groups, all blood glucose concentrations measured after the beginning of surgery were higher than baseline values. However, the dexamethasone group showed higher glucose concentrations than the control group from the 6th to the 12th hour of the study. In addition, the maximum blood glucose value in the dexamethasone group (10.4 ± 1.6 mmol l−1) was higher than in the controls (8.8 ± 1.7 mmol l−1) (P < 0.05). Conclusion Dexamethasone, 8 mg, intravenously administered at the beginning of laparoscopic bariatric surgery in patients with impaired glucose tolerance is associated with significantly increased postoperative blood glucose concentrations.

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

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 IV, 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 i.v. 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.

Obesidad y embarazo: implicancias anestésicas

RESUMEN La obesidad es una epidemia a nivel mundial, con mas de 2.000 millones de adultos con sobrepeso u obe-sidad, por lo que cada vez es mas probable enfrentarse a una embarazada obesa en la practica clinica del equipo obstetrico. La obesidad incrementa los cambios fisiologicos del embarazo a nivel cardiovascular, respiratorio, metabolico y gastrointestinal, lo que tiene implicancias clinicas que aumentan los costos en salud y la morbimortalidad materna y fetal. Las embarazadas obesas son un constante desafio para el equipo obstetrico, anestesiologico y de salud, debiendo ser enfrentadas de forma multidisciplinaria para la obtencion de mejores resultados obstetricos y perinatales. El anestesiologo debe tener especial cuidado en el manejo analgesico del trabajo de parto y en la tecnica anestesica para la operacion cesarea. El objetivo central de la siguiente revision es explicar, analizar y desarrollar las principales implicancias anestesicas a las cuales se ve enfrentado el especialista en una embarazada obesa.PALABRAS CLAVE:

BEHAVIOURAL TESTING AND HISTOLOGICAL ASSESSMENTS OF RABBIT SPINAL CORD FOLLOWING INTRATHECAL ADMINISTRATION OF ONDANSETRON

1 Intrathecal injection of ondansetron has the potential to reduce opioid‐related side‐effects. The aim of the present study was to determine whether this route of administration produces neuraxial injury. 2 Adult, non‐pregnant female New Zealand white rabbits received a single bolus injection of a low (40 mg) or high (4.0 mg) dose of ondansetron into the intrathecal space between the 4th and 5th lumbar vertebrae. In some cases, ondansetron was coadministered with morphine (5 mg/kg). Control animals received a bolus injection of normal saline. Behavioural assessments were conducted at 1 and 24 h to determine overt changes in arousal and mobility, followed by histological evaluation of the excised spinal cord. 3 Of 45 animals investigated, 10 rabbits exhibited modest behavioural evidence of spinal injury, the incidence of which was equally distributed between the treatment groups. Haematoxylin and eosin, along with HAM56, staining of cross‐sections of the cervical, thoracic and upper and lower lumbar areas revealed mild signs of inflammation. This, too, was equally distributed between the treatment groups, suggesting that any observed neuraxial injury was the result of needle trauma and not ondansetron neurotoxicity. 4 Collectively, these negative findings support conducting further experiments to fully assess the clinical usefulness of intrathecal ondansetron administration.

Intubação traqueal difícil com fibra óptica em bebê de um mês de idade com síndrome de Treacher Collins

Neonates and small infants with craniofacial malformation may be very difficult or impossible to mask ventilate or intubate. We would like to report the fiberoptic intubation of a small infant with Treacher Collins Syndrome using the technique described by Ellis et al. CASE REPORT An one month-old infant with Treacher Collins Syndrome was scheduled for mandibular surgery under general endotracheal anesthesia. Direct laryngoscopy for oral intubation failed to reveal the glottis. Fiberoptic intubation using nasal approach and using oral approach through a 1.5 size laryngeal mask airway were performed; however, both approach failed because the fiberscope loaded with a one 3.5mm ID uncuffed tube was stuck inside the nasal cavity or inside the laryngeal mask airway respectively. Therefore, the laryngeal mask airway was keep in place and the fiberoptic intubation technique described by Ellis et al. was planned: the tracheal tube with the 15mm adapter removed was loaded proximally over the fiberscope; the fiberscope was advanced under video-screen visualization into the trachea; the laryngeal mask airway was removed, leaving the fiberscope in place; the tracheal tube was passed completely through the laryngeal mask airway and advanced down over the fiberscope into the trachea; the fiberscope was removed and the 15mm adapter was reattached to the tracheal tube. CONCLUSION The fiberoptic intubation method through a laryngeal mask airway described by Ellis et al. can be successfully used in small infants with Treacher Collins Syndrome.

Dosis efectiva 90 de oxitocina profiláctica en infusión luego del alumbramiento durante operación cesárea en pacientes en trabajo de parto o cesárea primaria: Un estudio dosis-respuesta con distribución secuencial arriba-abajo

Introduccion: La administracion profilactica de oxitocina es parte del manejo activo de la tercera etapa del trabajo de parto y reduce el riesgo de hemorragia posparto. Objetivo: estimar con un modelo dosis-respuesta la dosis de oxitocina endovenosa en infusion continua, efectiva en 90% (ED90) para contraccion uterina adecuada luego de trabajo de parto fracasado en pacientes que seran sometidas a operacion cesarea versus aquellas sometidas a cesarea electiva. Metodos: Estudio dosis-respuesta, ciego unico, de dos ramas utilizando la metodologia de la moneda sesgada en relacion 9:1 para determinar la DE90. El grupo experimental fueron parturientas sometidas a operacion cesarea, secundaria a fracaso en la progresion del trabajo de parto y que habian recibido oxitocina. El grupo control, pacientes sometidas a cesarea electiva. Se les administro oxitocina en infusion continua inmediatamente post nacimiento, de acuerdo a la metodologia de la moneda sesgada. Posteriormente, a los 4 minutos del nacimiento, el cirujano estimo si el tono uterino era satisfactorio o no. Los desenlaces secundarios incluyeron requerimientos de uterotonicos adicionales y efectos colaterales maternos. Los datos se analizaron por medio de un modelo de regresion logistica y la estimacion de la DE90 fue derivada del ajuste de curvas. Resultados: Participaron 38 pacientes sometidas a cesarea electiva y 32 que venian de un trabajo de parto. La DE90 de oxitocina estimada fue significativamente mayor para las pacientes en trabajo de parto (44,2 IU/h, iC95% 33,8-55,6), comparadas con las sometidas a cesarea electiva (16,2 IU/h (iC95% 13,1-19,3)). Significativamente mas mujeres en el grupo experimental requirieron uterotonicos suplementarios (34% vs/ 8%, p=0,008). La incidencia global de efectos colaterales fue mayor en el grupo experimental (69% vs/ 34%, p=0.004). Conclusion: La mujeres con exposicion previa a oxitocina exogena requieren una mayor dosis de infusion inicial de oxitocina para prevenir atonia uterina post operacion cesarea que aquellas sin exposicion previa.

Diagrama de flujo para la evaluación de Programas de Postítulo para la formación de especialistas en Medicina

Sr. Editor: En una carta previa1 propusimos un diagrama de flujo para la evaluacion y autoevaluacion de Programas de Postitulo para la formacion de Especialistas en Medicina, la que fue corregida por el Dr. Vicente Valdivieso, Secretario Ejecutivo de la Agencia Acreditadora de Programas y Centros Formadores de Especialistas Medicos (APICE) 2. Dicho diagrama ha debido mutar de acuerdo a los cambios que ha sufrido la legislacion sobre acreditacion. En particular, hay dos cambios que son los mas relevantes y se refieren a la no interferencia de la acreditacion en la autonomia universitaria: 1) Acreditacion limitando el numero de residentes, 2) Limitacion por el metodo de financiamiento de los alumnos. Desde abril de 2012 y por decision de la Comision Nacional de Acreditacion (CNA), se prohibio a las agencias establecer en sus acuerdos cupos numericos de alumnos (Dr. Vicente Valdivieso, comunicacion personal, octubre de 2014). En este sentido, los pares evaluadores de las agencias acreditadoras (por ejemplo: APICE), pueden opinar en su informe final sobre si el numero de alumnos matriculados anualmente por la institucion que postula a ser evaluada es concordante o no con su capacidad formadora y de supervision, pero sin tener injerencia en el numero maximo o eventual incremento en el numero de residentes que pudiese tolerar un programa. Queda establecido asi que las agencias acreditadoras no seran un factor limitante en este aspecto. Leer mas...