Usefulness of the thromboelastogram in children: correlation with habitual coagulation tests. / Utilidad del tromboelastograma en pediatría: Correlación con pruebas habituales de la coagulación.

INTRODUCTION: Usual coagulation tests partially evaluate different elements of hemostasis, and do not translate cell interactions, which is an especially sensitive issue in critically ill patients. Viscoelastic measurement techniques, such as thromboelastogram (TEG) show the complete coagulation pro cess and are being evaluated as global coagulation tests. OBJECTIVE: To determine the correlation of the usual coagulation tests with the TEG values, in children treated in an intensive care unit (ICU). PATIENTS AND METHOD: We reviewed 238 TEGs of patients under 18 years of age, with evidence of clinical and/or laboratory coagulation alterations, who were hospitalized in the ICU. The TEG para meter values were correlated with each of the usual coagulation test values. The tests were obtained according to the protocol, using a 4.5 ml blood sample for TEG with TEG® 5000 Thrombelastograph Hemostasis System, through an electromagnetic transducer that allows the measurement of resis tance during the clot formation and lysis. Platelet count was obtained using an automated method or phase-contrast microscopy, and fibrinogen levels, prothrombin time, and partial thromboplastin time activated by nephelometric methods. RESULTS: 201 TEGs corresponding to 59 patients were re viewed. A moderate to low correlation was observed in all the measured parameters. No correlation was found between the percentages of clot lysis or clot firmness. CONCLUSIONS: There is a low corre lation between the information provided by TEG and the usual coagulation tests. This suggests that the TEG provides different information about the coagulation status of the evaluated critical patients.

[Sickle cell disease: A diagnosis to keep in mind]. / Enfermedad de células falciformes: Un diagnóstico para tener presente.

Sickle cell disease (SCD) is an autosomal recessive genetic disorder. It is the most frequent structural hemoglobinopathy worldwide, and it is produced by an alteration in the globin chain genes. In Chile, there is no data on the prevalence of SCD since it is considered a very rare condition. The incidence of this disease has been increasing due to migration of people from areas with greater presence of SCD. It is important to know and consider this diagnosis in a selected group of patients with anemia, in order to prevent and treat the different complications of this disease. This article reviews the most recent information that shows new concepts in the knowledge of the physiopathology, and especially publications of guidelines and consensus in relation to the diagnosis and management of this con dition.

[Subcutaneous catheter used for administration of low-molecular-weight-heparin in pediatrics]. / Catéter subcutáneo para la administración de heparina de bajo peso molecular en pediatría.

INTRODUCTION: Subcutaneous catheter is a device easy to assemble, which was created for the administration of insulin in diabetic patients, especially in children, aiming to reduce the number of punctures, pain and anxiety of patients and their parents. OBJECTIVE: To describe the experience using the catheter for subcutaneous administration of low molecular weight heparin (LMWH) in hospitalized pediatric patients. PATIENTS AND METHOD: A prospective descriptive study in 28 patients who used 87 subcutaneous catheters for the administration of LMWH in the Pediatric Service of the Universidad Catolica de Chile between July, 2010 and November, 2011. RESULTS: Complications associated with the catheter had an incidence of 33 % in total catheters evaluated; the most frequent complication was the presence of hematoma at the site of insertion (26%). These complications occurred more frequently in male (38% versus 31% in females) and younger patients (9 months versus 12 months), who received dalteparin (54% versus 30% of other types of heparin) administered every 24 hours (41% versus 30%, administered every 12 hours), and when the catheter was located on both thighs (36 % versus 32% in both arms); however, these differences were not statistically confirmed. CONCLUSION: The subcutaneous catheter is a good technique to be considered for LMWH in children as it presents minor complications for drug administration.

Utilidad del tromboelastograma en pediatría: correlación con pruebas habituales de la coagulación / Usefulness of the thromboelastogram in children: correlation with habitual coagulation tests

INTRODUCCIÓN: Los exámenes habituales de coagulación evalúan distintos elementos de la hemostasia en forma par cial, y no traducen las interacciones celulares, lo que es especialmente sensible en pacientes críticos. Las técnicas viscoelásticas, como el tromboelastograma (TEG) muestran el proceso de coagulación completo, y están siendo evaluadas como exámenes de la coagulación global. OBJETIVO: determinar la correlación de los exámenes habituales de coagulación con los valores del TEG, en niños atendidos en una unidad de cuidados intensivos (UCI). PACIENTES Y MÉTODO: Se revisaron 238 TEG de pacientes <18 años, con evidencia de alteración de coagulación clínica y/o de laboratorio, hospitalizados en UCI. Se correlacionaron los valores de los parámetros del TEG con cada uno de los valores de los exámenes habituales de coagulación. Los exámenes se obtuvieron según protocolo, utilizando una muestra de sangre de 4,5 ml para TEG con equipo TEG® 5000 Thrombelastograph Hemostasis Sys tem, mediante un transductor electromagnético que permite la medición de la resistencia durante la formación y lisis del coágulo. El recuento de plaquetas se obtuvo utilizando método automatizado o microscopía con contraste de fase; el fibrinógeno, tiempo de protrombina y de tromboplastina parcial activada por métodos nefelométricos. RESULTADOS: 201 TEGs correspondientes a 59 pacientes. Se evidenció una correlación moderada a baja en todos los parámetros medidos. No se encontró co rrelación entre porcentaje de lisis del coágulo, ni firmeza del coágulo. CONCLUSIONES: Existe una baja correlación entre la información entregada por TEG y los exámenes de coagulación habituales, esto sugiere que el TEG aporta información diferente acerca del estado de coagulación de los pacientes críticos evaluados.

INTRODUCTION: Usual coagulation tests partially evaluate different elements of hemostasis, and do not translate cell interactions, which is an especially sensitive issue in critically ill patients. Viscoelastic measurement techniques, such as thromboelastogram (TEG) show the complete coagulation pro cess and are being evaluated as global coagulation tests. OBJECTIVE: To determine the correlation of the usual coagulation tests with the TEG values, in children treated in an intensive care unit (ICU). PATIENTS AND METHOD: We reviewed 238 TEGs of patients under 18 years of age, with evidence of clinical and/or laboratory coagulation alterations, who were hospitalized in the ICU. The TEG para meter values were correlated with each of the usual coagulation test values. The tests were obtained according to the protocol, using a 4.5 ml blood sample for TEG with TEG® 5000 Thrombelastograph Hemostasis System, through an electromagnetic transducer that allows the measurement of resis tance during the clot formation and lysis. Platelet count was obtained using an automated method or phase-contrast microscopy, and fibrinogen levels, prothrombin time, and partial thromboplastin time activated by nephelometric methods. RESULTS: 201 TEGs corresponding to 59 patients were re viewed. A moderate to low correlation was observed in all the measured parameters. No correlation was found between the percentages of clot lysis or clot firmness. CONCLUSIONS: There is a low corre lation between the information provided by TEG and the usual coagulation tests. This suggests that the TEG provides different information about the coagulation status of the evaluated critical patients.

Enfermedad de células falciformes: un diagnóstico para tener presente / Sickle cell disease: a diagnosis to keep in mind

La enfermedad de células falciformes (ECF) es un trastorno genético autosómico recesivo. Es la hemoglobinopatía estructural más frecuente en todo el mundo y se produce por alteración en los genes de la cadena de globina. En Chile, no hay datos sobre la prevalencia de la ECF ya que es considerada una condición muy rara. La incidencia de esta enfermedad ha venido aumentando debido a la migra ción de personas de áreas con mayor prevalencia de ECF. Por esta razón resulta importante conocer y considerar este diagnóstico en un grupo seleccionado de pacientes con anemia, para prevenir y tratar las diferentes complicaciones de la enfermedad. En este artículo se revisan los nuevos aportes en el conocimiento de la fisiopatología, con especial énfasis en aquellas publicaciones de consenso y guías relacionadas al diagnóstico y manejo de esta entidad.

Sickle cell disease (SCD) is an autosomal recessive genetic disorder. It is the most frequent structural hemoglobinopathy worldwide, and it is produced by an alteration in the globin chain genes. In Chile, there is no data on the prevalence of SCD since it is considered a very rare condition. The incidence of this disease has been increasing due to migration of people from areas with greater presence of SCD. It is important to know and consider this diagnosis in a selected group of patients with anemia, in order to prevent and treat the different complications of this disease. This article reviews the most recent information that shows new concepts in the knowledge of the physiopathology, and especially publications of guidelines and consensus in relation to the diagnosis and management of this con dition.

Coagulación en daño hepático crónico / Coagulation in chronic liver disease

Cirrhotic patients frequently exhibit abnormal coagulation tests such as prothrombin time (PT) and activated partial thromboplastin time (APTT) due to impairment in hepatic synthesis of coagulation factors. Due to these abnormalities and also to the numerous bleeding episodes that characterize advanced or decompensated liver cirrhosis, these patients were traditionally considered as “anticoagulated”. More recently, this paradigm has been challenged due to the increased occurrence of thrombotic complications among this population. This can only be understood when analyzed under the prism of the cellular theory of coagulation, which describes the complex interactions between endothelial, platelets and inflammatory cells that determine the status of coagulation, anticoagulation and fibrinolysis. The liver participates actively in this process contributing to the maintenance of a dynamic equilibrium in healthy patients. During liver failure there is evidence of impairment of synthesis of factors involved in the coagulation process, but also in anticoagulation and fibrinolysis. However, stable cirrhotic patients tend to maintain a delicate dynamic equilibrium. This equilibrium can be altered in acute decompensations leading to hemorrhagic or thrombotic complications.

Los pacientes con cirrosis presentan disminución en la producción de factores de coagulación de síntesis hepática, esto determina alteración del tiempo de protrombina (TP) y tiempo de tromboplastina parcial activada (TTPa). Esta característica, junto con los episodios de sangrado, que se presentan frecuentemente en pacientes descompensados y en etapa avanzada de la enfermedad, significó que por muchos años se considerara a los pacientes con daño hepático crónico como “anticoagulados”. En los últimos años este paradigma ha sido desafiado por estudios que muestran una mayor frecuencia de trombosis en esta población. Este fenómeno se comprende mejor con la teoría celular de la coagulación que integra a la ecuación las membranas celulares, especialmente de endotelio, plaquetas y células inflamatorias, y que permite visualizar las complejas interacciones entre factores coagulantes, anticoagulantes y fibrinolisis. El hígado participa en forma activa en este proceso que determina un amplio equilibrio dinámico en individuos sanos. El daño hepático claramente altera la coagulación, sin embargo, la evidencia actual demuestra que en la mayoría de los pacientes se produce un delicado rebalance hemostático, que determina una coagulación efectiva. Si este frágil equilibrio se altera, se produce un desbalance que puede generar un estado hemorrágico o trombótico.

Catéter subcutáneo para la administración de heparina de bajo peso molecular en pediatría / Subcutaneous catheter used for administration of low-molecular-weight-heparin in pediatrics

Introduction: Subcutaneous catheter is a device easy to assemble, which was created for the administration of insulin in diabetic patients, especially in children, aiming to reduce the number of punctures, pain and anxiety of patients and their parents. Objective: To describe the experience using the catheter for subcutaneous administration of low molecular weight heparin (LMWH) in hospitalized pediatric patients. Patients and Method: A prospective descriptive study in 28 patients who used 87 subcutaneous catheters for the administration of LMWH in the Pediatric Service of the Universidad Catolica de Chile between July, 2010 and November, 2011. Results: Complications associated with the catheter had an incidence of 33 percentin total catheters evaluated; the most frequent complication was the presence of hematoma at the site of insertion (26 percent). These complications occurred more frequently in male (38 percent versus 31 percent in females) and younger patients (9 months versus 12 months), who received dalteparin (54 percent versus 30 percent of other types of heparin) administered every 24 hours (41percent versus 30 percent, administered every 12 hours), and when the catheter was located on both thighs (36 percent versus 32 percent in both arms); however, these differences were not statistically confirmed. Conclusion: The subcutaneous catheter is a good technique to be considered for LMWH in children as it presents minor complications for drug administration.

Introducción: El catéter subcutáneo es un dispositivo de fácil instalación, el cual fue ideado para la administración de insulinas en pacientes diabéticos, especialmente en pediatría, con el fin de disminuir el número de punciones, el dolor y la ansiedad de los pacientes y sus padres. Objetivo: Describir la experiencia del uso del catéter subcutáneo para la administración de heparina de bajo peso molecular (HBPM) en pacientes pediátricos hospitalizados. Pacientes y Método: Estudio descriptivo prospectivo en 28 pacientes que utilizaron 87 catéteres subcutáneos instalados para la administración de HBPM, en el Servicio de Pediatría de la Pontificia Universidad Católica de Chile en el período comprendido entre los meses de julio de 2010 y noviembre de 2011. Resultados: Las complicaciones asociadas al catéter presentaron una incidencia de 33 por ciento en el total de catéteres evaluados, siendo la más frecuente la presencia de hematoma en el sitio de inserción (26 por ciento). Estas complicaciones se presentaron con mayor frecuencia en pacientes de sexo masculino (38 por ciento versus 31 por ciento en sexo femenino) de menor edad (9 meses versus 12 meses), con indicación de dalteparina (54 por ciento versus 30 por ciento con otros tipos de heparina) administrada cada 24 h (41 por ciento versus 30 por ciento cuando fue administrada cada 12 h), y cuando el catéter estuvo ubicado en ambos muslos (36 por ciento versus 32 por ciento en ambos brazos); sin embargo, estas diferencias no fueron confirmadas estadísticamente. Conclusión: El catéter subcutáneo es una buena técnica a considerar para la administración de HBPM en la edad pediátrica, ya que permite la administración del medicamento con complicaciones leves asociadas a su uso.

[Hematopoietic stem cell transplantation for patients with Wiskott-Aldrich syndrome]. / Trasplante alogénico de precursores hematopoyéticos en pacientes con síndrome de Wiskott-Aldrich.

BACKGROUND: Wiskott-Aldrich syndrome (WAS) is an X linked congenital disease that presents as eczema, thrombocytopenia and immune deficiency. The only curative procedure for this illness is hematopoietic stem cell transplant (HSCT), preferably from a healthy HLA identical sibling donor. Cord blood is becoming an excellent alternative as stem cell source from unrelated donors. AIM: To report our experience with HSCT in children with WAS. PATIENTS AND METHODS: Six boys with WAS diagnosed at 1 to 6 months of age were transplanted at our institution. All of them developed eczema and thrombocytopenia. Two had episodes of severe bleeding and three had repetitive infections (two with recurrent pulmonary infections and one a recurrent otitis). Three patients had a positive family history. Two received HSCT from sibling donors and four from unrelated cord blood donors at 7 months to 4 years of age. RESULTS: AH 6 patients had full hematopoietic engraftment after transplantation. Three had mild chronic graft-versus- host disease which responded to immune suppressive therapy. One patient died of cytomegalovirus related pneumonia 111 days after grafting. The other 5 patients are alive and healthy 11 to 104 months after transplantation. CONCLUSIONS: HSCT is an effective treatment for patients with WAS. The procedure should be done as soon as diagnosis is confirmed and before life threatening infections occur.

[Treatment of acquired severe aplastic anemia in pediatric patients with immunosuppression and allogeneic stem cell hematopoietic transplant]. / Tratamiento de anemia aplásica severa adquirida en pacientes pediátricos con inmunosupresión y trasplante alogénico de precursores hematopoiéticos.

BACKGROUND: Severe acquired aplastic anemia (SAA) is an uncommon disease of childhood. Patients with SAA receive supportive care with transfusions and timely treatment of opportunistic infections, along with specific therapies, which may be allogenic stem cell transplantation (SCT) from a matched sibling or immunosuppressive therapy (IT). AIM: To report the experience in the management of SAA. PATIENTS AND METHODS: Twenty five children with acquired SAA were treated from July 1992 to September 2005. Patients with full matched sibling donors received allogenic SCT after conditioning with a cyclophosphamide containing regimen. The other patients received immune suppression with cyclosporine plus methylprednisolone (n= 18) plus ATG (n=17). All received supportive care until recovery of hematopoietic function. Those who had severe opportunistic infections at diagnosis or did not respond to two cycles of ATG were evaluated for unrelated donor SCT. RESULTS: Seven patients received sibling donor SCT and 18 IT, which was repeated in six. Three patients received mismatched related (1) or unrelated (2) SCT. Nineteen patients survived with a median follow up time of 4 years, 14 with full hematologic recovery. Six patients died: four due to infections after IT or SCT, one due to intracranial hemorrhage and one with secondary myelodysplasia 12 years after IT. CONCLUSIONS: Most children with SAA can be treated successfully with sibling donor SCT or IT. Patients without a histocompatible sibling who fail to respond to IS have a worse prognosis.

Pileflebitis asociada a apendicitis aguda en una niña de 11 años / Pylephlebitis associated to acute appendicitis: report of an eleven years old patient

We report a 11 years old female who presented fever and pain in the lower abdomen. An abdominal CAT sean showed the presence of an acute appendicitis and a mesenteric vein thrombosis. The patient was operated laparoscopically and received antimicrobials and anticoagulants, with a good evolution. It is important an early suspicion and aecurate treatment for this complication.

Se presenta el caso clínico de una paciente de 11 años de edad, que cursa un cuadro febril asociado a dolor abdominal hipogástrico. Se realizan estudios de laboratorio e imágenes y se diagnostica una apendicitis aguda asociada a una trombosis de la vena mesentérica superior. Se efectúa apendicectomía laparoscópica y se administra tratamiento antibiótico y anticoagulante, tras lo cual la paciente evoluciona en buenas condiciones. Es importante una sospecha precoz y un tratamiento adecuado para tratar esta complicación.

Trasplante alogénico de precursores hematopoyéticos en pacientes con síndrome de Wiskott-Aldrich / Hematopoietic stem cell transplantation for patients with Wiskott-Aldrich syndrome

Background: Wiskott-Aldrich syndrome (WAS) is an X linked congenital disease that presents as eczema, thrombocytopenia and immune deficiency. The only curative procedure for this illness is hematopoietic stem cell transplant (HSCT), preferably from a healthy HLA identical sibling donor. Cord blood is becoming an excellent alternative as stem cell source from unrelated donors. Aim: To report our experience with HSCT in children with WAS. Patients and methods: Six boys with WAS diagnosed at 1 to 6 months of age were transplanted at our institution. All of them developed eczema and thrombocytopenia. Two had episodes of severe bleeding and three had repetitive infections (two with recurrent pulmonary infections and one a recurrent otitis). Three patients had a positive family history. Two received HSCT from sibling donors and four from unrelated cord blood donors at 7 months to 4 years of age. Results: AH 6 patients had full hematopoietic engraftment after transplantation. Three had mild chronic graft-versus- host disease which responded to immune suppressive therapy. One patient died of cytomegalovirus related pneumonia 111 days after grafting. The other 5 patients are alive and healthy 11 to 104 months after transplantation. Conclusions: HSCT is an effective treatment for patients with WAS. The procedure should be done as soon as diagnosis is confirmed and before life threatening infections occur.

Tratamiento de anemia aplásica severa adquirida en pacientes pediátricos con inmunosupresión y trasplante alogénico de precursores hematopoiéticos / Treatment of acquired severe aplastic anemia in pediatric patients with immunosupression and allogeneic stem cell hematopoyetic transplant

Background: Severe acquired aplastic anemia (SAA) is an uncommon disease of childhood. Patients with SAA receive supportive care with transfusions and timely treatment of opportunistic infections, along with specific therapies, which may be allogenic stem cell transplantation (SCT) from a matched sibling or immunosupressive therapy (IT). Aim: To report the experience in the management of SAA. Patients and methods: Twenty five children with acquired SAA were treated from July 1992 to September 2005. Patients with full matched sibling donors received allogenic SCT after conditioning with a cyclophosphamide containing regimen. The other patients received immune suppression with cyclosporine plus methylprednisolone (n= 18) plus ATG (n=17). All received supportive care until recovery of hematopoietic function. Those who had severe opportunistic infections at diagnosis or did not respond to two cycles of ATG were evaluated for unrelated donor SCT. Results: Seven patients received sibling donor SCT and 18 IT, which was repeated in six. Three patients received mismatched related (1) or unrelated (2) SCT. Nineteen patients survived with a median follow up time of 4 years, 14 with full hematologic recovery. Six patients died: four due to infections after IT or SCT, one due to intracranial hemorrhage and one with secondary myelodysplasia 12 years after IT. Conclusions: Most children with SAA can be treated successfully with sibling donor SCT or IT. Patients without a histocompatible sibling who fail to respond to IS have a worse prognosis.

Manejo intraparto de embarazadas con trastornos hereditarios de la coagulación / Management of pregnant women with hereditary blood coagulation disorders

Las coagulopatías hereditarias que afectan a mujeres jóvenes, representan un problema durante el embarazo, debido a que conllevan un aumento significativo en el riesgo de hemorragia durante el embarazo, parto y puerperio. Las alteraciones más frecuentes corresponden a la enfermedad de von Willebrand (1 a 2 por ciento de la población) y la hemofilia A (1/10.000 personas). Presentamos el caso clínico de una embarazada con antecedentes familiares de hemofilia A que controló su embarazo en nuestro centro; además entregamos una revisión sobre el tema coagulopatías hereditarias y embarazo.

Características del castigo físico infantil administrado por padres de tres colegios de Santiago / Features of infant physical punishment given by parents of 3 schools in Santiago

Para conocer opiniones y conductas sobre castigo físico a los niños se aplicó una encuesta anónima, de respuestas cerradas a 527 padres y apoderados de Santiago metropolitano: 173(32,8 por ciento ) de un colegio municipal, 250 (45,5 por ciento ) de uno subvencionado (ambos gratuitos y laicos) y 104 (19,7 por ciento ) de uno particular, pagado y católico. En este último los padres declararon mejor nivel educacional y hubo una mayor proporción de hombres entre los encuestados. La proporción que reconoció golpear a los niños varió de 56,7 por ciento (particular) a (78,0 por ciento ) municipal y 82 por ciento (subvencionado); a pesar de que proporciones entre 34,1 por ciento (municipal) y 51,9 por ciento (particular) decían que nunca se debía golpearlos. En dos colegios las mujeres reconocieron, con mas frecuencia que los hombres, que golpeaban a los niños (p<0,01). No estudiar, desafiar y escapar de casa fueron las razones mas frecuentes para justificar el castigo físico, en los colegios gratuitos; mientras que desafiar lo fue en el particular. Las mujeres tendieron a justificar todas las razones de castigo en porcentajes mayores que los hombres. No hubo diferencias marcadas en los castigos físicos usados, aunque en el colegio particular no se declaró usar correa para golpear. Se concluye que el castigo físico a los niños puede estar asociado al nivel socioeconómico

Uso de DDAVP en pacientes portadores de enfermedad de von Willebrand sometidos a adenoamigdalectomía / Use of DDAVP in patients with von Willebrand disease undergoing adenotonsillectomy

La enfermedad de von Willebrand (EVW) es la coagulopatía más frecuente en niños. Una de las principales complicaciones de la adenoamigdalectomía es la hemorragia. Debido a su patología de base, representan un gran desafío aquellos pacientes con EVW a quienes se efectúa esta cirugía. Desde hace algunos años, se utiliza desmopresina (DDAVP) para el manejo de esta patología. Se estudiaron restrospectivamente 15 pacientes pediátricos portadores de EVW tipo I, adenoamigdalectomizados en el Hospital Clínico de la Pontificia Universidad Católica de Chile. Todos fueron hospitalizados y, previa medición del Factor VIII plasmático, se les proporcionó DDAVP. Una hora después de iniciada la infusión, se controló este factor. Si se incrementaba en 50 por ciento del valor basal, la cirugía se efectuaba sin aporte de hemoderivados; de lo contrario, se indicaba crioprecipitado. En ambos casos se utilizó ácido tranexámico como coadyuvante.La respuesta a DDAVP fue positiva en 13 pacientes (87 por ciento). En los 2 pacientes en quienes ésta no se observó se les suministró crioprecipitado. Todo el grupo estudiado evolucionó satisfactoriamente. No fue necesario utilizar crioprecipitado de apoyo o cirugías de revisión. Se concluye que DDAVP evita el uso de hemoderivados en la mayoría de los pacientes con EVW tipo I sometidos a adenoamigdalectomía, no posee efectos adversos relevantes y no aumenta los costos de la cirugía.