Apoptosis in fresh and cryopreserved cardiac valves of pig samples.

To analyse the influence of cold ischemic time (CIT) (2-24 h) and of cryopreservation (liquid phase) on the viability of the valvular fibroblasts and in the presence of apoptosis. Cardiac valves from 10 pigs were evaluated by anatomo-pathological study of the wall, muscle and leaflet. At the same time, the presence of cellular death due to apoptosis was investigated in two ways; directly on tissue by Apodetec system and by two-colour flow cytometry assay analyzing a suspension of fibroblast from valve leaflets using Anexina V and propidium iodure (PI). We established three groups of samples to compare different experimental conditions: 2 h of ischemia (group 1), 24 h of ischemia (group 2), and a programme of cryopreservation (-1 degrees C/min) after 2 h of ischemia, followed by storage in liquid nitrogen during a week and thawing was performed (group 3). The analysis of viabilities showed slight differences between all three groups. The results indicated CIT of 24 h undergoing more structural affectation than CIT of 2 h. Flow cytometry analysis did not show important differences between groups; however cryopreserved samples (group 3) slightly less viability and a higher percentage of death by apoptosis than group 1 and 2 using flow cytometry. Apoptosis was confirmed on tissue from all valves but mainly in samples of group 2 and group 3. In summary, the viability of the valves in the case of ischemic times of 2 h, 24 h or after cryopreservation/thawing differs slightly. The death of the cells is mainly mediated by necrosis and not by apoptosis.

[Early extubation with caudal morphine after pediatric heart surgery]. / Extubación precoz con morfina caudal tras cirugía cardíaca pediátrica.

OBJECTIVES: To analyze the viability of immediate extubation of children after corrective surgery for congenital heart defects with extracorporeal membrane oxygenation using an anesthetic technique involving caudal morphine, and to study the effect on length of stay in the pediatric intensive care unit (PICU) or elsewhere in the hospital. MATERIAL AND METHODS: Twenty-nine ASA I-II patients without coagulation alterations undergoing surgery to correct simple heart defects were selected for extubation after surgery. Anesthesia was provided with with sevoflurane, midazolam, rocuronium, fentanil (maximum dose 10 micrograms/Kg) and a bolus of caudal morphine (50-60 micrograms/Kg) after anesthetic induction. Patient characteristics, type of surgery, times of extracorporeal circulation and of ischemia, arterial blood gases upon arrival in the PICU, postoperative complications and quality of analgesia were the variables analyzed. We also compared length of stay in the PICU and hospital for the study group and for a historical control group of 23 patients who had no received caudal morphine or been selected for early extubation. RESULTS: All patients were extubated satisfactorily in the operating room. None required reintubation or reoperation. Postoperative pain was controlled with metamizol alone for 79.3%. No episodes of respiratory depression or neurological complications were observed. PICU and hospital stays were significantly shorter in the study group than in the control group. CONCLUSIONS: Of patients undergoing simple corrective heart surgery with extracorporeal membrane oxygenation immediate extubation did not increase postoperative morbimortality and shortened the hospital stay. A single dose of caudal morphine provided optimum conditions for extubation and good control of postoperative pain. Strict measures must be taken, however, to avoid postpuncture bleeding.

Extubación precoz con morfina caudal tras cirugía cardíacapediátrica / Early exttubation with caudal morphine after pediatric heart surgery

OBJETIVO: Analizar la viabilidad y la influencia en la estancia en la Unidad de Cuidados Intensivos Pediátricos (UCIP) y en el hospital de la extubación inmediata de niños sometidos a corrección de cardiopatías congénitas bajo circulación extracorpórea (CEC) utilizando una técnica anestésica basada en la administración de morfina caudal. MATERIAL Y MÉTODOS: 29 pacientes ASA I-II, sin alteraciones de la coagulación y sometidos a corrección de una cardiopatía simple, fueron seleccionados para ser extubados tras la intervención. La anestesia se realizó con sevoflurano, midazolam, rocuronio, fentanilo (dosis máxima de 10 µg/Kg) y bolo de morfina caudal (50-60 µg/Kg) tras la inducción anestésica. Se analizaron las variables demográficas, tipo de cirugía, tiempo de CEC y de isquemia, gasometría arterial a su llegada a UCIP, complicaciones postoperatorias y grado de analgesia. Asimismo se compararon las estancias en la UCIP y en el hospital con las de un grupo control histórico de 23 pacientes a los que no se administró morfina caudal ni hubo intencionalidad de conseguir su extubación precoz. RESULTADOS: Todos los pacientes fueron extubados satisfactoriamente en quirófano. Ninguno requirió reintubación o reintervención. En el 79,3 por ciento de los casos el dolor se controló sólo con metamizol durante el postoperatorio. No se registraron episodios de depresión respiratoria ni complicaciones neurológicas. La estancia en UCIP y hospitalaria fueron significativamente más bajas que en el grupo control. CONCLUSIONES: La extubación inmediata de pacientes intervenidos por cardiopatía simple bajo CEC no aumentó la morbimortalidad postoperatoria y acortó la estancia hospitalaria. La morfina caudal en dosis única proporcionó unas condiciones óptimas para la extubación y un buen control del dolor postoperatorio, aunque deben extremarse las precauciones para prevenir un sangrado postpunción (AU)