Estudio de la agregación plaquetaria en el postoperatorio de cirugía cardiovascular mediante circulación extracorpórea en edad pediátrica / Effects of cardiac surgery with extracorporeal circulation on platelet aggregation in children

Introducción: Hay aspectos no bien aclarados en el postoperatorio de cirugía extracorpórea infantil, como la importancia de las alteraciones de la agregación plaquetaria. Objetivo: Analizar las alteraciones de agregación plaquetaria presentes en el postoperatorio de circulación extracorpórea pediátrico y ver su evolución temporal en primeras 24 h. Material y métodos: Estudio analítico, de cohortes, prospectivo, observacional en niños de un mes a 14 años, sometidos a cirugía cardiaca mediante circulación extracorpórea entre 2010-2011. Muestras de sangre previo a la intervención (PRE), tras 1 h del desclampaje (PO1) y tras 18-20 h (PO2). Se analiza la agregación plaquetaria inducida por colágeno, araquidónico y ADP, valorando su correlación con los tiempos quirúrgicos y de clampaje aórtico. Resultados: Treinta pacientes; mediana 4,1 años (IQ: 2,7; 8,0); 62,1% niñas; mediana de desviaciones estándar de peso -0,39 (IQ: -0,76; 0,24), de talla -0,22 (IQ: -0,74; 0,27) y de IMC -0,43 (IQ: -1; 0,45). Mediana de tiempo quirúrgico 79 min (IQ: 52,5; 125,5), mediana de clampaje 38,5 min (IQ: 22, 59). La agregación inducida por colágeno es menor en PO1 (15,20 ± 5,07) que en PRE (28,60 ± 4,22) y en PO2 (20,60 ± 3,98) empieza a ascender, pero aún es menor que en PRE; igual pasa con la inducida por araquidónico (25,00 ± 2,94; 14,10 ± 1,52; 19,50 ± 1,43) y por ADP (22,90 ± 1,66; 12,90 ± 1,52; 18,00 ± 2,49). Conclusiones: La circulación extracorpórea infantil genera disfunción plaquetaria grave, máxima en postoperatorio inmediato y aún persistente tras 24 h, independiente de tiempos de cirugía o clampaje; esto puede facilitar el sangrado en postoperatorio e influir en el uso de hemoderivados (AU)

Introduction: Some aspects of Cardiac Surgery with Extracorporeal Circulation in children are still not clear, one of which is impaired platelet aggregation. Objective: To analyze the Influence of Extracorporeal Circulation on changes in platelet aggregation in children < 15 years in our center, and to observe these changes over time in first 24 hours. Material and Methods: Analytical, cohort, prospective, observational study in children aged 1 month to 14 years, weight > 5 kg, undergoing cardiac surgery using cardiopulmonary bypass between 2010 and 2011. Blood samples were taken just before the intervention (PRE), after 1 h of declamping (PO1), and after 18-20 h (PO2). Platelet aggregation induced by collagen, arachidonic acid‘, and ADP were measured, assessing their correlation with surgery times and aortic clamping. Results: A total of 30 patients were included, with a median age of 4.1 years (IQR:2.7,8.0), 62.1% female, median weight of standard deviations of -0.39 (IQR:-0.76,0.24) of size -0.22 (IQR:- 0.74,0.27) and BMI -0.43 (IQR:-1,0,45). Median surgery time 79 min (IQR:52.5,125.5), clamping median 38.5 min (IQR:22,59). Collagen induced aggregation is lower in PO1 (15.20 ± 5.07) than in PRE (28.60 ± 4.22), and rises again in PO2 (20.60 ± 3.98), but is still less than in PRE; similarlywith arachidonic acid (25.00 ± 2.94, 14.10 ± 1.52, 19.50 ± 1.43), and ADP (22.90 ± 1.66, 12.90 ± 1.52, 18.00 ± 2.49). Conclusions: Cardiopulmonary bypass activates inflammatory mediators and causes a severe platelet dysfunction, which is maximum in immediate postoperative, and persistent even after 24 hours, regardless of surgery and clamping times, which may lead to postoperative bleeding and determine the use of blood and even furher surgery (AU)

Effects of bemiparin, dalteparin, and unfractionated heparin on platelet interaction with human subendothelium under flow conditions.

We compared the effects of the low-molecular-weight heparin (LMWH), bemiparin, and dalteparin with unfractionated heparin (UFH) on the platelet subendothelium interaction under flow conditions. All three compounds decreased the percentage of subendothelial matrix covered by platelets, although the effect of LMWH was greater than that of UFH. Subendothelial matrix covered with platelet structures greater than 100 square microns was significantly reduced by all three compounds; the effect of bemiparin tended to be greater than that of the other two heparins.