Ecologic Myocardial Protection-1

Ecologic myocardial protection: Minicardioplegia To be presented at Cardiology2010 conference Orlando, Fl B.Aguerrevere RN-CCP, J.Russo RN-CP, E.Medina RN-CP, J.Iribarren MD, A. Sanchez MD, A. Alaña MD, J.Castejon M.D. Fundación De Todo Corazón Richard Gibson. Hospital de Especialidades Pediátricas Maracaibo, Venezuela Background Myocardial protection has always been a topic to discuss and a subject where changes in paradigms are not seen so often. It is an important issue of the surgical success that is reviewed and updated once in a while, maybe because sometimes we take for granted the nobility and tolerance to ischemia of the pediatric heart. Objectives To share the experience of a team who believes that when more physiologic the heart is treated protecting it with minicardioplegia, faster and better the spontaneous activity recovery will be. Methods From 2008-2009 we evaluated 96 patients undergoing CPB. Mean complexity RACHS score: 2. Mean age was 3.7 years (3 month - 12 years) The average time of cardiopulmonary bypass (CPB) was 33.7 min. (14 min-78 min), mean xclamp time was 21.2 min (7 min– 64 minutes) Mean nasopharyngeal and rectal temps were 34.5 y 35 ºC respectively. Pump prime consisted of Normosaline 0.9%, Sodium bicarbonate, heparin and packed red blood cells to maintain a postdilutional hematocrit (Htc) of 30%. Isotermic Miniplegia was given antegrade every 20 minutes to all patients through a ¼ inch tubing line from the arterial port of the oxygenator membrane to a Roller head and to a manifold were we connected 3 lines: 1) Line pressure. 2) Table line with a bubble trap. 3) Line with a 20cc syringe, containing the arresting agents (Potassium K+ and Magnesium), which were added to the blood cardioplegia circuit by means of an electrical syringe pump (ESP). Flow rate (ml/hr) of the ESP was calculated through a nomogram based on: Total blood volume to be delivered through the roller head (20ml/kg), Time (minutes to deliver the blood volume) and target K+ concentration (20 meq/L for induction of arrest, 10 meq/L for its maintenance) Results

Spontaneous recovery rhythm was achieved in a mean of 23 seconds for 95 patients after cross clamp removal. Defibrillation was needed only for 1 case, no need of hemoconcentrator in all cases, final mean Hct was 31.74% and average Potassium blood level post minicardioplegia administration was 4.4 meq/l. Conclusions Myocardial protection strategy must balance the complexity of: effectiveness, simplicity, cost and evolution Administering blood rather than crystalloid solutions into the myocardium provides nutrients to the muscle. Aerobic blood cardioplegia shifts the oxyhemoglobin dissociation curve to the right. It has shown to be cost-effective because its functional simplicity at low cost and has no impact in the decision of the use of fluid removing devices like hemoconcentrators or cell saving devices. Custom-made cardioplegia circuits with a heat exchange integrated can also be used for this purpose. Minicardioplegia resulted for us: An ecological way of treating the heart.