Single-dose lignocaine-based blood cardioplegia in single valve replacement patients

Abstract OBJECTIVE: Myocardial protection is the most important in cardiac surgery. We compared our modified single-dose long-acting lignocaine-based blood cardioplegia with short-acting St Thomas 1 blood cardioplegia in patients undergoing single valve replacement. METHODS: A total of 110 patients who underwent single (aortic or mitral) valve replacement surgery were enrolled. Patients were divided in two groups based on the cardioplegia solution used. In group 1 (56 patients), long-acting lignocaine based-blood cardioplegia solution was administered as a single dose while in group 2 (54 patients), standard St Thomas IB (short-acting blood-based cardioplegia solution) was administered and repeated every 20 minutes. All the patients were compared for preoperative baseline parameters, intraoperative and all the postoperative parameters. RESULTS: We did not find any statistically significant difference in preoperative baseline parameters. Cardiopulmonary bypass time were 73.8±16.5 and 76.4±16.9 minutes (P=0.43) and cross clamp time were 58.9±10.3 and 66.3±11.2 minutes (P=0.23) in group 1 and group 2, respectively. Mean of maximum inotrope score was 6.3±2.52 and 6.1±2.13 (P=0.65) in group 1 and group 2, respectively. We also did not find any statistically significant difference in creatine-phosphokinase-MB (CPK-MB), Troponin-I levels, lactate level and cardiac functions postoperatively. CONCLUSION: This study proves the safety and efficacy of long-acting lignocaine-based single-dose blood cardioplegia compared to the standard short-acting multi-dose blood cardioplegia in patients requiring the single valve replacement. Further studies need to be undertaken to establish this non-inferiority in situations of complex cardiac procedures especially in compromised patients.

Chemical sterilization of dogs using single bilateral intra-testicular injection of calcium chloride or clove oil

The current study was designed to evaluate the efficacy of single bilateral intra-testicular injection of calcium chloride or clove oil to induce chemical sterilization in ten dogs divided into two groups each of five animals. Chemical sterilization was evaluated by clinical signs, hormonal analysis and histopathological examination. Testosterone level was decreased significantly after injection of both agents with complete degeneration of the interstitial leydig cells and seminiferous tubules while cortisol level was increased during the 1[st] week after calcium chloride injection. The single bilateral intra-testicular injection of calcium chloride or clove oil proved to be accepted as a suitable alternative to the surgical sterilization of dogs; however clove oil was superior to calcium chloride as it induced less pain and irritation to the dogs

Platelet activation: ultrastructure and morphometry in platelet-rich plasma of horses / Ativação plaquetária: ultraestrutura e morfometria no plasma rico em plaquetas de equinos

This study was conducted to investigate the activation ability of the platelet-rich plasma (PRP) by pharmacological agents, as well as to verify the need or not of this activation for therapeutic use. The PRP was obtained from four healthy crossbred geldings aged 13 to 16 years (15±1years), and was processed for observation and quantification of the platelet morphology by using the transmission electron microscopy. All PRP samples were activated with 10 percent calcium chloride (CaCl2) solution, pure bovine thrombin or associated with CaCl2. The control (pure PRP) was not pharmacologically activated. In the pure PRP samples, 49 percent of the platelets were classified as state of activation uncertain, 41 percent as resting, 9 percent as fully activated and 1 percent as irreversibly damaged. Treatment with 10 percent CaCl2 provided a distribution of 54 percent platelets in state of activation uncertain, 24 percent as fully activated, 20 percent as resting, and 2 percent as irreversibly damaged. The platelet morphology of the bovine thrombin treated samples did not fit into classification adopted, as showing irregular shape with emission of large filamentous pseudopods, appearance of ruptured and whole granules in the remaining cytoplasm and extracellular environment. There was effect of the treatment on the platelet morphology (P=0.03). The 10 percent CaCl2 is an adequate platelet-activating agent. However, in cases the use of PRP under its liquid form is necessary, the use of pure PRP is recommended, since besides presenting an adequate percentage of fully activated platelets it also has significant amount of the resting type, which can be activated by substances found in the injured tissue.

O objetivo desse estudo foi investigar a capacidade de ativação do plasma rico em plaquetas (PRP) por substâncias farmacológicas, assim como verificar a necessidade ou não dessa ativação para uso terapêutico. O PRP foi obtido de quatro equinos mestiços hígidos, machos castrados, com 13 a 16 anos (15±1anos) de idade, e processado para observação e quantificação da morfologia plaquetária mediante a utilização da microscopia eletrônica de transmissão. Todas as amostras de PRP foram ativadas com cloreto de cálcio (CaCl2) a 10 por cento, trombina bovina pura ou associada a CaCl2. O controle (PRP puro) não foi ativado farmacologicamente. Nas amostras de PRP puro, 49 por cento das plaquetas foram classificadas como ativação incerta, 41 por cento em repouso, 9 por cento totalmente ativada e 1 por cento com dano irreversível. O tratamento com CaCl2 a 10 por cento proporcionou uma distribuição de 54 por cento de plaquetas com ativação incerta, 24 por cento totalmente ativada, 20 por cento em repouso, e 2 por cento como com dano irreversível. Amostras tratadas com trombina bovina apresentaram morfologia plaquetária que não se enquadraram na classificação adotada, apresentando forma irregular com emissão de grandes pseudópodes filamentosos, aspecto de rompimento e grânulos inteiros no citoplasma remanescente e meio extracelular. Houve efeito do tratamento sobre a morfologia plaquetária (P=0,03). O CaCl2 a 10 por cento é um adequado agente ativador de plaquetas. Entretanto, nos casos onde se faz necessário o uso de PRP na forma mais líquida, recomenda-se o uso do PRP puro, que além de apresentar uma adequada porcentagem de plaquetas totalmente ativadas, também possui importante quantidade do tipo em repouso, que pode ser ativado por substâncias presentes no tecido lesionado.

Padronização de modelo de coração isolado "working heart" com circulação parabiótica / Development of isolated swine "working heart model" with parabiotic circulation

OBJETIVO: Desenvolver modelo de coração isolado de suíno "working heart" sob suporte por circulação parabiótica e verificar se o mesmo é estável e se possibilitou de forma efetiva a mensuração dos dados propostos. MÉTODOS: O modelo foi padronizado durante preparação para estudo de associação de agente à solução cardioplégica. Foram realizados 18 experimentos com um animal suporte e um animal doador em cada. O coração do animal doador foi perfundido como coração isolado pelo animal suporte em modo de execução de trabalho ("coração ejetante"). O coração isolado foi submetido à isquemia regional por pinçamento da artéria interventricular anterior seguido de isquemia global. Durante reperfusão, com o coração ejetante (em modo "working heart"), aos 30, 60 e 90 minutos foram medidos parâmetros hemodinâmicos de contratilidade e metabólicos, obtendo-se assim a elastância máxima (Emáx), o trabalho sistólico pré-recrutável (PRSW), rigidez do ventrículo (EDPRV), fluxo coronariano, consumo de oxigênio e dosagens de lactato e glicose. RESULTADOS: Os animais suporte ficaram estáveis durante todo o experimento. O pH, a pressão parcial de oxigênio e o hematócrito foram mantidos estáveis e dentro da faixa fisiológica. O coração isolado foi perfundido de forma adequada durante todo o experimento. Os dados hemodinâmicos e metabólicos propostos puderam ser mensurados adequadamente e sempre com o coração ejetante, em modo de execução de trabalho ("working heart"). CONCLUSÃO: O modelo de coração isolado desenvolvido tipo "working heart" se manteve estável durante todo o experimento, sem a administração de drogas cardiotônicas e possibilitou a mensuração de todos os dados propostos de forma efetiva com o coração executando trabalho.

OBJECTIVE: To develop an isolated working heart model with parabiotic circulaton in swines and verify its stability and possibility to allow effective measurements of hemodinamic and metabolic data. METHODS: This model was developed during study of association of agents to cardiolegia. There were performed 18 experiments, each with a support animal and a donor animal. Donor animal heart was perfused as isolated working heart with parabiotic circulation from support animal. Isolated heart underwent regional ischemia by interventricular artery clamping, followed by global ischemia. During reperfusion in working heart state mode at 30, 60 and 90 minutes, contractility indices such as elastance, preload recruitable stroke work index and metabolic data were acquired. RESULTS: Support animals were kept stable throughout the procedures without use of blood transfusions or vasoactive drugs. pH, oxygen partial pressure and hematocrit were kept stable and within physiologic ranges. Isolated heart was perfused adequately throughout the experiment. All hemodinamic and metabolic data proposed were adequately measured in working heart state mode. CONCLUSION: This swine isolated "working heart" model was kept stable throughout the experiments with no administration of vasoactive drugs and it allowed adequate measurements of metabolic and hemodinamic data.

Cor, capacidade de retenção de água e maciez da carne de cordeiro maturada e injetada com cloreto de cálcio / Colour, water holding capacity and tenderness of lamb aged and injected with calcium chloride

Os músculos Biceps femoris, Longissimus e Triceps brachii submetidos aos efeitos do tempo de maturação e da injeção com cloreto de cálcio de cordeiros Morada Nova foram estudados quanto às características de cor, capacidade de retenção de água e maciez. Os cordeiros foram abatidos ao atingirem 25kg de peso vivo. Os músculos apresentaram diferenças na cor (luminosidade-L*, teor de vermelho-a* e teor de amarelo-b*) 24 horas após o abate. A maturação tendeu a escurecer a carne. O cloreto de cálcio não modificou a cor das carnes provenientes dos músculos Longissimus e Triceps brachii, entretanto as do Biceps femoris apresentaram-se mais vermelhas quando receberam cloreto de cálcio. Quanto à capacidade de retenção de água, a maturação afetou as carnes do Triceps brachii, mas não influenciou as carnes dos músculos Biceps femoris e Longissimus. O cloreto de cálcio não modificou a capacidade de retenção de água dos músculos avaliados. A maturação influiu sobre a maciez do Biceps femoris e do Longissimus

Biceps femoris, Longissimus and Triceps brachii muscles from Morada Nova lambs were submitted to ageing and calcium chloride injection. Colour, water holding capacity and tenderness were studied. Lambs were slaughtered weighting 25kg.. The muscles presented differences in colour (lightness-L*, redness-a* and yellowness- b*) 24 hours after rigor mortis instalation. Ageing intensified redness of the meats. Calcium chloride did not modify the colour of Longissimus and Triceps brachii, however, Biceps femoris became more redness after receiving calcium chloride. In relation to water holding capacity, ageing affected meats from Triceps brachii. However, it did not affect Biceps femoris and Longissimus. The calcium chloride didn't modify the water holding capacity of the muscles. Ageing influenced tenderness of Biceps femoris and Longissimus

Effects of Inotropic Drugs on Mechanical Function and Oxygen Balance in Postischemic Canine Myocardium: Comparison of Dobutamine, Epinephrine, Amrinone, and Calcium Chloride

Brief ischemic episodes that induce myocardial and coronary endothelial dysfunction may alter the responses to inotropic drugs. To determine the effects of inotropic drugs in stunned myocardium, the coronary blood flow (CBF), myocardial oxygen consumption (MVO2), and regional mechanical function in response to intracoronary dobutamine, epinephrine, amrinone, and calcium chloride (CaCl2) were measured before (normal) and 30 min after a 15-min-period occlusion of the left anterior descending artery (stunned) in an open-chest canine model. Percent segment shortening (%SS) and post-systolic shortening (%PSS) were determined. Myocardial extraction of oxygen (EO2) and lactate (E(lac)) was calculated. The inotropic drugs increased %SS, CBF, and MVO2 in normal myocardium. Epinephrine and amrinone decreased, while dobutamine and CaCl2 did not affect EO2. The ischemia and reperfusion itself significantly reduced %SS and E(lac), and increased %PSS. In stunned myocardium, the responses to inotropic drugs were not significantly altered, except that they progressively reduced %PSS and epinephrine did not affect EO2. These findings indicate that a brief episode of ischemia does not affect the mechanical and metabolic coronary flow responses to inotropic drugs, although it abolishes direct vasodilator responses to epinephrine.