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Abstract(s)
A hipoperfusão subsequente a um trauma ou decorrente de procedimentos cirúrgicos com hemorragia severa, apesar de todos os avanços na Medicina Veterinária, continua a ser uma das mais frequentes causas de encaminhamento de animais de companhia aos CAMV´s. Esta situação clínica pode conduzir a um estado de choque denominado choque hipovolémico, tornando-se, deste modo, uma das causas de maior morbilidade e mortalidade. O déficit de volume intravascular desencadeia um estado hipovolémico que conduz a uma série de eventos a nível fisiológico, sendo que, entre os mais severos
e condutores de graves lesões estão a diminuição da perfusão tecidular, do débito cardíaco e consequentemente do aporte de oxigénio aos tecidos. Estes eventos
desencadeiam o mecanismo anaeróbio, comprometendo gravemente o funcionamento celular normal. O rim é um órgão bastante suscetível à hipoperfusão, podendo, deste modo, ser severamente afetado pela diminuição da sua perfusão. Esta diminuição poderá originar uma insuficiência renal aguda com oligúria/anúria e graves distúrbios
eletrolíticos. Para impedir a ocorrência de lesões irreversíveis ou mesmo a morte, deverá ser efetuada a reposição imediata da volémia. Previamente, deverão ser tidas em conta uma série de considerações, incluindo a escolha do melhor soluto a infundir, a
quantidade e o tempo de infusão. Estas considerações deverão estar de acordo com
os objetivos terapêuticos, os parâmetros hemodinâmicos, a taxa de sangramento e
riscos ou eficácia de determinadas substâncias, visto que existem alguns expansores
prejudiciais ao rim. Mesmo à presente data, ainda não existe consenso na comunidade científica de qual o melhor soluto para repor a volémia, e, deste modo, o presente estudo tem como objetivo o aprofundamento do conhecimento das lesões histopatológicas e fenómenos apoptóticos a nível renal, avaliando qual o melhor soluto a utilizar. Para este fim, foram selecionados e comparados entre si, um coloide, o hidroxietilamido 130/0,4 e um cristaloide, o Lactato de ringer. Para a realização do presente estudo, 28 porcos saudáveis, da raça Large White, foram submetidos a um sangramento agudo (25ml/kg) sob efeito de uma anestesia total intravenosa com propofol e remifentanil. Os animais foram distribuídos aleatoriamente em 3 grupos, grupo 1 - LR (n=11), grupo 2 - HES (n=11) e grupo controlo (n=6). O Grupo 1 recebeu solução de lactato de ringer, o grupo 2 recebeu solução de hidroxietilamido 130/0,4 e o grupo controlo não foi submetido a qualquer tipo de procedimento, apenas à anestesia.
Os resultados deste estudo sugerem que no caso de hemorragia severa, o LR comparando com a solução de HES 130/0,4, quando utilizado para reposição de
volémia, pode minimizar o grau de lesão a nível renal. Apesar de a H&E não revelar
resultados significativos, os métodos imunohistoquímicos utilizados para avaliar os
eventos apoptóticos (o método citocromo c, o método TUNEL e o método M30), vieram revelar diferenças significativas nos grupos.
ABSTRACT: The consequent hypoperfusion following a trauma or due to surgical procedures with severe hemorrhage continues to be one of the most frequent reasons that take domestic animals to the VMC’s, despite all advances in veterinary medicine. This clinical situation may lead to a state of shock called hypovolemic shock, becoming one of the causes of increased morbidity and mortality. Intravascular volume deficit triggers a hypovolemic state that leads to a series of physiological events, with the reduction of tissue perfusion, cardiac output and consequent oxygen supply to the tissues, being the most serious and severe lesions trigger. These disorders can trigger the anaerobic mechanism, severely compromising the normal cellular functioning. Since the kidney is an organ greatly susceptible to hypoperfusion, it can thus be severely affected by the decrease in its perfusion. As a consequence, an acute renal failure with oliguria/anuria may occur, leading to severe electrolyte disturbances. To prevent the occurrence of irreversible injuries or even death, an immediate replacement of the volume should be performed. Beforehand, a number of considerations should be taken into account, including the choice of the best solute to infuse, the amount and time of infusion. These considerations should be in accordance with the therapeutic objectives, hemodynamic parameters, bleeding rate and risks or efficacy of certain substances, since there are some expanders that are harmful to the kidney. To date, the scientific community has not yet reached a consensus on what the best solution is to restore the volume. Therefore, the present study aims to deepen the knowledge of histopathological lesions and apoptotic phenomena at the renal level, evaluating which is the best solution to use. To this end, a colloid, hydroxyethyl starch 130 / 0.4 and a crystalloid, ringer's lactate, were selected and compared. For the present study, 28 healthy Large White pigs were submitted to an acute bleeding (25 ml/kg) under the effect of total intravenous anesthesia with propofol and remifentanil. The animals were randomly assigned to 3 groups, the group 1 - RL (n = 11), the group 2 - HES (n = 11) and the control group (n = 6). The RL group received ringer's lactate solution, the HES group received 130 / 0.4 hydroxyethyl starch solution and the control group was not subjected to any type of procedure, only to anesthesia. The results of this study suggest that in the case of severe hemorrhage, the RL comparing with the solution of HES 130 / 0.4 can minimize the degree of renal damage, when used for volume replacement. Although H&E did not reveal significant results, the immunohistochemical methods used to evaluate apoptotic events (cytochrome c method, TUNEL method and M30 method) revealed significant differences in the groups.
ABSTRACT: The consequent hypoperfusion following a trauma or due to surgical procedures with severe hemorrhage continues to be one of the most frequent reasons that take domestic animals to the VMC’s, despite all advances in veterinary medicine. This clinical situation may lead to a state of shock called hypovolemic shock, becoming one of the causes of increased morbidity and mortality. Intravascular volume deficit triggers a hypovolemic state that leads to a series of physiological events, with the reduction of tissue perfusion, cardiac output and consequent oxygen supply to the tissues, being the most serious and severe lesions trigger. These disorders can trigger the anaerobic mechanism, severely compromising the normal cellular functioning. Since the kidney is an organ greatly susceptible to hypoperfusion, it can thus be severely affected by the decrease in its perfusion. As a consequence, an acute renal failure with oliguria/anuria may occur, leading to severe electrolyte disturbances. To prevent the occurrence of irreversible injuries or even death, an immediate replacement of the volume should be performed. Beforehand, a number of considerations should be taken into account, including the choice of the best solute to infuse, the amount and time of infusion. These considerations should be in accordance with the therapeutic objectives, hemodynamic parameters, bleeding rate and risks or efficacy of certain substances, since there are some expanders that are harmful to the kidney. To date, the scientific community has not yet reached a consensus on what the best solution is to restore the volume. Therefore, the present study aims to deepen the knowledge of histopathological lesions and apoptotic phenomena at the renal level, evaluating which is the best solution to use. To this end, a colloid, hydroxyethyl starch 130 / 0.4 and a crystalloid, ringer's lactate, were selected and compared. For the present study, 28 healthy Large White pigs were submitted to an acute bleeding (25 ml/kg) under the effect of total intravenous anesthesia with propofol and remifentanil. The animals were randomly assigned to 3 groups, the group 1 - RL (n = 11), the group 2 - HES (n = 11) and the control group (n = 6). The RL group received ringer's lactate solution, the HES group received 130 / 0.4 hydroxyethyl starch solution and the control group was not subjected to any type of procedure, only to anesthesia. The results of this study suggest that in the case of severe hemorrhage, the RL comparing with the solution of HES 130 / 0.4 can minimize the degree of renal damage, when used for volume replacement. Although H&E did not reveal significant results, the immunohistochemical methods used to evaluate apoptotic events (cytochrome c method, TUNEL method and M30 method) revealed significant differences in the groups.
Description
Keywords
Hipoperfusão Reposição da volémia Rim Hidroxietilamido Lactato de ringer Hypoperfusion Replacement of the volume Kidney Hydroxyethyl starch Lactated ringer
Citation
Publisher
Instituto Politécnico de Viseu, Escola Superior Agrária de Viseu