Efeito alcalinizante de soluções eletrolíticas com concentração elevada de lactato de sódio administradas em bezerros sadios e diarréicos com acidose metabólica

• Main Author: José Ricardo Cecilio Junqueira
• Other Authors: Júlio Augusto Naylor Lisbôa .
• Language: Portuguese
• Published: Universidade Estadual de Londrina. Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência Animal. 2012
• Online Access: http://www.bibliotecadigital.uel.br/document/?code=vtls000184646

O trabalho foi desenvolvido com o intuito de investigar o potencial alcalinizante de solucoes eletroliticas com diferentes concentracoes de lactato e de bicarbonato de sodio, administradas por via intravenosa, em bezerros sadios e portadores de acidose metabolica. Foram desenvolvidas seis solucoes contendo 28, 56 e 84 mEq/L de lactato (L28, L56 e L84) ou de bicarbonato (B28, B56 e B84) de sodio, com concentracoes de sodio, de potassio e de calcio identicas e com teores de cloretos inferiores aos da solucao de Ringer com lactato (SRL). Foram utilizados 6 bezerros mesticos sadios, com aproximadamente 50 kg de peso vivo. As solucoes estudadas foram infundidas por via intravenosa em cada um dos bezerros a uma velocidade de 20ml/kg/hora totalizando 5L por bezerro em 5 horas de administracao continua. Cada bezerro sadio recebeu todas as seis solucoes estudadas, uma a cada vez, com intervalo de 5 dias entre as infusoes. Quadros de diarreia foram induzidos em 20 bezerros, Girolanda, com peso de 46,2 } 5,7 kg, entre 9 e 30 dias de idade, por meio da infeccao oral com rotavirus e da ingestao de sacarose. Apos desenvolverem desidratacao e acidose metabolica foram tratados com as solucoes L84 (n=10) ou B84 (n=10), infundidas uma unica vez conforme o protocolo adotado para os bezerros sadios. Amostras de sangue venoso e de urina foram colhidas em quatro momentos: antes do inicio da infusao, na metade da infusao (2,5 horas), ao termino da infusao (5 horas) e 2,5 horas apos o termino da infusao (7,5 horas). Os exames laboratoriais consistiram nas determinacoes plasmaticas de proteina total, fibrinogenio e lactato L; nas determinacoes sanguineas de pH, pCO2, HCO3 -, BE, Na+, K+ e Cl-; e nas determinacoes de pH, lactato L e densidade na urina. A solucao L28, equivalente a SRL, provocou discreto incremento da reserva alcalina nos bezerros sadios. A solucao com 84 mEq/L de lactato (L84) mostrou-se mais eficaz no aumento da reserva alcalina, mesmo quando comparada com a solucao contendo bicarbonato na mesma concentracao. A solucao L84 foi eficaz para a correcao da desidratacao e da acidose metabolica ocasionada pela diarreia nos bezerros, com resultados semelhantes aos obtidos pela solucao de bicarbonato na mesma concentracao. Nao foram observados efeitos colaterais com a administracao das solucoes eletroliticas estudadas. === This study was carried out with the aim of investigating, in healthy calves and in calves with metabolic acidosis, the alkalinizing potential of electrolyte solutions with different concentrations of lactate and sodium bicarbonate. Six solutions were formulated containing 28, 56 and 84 mEq/L of lactate (L28, L56 and L84) or sodium bicarbonate (B28, B56 and B84). The solutions were constituted by sodium, potassium and calcium in similar concentrations, and with concentration of chlorides lower than the Ringer solution with commercial lactate (SRL). Six healthy crossbred calves, over 50 kg of live weight, were evaluated. The studied solutions were infused intravenously in each calf at a speed of 20.0 ml/kg per hour, totalizing 5.0 L per calf, in five hours of continuously administration. Each healthy calf was treated with all the six studied solutions, one at a time, with a five day interval between the infusions. Diarrhea cases were induced in twenty Girolando calves, aging from 9 to 30 days old, 46,2 } 5,7 kg of live weight. Diarrhea was caused by oral infection with rotavirus and by nourishing the animals with sucrose. After developing dehydration and metabolic acidosis, the calves were treated by infusion of L 84 (n=10) or B84 (n=10) solutions, one time, according to the adopted protocol for healthy calves. Samples of venous blood and urine were collected in four different stages: before the infusion, in the middle of the infusion (after two and a half hours), at the end of the infusion (five hours after), and two and a half hours after the end of the infusion (seven and a half hours). The laboratory tests consisted in blood determinations of: total plasmatic protein, fibrinogen and L lactate; pH, pCO2, HCO3 -, BE, Na+, K+ and Cl- in blood. In the urine were determined: density, pH and L lactate. The solution L28, equivalent to SRL, caused, in the healthy calves, a slight increment in the alkaline reserve. The solution with 84 mEq/L of lactate (L84) proved to be more effective in increasing the alkaline reserve (alkaline buffer), even when compared with to the solution containing bicarbonate at the same concentration. The solution L84 was effective for the correction of metabolic acidosis and dehydration caused by diarrhea in calves, with the results similar to those obtained by the bicarbonate solution in the same concentration. No side effects were found with the administration of the electrolyte solutions studied.