The intravenous polyionic solution with 84mEq/L of lactate infusion rate determines the intensity of the alkalizing effect in horses

ABSTRACT The aim of this study was to investigate the effects of an intravenous polyionic solution containing 84mEq/L of lactate (L84) on the hydroelectrolyte and acid-base balances when administered quickly or slowly in horses. Five healthy adult horses received the L84 solution, in a volume corresponding to 10% of BW, by continuous intravenous infusion, in two instants: a) rapid infusion (16.66mL/kg/h) during 6 hours; b) slow infusion (8.33mL/kg/h) during 12 hours. Venous blood samples were taken at the beginning of the infusion (hour 0) and 3, 6, 9, 12, and 24 hours after. Urine samples were taken at 0, 6, 12, and 24h. pH (blood and urine), pCO2, HCO3-, BE, TPP, L-lactate, Na+, K+, Cl-, AG, SID, Atot, PVV, urine specific gravity, and L-lactate, Na+, K+, and Cl- renal fractional clearance were determined. The L84 solution causes lower magnitude alkalizing effect when administered slowly, due to the gradual correction of the iatrogenic imbalance by the kidneys during the infusion period. The L84 solution infused at a low rate in horses could be recommended in cases where metabolic acidosis is suspected and it is not possible to quantify the imbalance degree.

摘要 本研究旨在探讨含84mEq/L乳酸盐的静脉用多电解质溶液（L84）在马体内快速或慢速输注时，对其水电解质与酸碱平衡的影响。选取5匹健康成年马，以其体重10%的容量接受L84溶液持续静脉输注，分为两种输注方案：a) 快速输注（16.66mL/kg/h），持续6小时；b) 慢速输注（8.33mL/kg/h），持续12小时。分别于输注开始时（0小时）及输注后3、6、9、12、24小时采集静脉血样本，于0、6、12、24小时采集尿液样本。检测指标包括：血液及尿液pH、pCO2、碳酸氢根（HCO3-）、碱剩余（base excess, BE）、总血浆蛋白（total plasma protein, TPP）、L-乳酸（L-lactate）、钠离子（Na+）、钾离子（K+）、氯离子（Cl-）、阴离子间隙（anion gap, AG）、强离子差（strong ion difference, SID）、总弱离子浓度（total weak acid concentration, Atot）、PVV、尿比重，以及L-乳酸、Na+、K+、Cl-的肾脏分数清除率。结果显示，慢速输注L84溶液时，其引发的碱化效应幅度更低，这是因为输注期间肾脏可逐步纠正此次医源性失衡。对于疑似代谢性酸中毒且无法量化失衡程度的病例，推荐以低速向马输注L84溶液。