McGrath C J
Mod Vet Pract. 1984 Jul;65(7):522-4.
Respiratory minute volume, blood volume, RBC mass and cardiac output increase while the functional residual capacity decreases during late pregnancy. General anesthetics reach the fetus in high concentrations and tend to persist in the fetus after delivery. Use of small doses of a combination of anesthetics is recommended. Ephedrine increases vascular tone and cardiac output. Glycopyrrolate and fentanyl-droperidol are used to restrain sows for cesarean section. Morphine alone or with acepromazine works well in depressed sows. Acepromazine or xylazine, used with ketamine, is good in restraining small ruminants. A sedative and local blocks can be used in standing cows. Anesthesia in mares is induced with xylazine, guaifenesin and ketamine and maintained with halothane, guaifenesin or thiopental. Large doses of xylazine should be avoided. Lidocaine toxicity can result from overuse in local blocks.
妊娠晚期呼吸分钟通气量、血容量、红细胞量和心输出量增加，而功能残气量减少。全身麻醉药会以高浓度到达胎儿体内，且在分娩后往往会在胎儿体内持续存在。建议使用小剂量的麻醉药组合。麻黄碱可增加血管张力和心输出量。甘吡咯烷和氟哌利多用于母猪剖腹产时的保定。吗啡单独使用或与乙酰丙嗪合用对镇静的母猪效果良好。乙酰丙嗪或赛拉嗪与氯胺酮合用，对小反刍动物有良好的保定效果。站立的奶牛可使用镇静剂和局部阻滞麻醉。母马麻醉诱导使用赛拉嗪、愈创甘油醚和氯胺酮，维持麻醉使用氟烷、愈创甘油醚或硫喷妥钠。应避免大剂量使用赛拉嗪。局部阻滞麻醉中过度使用利多卡因可能导致毒性反应。
