Clinic of Reproductive Medicine, Department of Food Animals, Vetsuisse-Faculty University of Zurich, Zurich, Switzerland.
Theriogenology. 2010 Mar 15;73(5):612-9. doi: 10.1016/j.theriogenology.2009.10.017.
Respiratory stimulants are widely used in asphyxic neonatal calves despite a lack of data about their effectiveness and indications of possible side effects. The effect of doxapram and theophylline on respiratory, cardiovascular, and acid-base variables was investigated in 10 healthy neonatal calves (Bos Taurus). A venous, a peripheral arterial, and a pulmonary arterial catheter were placed, and central venous, pulmonary, and systemic blood pressures and cardiac output were measured using thermodilution technique. Doxapram, but not theophylline, led to an immediate increase in respiratory rate (P <or= 0.01). The arterial pCO(2) decreased to 27.1+/-4.7 mm Hg within 30 sec after doxapram administration and to 46.3+/-5.8 mm Hg within 120 min after theophylline administration (P<0.0001). The systolic pulmonary pressure increased from 70+/-8mm Hg (mean+/-SD) to 93+/-19 mm Hg within 30 sec after doxapram, but decreased after theophylline. The pulmonary vascular resistance also increased after doxapram and decreased after theophylline (P<0.01). Doxapram had a more pronounced and faster effect on respiratory rate and elimination of CO(2) than theophylline. Doxapram, but not theophylline, is indicated for treatment of postnatal asphyxia in calves, but there are potential cardiovascular side effects.
呼吸兴奋剂在窒息新生牛犊中广泛应用，尽管缺乏其疗效和可能副作用的相关数据。本研究旨在探讨氨茶碱和多沙普仑对 10 头健康新生牛犊（Bos Taurus）的呼吸、心血管和酸碱变量的影响。通过放置静脉、外周动脉和肺动脉导管，使用热稀释技术测量中心静脉压、肺动脉压和系统血压以及心输出量。多沙普仑而非氨茶碱可立即增加呼吸频率（P≤0.01）。给予多沙普仑 30 秒后，动脉 pCO2 降低至 27.1±4.7mmHg，并在给予氨茶碱 120 分钟后降低至 46.3±5.8mmHg（P＜0.0001）。收缩期肺动脉压从 70±8mmHg（均值±标准差）增加至多沙普仑给药后 30 秒的 93±19mmHg，但在给予氨茶碱后降低。给予多沙普仑后肺血管阻力增加，给予氨茶碱后降低（P＜0.01）。多沙普仑对呼吸频率和 CO2 清除的作用比氨茶碱更显著、更快。多沙普仑而非氨茶碱可用于治疗新生牛犊的产后窒息，但存在潜在的心血管副作用。
