Andersen Johnnie Bremholm, Wang Tobias
Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, Building 131, Universitetsparken, DK-8000 Aarhus C, Denmark.
Comp Biochem Physiol A Mol Integr Physiol. 2002 Mar;131(3):639-46. doi: 10.1016/s1095-6433(01)00498-6.
It is common practice to chronically implant catheters for subsequent blood sampling from conscious and undisturbed animals. This method reduces stress associated with blood sampling, but anaesthesia per se can also be a source of stress in animals. Therefore, it is imperative to evaluate the time required for physiological parameters (e.g. blood gases, acid-base status, plasma ions, heart rate and blood pressure) to stabilise following surgery. Here, we report physiological parameters during and after anaesthesia in the toad Bufo marinus. For anaesthesia, toads were immersed in benzocaine (1 g l(-1)) for 15 min or until the corneal reflex disappeared, and the femoral artery was cannulated. A 1-ml blood sample was taken immediately after surgery and subsequently after 2, 5, 24 and 48 h. Breathing ceased during anaesthesia, which resulted in arterial Po(2) values below 30 mmHg, and respiratory acidosis developed, with arterial Pco(2) levels reaching 19.5+/-2 mmHg and pH 7.64+/-0.04. The animals resumed pulmonary ventilation shortly after the operation, and oxygen levels increased to a constant level within 2 h. Acid--base status, however, did not stabilise until 24 h after anaesthesia. Haematocrit doubled immediately after cannulation (26+/-1%), but reached a constant level of 13% within 24 h. Blood pressure and heart rate were elevated for the first 5 h, but decreased after 24 h to a constant level of approximately 30 cm H2O and 35 beats min(-1), respectively. There were no changes following anaesthesia in mean cellular haemoglobin concentration, [K+], [Cl-], [Na+], [lactate] or osmolarity. Toads fully recovered from anaesthesia after 24 h.
长期植入导管以便从清醒且不受干扰的动物身上采集血液样本是一种常见的做法。这种方法可减少与采血相关的应激，但麻醉本身也可能是动物应激的一个来源。因此，评估生理参数（如血气、酸碱状态、血浆离子、心率和血压）在手术后达到稳定所需的时间至关重要。在此，我们报告了海蟾蜍麻醉期间及麻醉后的生理参数。为进行麻醉，将蟾蜍浸入苯佐卡因（1 g l(-1)）中15分钟或直至角膜反射消失，然后对股动脉进行插管。术后立即采集1毫升血样，随后在2小时、5小时、24小时和48小时后再次采集。麻醉期间呼吸停止，导致动脉血氧分压值低于30 mmHg，并出现呼吸性酸中毒，动脉血二氧化碳分压水平达到19.5±2 mmHg，pH值为7.64±0.04。动物在手术后不久恢复肺通气，氧气水平在2小时内升至恒定水平。然而，酸碱状态直到麻醉后24小时才稳定。插管后血细胞比容立即翻倍（26±1%），但在24小时内达到13%的恒定水平。血压和心率在最初5小时升高，但在24小时后下降至分别约为30 cm H2O和35次/分钟的恒定水平。麻醉后平均细胞血红蛋白浓度、[K+]、[Cl-]、[Na+]、[乳酸]或渗透压均无变化。蟾蜍在24小时后从麻醉中完全恢复。
