Grint Nicola J, Lorena Silvia E R de Sa, Johnson Craig B, Luna Stelio P L, Whay Helen R, Murrell Joanna C
School of Veterinary Sciences, University of Bristol, Langford, Bristol, UK.
Vet Anaesth Analg. 2011 Sep;38(5):484-9. doi: 10.1111/j.1467-2995.2011.00632.x.
To report the severe metabolic acidosis identified in a group of 11 healthy mules anaesthetized with halothane for castration.
Data generated from a prospective study.
Eleven mules aged 2.5-8 years, weighing 230-315 kg and 11 horses aged 1.5-3.5 years, weighing 315-480 kg.
Animals were anaesthetized for castration as part of an electroencephalographic study. Preanaesthetic medication was acepromazine (0.03 mg kg(-1) ) administered through a preplaced jugular venous catheter. Anaesthesia was induced 30-90 minutes later with intravenous thiopental (10 mg kg(-1) ). After orotracheal intubation, anaesthesia was maintained with halothane vaporised in oxygen. The animals' lungs were ventilated to maintain the end-tidal CO(2) concentration between 3.9 and 4.5 kPa (29-34 mmHg). Anaesthetic monitoring included invasive blood pressure measurement via the auricular artery (mules) and submandibular branch of the facial artery (horses). Arterial blood gas samples were drawn from these catheters at three time points during surgery and pH, PaCO(2) , base excess (ecf) and were measured. Values were compared between groups using a Mann-Whitney test. p was taken as <0.05. Results are reported as median (range).
PaCO(2) did not differ between groups but pH was significantly lower in mules [7.178 (7.00-7.29)] compared to horses [7.367 (7.24-7.43)] (p=0.0002). values were significantly lower in the mules [16.6 (13.0-22.3) mM] compared to horses [23.7 (20.9-23.7) mM] (p=0.0001), whilst base excess (ecf) was significantly more negative in the mules [-11.4 (-1.27 to -16) mM] compared to horses [-1.3 (-5.8 to +2.4) mM] (p=0.0004).
This study demonstrated severe metabolic acidosis in healthy mules, which may have prompted intervention with drug therapies in a clinical arena. It is probable that the acidosis existed prior to anaesthesia and caused by diet, but other possible causes are considered.
报告一组11头接受氟烷麻醉去势的健康骡子中发现的严重代谢性酸中毒情况。
前瞻性研究产生的数据。
11头年龄在2.5至8岁、体重230至315千克的骡子，以及11匹年龄在1.5至3.5岁、体重315至480千克的马。
作为脑电图研究的一部分，动物接受去势麻醉。麻醉前用药为通过预先放置的颈静脉导管给予乙酰丙嗪（0.03毫克/千克）。30至90分钟后，静脉注射硫喷妥钠（10毫克/千克）诱导麻醉。经口气管插管后，用氧气中蒸发的氟烷维持麻醉。对动物肺部进行通气，使呼气末二氧化碳浓度维持在3.9至4.5千帕（29至34毫米汞柱）之间。麻醉监测包括通过耳动脉（骡子）和面部动脉下颌分支（马）进行有创血压测量。在手术期间的三个时间点从这些导管抽取动脉血气样本，测量pH值、动脉血二氧化碳分压、碱剩余（细胞外液）。组间比较采用曼-惠特尼检验。以p<0.05为有统计学意义。结果以中位数（范围）报告。
两组之间动脉血二氧化碳分压无差异，但骡子的pH值[7.178（7.00至7.29）]显著低于马[7.367（7.24至7.43）]（p = 0.0002）。骡子的碱剩余值[16.6（13.0至22.3）毫摩尔]显著低于马[23.7（20.9至23.7）毫摩尔]（p = 0.0001），而骡子的碱剩余（细胞外液）[ - 11.4（ - 1.27至 - 16）毫摩尔]显著比马[ - 1.3（ - 5.8至 + 2.4）毫摩尔]更负（p = 0.0004）。
本研究证明健康骡子存在严重代谢性酸中毒，这在临床领域可能促使采用药物治疗进行干预。酸中毒可能在麻醉前就已存在且由饮食引起，但也考虑了其他可能原因。
