Varner Kelley M, Curtiss Alexandra L, Hogan Patricia M, Love Kim, Dodam John R
Department of Molecular Biomedical Sciences, North Carolina State University, College of Veterinary Medicine, Raleigh, North Carolina, USA.
Hogan Equine LLC, Cream Ridge, New Jersey, USA.
Equine Vet J. 2025 Jul;57(4):924-930. doi: 10.1111/evj.14428. Epub 2024 Oct 29.
In anaesthetised horses, bradycardia secondary to high vagal tone can reduce cardiac output and blood pressure. The use of anticholinergics in horses is limited due to concerns about ileus and abdominal discomfort. This retrospective study sought to determine the prevalence of post-operative abdominal discomfort in healthy horses that received atropine under isoflurane anaesthesia.
A retrospective evaluation of 222 general anaesthesia events between January 2019 and December 2019 was undertaken.
One hundred and eleven horses that received atropine were identified, and 111 case match controls that did not receive atropine were also selected. Information gathered from the medical records included signalment, anaesthetic drugs, surgical procedures, duration of anaesthesia and surgery, dobutamine and atropine administration, and the occurrence of abdominal discomfort for 24 h after anaesthesia. After initial data analysis, a second cohort of records was assessed separately. The horses in this group were castrated under general anaesthesia (with or without atropine; n = 68). Logistic regression models and Fisher's exact tests were used to look for factors contributing to abdominal discomfort post-anaesthesia. The significance level was set to 5% (p < 0.05).
Atropine administration was not associated with the development of post-anaesthetic abdominal discomfort (OR = 2.121, 95% CI [0.767, 5.869]; p = 0.2). Overall, 18/222 (8.1%) incidences of abdominal discomfort were identified. All incidents occurred in colts undergoing castration. In a separate analysis of only horses anaesthetised for castration, atropine was associated with developing abdominal discomfort (OR = 3.143, 95% CI [1.082, 9.132]; p = 0.04).
Atropine was not associated with post-operative abdominal discomfort except in colts undergoing castration. All episodes of discomfort were mild and resolved with minimal intervention. The potential impact of insufficient analgesia in horses undergoing castration is a confounding factor and requires prospective investigation.
Overall, atropine at a dose of 0.006 mg/kg IV appears to be a safe method to treat bradycardia in otherwise healthy horses anaesthetised for orthopaedic and upper airway procedures. Further work is required to determine if atropine is safe for colts undergoing castration.
在麻醉的马匹中，高迷走神经张力继发的心动过缓会降低心输出量和血压。由于担心肠梗阻和腹部不适，抗胆碱能药物在马匹中的使用受到限制。这项回顾性研究旨在确定在异氟烷麻醉下接受阿托品的健康马匹术后腹部不适的发生率。
对2019年1月至2019年12月期间的222例全身麻醉事件进行回顾性评估。
确定111匹接受阿托品治疗的马匹，并选择111例未接受阿托品治疗的病例匹配对照。从病历中收集的信息包括特征、麻醉药物、手术程序、麻醉和手术持续时间、多巴酚丁胺和阿托品的使用情况，以及麻醉后24小时内腹部不适的发生情况。在初步数据分析后，对第二批记录进行单独评估。该组中的马匹在全身麻醉下进行去势手术（使用或不使用阿托品；n = 68）。使用逻辑回归模型和Fisher精确检验来寻找导致麻醉后腹部不适的因素。显著性水平设定为5%（p < 0.05）。
阿托品的使用与麻醉后腹部不适的发生无关（OR = 2.121，95% CI [0.767, 5.869]；p = 0.2）。总体而言，共发现18/222（8.1%）例腹部不适事件。所有事件均发生在接受去势手术的小马驹身上。在仅对接受去势手术麻醉的马匹进行的单独分析中，阿托品与腹部不适的发生有关（OR = 3.143，95% CI [1.082, 9.132]；p = 0.04）。
除了接受去势手术的小马驹外，阿托品与术后腹部不适无关。所有不适发作均较轻，只需进行最小程度的干预即可缓解。去势手术马匹镇痛不足的潜在影响是一个混杂因素，需要进行前瞻性研究。
总体而言，静脉注射剂量为0.006 mg/kg的阿托品似乎是治疗接受骨科和上呼吸道手术麻醉的健康马匹心动过缓的安全方法。需要进一步研究以确定阿托品对接受去势手术的小马驹是否安全。
