Influence of epidural morphine or tramadol in gastrointestinal transit of horses

ABSTRACT Opioids provide analgesia and are used in veterinary, however there is a restriction regarding the use of these drugs in horses, because may lead to ileus, but epidural opioids minimize those side effects. Eight healthy horses were used in three experimental groups, to evaluate the gastrointestinal influence after epidural morphine (0.2mg / kg), tramadol (1.0mg / kg) or NaCl 0.9%. Intestinal transit was evaluated with the administration of Lipe® (purified enriched isolated lignin) and later analyzed in the feces. Feces were collected before the epidural and at intervals up to 48 hours after the beginning of the experiment. The data were analyzed by a one-way analysis of variance or Friedman or Kruskal-Wallis and Student-Newman Keuls test as a post hoc. A value of P≤ 0.05 was considered significant. Epidural morphine or tramadol did not change the mean time for retention of the liquid phase, passage rate, and the transit time of the marker used. In conclusion, epidural morphine or tramadol does not change gastrointestinal transit.

摘要 阿片类药物（Opioids）具有镇痛作用，可应用于兽医学领域，但此类药物在马匹中的使用存在限制，因其可能引发肠梗阻（ileus），而硬膜外给予阿片类药物可减轻此类不良反应。本研究将8匹健康马匹分为三个实验组，以评估硬膜外注射吗啡（0.2mg/kg）、曲马多（1.0mg/kg）或0.9%氯化钠注射液后对胃肠道的影响。采用Lipe®（纯化富集分离木质素）作为标记物评估胃肠道转运，并通过检测粪便中的标记物完成后续分析。分别于硬膜外给药前及实验开始后48小时内的多个时间间隔采集粪便样本。数据采用单因素方差分析（one-way analysis of variance）、弗里德曼检验（Friedman test）或克鲁斯卡尔-沃利斯检验（Kruskal-Wallis test）进行分析，并以Student-Newman-Keuls检验作为事后多重比较检验，以P≤0.05作为具有统计学显著性的判定标准。结果显示，硬膜外注射吗啡或曲马多未改变液相滞留平均时间、转运速率及所用标记物的转运时间。综上，硬膜外给予吗啡或曲马多不会改变马匹的胃肠道转运功能。