Epidural Analgesia with Bupivacaine, Ketamine, and the Combination of Bupivacaine and Ketamine in Sheep

To evaluate the effects of bupivacaine (B), ketamine (K), and a combination of bupivacaine and ketamine (BK) after lumbosacral epidural analgesia in sheep.Design:Experimental study.Animals: Nine healthy male and non-pregnant female Iranian Chall sheep with mean bodyweight of 38.9 ± 15.1 kg.Procedures: Animals were selected randomly and three treatments administered. The drugswere administered in the lumbosacral epidural space. The onset and duration of analgesia andsedation were determined and heart rate, respiratory rate, and rectal temperature, wererecorded at 0, 5, 10, 15, 20, 30, 40, 50, and 60 min after administration. Analgesia wasdetermined by lack of response to pin pricking and pinch test in the skin of caudal areas.The onset of analgesia was significantly faster in BK than that in B and K alone.Treatments with ketamine, either alone (K) or in combination (BK) lead to mild sedation. Theheart rate increased significantly with B treatment at 15 and 20 min, and the respiratory rateshowed a significant decrease with K treatment at 10 and 15 min.Conclusion and Clinical Relevance: Epidural administration of bupivacaine/ketaminecombination resulted in fast onset and moderate duration of analgesia of caudal areas. Theemployed doses in BK treatment probably reduced the side effects observed in B and Ktreatments. It is concluded that the combination of BK could be used epidurally in sheep toperform operations without any marked side effects.