Epidural delivery of lidocaine and tramadol to control pain during ovariohisterectomy in the bitch

Epidural anesthesia is a simple, safe and effective way to administer anesthesic and analgesic drugs for caudal abdominal surgeries in canines. The aim of the study was to compare the analgesic effect of lidocaine or lidocainetramadol association administered epiduraly during ovariohisterectomy in the bitch. 14 bitches, ASA status 2 to 4, were premedicated with midazolam 0,2 mg/kg, butorphanol 0,2 mg/kg, induced with propofol 5 mg/kg iv and mantained with isoflurane. For 7 bitches lidocaine 2 mg/kg was administered epiduraly (L batch), while for the other 7 lidocaine was associated v:v with tramadol (LT batch). Analgesia was monitored intraoperatory (pulse frequency, non invasive blood presure, muscle relaxation) and postoperatory for the first 4 hours using the Glasgow pain scale. Blood pressure remained constant for both groups. There was a deduction of volatile agents in both groups, the bitches being extubated soon after stopping the delivery of anesthesic gas. Glasgow pain score was higher for the L batch (10) ompared to the LT batch (5), showing a higher analgesic capacity for the lidocaine-tramadol association. There were no complications, adverse effects or technique related difficulties for the epidural anesthesia in the bitches included in this study. In conclusion, the association between lidocaine and tramadol for epidural anesthesia represents an efective, cheap and simple alternative for analgesia during ovariohisterectomy in the bitch.