Administração peridural de morfina ou tramadol em cães: efeito analgésico e cardiorespiratório

Abstract

This double-blind study compared the analgesic and cardiopulmonary effects of the peridural morphine or tramadol in bitches submitted to ovariohisterectomy. Dogs were randomly assigned to three groups of 08 animals each and received morphine (0.1mg.kg-1 GM), tramadol (2mg kg-1 GT) or a saline placebo (0.2ml.kg-1 GS). Pre-anaesthetic medication was acepromazine (0.05mg kg-1 iv). Anaesthesia was induced with propofol (4mg kg-1 iv) and maintained with isoflurane. Heart and respiratory rates, systolic arterial pressure, rectal temperature, arterial blood gases and analgesia degree were evaluated. The quality and duration of postoperative pain relief did not differ between morphine or tramadol treatments. Rescue analgesia was administered to 06 dogs in the GS and just to 01 dog in the GT. During anesthesia, mild respiratory and cardiovascular depression was reported. It was concluded that peridural administration of morphine or tramadol is a safe and effective method to inducing long-lasting analgesia in dogs submitted to ovariohysterectomy.